| /* stb_image_resize - v0.95 - public domain image resizing |
| by Jorge L Rodriguez (@VinoBS) - 2014 |
| http://github.com/nothings/stb |
| |
| Written with emphasis on usability, portability, and efficiency. (No |
| SIMD or threads, so it be easily outperformed by libs that use those.) |
| Only scaling and translation is supported, no rotations or shears. |
| Easy API downsamples w/Mitchell filter, upsamples w/cubic interpolation. |
| |
| COMPILING & LINKING |
| In one C/C++ file that #includes this file, do this: |
| #define STB_IMAGE_RESIZE_IMPLEMENTATION |
| before the #include. That will create the implementation in that file. |
| |
| QUICKSTART |
| stbir_resize_uint8( input_pixels , in_w , in_h , 0, |
| output_pixels, out_w, out_h, 0, num_channels) |
| stbir_resize_float(...) |
| stbir_resize_uint8_srgb( input_pixels , in_w , in_h , 0, |
| output_pixels, out_w, out_h, 0, |
| num_channels , alpha_chan , 0) |
| stbir_resize_uint8_srgb_edgemode( |
| input_pixels , in_w , in_h , 0, |
| output_pixels, out_w, out_h, 0, |
| num_channels , alpha_chan , 0, STBIR_EDGE_CLAMP) |
| // WRAP/REFLECT/ZERO |
| |
| FULL API |
| See the "header file" section of the source for API documentation. |
| |
| ADDITIONAL DOCUMENTATION |
| |
| SRGB & FLOATING POINT REPRESENTATION |
| The sRGB functions presume IEEE floating point. If you do not have |
| IEEE floating point, define STBIR_NON_IEEE_FLOAT. This will use |
| a slower implementation. |
| |
| MEMORY ALLOCATION |
| The resize functions here perform a single memory allocation using |
| malloc. To control the memory allocation, before the #include that |
| triggers the implementation, do: |
| |
| #define STBIR_MALLOC(size,context) ... |
| #define STBIR_FREE(ptr,context) ... |
| |
| Each resize function makes exactly one call to malloc/free, so to use |
| temp memory, store the temp memory in the context and return that. |
| |
| ASSERT |
| Define STBIR_ASSERT(boolval) to override assert() and not use assert.h |
| |
| OPTIMIZATION |
| Define STBIR_SATURATE_INT to compute clamp values in-range using |
| integer operations instead of float operations. This may be faster |
| on some platforms. |
| |
| DEFAULT FILTERS |
| For functions which don't provide explicit control over what filters |
| to use, you can change the compile-time defaults with |
| |
| #define STBIR_DEFAULT_FILTER_UPSAMPLE STBIR_FILTER_something |
| #define STBIR_DEFAULT_FILTER_DOWNSAMPLE STBIR_FILTER_something |
| |
| See stbir_filter in the header-file section for the list of filters. |
| |
| NEW FILTERS |
| A number of 1D filter kernels are used. For a list of |
| supported filters see the stbir_filter enum. To add a new filter, |
| write a filter function and add it to stbir__filter_info_table. |
| |
| PROGRESS |
| For interactive use with slow resize operations, you can install |
| a progress-report callback: |
| |
| #define STBIR_PROGRESS_REPORT(val) some_func(val) |
| |
| The parameter val is a float which goes from 0 to 1 as progress is made. |
| |
| For example: |
| |
| static void my_progress_report(float progress); |
| #define STBIR_PROGRESS_REPORT(val) my_progress_report(val) |
| |
| #define STB_IMAGE_RESIZE_IMPLEMENTATION |
| #include "stb_image_resize.h" |
| |
| static void my_progress_report(float progress) |
| { |
| printf("Progress: %f%%\n", progress*100); |
| } |
| |
| MAX CHANNELS |
| If your image has more than 64 channels, define STBIR_MAX_CHANNELS |
| to the max you'll have. |
| |
| ALPHA CHANNEL |
| Most of the resizing functions provide the ability to control how |
| the alpha channel of an image is processed. The important things |
| to know about this: |
| |
| 1. The best mathematically-behaved version of alpha to use is |
| called "premultiplied alpha", in which the other color channels |
| have had the alpha value multiplied in. If you use premultiplied |
| alpha, linear filtering (such as image resampling done by this |
| library, or performed in texture units on GPUs) does the "right |
| thing". While premultiplied alpha is standard in the movie CGI |
| industry, it is still uncommon in the videogame/real-time world. |
| |
| If you linearly filter non-premultiplied alpha, strange effects |
| occur. (For example, the 50/50 average of 99% transparent bright green |
| and 1% transparent black produces 50% transparent dark green when |
| non-premultiplied, whereas premultiplied it produces 50% |
| transparent near-black. The former introduces green energy |
| that doesn't exist in the source image.) |
| |
| 2. Artists should not edit premultiplied-alpha images; artists |
| want non-premultiplied alpha images. Thus, art tools generally output |
| non-premultiplied alpha images. |
| |
| 3. You will get best results in most cases by converting images |
| to premultiplied alpha before processing them mathematically. |
| |
| 4. If you pass the flag STBIR_FLAG_ALPHA_PREMULTIPLIED, the |
| resizer does not do anything special for the alpha channel; |
| it is resampled identically to other channels. This produces |
| the correct results for premultiplied-alpha images, but produces |
| less-than-ideal results for non-premultiplied-alpha images. |
| |
| 5. If you do not pass the flag STBIR_FLAG_ALPHA_PREMULTIPLIED, |
| then the resizer weights the contribution of input pixels |
| based on their alpha values, or, equivalently, it multiplies |
| the alpha value into the color channels, resamples, then divides |
| by the resultant alpha value. Input pixels which have alpha=0 do |
| not contribute at all to output pixels unless _all_ of the input |
| pixels affecting that output pixel have alpha=0, in which case |
| the result for that pixel is the same as it would be without |
| STBIR_FLAG_ALPHA_PREMULTIPLIED. However, this is only true for |
| input images in integer formats. For input images in float format, |
| input pixels with alpha=0 have no effect, and output pixels |
| which have alpha=0 will be 0 in all channels. (For float images, |
| you can manually achieve the same result by adding a tiny epsilon |
| value to the alpha channel of every image, and then subtracting |
| or clamping it at the end.) |
| |
| 6. You can suppress the behavior described in #5 and make |
| all-0-alpha pixels have 0 in all channels by #defining |
| STBIR_NO_ALPHA_EPSILON. |
| |
| 7. You can separately control whether the alpha channel is |
| interpreted as linear or affected by the colorspace. By default |
| it is linear; you almost never want to apply the colorspace. |
| (For example, graphics hardware does not apply sRGB conversion |
| to the alpha channel.) |
| |
| CONTRIBUTORS |
| Jorge L Rodriguez: Implementation |
| Sean Barrett: API design, optimizations |
| Aras Pranckevicius: bugfix |
| Nathan Reed: warning fixes |
| |
| REVISIONS |
| 0.95 (2017-07-23) fixed warnings |
| 0.94 (2017-03-18) fixed warnings |
| 0.93 (2017-03-03) fixed bug with certain combinations of heights |
| 0.92 (2017-01-02) fix integer overflow on large (>2GB) images |
| 0.91 (2016-04-02) fix warnings; fix handling of subpixel regions |
| 0.90 (2014-09-17) first released version |
| |
| LICENSE |
| See end of file for license information. |
| |
| TODO |
| Don't decode all of the image data when only processing a partial tile |
| Don't use full-width decode buffers when only processing a partial tile |
| When processing wide images, break processing into tiles so data fits in L1 cache |
| Installable filters? |
| Resize that respects alpha test coverage |
| (Reference code: FloatImage::alphaTestCoverage and FloatImage::scaleAlphaToCoverage: |
| https://code.google.com/p/nvidia-texture-tools/source/browse/trunk/src/nvimage/FloatImage.cpp ) |
| */ |
| |
| #ifndef STBIR_INCLUDE_STB_IMAGE_RESIZE_H |
| #define STBIR_INCLUDE_STB_IMAGE_RESIZE_H |
| |
| #ifdef _MSC_VER |
| typedef unsigned char stbir_uint8; |
| typedef unsigned short stbir_uint16; |
| typedef unsigned int stbir_uint32; |
| #else |
| #include <stdint.h> |
| typedef uint8_t stbir_uint8; |
| typedef uint16_t stbir_uint16; |
| typedef uint32_t stbir_uint32; |
| #endif |
| |
| #ifdef STB_IMAGE_RESIZE_STATIC |
| #define STBIRDEF static |
| #else |
| #ifdef __cplusplus |
| #define STBIRDEF extern "C" |
| #else |
| #define STBIRDEF extern |
| #endif |
| #endif |
| |
| |
| ////////////////////////////////////////////////////////////////////////////// |
| // |
| // Easy-to-use API: |
| // |
| // * "input pixels" points to an array of image data with 'num_channels' channels (e.g. RGB=3, RGBA=4) |
| // * input_w is input image width (x-axis), input_h is input image height (y-axis) |
| // * stride is the offset between successive rows of image data in memory, in bytes. you can |
| // specify 0 to mean packed continuously in memory |
| // * alpha channel is treated identically to other channels. |
| // * colorspace is linear or sRGB as specified by function name |
| // * returned result is 1 for success or 0 in case of an error. |
| // #define STBIR_ASSERT() to trigger an assert on parameter validation errors. |
| // * Memory required grows approximately linearly with input and output size, but with |
| // discontinuities at input_w == output_w and input_h == output_h. |
| // * These functions use a "default" resampling filter defined at compile time. To change the filter, |
| // you can change the compile-time defaults by #defining STBIR_DEFAULT_FILTER_UPSAMPLE |
| // and STBIR_DEFAULT_FILTER_DOWNSAMPLE, or you can use the medium-complexity API. |
| |
| STBIRDEF int stbir_resize_uint8( const unsigned char *input_pixels , int input_w , int input_h , int input_stride_in_bytes, |
| unsigned char *output_pixels, int output_w, int output_h, int output_stride_in_bytes, |
| int num_channels); |
| |
| STBIRDEF int stbir_resize_float( const float *input_pixels , int input_w , int input_h , int input_stride_in_bytes, |
| float *output_pixels, int output_w, int output_h, int output_stride_in_bytes, |
| int num_channels); |
| |
| |
| // The following functions interpret image data as gamma-corrected sRGB. |
| // Specify STBIR_ALPHA_CHANNEL_NONE if you have no alpha channel, |
| // or otherwise provide the index of the alpha channel. Flags value |
| // of 0 will probably do the right thing if you're not sure what |
| // the flags mean. |
| |
| #define STBIR_ALPHA_CHANNEL_NONE -1 |
| |
| // Set this flag if your texture has premultiplied alpha. Otherwise, stbir will |
| // use alpha-weighted resampling (effectively premultiplying, resampling, |
| // then unpremultiplying). |
| #define STBIR_FLAG_ALPHA_PREMULTIPLIED (1 << 0) |
| // The specified alpha channel should be handled as gamma-corrected value even |
| // when doing sRGB operations. |
| #define STBIR_FLAG_ALPHA_USES_COLORSPACE (1 << 1) |
| |
| STBIRDEF int stbir_resize_uint8_srgb(const unsigned char *input_pixels , int input_w , int input_h , int input_stride_in_bytes, |
| unsigned char *output_pixels, int output_w, int output_h, int output_stride_in_bytes, |
| int num_channels, int alpha_channel, int flags); |
| |
| |
| typedef enum |
| { |
| STBIR_EDGE_CLAMP = 1, |
| STBIR_EDGE_REFLECT = 2, |
| STBIR_EDGE_WRAP = 3, |
| STBIR_EDGE_ZERO = 4, |
| } stbir_edge; |
| |
| // This function adds the ability to specify how requests to sample off the edge of the image are handled. |
| STBIRDEF int stbir_resize_uint8_srgb_edgemode(const unsigned char *input_pixels , int input_w , int input_h , int input_stride_in_bytes, |
| unsigned char *output_pixels, int output_w, int output_h, int output_stride_in_bytes, |
| int num_channels, int alpha_channel, int flags, |
| stbir_edge edge_wrap_mode); |
| |
| ////////////////////////////////////////////////////////////////////////////// |
| // |
| // Medium-complexity API |
| // |
| // This extends the easy-to-use API as follows: |
| // |
| // * Alpha-channel can be processed separately |
| // * If alpha_channel is not STBIR_ALPHA_CHANNEL_NONE |
| // * Alpha channel will not be gamma corrected (unless flags&STBIR_FLAG_GAMMA_CORRECT) |
| // * Filters will be weighted by alpha channel (unless flags&STBIR_FLAG_ALPHA_PREMULTIPLIED) |
| // * Filter can be selected explicitly |
| // * uint16 image type |
| // * sRGB colorspace available for all types |
| // * context parameter for passing to STBIR_MALLOC |
| |
| typedef enum |
| { |
| STBIR_FILTER_DEFAULT = 0, // use same filter type that easy-to-use API chooses |
| STBIR_FILTER_BOX = 1, // A trapezoid w/1-pixel wide ramps, same result as box for integer scale ratios |
| STBIR_FILTER_TRIANGLE = 2, // On upsampling, produces same results as bilinear texture filtering |
| STBIR_FILTER_CUBICBSPLINE = 3, // The cubic b-spline (aka Mitchell-Netrevalli with B=1,C=0), gaussian-esque |
| STBIR_FILTER_CATMULLROM = 4, // An interpolating cubic spline |
| STBIR_FILTER_MITCHELL = 5, // Mitchell-Netrevalli filter with B=1/3, C=1/3 |
| } stbir_filter; |
| |
| typedef enum |
| { |
| STBIR_COLORSPACE_LINEAR, |
| STBIR_COLORSPACE_SRGB, |
| |
| STBIR_MAX_COLORSPACES, |
| } stbir_colorspace; |
| |
| // The following functions are all identical except for the type of the image data |
| |
| STBIRDEF int stbir_resize_uint8_generic( const unsigned char *input_pixels , int input_w , int input_h , int input_stride_in_bytes, |
| unsigned char *output_pixels, int output_w, int output_h, int output_stride_in_bytes, |
| int num_channels, int alpha_channel, int flags, |
| stbir_edge edge_wrap_mode, stbir_filter filter, stbir_colorspace space, |
| void *alloc_context); |
| |
| STBIRDEF int stbir_resize_uint16_generic(const stbir_uint16 *input_pixels , int input_w , int input_h , int input_stride_in_bytes, |
| stbir_uint16 *output_pixels , int output_w, int output_h, int output_stride_in_bytes, |
| int num_channels, int alpha_channel, int flags, |
| stbir_edge edge_wrap_mode, stbir_filter filter, stbir_colorspace space, |
| void *alloc_context); |
| |
| STBIRDEF int stbir_resize_float_generic( const float *input_pixels , int input_w , int input_h , int input_stride_in_bytes, |
| float *output_pixels , int output_w, int output_h, int output_stride_in_bytes, |
| int num_channels, int alpha_channel, int flags, |
| stbir_edge edge_wrap_mode, stbir_filter filter, stbir_colorspace space, |
| void *alloc_context); |
| |
| |
| |
| ////////////////////////////////////////////////////////////////////////////// |
| // |
| // Full-complexity API |
| // |
| // This extends the medium API as follows: |
| // |
| // * uint32 image type |
| // * not typesafe |
| // * separate filter types for each axis |
| // * separate edge modes for each axis |
| // * can specify scale explicitly for subpixel correctness |
| // * can specify image source tile using texture coordinates |
| |
| typedef enum |
| { |
| STBIR_TYPE_UINT8 , |
| STBIR_TYPE_UINT16, |
| STBIR_TYPE_UINT32, |
| STBIR_TYPE_FLOAT , |
| |
| STBIR_MAX_TYPES |
| } stbir_datatype; |
| |
| STBIRDEF int stbir_resize( const void *input_pixels , int input_w , int input_h , int input_stride_in_bytes, |
| void *output_pixels, int output_w, int output_h, int output_stride_in_bytes, |
| stbir_datatype datatype, |
| int num_channels, int alpha_channel, int flags, |
| stbir_edge edge_mode_horizontal, stbir_edge edge_mode_vertical, |
| stbir_filter filter_horizontal, stbir_filter filter_vertical, |
| stbir_colorspace space, void *alloc_context); |
| |
| STBIRDEF int stbir_resize_subpixel(const void *input_pixels , int input_w , int input_h , int input_stride_in_bytes, |
| void *output_pixels, int output_w, int output_h, int output_stride_in_bytes, |
| stbir_datatype datatype, |
| int num_channels, int alpha_channel, int flags, |
| stbir_edge edge_mode_horizontal, stbir_edge edge_mode_vertical, |
| stbir_filter filter_horizontal, stbir_filter filter_vertical, |
| stbir_colorspace space, void *alloc_context, |
| float x_scale, float y_scale, |
| float x_offset, float y_offset); |
| |
| STBIRDEF int stbir_resize_region( const void *input_pixels , int input_w , int input_h , int input_stride_in_bytes, |
| void *output_pixels, int output_w, int output_h, int output_stride_in_bytes, |
| stbir_datatype datatype, |
| int num_channels, int alpha_channel, int flags, |
| stbir_edge edge_mode_horizontal, stbir_edge edge_mode_vertical, |
| stbir_filter filter_horizontal, stbir_filter filter_vertical, |
| stbir_colorspace space, void *alloc_context, |
| float s0, float t0, float s1, float t1); |
| // (s0, t0) & (s1, t1) are the top-left and bottom right corner (uv addressing style: [0, 1]x[0, 1]) of a region of the input image to use. |
| |
| // |
| // |
| //// end header file ///////////////////////////////////////////////////// |
| #endif // STBIR_INCLUDE_STB_IMAGE_RESIZE_H |
| |
| |
| |
| |
| |
| #ifdef STB_IMAGE_RESIZE_IMPLEMENTATION |
| |
| #ifndef STBIR_ASSERT |
| #include <assert.h> |
| #define STBIR_ASSERT(x) assert(x) |
| #endif |
| |
| // For memset |
| #include <string.h> |
| |
| #include <math.h> |
| |
| #ifndef STBIR_MALLOC |
| #include <stdlib.h> |
| // use comma operator to evaluate c, to avoid "unused parameter" warnings |
| #define STBIR_MALLOC(size,c) ((void)(c), malloc(size)) |
| #define STBIR_FREE(ptr,c) ((void)(c), free(ptr)) |
| #endif |
| |
| #ifndef _MSC_VER |
| #ifdef __cplusplus |
| #define stbir__inline inline |
| #else |
| #define stbir__inline |
| #endif |
| #else |
| #define stbir__inline __forceinline |
| #endif |
| |
| |
| // should produce compiler error if size is wrong |
| typedef unsigned char stbir__validate_uint32[sizeof(stbir_uint32) == 4 ? 1 : -1]; |
| |
| #ifdef _MSC_VER |
| #define STBIR__NOTUSED(v) (void)(v) |
| #else |
| #define STBIR__NOTUSED(v) (void)sizeof(v) |
| #endif |
| |
| #define STBIR__ARRAY_SIZE(a) (sizeof((a))/sizeof((a)[0])) |
| |
| #ifndef STBIR_DEFAULT_FILTER_UPSAMPLE |
| #define STBIR_DEFAULT_FILTER_UPSAMPLE STBIR_FILTER_CATMULLROM |
| #endif |
| |
| #ifndef STBIR_DEFAULT_FILTER_DOWNSAMPLE |
| #define STBIR_DEFAULT_FILTER_DOWNSAMPLE STBIR_FILTER_MITCHELL |
| #endif |
| |
| #ifndef STBIR_PROGRESS_REPORT |
| #define STBIR_PROGRESS_REPORT(float_0_to_1) |
| #endif |
| |
| #ifndef STBIR_MAX_CHANNELS |
| #define STBIR_MAX_CHANNELS 64 |
| #endif |
| |
| #if STBIR_MAX_CHANNELS > 65536 |
| #error "Too many channels; STBIR_MAX_CHANNELS must be no more than 65536." |
| // because we store the indices in 16-bit variables |
| #endif |
| |
| // This value is added to alpha just before premultiplication to avoid |
| // zeroing out color values. It is equivalent to 2^-80. If you don't want |
| // that behavior (it may interfere if you have floating point images with |
| // very small alpha values) then you can define STBIR_NO_ALPHA_EPSILON to |
| // disable it. |
| #ifndef STBIR_ALPHA_EPSILON |
| #define STBIR_ALPHA_EPSILON ((float)1 / (1 << 20) / (1 << 20) / (1 << 20) / (1 << 20)) |
| #endif |
| |
| |
| |
| #ifdef _MSC_VER |
| #define STBIR__UNUSED_PARAM(v) (void)(v) |
| #else |
| #define STBIR__UNUSED_PARAM(v) (void)sizeof(v) |
| #endif |
| |
| // must match stbir_datatype |
| static unsigned char stbir__type_size[] = { |
| 1, // STBIR_TYPE_UINT8 |
| 2, // STBIR_TYPE_UINT16 |
| 4, // STBIR_TYPE_UINT32 |
| 4, // STBIR_TYPE_FLOAT |
| }; |
| |
| // Kernel function centered at 0 |
| typedef float (stbir__kernel_fn)(float x, float scale); |
| typedef float (stbir__support_fn)(float scale); |
| |
| typedef struct |
| { |
| stbir__kernel_fn* kernel; |
| stbir__support_fn* support; |
| } stbir__filter_info; |
| |
| // When upsampling, the contributors are which source pixels contribute. |
| // When downsampling, the contributors are which destination pixels are contributed to. |
| typedef struct |
| { |
| int n0; // First contributing pixel |
| int n1; // Last contributing pixel |
| } stbir__contributors; |
| |
| typedef struct |
| { |
| const void* input_data; |
| int input_w; |
| int input_h; |
| int input_stride_bytes; |
| |
| void* output_data; |
| int output_w; |
| int output_h; |
| int output_stride_bytes; |
| |
| float s0, t0, s1, t1; |
| |
| float horizontal_shift; // Units: output pixels |
| float vertical_shift; // Units: output pixels |
| float horizontal_scale; |
| float vertical_scale; |
| |
| int channels; |
| int alpha_channel; |
| stbir_uint32 flags; |
| stbir_datatype type; |
| stbir_filter horizontal_filter; |
| stbir_filter vertical_filter; |
| stbir_edge edge_horizontal; |
| stbir_edge edge_vertical; |
| stbir_colorspace colorspace; |
| |
| stbir__contributors* horizontal_contributors; |
| float* horizontal_coefficients; |
| |
| stbir__contributors* vertical_contributors; |
| float* vertical_coefficients; |
| |
| int decode_buffer_pixels; |
| float* decode_buffer; |
| |
| float* horizontal_buffer; |
| |
| // cache these because ceil/floor are inexplicably showing up in profile |
| int horizontal_coefficient_width; |
| int vertical_coefficient_width; |
| int horizontal_filter_pixel_width; |
| int vertical_filter_pixel_width; |
| int horizontal_filter_pixel_margin; |
| int vertical_filter_pixel_margin; |
| int horizontal_num_contributors; |
| int vertical_num_contributors; |
| |
| int ring_buffer_length_bytes; // The length of an individual entry in the ring buffer. The total number of ring buffers is stbir__get_filter_pixel_width(filter) |
| int ring_buffer_num_entries; // Total number of entries in the ring buffer. |
| int ring_buffer_first_scanline; |
| int ring_buffer_last_scanline; |
| int ring_buffer_begin_index; // first_scanline is at this index in the ring buffer |
| float* ring_buffer; |
| |
| float* encode_buffer; // A temporary buffer to store floats so we don't lose precision while we do multiply-adds. |
| |
| int horizontal_contributors_size; |
| int horizontal_coefficients_size; |
| int vertical_contributors_size; |
| int vertical_coefficients_size; |
| int decode_buffer_size; |
| int horizontal_buffer_size; |
| int ring_buffer_size; |
| int encode_buffer_size; |
| } stbir__info; |
| |
| |
| static const float stbir__max_uint8_as_float = 255.0f; |
| static const float stbir__max_uint16_as_float = 65535.0f; |
| static const double stbir__max_uint32_as_float = 4294967295.0; |
| |
| |
| static stbir__inline int stbir__min(int a, int b) |
| { |
| return a < b ? a : b; |
| } |
| |
| static stbir__inline float stbir__saturate(float x) |
| { |
| if (x < 0) |
| return 0; |
| |
| if (x > 1) |
| return 1; |
| |
| return x; |
| } |
| |
| #ifdef STBIR_SATURATE_INT |
| static stbir__inline stbir_uint8 stbir__saturate8(int x) |
| { |
| if ((unsigned int) x <= 255) |
| return x; |
| |
| if (x < 0) |
| return 0; |
| |
| return 255; |
| } |
| |
| static stbir__inline stbir_uint16 stbir__saturate16(int x) |
| { |
| if ((unsigned int) x <= 65535) |
| return x; |
| |
| if (x < 0) |
| return 0; |
| |
| return 65535; |
| } |
| #endif |
| |
| static float stbir__srgb_uchar_to_linear_float[256] = { |
| 0.000000f, 0.000304f, 0.000607f, 0.000911f, 0.001214f, 0.001518f, 0.001821f, 0.002125f, 0.002428f, 0.002732f, 0.003035f, |
| 0.003347f, 0.003677f, 0.004025f, 0.004391f, 0.004777f, 0.005182f, 0.005605f, 0.006049f, 0.006512f, 0.006995f, 0.007499f, |
| 0.008023f, 0.008568f, 0.009134f, 0.009721f, 0.010330f, 0.010960f, 0.011612f, 0.012286f, 0.012983f, 0.013702f, 0.014444f, |
| 0.015209f, 0.015996f, 0.016807f, 0.017642f, 0.018500f, 0.019382f, 0.020289f, 0.021219f, 0.022174f, 0.023153f, 0.024158f, |
| 0.025187f, 0.026241f, 0.027321f, 0.028426f, 0.029557f, 0.030713f, 0.031896f, 0.033105f, 0.034340f, 0.035601f, 0.036889f, |
| 0.038204f, 0.039546f, 0.040915f, 0.042311f, 0.043735f, 0.045186f, 0.046665f, 0.048172f, 0.049707f, 0.051269f, 0.052861f, |
| 0.054480f, 0.056128f, 0.057805f, 0.059511f, 0.061246f, 0.063010f, 0.064803f, 0.066626f, 0.068478f, 0.070360f, 0.072272f, |
| 0.074214f, 0.076185f, 0.078187f, 0.080220f, 0.082283f, 0.084376f, 0.086500f, 0.088656f, 0.090842f, 0.093059f, 0.095307f, |
| 0.097587f, 0.099899f, 0.102242f, 0.104616f, 0.107023f, 0.109462f, 0.111932f, 0.114435f, 0.116971f, 0.119538f, 0.122139f, |
| 0.124772f, 0.127438f, 0.130136f, 0.132868f, 0.135633f, 0.138432f, 0.141263f, 0.144128f, 0.147027f, 0.149960f, 0.152926f, |
| 0.155926f, 0.158961f, 0.162029f, 0.165132f, 0.168269f, 0.171441f, 0.174647f, 0.177888f, 0.181164f, 0.184475f, 0.187821f, |
| 0.191202f, 0.194618f, 0.198069f, 0.201556f, 0.205079f, 0.208637f, 0.212231f, 0.215861f, 0.219526f, 0.223228f, 0.226966f, |
| 0.230740f, 0.234551f, 0.238398f, 0.242281f, 0.246201f, 0.250158f, 0.254152f, 0.258183f, 0.262251f, 0.266356f, 0.270498f, |
| 0.274677f, 0.278894f, 0.283149f, 0.287441f, 0.291771f, 0.296138f, 0.300544f, 0.304987f, 0.309469f, 0.313989f, 0.318547f, |
| 0.323143f, 0.327778f, 0.332452f, 0.337164f, 0.341914f, 0.346704f, 0.351533f, 0.356400f, 0.361307f, 0.366253f, 0.371238f, |
| 0.376262f, 0.381326f, 0.386430f, 0.391573f, 0.396755f, 0.401978f, 0.407240f, 0.412543f, 0.417885f, 0.423268f, 0.428691f, |
| 0.434154f, 0.439657f, 0.445201f, 0.450786f, 0.456411f, 0.462077f, 0.467784f, 0.473532f, 0.479320f, 0.485150f, 0.491021f, |
| 0.496933f, 0.502887f, 0.508881f, 0.514918f, 0.520996f, 0.527115f, 0.533276f, 0.539480f, 0.545725f, 0.552011f, 0.558340f, |
| 0.564712f, 0.571125f, 0.577581f, 0.584078f, 0.590619f, 0.597202f, 0.603827f, 0.610496f, 0.617207f, 0.623960f, 0.630757f, |
| 0.637597f, 0.644480f, 0.651406f, 0.658375f, 0.665387f, 0.672443f, 0.679543f, 0.686685f, 0.693872f, 0.701102f, 0.708376f, |
| 0.715694f, 0.723055f, 0.730461f, 0.737911f, 0.745404f, 0.752942f, 0.760525f, 0.768151f, 0.775822f, 0.783538f, 0.791298f, |
| 0.799103f, 0.806952f, 0.814847f, 0.822786f, 0.830770f, 0.838799f, 0.846873f, 0.854993f, 0.863157f, 0.871367f, 0.879622f, |
| 0.887923f, 0.896269f, 0.904661f, 0.913099f, 0.921582f, 0.930111f, 0.938686f, 0.947307f, 0.955974f, 0.964686f, 0.973445f, |
| 0.982251f, 0.991102f, 1.0f |
| }; |
| |
| static float stbir__srgb_to_linear(float f) |
| { |
| if (f <= 0.04045f) |
| return f / 12.92f; |
| else |
| return (float)pow((f + 0.055f) / 1.055f, 2.4f); |
| } |
| |
| static float stbir__linear_to_srgb(float f) |
| { |
| if (f <= 0.0031308f) |
| return f * 12.92f; |
| else |
| return 1.055f * (float)pow(f, 1 / 2.4f) - 0.055f; |
| } |
| |
| #ifndef STBIR_NON_IEEE_FLOAT |
| // From https://gist.github.com/rygorous/2203834 |
| |
| typedef union |
| { |
| stbir_uint32 u; |
| float f; |
| } stbir__FP32; |
| |
| static const stbir_uint32 fp32_to_srgb8_tab4[104] = { |
| 0x0073000d, 0x007a000d, 0x0080000d, 0x0087000d, 0x008d000d, 0x0094000d, 0x009a000d, 0x00a1000d, |
| 0x00a7001a, 0x00b4001a, 0x00c1001a, 0x00ce001a, 0x00da001a, 0x00e7001a, 0x00f4001a, 0x0101001a, |
| 0x010e0033, 0x01280033, 0x01410033, 0x015b0033, 0x01750033, 0x018f0033, 0x01a80033, 0x01c20033, |
| 0x01dc0067, 0x020f0067, 0x02430067, 0x02760067, 0x02aa0067, 0x02dd0067, 0x03110067, 0x03440067, |
| 0x037800ce, 0x03df00ce, 0x044600ce, 0x04ad00ce, 0x051400ce, 0x057b00c5, 0x05dd00bc, 0x063b00b5, |
| 0x06970158, 0x07420142, 0x07e30130, 0x087b0120, 0x090b0112, 0x09940106, 0x0a1700fc, 0x0a9500f2, |
| 0x0b0f01cb, 0x0bf401ae, 0x0ccb0195, 0x0d950180, 0x0e56016e, 0x0f0d015e, 0x0fbc0150, 0x10630143, |
| 0x11070264, 0x1238023e, 0x1357021d, 0x14660201, 0x156601e9, 0x165a01d3, 0x174401c0, 0x182401af, |
| 0x18fe0331, 0x1a9602fe, 0x1c1502d2, 0x1d7e02ad, 0x1ed4028d, 0x201a0270, 0x21520256, 0x227d0240, |
| 0x239f0443, 0x25c003fe, 0x27bf03c4, 0x29a10392, 0x2b6a0367, 0x2d1d0341, 0x2ebe031f, 0x304d0300, |
| 0x31d105b0, 0x34a80555, 0x37520507, 0x39d504c5, 0x3c37048b, 0x3e7c0458, 0x40a8042a, 0x42bd0401, |
| 0x44c20798, 0x488e071e, 0x4c1c06b6, 0x4f76065d, 0x52a50610, 0x55ac05cc, 0x5892058f, 0x5b590559, |
| 0x5e0c0a23, 0x631c0980, 0x67db08f6, 0x6c55087f, 0x70940818, 0x74a007bd, 0x787d076c, 0x7c330723, |
| }; |
| |
| static stbir_uint8 stbir__linear_to_srgb_uchar(float in) |
| { |
| static const stbir__FP32 almostone = { 0x3f7fffff }; // 1-eps |
| static const stbir__FP32 minval = { (127-13) << 23 }; |
| stbir_uint32 tab,bias,scale,t; |
| stbir__FP32 f; |
| |
| // Clamp to [2^(-13), 1-eps]; these two values map to 0 and 1, respectively. |
| // The tests are carefully written so that NaNs map to 0, same as in the reference |
| // implementation. |
| if (!(in > minval.f)) // written this way to catch NaNs |
| in = minval.f; |
| if (in > almostone.f) |
| in = almostone.f; |
| |
| // Do the table lookup and unpack bias, scale |
| f.f = in; |
| tab = fp32_to_srgb8_tab4[(f.u - minval.u) >> 20]; |
| bias = (tab >> 16) << 9; |
| scale = tab & 0xffff; |
| |
| // Grab next-highest mantissa bits and perform linear interpolation |
| t = (f.u >> 12) & 0xff; |
| return (unsigned char) ((bias + scale*t) >> 16); |
| } |
| |
| #else |
| // sRGB transition values, scaled by 1<<28 |
| static int stbir__srgb_offset_to_linear_scaled[256] = |
| { |
| 0, 40738, 122216, 203693, 285170, 366648, 448125, 529603, |
| 611080, 692557, 774035, 855852, 942009, 1033024, 1128971, 1229926, |
| 1335959, 1447142, 1563542, 1685229, 1812268, 1944725, 2082664, 2226148, |
| 2375238, 2529996, 2690481, 2856753, 3028870, 3206888, 3390865, 3580856, |
| 3776916, 3979100, 4187460, 4402049, 4622919, 4850123, 5083710, 5323731, |
| 5570236, 5823273, 6082892, 6349140, 6622065, 6901714, 7188133, 7481369, |
| 7781466, 8088471, 8402427, 8723380, 9051372, 9386448, 9728650, 10078021, |
| 10434603, 10798439, 11169569, 11548036, 11933879, 12327139, 12727857, 13136073, |
| 13551826, 13975156, 14406100, 14844697, 15290987, 15745007, 16206795, 16676389, |
| 17153826, 17639142, 18132374, 18633560, 19142734, 19659934, 20185196, 20718552, |
| 21260042, 21809696, 22367554, 22933648, 23508010, 24090680, 24681686, 25281066, |
| 25888850, 26505076, 27129772, 27762974, 28404716, 29055026, 29713942, 30381490, |
| 31057708, 31742624, 32436272, 33138682, 33849884, 34569912, 35298800, 36036568, |
| 36783260, 37538896, 38303512, 39077136, 39859796, 40651528, 41452360, 42262316, |
| 43081432, 43909732, 44747252, 45594016, 46450052, 47315392, 48190064, 49074096, |
| 49967516, 50870356, 51782636, 52704392, 53635648, 54576432, 55526772, 56486700, |
| 57456236, 58435408, 59424248, 60422780, 61431036, 62449032, 63476804, 64514376, |
| 65561776, 66619028, 67686160, 68763192, 69850160, 70947088, 72053992, 73170912, |
| 74297864, 75434880, 76581976, 77739184, 78906536, 80084040, 81271736, 82469648, |
| 83677792, 84896192, 86124888, 87363888, 88613232, 89872928, 91143016, 92423512, |
| 93714432, 95015816, 96327688, 97650056, 98982952, 100326408, 101680440, 103045072, |
| 104420320, 105806224, 107202800, 108610064, 110028048, 111456776, 112896264, 114346544, |
| 115807632, 117279552, 118762328, 120255976, 121760536, 123276016, 124802440, 126339832, |
| 127888216, 129447616, 131018048, 132599544, 134192112, 135795792, 137410592, 139036528, |
| 140673648, 142321952, 143981456, 145652208, 147334208, 149027488, 150732064, 152447968, |
| 154175200, 155913792, 157663776, 159425168, 161197984, 162982240, 164777968, 166585184, |
| 168403904, 170234160, 172075968, 173929344, 175794320, 177670896, 179559120, 181458992, |
| 183370528, 185293776, 187228736, 189175424, 191133888, 193104112, 195086128, 197079968, |
| 199085648, 201103184, 203132592, 205173888, 207227120, 209292272, 211369392, 213458480, |
| 215559568, 217672656, 219797792, 221934976, 224084240, 226245600, 228419056, 230604656, |
| 232802400, 235012320, 237234432, 239468736, 241715280, 243974080, 246245120, 248528464, |
| 250824112, 253132064, 255452368, 257785040, 260130080, 262487520, 264857376, 267239664, |
| }; |
| |
| static stbir_uint8 stbir__linear_to_srgb_uchar(float f) |
| { |
| int x = (int) (f * (1 << 28)); // has headroom so you don't need to clamp |
| int v = 0; |
| int i; |
| |
| // Refine the guess with a short binary search. |
| i = v + 128; if (x >= stbir__srgb_offset_to_linear_scaled[i]) v = i; |
| i = v + 64; if (x >= stbir__srgb_offset_to_linear_scaled[i]) v = i; |
| i = v + 32; if (x >= stbir__srgb_offset_to_linear_scaled[i]) v = i; |
| i = v + 16; if (x >= stbir__srgb_offset_to_linear_scaled[i]) v = i; |
| i = v + 8; if (x >= stbir__srgb_offset_to_linear_scaled[i]) v = i; |
| i = v + 4; if (x >= stbir__srgb_offset_to_linear_scaled[i]) v = i; |
| i = v + 2; if (x >= stbir__srgb_offset_to_linear_scaled[i]) v = i; |
| i = v + 1; if (x >= stbir__srgb_offset_to_linear_scaled[i]) v = i; |
| |
| return (stbir_uint8) v; |
| } |
| #endif |
| |
| static float stbir__filter_trapezoid(float x, float scale) |
| { |
| float halfscale = scale / 2; |
| float t = 0.5f + halfscale; |
| STBIR_ASSERT(scale <= 1); |
| |
| x = (float)fabs(x); |
| |
| if (x >= t) |
| return 0; |
| else |
| { |
| float r = 0.5f - halfscale; |
| if (x <= r) |
| return 1; |
| else |
| return (t - x) / scale; |
| } |
| } |
| |
| static float stbir__support_trapezoid(float scale) |
| { |
| STBIR_ASSERT(scale <= 1); |
| return 0.5f + scale / 2; |
| } |
| |
| static float stbir__filter_triangle(float x, float s) |
| { |
| STBIR__UNUSED_PARAM(s); |
| |
| x = (float)fabs(x); |
| |
| if (x <= 1.0f) |
| return 1 - x; |
| else |
| return 0; |
| } |
| |
| static float stbir__filter_cubic(float x, float s) |
| { |
| STBIR__UNUSED_PARAM(s); |
| |
| x = (float)fabs(x); |
| |
| if (x < 1.0f) |
| return (4 + x*x*(3*x - 6))/6; |
| else if (x < 2.0f) |
| return (8 + x*(-12 + x*(6 - x)))/6; |
| |
| return (0.0f); |
| } |
| |
| static float stbir__filter_catmullrom(float x, float s) |
| { |
| STBIR__UNUSED_PARAM(s); |
| |
| x = (float)fabs(x); |
| |
| if (x < 1.0f) |
| return 1 - x*x*(2.5f - 1.5f*x); |
| else if (x < 2.0f) |
| return 2 - x*(4 + x*(0.5f*x - 2.5f)); |
| |
| return (0.0f); |
| } |
| |
| static float stbir__filter_mitchell(float x, float s) |
| { |
| STBIR__UNUSED_PARAM(s); |
| |
| x = (float)fabs(x); |
| |
| if (x < 1.0f) |
| return (16 + x*x*(21 * x - 36))/18; |
| else if (x < 2.0f) |
| return (32 + x*(-60 + x*(36 - 7*x)))/18; |
| |
| return (0.0f); |
| } |
| |
| static float stbir__support_zero(float s) |
| { |
| STBIR__UNUSED_PARAM(s); |
| return 0; |
| } |
| |
| static float stbir__support_one(float s) |
| { |
| STBIR__UNUSED_PARAM(s); |
| return 1; |
| } |
| |
| static float stbir__support_two(float s) |
| { |
| STBIR__UNUSED_PARAM(s); |
| return 2; |
| } |
| |
| static stbir__filter_info stbir__filter_info_table[] = { |
| { NULL, stbir__support_zero }, |
| { stbir__filter_trapezoid, stbir__support_trapezoid }, |
| { stbir__filter_triangle, stbir__support_one }, |
| { stbir__filter_cubic, stbir__support_two }, |
| { stbir__filter_catmullrom, stbir__support_two }, |
| { stbir__filter_mitchell, stbir__support_two }, |
| }; |
| |
| stbir__inline static int stbir__use_upsampling(float ratio) |
| { |
| return ratio > 1; |
| } |
| |
| stbir__inline static int stbir__use_width_upsampling(stbir__info* stbir_info) |
| { |
| return stbir__use_upsampling(stbir_info->horizontal_scale); |
| } |
| |
| stbir__inline static int stbir__use_height_upsampling(stbir__info* stbir_info) |
| { |
| return stbir__use_upsampling(stbir_info->vertical_scale); |
| } |
| |
| // This is the maximum number of input samples that can affect an output sample |
| // with the given filter |
| static int stbir__get_filter_pixel_width(stbir_filter filter, float scale) |
| { |
| STBIR_ASSERT(filter != 0); |
| STBIR_ASSERT(filter < STBIR__ARRAY_SIZE(stbir__filter_info_table)); |
| |
| if (stbir__use_upsampling(scale)) |
| return (int)ceil(stbir__filter_info_table[filter].support(1/scale) * 2); |
| else |
| return (int)ceil(stbir__filter_info_table[filter].support(scale) * 2 / scale); |
| } |
| |
| // This is how much to expand buffers to account for filters seeking outside |
| // the image boundaries. |
| static int stbir__get_filter_pixel_margin(stbir_filter filter, float scale) |
| { |
| return stbir__get_filter_pixel_width(filter, scale) / 2; |
| } |
| |
| static int stbir__get_coefficient_width(stbir_filter filter, float scale) |
| { |
| if (stbir__use_upsampling(scale)) |
| return (int)ceil(stbir__filter_info_table[filter].support(1 / scale) * 2); |
| else |
| return (int)ceil(stbir__filter_info_table[filter].support(scale) * 2); |
| } |
| |
| static int stbir__get_contributors(float scale, stbir_filter filter, int input_size, int output_size) |
| { |
| if (stbir__use_upsampling(scale)) |
| return output_size; |
| else |
| return (input_size + stbir__get_filter_pixel_margin(filter, scale) * 2); |
| } |
| |
| static int stbir__get_total_horizontal_coefficients(stbir__info* info) |
| { |
| return info->horizontal_num_contributors |
| * stbir__get_coefficient_width (info->horizontal_filter, info->horizontal_scale); |
| } |
| |
| static int stbir__get_total_vertical_coefficients(stbir__info* info) |
| { |
| return info->vertical_num_contributors |
| * stbir__get_coefficient_width (info->vertical_filter, info->vertical_scale); |
| } |
| |
| static stbir__contributors* stbir__get_contributor(stbir__contributors* contributors, int n) |
| { |
| return &contributors[n]; |
| } |
| |
| // For perf reasons this code is duplicated in stbir__resample_horizontal_upsample/downsample, |
| // if you change it here change it there too. |
| static float* stbir__get_coefficient(float* coefficients, stbir_filter filter, float scale, int n, int c) |
| { |
| int width = stbir__get_coefficient_width(filter, scale); |
| return &coefficients[width*n + c]; |
| } |
| |
| static int stbir__edge_wrap_slow(stbir_edge edge, int n, int max) |
| { |
| switch (edge) |
| { |
| case STBIR_EDGE_ZERO: |
| return 0; // we'll decode the wrong pixel here, and then overwrite with 0s later |
| |
| case STBIR_EDGE_CLAMP: |
| if (n < 0) |
| return 0; |
| |
| if (n >= max) |
| return max - 1; |
| |
| return n; // NOTREACHED |
| |
| case STBIR_EDGE_REFLECT: |
| { |
| if (n < 0) |
| { |
| if (n < max) |
| return -n; |
| else |
| return max - 1; |
| } |
| |
| if (n >= max) |
| { |
| int max2 = max * 2; |
| if (n >= max2) |
| return 0; |
| else |
| return max2 - n - 1; |
| } |
| |
| return n; // NOTREACHED |
| } |
| |
| case STBIR_EDGE_WRAP: |
| if (n >= 0) |
| return (n % max); |
| else |
| { |
| int m = (-n) % max; |
| |
| if (m != 0) |
| m = max - m; |
| |
| return (m); |
| } |
| // NOTREACHED |
| |
| default: |
| STBIR_ASSERT(!"Unimplemented edge type"); |
| return 0; |
| } |
| } |
| |
| stbir__inline static int stbir__edge_wrap(stbir_edge edge, int n, int max) |
| { |
| // avoid per-pixel switch |
| if (n >= 0 && n < max) |
| return n; |
| return stbir__edge_wrap_slow(edge, n, max); |
| } |
| |
| // What input pixels contribute to this output pixel? |
| static void stbir__calculate_sample_range_upsample(int n, float out_filter_radius, float scale_ratio, float out_shift, int* in_first_pixel, int* in_last_pixel, float* in_center_of_out) |
| { |
| float out_pixel_center = (float)n + 0.5f; |
| float out_pixel_influence_lowerbound = out_pixel_center - out_filter_radius; |
| float out_pixel_influence_upperbound = out_pixel_center + out_filter_radius; |
| |
| float in_pixel_influence_lowerbound = (out_pixel_influence_lowerbound + out_shift) / scale_ratio; |
| float in_pixel_influence_upperbound = (out_pixel_influence_upperbound + out_shift) / scale_ratio; |
| |
| *in_center_of_out = (out_pixel_center + out_shift) / scale_ratio; |
| *in_first_pixel = (int)(floor(in_pixel_influence_lowerbound + 0.5)); |
| *in_last_pixel = (int)(floor(in_pixel_influence_upperbound - 0.5)); |
| } |
| |
| // What output pixels does this input pixel contribute to? |
| static void stbir__calculate_sample_range_downsample(int n, float in_pixels_radius, float scale_ratio, float out_shift, int* out_first_pixel, int* out_last_pixel, float* out_center_of_in) |
| { |
| float in_pixel_center = (float)n + 0.5f; |
| float in_pixel_influence_lowerbound = in_pixel_center - in_pixels_radius; |
| float in_pixel_influence_upperbound = in_pixel_center + in_pixels_radius; |
| |
| float out_pixel_influence_lowerbound = in_pixel_influence_lowerbound * scale_ratio - out_shift; |
| float out_pixel_influence_upperbound = in_pixel_influence_upperbound * scale_ratio - out_shift; |
| |
| *out_center_of_in = in_pixel_center * scale_ratio - out_shift; |
| *out_first_pixel = (int)(floor(out_pixel_influence_lowerbound + 0.5)); |
| *out_last_pixel = (int)(floor(out_pixel_influence_upperbound - 0.5)); |
| } |
| |
| static void stbir__calculate_coefficients_upsample(stbir_filter filter, float scale, int in_first_pixel, int in_last_pixel, float in_center_of_out, stbir__contributors* contributor, float* coefficient_group) |
| { |
| int i; |
| float total_filter = 0; |
| float filter_scale; |
| |
| STBIR_ASSERT(in_last_pixel - in_first_pixel <= (int)ceil(stbir__filter_info_table[filter].support(1/scale) * 2)); // Taken directly from stbir__get_coefficient_width() which we can't call because we don't know if we're horizontal or vertical. |
| |
| contributor->n0 = in_first_pixel; |
| contributor->n1 = in_last_pixel; |
| |
| STBIR_ASSERT(contributor->n1 >= contributor->n0); |
| |
| for (i = 0; i <= in_last_pixel - in_first_pixel; i++) |
| { |
| float in_pixel_center = (float)(i + in_first_pixel) + 0.5f; |
| coefficient_group[i] = stbir__filter_info_table[filter].kernel(in_center_of_out - in_pixel_center, 1 / scale); |
| |
| // If the coefficient is zero, skip it. (Don't do the <0 check here, we want the influence of those outside pixels.) |
| if (i == 0 && !coefficient_group[i]) |
| { |
| contributor->n0 = ++in_first_pixel; |
| i--; |
| continue; |
| } |
| |
| total_filter += coefficient_group[i]; |
| } |
| |
| STBIR_ASSERT(stbir__filter_info_table[filter].kernel((float)(in_last_pixel + 1) + 0.5f - in_center_of_out, 1/scale) == 0); |
| |
| STBIR_ASSERT(total_filter > 0.9); |
| STBIR_ASSERT(total_filter < 1.1f); // Make sure it's not way off. |
| |
| // Make sure the sum of all coefficients is 1. |
| filter_scale = 1 / total_filter; |
| |
| for (i = 0; i <= in_last_pixel - in_first_pixel; i++) |
| coefficient_group[i] *= filter_scale; |
| |
| for (i = in_last_pixel - in_first_pixel; i >= 0; i--) |
| { |
| if (coefficient_group[i]) |
| break; |
| |
| // This line has no weight. We can skip it. |
| contributor->n1 = contributor->n0 + i - 1; |
| } |
| } |
| |
| static void stbir__calculate_coefficients_downsample(stbir_filter filter, float scale_ratio, int out_first_pixel, int out_last_pixel, float out_center_of_in, stbir__contributors* contributor, float* coefficient_group) |
| { |
| int i; |
| |
| STBIR_ASSERT(out_last_pixel - out_first_pixel <= (int)ceil(stbir__filter_info_table[filter].support(scale_ratio) * 2)); // Taken directly from stbir__get_coefficient_width() which we can't call because we don't know if we're horizontal or vertical. |
| |
| contributor->n0 = out_first_pixel; |
| contributor->n1 = out_last_pixel; |
| |
| STBIR_ASSERT(contributor->n1 >= contributor->n0); |
| |
| for (i = 0; i <= out_last_pixel - out_first_pixel; i++) |
| { |
| float out_pixel_center = (float)(i + out_first_pixel) + 0.5f; |
| float x = out_pixel_center - out_center_of_in; |
| coefficient_group[i] = stbir__filter_info_table[filter].kernel(x, scale_ratio) * scale_ratio; |
| } |
| |
| STBIR_ASSERT(stbir__filter_info_table[filter].kernel((float)(out_last_pixel + 1) + 0.5f - out_center_of_in, scale_ratio) == 0); |
| |
| for (i = out_last_pixel - out_first_pixel; i >= 0; i--) |
| { |
| if (coefficient_group[i]) |
| break; |
| |
| // This line has no weight. We can skip it. |
| contributor->n1 = contributor->n0 + i - 1; |
| } |
| } |
| |
| static void stbir__normalize_downsample_coefficients(stbir__contributors* contributors, float* coefficients, stbir_filter filter, float scale_ratio, int input_size, int output_size) |
| { |
| int num_contributors = stbir__get_contributors(scale_ratio, filter, input_size, output_size); |
| int num_coefficients = stbir__get_coefficient_width(filter, scale_ratio); |
| int i, j; |
| int skip; |
| |
| for (i = 0; i < output_size; i++) |
| { |
| float scale; |
| float total = 0; |
| |
| for (j = 0; j < num_contributors; j++) |
| { |
| if (i >= contributors[j].n0 && i <= contributors[j].n1) |
| { |
| float coefficient = *stbir__get_coefficient(coefficients, filter, scale_ratio, j, i - contributors[j].n0); |
| total += coefficient; |
| } |
| else if (i < contributors[j].n0) |
| break; |
| } |
| |
| STBIR_ASSERT(total > 0.9f); |
| STBIR_ASSERT(total < 1.1f); |
| |
| scale = 1 / total; |
| |
| for (j = 0; j < num_contributors; j++) |
| { |
| if (i >= contributors[j].n0 && i <= contributors[j].n1) |
| *stbir__get_coefficient(coefficients, filter, scale_ratio, j, i - contributors[j].n0) *= scale; |
| else if (i < contributors[j].n0) |
| break; |
| } |
| } |
| |
| // Optimize: Skip zero coefficients and contributions outside of image bounds. |
| // Do this after normalizing because normalization depends on the n0/n1 values. |
| for (j = 0; j < num_contributors; j++) |
| { |
| int range, max, width; |
| |
| skip = 0; |
| while (*stbir__get_coefficient(coefficients, filter, scale_ratio, j, skip) == 0) |
| skip++; |
| |
| contributors[j].n0 += skip; |
| |
| while (contributors[j].n0 < 0) |
| { |
| contributors[j].n0++; |
| skip++; |
| } |
| |
| range = contributors[j].n1 - contributors[j].n0 + 1; |
| max = stbir__min(num_coefficients, range); |
| |
| width = stbir__get_coefficient_width(filter, scale_ratio); |
| for (i = 0; i < max; i++) |
| { |
| if (i + skip >= width) |
| break; |
| |
| *stbir__get_coefficient(coefficients, filter, scale_ratio, j, i) = *stbir__get_coefficient(coefficients, filter, scale_ratio, j, i + skip); |
| } |
| |
| continue; |
| } |
| |
| // Using min to avoid writing into invalid pixels. |
| for (i = 0; i < num_contributors; i++) |
| contributors[i].n1 = stbir__min(contributors[i].n1, output_size - 1); |
| } |
| |
| // Each scan line uses the same kernel values so we should calculate the kernel |
| // values once and then we can use them for every scan line. |
| static void stbir__calculate_filters(stbir__contributors* contributors, float* coefficients, stbir_filter filter, float scale_ratio, float shift, int input_size, int output_size) |
| { |
| int n; |
| int total_contributors = stbir__get_contributors(scale_ratio, filter, input_size, output_size); |
| |
| if (stbir__use_upsampling(scale_ratio)) |
| { |
| float out_pixels_radius = stbir__filter_info_table[filter].support(1 / scale_ratio) * scale_ratio; |
| |
| // Looping through out pixels |
| for (n = 0; n < total_contributors; n++) |
| { |
| float in_center_of_out; // Center of the current out pixel in the in pixel space |
| int in_first_pixel, in_last_pixel; |
| |
| stbir__calculate_sample_range_upsample(n, out_pixels_radius, scale_ratio, shift, &in_first_pixel, &in_last_pixel, &in_center_of_out); |
| |
| stbir__calculate_coefficients_upsample(filter, scale_ratio, in_first_pixel, in_last_pixel, in_center_of_out, stbir__get_contributor(contributors, n), stbir__get_coefficient(coefficients, filter, scale_ratio, n, 0)); |
| } |
| } |
| else |
| { |
| float in_pixels_radius = stbir__filter_info_table[filter].support(scale_ratio) / scale_ratio; |
| |
| // Looping through in pixels |
| for (n = 0; n < total_contributors; n++) |
| { |
| float out_center_of_in; // Center of the current out pixel in the in pixel space |
| int out_first_pixel, out_last_pixel; |
| int n_adjusted = n - stbir__get_filter_pixel_margin(filter, scale_ratio); |
| |
| stbir__calculate_sample_range_downsample(n_adjusted, in_pixels_radius, scale_ratio, shift, &out_first_pixel, &out_last_pixel, &out_center_of_in); |
| |
| stbir__calculate_coefficients_downsample(filter, scale_ratio, out_first_pixel, out_last_pixel, out_center_of_in, stbir__get_contributor(contributors, n), stbir__get_coefficient(coefficients, filter, scale_ratio, n, 0)); |
| } |
| |
| stbir__normalize_downsample_coefficients(contributors, coefficients, filter, scale_ratio, input_size, output_size); |
| } |
| } |
| |
| static float* stbir__get_decode_buffer(stbir__info* stbir_info) |
| { |
| // The 0 index of the decode buffer starts after the margin. This makes |
| // it okay to use negative indexes on the decode buffer. |
| return &stbir_info->decode_buffer[stbir_info->horizontal_filter_pixel_margin * stbir_info->channels]; |
| } |
| |
| #define STBIR__DECODE(type, colorspace) ((type) * (STBIR_MAX_COLORSPACES) + (colorspace)) |
| |
| static void stbir__decode_scanline(stbir__info* stbir_info, int n) |
| { |
| int c; |
| int channels = stbir_info->channels; |
| int alpha_channel = stbir_info->alpha_channel; |
| int type = stbir_info->type; |
| int colorspace = stbir_info->colorspace; |
| int input_w = stbir_info->input_w; |
| size_t input_stride_bytes = stbir_info->input_stride_bytes; |
| float* decode_buffer = stbir__get_decode_buffer(stbir_info); |
| stbir_edge edge_horizontal = stbir_info->edge_horizontal; |
| stbir_edge edge_vertical = stbir_info->edge_vertical; |
| size_t in_buffer_row_offset = stbir__edge_wrap(edge_vertical, n, stbir_info->input_h) * input_stride_bytes; |
| const void* input_data = (char *) stbir_info->input_data + in_buffer_row_offset; |
| int max_x = input_w + stbir_info->horizontal_filter_pixel_margin; |
| int decode = STBIR__DECODE(type, colorspace); |
| |
| int x = -stbir_info->horizontal_filter_pixel_margin; |
| |
| // special handling for STBIR_EDGE_ZERO because it needs to return an item that doesn't appear in the input, |
| // and we want to avoid paying overhead on every pixel if not STBIR_EDGE_ZERO |
| if (edge_vertical == STBIR_EDGE_ZERO && (n < 0 || n >= stbir_info->input_h)) |
| { |
| for (; x < max_x; x++) |
| for (c = 0; c < channels; c++) |
| decode_buffer[x*channels + c] = 0; |
| return; |
| } |
| |
| switch (decode) |
| { |
| case STBIR__DECODE(STBIR_TYPE_UINT8, STBIR_COLORSPACE_LINEAR): |
| for (; x < max_x; x++) |
| { |
| int decode_pixel_index = x * channels; |
| int input_pixel_index = stbir__edge_wrap(edge_horizontal, x, input_w) * channels; |
| for (c = 0; c < channels; c++) |
| decode_buffer[decode_pixel_index + c] = ((float)((const unsigned char*)input_data)[input_pixel_index + c]) / stbir__max_uint8_as_float; |
| } |
| break; |
| |
| case STBIR__DECODE(STBIR_TYPE_UINT8, STBIR_COLORSPACE_SRGB): |
| for (; x < max_x; x++) |
| { |
| int decode_pixel_index = x * channels; |
| int input_pixel_index = stbir__edge_wrap(edge_horizontal, x, input_w) * channels; |
| for (c = 0; c < channels; c++) |
| decode_buffer[decode_pixel_index + c] = stbir__srgb_uchar_to_linear_float[((const unsigned char*)input_data)[input_pixel_index + c]]; |
| |
| if (!(stbir_info->flags&STBIR_FLAG_ALPHA_USES_COLORSPACE)) |
| decode_buffer[decode_pixel_index + alpha_channel] = ((float)((const unsigned char*)input_data)[input_pixel_index + alpha_channel]) / stbir__max_uint8_as_float; |
| } |
| break; |
| |
| case STBIR__DECODE(STBIR_TYPE_UINT16, STBIR_COLORSPACE_LINEAR): |
| for (; x < max_x; x++) |
| { |
| int decode_pixel_index = x * channels; |
| int input_pixel_index = stbir__edge_wrap(edge_horizontal, x, input_w) * channels; |
| for (c = 0; c < channels; c++) |
| decode_buffer[decode_pixel_index + c] = ((float)((const unsigned short*)input_data)[input_pixel_index + c]) / stbir__max_uint16_as_float; |
| } |
| break; |
| |
| case STBIR__DECODE(STBIR_TYPE_UINT16, STBIR_COLORSPACE_SRGB): |
| for (; x < max_x; x++) |
| { |
| int decode_pixel_index = x * channels; |
| int input_pixel_index = stbir__edge_wrap(edge_horizontal, x, input_w) * channels; |
| for (c = 0; c < channels; c++) |
| decode_buffer[decode_pixel_index + c] = stbir__srgb_to_linear(((float)((const unsigned short*)input_data)[input_pixel_index + c]) / stbir__max_uint16_as_float); |
| |
| if (!(stbir_info->flags&STBIR_FLAG_ALPHA_USES_COLORSPACE)) |
| decode_buffer[decode_pixel_index + alpha_channel] = ((float)((const unsigned short*)input_data)[input_pixel_index + alpha_channel]) / stbir__max_uint16_as_float; |
| } |
| break; |
| |
| case STBIR__DECODE(STBIR_TYPE_UINT32, STBIR_COLORSPACE_LINEAR): |
| for (; x < max_x; x++) |
| { |
| int decode_pixel_index = x * channels; |
| int input_pixel_index = stbir__edge_wrap(edge_horizontal, x, input_w) * channels; |
| for (c = 0; c < channels; c++) |
| decode_buffer[decode_pixel_index + c] = (float)(((double)((const unsigned int*)input_data)[input_pixel_index + c]) / stbir__max_uint32_as_float); |
| } |
| break; |
| |
| case STBIR__DECODE(STBIR_TYPE_UINT32, STBIR_COLORSPACE_SRGB): |
| for (; x < max_x; x++) |
| { |
| int decode_pixel_index = x * channels; |
| int input_pixel_index = stbir__edge_wrap(edge_horizontal, x, input_w) * channels; |
| for (c = 0; c < channels; c++) |
| decode_buffer[decode_pixel_index + c] = stbir__srgb_to_linear((float)(((double)((const unsigned int*)input_data)[input_pixel_index + c]) / stbir__max_uint32_as_float)); |
| |
| if (!(stbir_info->flags&STBIR_FLAG_ALPHA_USES_COLORSPACE)) |
| decode_buffer[decode_pixel_index + alpha_channel] = (float)(((double)((const unsigned int*)input_data)[input_pixel_index + alpha_channel]) / stbir__max_uint32_as_float); |
| } |
| break; |
| |
| case STBIR__DECODE(STBIR_TYPE_FLOAT, STBIR_COLORSPACE_LINEAR): |
| for (; x < max_x; x++) |
| { |
| int decode_pixel_index = x * channels; |
| int input_pixel_index = stbir__edge_wrap(edge_horizontal, x, input_w) * channels; |
| for (c = 0; c < channels; c++) |
| decode_buffer[decode_pixel_index + c] = ((const float*)input_data)[input_pixel_index + c]; |
| } |
| break; |
| |
| case STBIR__DECODE(STBIR_TYPE_FLOAT, STBIR_COLORSPACE_SRGB): |
| for (; x < max_x; x++) |
| { |
| int decode_pixel_index = x * channels; |
| int input_pixel_index = stbir__edge_wrap(edge_horizontal, x, input_w) * channels; |
| for (c = 0; c < channels; c++) |
| decode_buffer[decode_pixel_index + c] = stbir__srgb_to_linear(((const float*)input_data)[input_pixel_index + c]); |
| |
| if (!(stbir_info->flags&STBIR_FLAG_ALPHA_USES_COLORSPACE)) |
| decode_buffer[decode_pixel_index + alpha_channel] = ((const float*)input_data)[input_pixel_index + alpha_channel]; |
| } |
| |
| break; |
| |
| default: |
| STBIR_ASSERT(!"Unknown type/colorspace/channels combination."); |
| break; |
| } |
| |
| if (!(stbir_info->flags & STBIR_FLAG_ALPHA_PREMULTIPLIED)) |
| { |
| for (x = -stbir_info->horizontal_filter_pixel_margin; x < max_x; x++) |
| { |
| int decode_pixel_index = x * channels; |
| |
| // If the alpha value is 0 it will clobber the color values. Make sure it's not. |
| float alpha = decode_buffer[decode_pixel_index + alpha_channel]; |
| #ifndef STBIR_NO_ALPHA_EPSILON |
| if (stbir_info->type != STBIR_TYPE_FLOAT) { |
| alpha += STBIR_ALPHA_EPSILON; |
| decode_buffer[decode_pixel_index + alpha_channel] = alpha; |
| } |
| #endif |
| for (c = 0; c < channels; c++) |
| { |
| if (c == alpha_channel) |
| continue; |
| |
| decode_buffer[decode_pixel_index + c] *= alpha; |
| } |
| } |
| } |
| |
| if (edge_horizontal == STBIR_EDGE_ZERO) |
| { |
| for (x = -stbir_info->horizontal_filter_pixel_margin; x < 0; x++) |
| { |
| for (c = 0; c < channels; c++) |
| decode_buffer[x*channels + c] = 0; |
| } |
| for (x = input_w; x < max_x; x++) |
| { |
| for (c = 0; c < channels; c++) |
| decode_buffer[x*channels + c] = 0; |
| } |
| } |
| } |
| |
| static float* stbir__get_ring_buffer_entry(float* ring_buffer, int index, int ring_buffer_length) |
| { |
| return &ring_buffer[index * ring_buffer_length]; |
| } |
| |
| static float* stbir__add_empty_ring_buffer_entry(stbir__info* stbir_info, int n) |
| { |
| int ring_buffer_index; |
| float* ring_buffer; |
| |
| stbir_info->ring_buffer_last_scanline = n; |
| |
| if (stbir_info->ring_buffer_begin_index < 0) |
| { |
| ring_buffer_index = stbir_info->ring_buffer_begin_index = 0; |
| stbir_info->ring_buffer_first_scanline = n; |
| } |
| else |
| { |
| ring_buffer_index = (stbir_info->ring_buffer_begin_index + (stbir_info->ring_buffer_last_scanline - stbir_info->ring_buffer_first_scanline)) % stbir_info->ring_buffer_num_entries; |
| STBIR_ASSERT(ring_buffer_index != stbir_info->ring_buffer_begin_index); |
| } |
| |
| ring_buffer = stbir__get_ring_buffer_entry(stbir_info->ring_buffer, ring_buffer_index, stbir_info->ring_buffer_length_bytes / sizeof(float)); |
| memset(ring_buffer, 0, stbir_info->ring_buffer_length_bytes); |
| |
| return ring_buffer; |
| } |
| |
| |
| static void stbir__resample_horizontal_upsample(stbir__info* stbir_info, float* output_buffer) |
| { |
| int x, k; |
| int output_w = stbir_info->output_w; |
| int channels = stbir_info->channels; |
| float* decode_buffer = stbir__get_decode_buffer(stbir_info); |
| stbir__contributors* horizontal_contributors = stbir_info->horizontal_contributors; |
| float* horizontal_coefficients = stbir_info->horizontal_coefficients; |
| int coefficient_width = stbir_info->horizontal_coefficient_width; |
| |
| for (x = 0; x < output_w; x++) |
| { |
| int n0 = horizontal_contributors[x].n0; |
| int n1 = horizontal_contributors[x].n1; |
| |
| int out_pixel_index = x * channels; |
| int coefficient_group = coefficient_width * x; |
| int coefficient_counter = 0; |
| |
| STBIR_ASSERT(n1 >= n0); |
| STBIR_ASSERT(n0 >= -stbir_info->horizontal_filter_pixel_margin); |
| STBIR_ASSERT(n1 >= -stbir_info->horizontal_filter_pixel_margin); |
| STBIR_ASSERT(n0 < stbir_info->input_w + stbir_info->horizontal_filter_pixel_margin); |
| STBIR_ASSERT(n1 < stbir_info->input_w + stbir_info->horizontal_filter_pixel_margin); |
| |
| switch (channels) { |
| case 1: |
| for (k = n0; k <= n1; k++) |
| { |
| int in_pixel_index = k * 1; |
| float coefficient = horizontal_coefficients[coefficient_group + coefficient_counter++]; |
| STBIR_ASSERT(coefficient != 0); |
| output_buffer[out_pixel_index + 0] += decode_buffer[in_pixel_index + 0] * coefficient; |
| } |
| break; |
| case 2: |
| for (k = n0; k <= n1; k++) |
| { |
| int in_pixel_index = k * 2; |
| float coefficient = horizontal_coefficients[coefficient_group + coefficient_counter++]; |
| STBIR_ASSERT(coefficient != 0); |
| output_buffer[out_pixel_index + 0] += decode_buffer[in_pixel_index + 0] * coefficient; |
| output_buffer[out_pixel_index + 1] += decode_buffer[in_pixel_index + 1] * coefficient; |
| } |
| break; |
| case 3: |
| for (k = n0; k <= n1; k++) |
| { |
| int in_pixel_index = k * 3; |
| float coefficient = horizontal_coefficients[coefficient_group + coefficient_counter++]; |
| STBIR_ASSERT(coefficient != 0); |
| output_buffer[out_pixel_index + 0] += decode_buffer[in_pixel_index + 0] * coefficient; |
| output_buffer[out_pixel_index + 1] += decode_buffer[in_pixel_index + 1] * coefficient; |
| output_buffer[out_pixel_index + 2] += decode_buffer[in_pixel_index + 2] * coefficient; |
| } |
| break; |
| case 4: |
| for (k = n0; k <= n1; k++) |
| { |
| int in_pixel_index = k * 4; |
| float coefficient = horizontal_coefficients[coefficient_group + coefficient_counter++]; |
| STBIR_ASSERT(coefficient != 0); |
| output_buffer[out_pixel_index + 0] += decode_buffer[in_pixel_index + 0] * coefficient; |
| output_buffer[out_pixel_index + 1] += decode_buffer[in_pixel_index + 1] * coefficient; |
| output_buffer[out_pixel_index + 2] += decode_buffer[in_pixel_index + 2] * coefficient; |
| output_buffer[out_pixel_index + 3] += decode_buffer[in_pixel_index + 3] * coefficient; |
| } |
| break; |
| default: |
| for (k = n0; k <= n1; k++) |
| { |
| int in_pixel_index = k * channels; |
| float coefficient = horizontal_coefficients[coefficient_group + coefficient_counter++]; |
| int c; |
| STBIR_ASSERT(coefficient != 0); |
| for (c = 0; c < channels; c++) |
| output_buffer[out_pixel_index + c] += decode_buffer[in_pixel_index + c] * coefficient; |
| } |
| break; |
| } |
| } |
| } |
| |
| static void stbir__resample_horizontal_downsample(stbir__info* stbir_info, float* output_buffer) |
| { |
| int x, k; |
| int input_w = stbir_info->input_w; |
| int channels = stbir_info->channels; |
| float* decode_buffer = stbir__get_decode_buffer(stbir_info); |
| stbir__contributors* horizontal_contributors = stbir_info->horizontal_contributors; |
| float* horizontal_coefficients = stbir_info->horizontal_coefficients; |
| int coefficient_width = stbir_info->horizontal_coefficient_width; |
| int filter_pixel_margin = stbir_info->horizontal_filter_pixel_margin; |
| int max_x = input_w + filter_pixel_margin * 2; |
| |
| STBIR_ASSERT(!stbir__use_width_upsampling(stbir_info)); |
| |
| switch (channels) { |
| case 1: |
| for (x = 0; x < max_x; x++) |
| { |
| int n0 = horizontal_contributors[x].n0; |
| int n1 = horizontal_contributors[x].n1; |
| |
| int in_x = x - filter_pixel_margin; |
| int in_pixel_index = in_x * 1; |
| int max_n = n1; |
| int coefficient_group = coefficient_width * x; |
| |
| for (k = n0; k <= max_n; k++) |
| { |
| int out_pixel_index = k * 1; |
| float coefficient = horizontal_coefficients[coefficient_group + k - n0]; |
| STBIR_ASSERT(coefficient != 0); |
| output_buffer[out_pixel_index + 0] += decode_buffer[in_pixel_index + 0] * coefficient; |
| } |
| } |
| break; |
| |
| case 2: |
| for (x = 0; x < max_x; x++) |
| { |
| int n0 = horizontal_contributors[x].n0; |
| int n1 = horizontal_contributors[x].n1; |
| |
| int in_x = x - filter_pixel_margin; |
| int in_pixel_index = in_x * 2; |
| int max_n = n1; |
| int coefficient_group = coefficient_width * x; |
| |
| for (k = n0; k <= max_n; k++) |
| { |
| int out_pixel_index = k * 2; |
| float coefficient = horizontal_coefficients[coefficient_group + k - n0]; |
| STBIR_ASSERT(coefficient != 0); |
| output_buffer[out_pixel_index + 0] += decode_buffer[in_pixel_index + 0] * coefficient; |
| output_buffer[out_pixel_index + 1] += decode_buffer[in_pixel_index + 1] * coefficient; |
| } |
| } |
| break; |
| |
| case 3: |
| for (x = 0; x < max_x; x++) |
| { |
| int n0 = horizontal_contributors[x].n0; |
| int n1 = horizontal_contributors[x].n1; |
| |
| int in_x = x - filter_pixel_margin; |
| int in_pixel_index = in_x * 3; |
| int max_n = n1; |
| int coefficient_group = coefficient_width * x; |
| |
| for (k = n0; k <= max_n; k++) |
| { |
| int out_pixel_index = k * 3; |
| float coefficient = horizontal_coefficients[coefficient_group + k - n0]; |
| STBIR_ASSERT(coefficient != 0); |
| output_buffer[out_pixel_index + 0] += decode_buffer[in_pixel_index + 0] * coefficient; |
| output_buffer[out_pixel_index + 1] += decode_buffer[in_pixel_index + 1] * coefficient; |
| output_buffer[out_pixel_index + 2] += decode_buffer[in_pixel_index + 2] * coefficient; |
| } |
| } |
| break; |
| |
| case 4: |
| for (x = 0; x < max_x; x++) |
| { |
| int n0 = horizontal_contributors[x].n0; |
| int n1 = horizontal_contributors[x].n1; |
| |
| int in_x = x - filter_pixel_margin; |
| int in_pixel_index = in_x * 4; |
| int max_n = n1; |
| int coefficient_group = coefficient_width * x; |
| |
| for (k = n0; k <= max_n; k++) |
| { |
| int out_pixel_index = k * 4; |
| float coefficient = horizontal_coefficients[coefficient_group + k - n0]; |
| STBIR_ASSERT(coefficient != 0); |
| output_buffer[out_pixel_index + 0] += decode_buffer[in_pixel_index + 0] * coefficient; |
| output_buffer[out_pixel_index + 1] += decode_buffer[in_pixel_index + 1] * coefficient; |
| output_buffer[out_pixel_index + 2] += decode_buffer[in_pixel_index + 2] * coefficient; |
| output_buffer[out_pixel_index + 3] += decode_buffer[in_pixel_index + 3] * coefficient; |
| } |
| } |
| break; |
| |
| default: |
| for (x = 0; x < max_x; x++) |
| { |
| int n0 = horizontal_contributors[x].n0; |
| int n1 = horizontal_contributors[x].n1; |
| |
| int in_x = x - filter_pixel_margin; |
| int in_pixel_index = in_x * channels; |
| int max_n = n1; |
| int coefficient_group = coefficient_width * x; |
| |
| for (k = n0; k <= max_n; k++) |
| { |
| int c; |
| int out_pixel_index = k * channels; |
| float coefficient = horizontal_coefficients[coefficient_group + k - n0]; |
| STBIR_ASSERT(coefficient != 0); |
| for (c = 0; c < channels; c++) |
| output_buffer[out_pixel_index + c] += decode_buffer[in_pixel_index + c] * coefficient; |
| } |
| } |
| break; |
| } |
| } |
| |
| static void stbir__decode_and_resample_upsample(stbir__info* stbir_info, int n) |
| { |
| // Decode the nth scanline from the source image into the decode buffer. |
| stbir__decode_scanline(stbir_info, n); |
| |
| // Now resample it into the ring buffer. |
| if (stbir__use_width_upsampling(stbir_info)) |
| stbir__resample_horizontal_upsample(stbir_info, stbir__add_empty_ring_buffer_entry(stbir_info, n)); |
| else |
| stbir__resample_horizontal_downsample(stbir_info, stbir__add_empty_ring_buffer_entry(stbir_info, n)); |
| |
| // Now it's sitting in the ring buffer ready to be used as source for the vertical sampling. |
| } |
| |
| static void stbir__decode_and_resample_downsample(stbir__info* stbir_info, int n) |
| { |
| // Decode the nth scanline from the source image into the decode buffer. |
| stbir__decode_scanline(stbir_info, n); |
| |
| memset(stbir_info->horizontal_buffer, 0, stbir_info->output_w * stbir_info->channels * sizeof(float)); |
| |
| // Now resample it into the horizontal buffer. |
| if (stbir__use_width_upsampling(stbir_info)) |
| stbir__resample_horizontal_upsample(stbir_info, stbir_info->horizontal_buffer); |
| else |
| stbir__resample_horizontal_downsample(stbir_info, stbir_info->horizontal_buffer); |
| |
| // Now it's sitting in the horizontal buffer ready to be distributed into the ring buffers. |
| } |
| |
| // Get the specified scan line from the ring buffer. |
| static float* stbir__get_ring_buffer_scanline(int get_scanline, float* ring_buffer, int begin_index, int first_scanline, int ring_buffer_num_entries, int ring_buffer_length) |
| { |
| int ring_buffer_index = (begin_index + (get_scanline - first_scanline)) % ring_buffer_num_entries; |
| return stbir__get_ring_buffer_entry(ring_buffer, ring_buffer_index, ring_buffer_length); |
| } |
| |
| |
| static void stbir__encode_scanline(stbir__info* stbir_info, int num_pixels, void *output_buffer, float *encode_buffer, int channels, int alpha_channel, int decode) |
| { |
| int x; |
| int n; |
| int num_nonalpha; |
| stbir_uint16 nonalpha[STBIR_MAX_CHANNELS]; |
| |
| if (!(stbir_info->flags&STBIR_FLAG_ALPHA_PREMULTIPLIED)) |
| { |
| for (x=0; x < num_pixels; ++x) |
| { |
| int pixel_index = x*channels; |
| |
| float alpha = encode_buffer[pixel_index + alpha_channel]; |
| float reciprocal_alpha = alpha ? 1.0f / alpha : 0; |
| |
| // unrolling this produced a 1% slowdown upscaling a large RGBA linear-space image on my machine - stb |
| for (n = 0; n < channels; n++) |
| if (n != alpha_channel) |
| encode_buffer[pixel_index + n] *= reciprocal_alpha; |
| |
| // We added in a small epsilon to prevent the color channel from being deleted with zero alpha. |
| // Because we only add it for integer types, it will automatically be discarded on integer |
| // conversion, so we don't need to subtract it back out (which would be problematic for |
| // numeric precision reasons). |
| } |
| } |
| |
| // build a table of all channels that need colorspace correction, so |
| // we don't perform colorspace correction on channels that don't need it. |
| for (x = 0, num_nonalpha = 0; x < channels; ++x) |
| { |
| if (x != alpha_channel || (stbir_info->flags & STBIR_FLAG_ALPHA_USES_COLORSPACE)) |
| { |
| nonalpha[num_nonalpha++] = (stbir_uint16)x; |
| } |
| } |
| |
| #define STBIR__ROUND_INT(f) ((int) ((f)+0.5)) |
| #define STBIR__ROUND_UINT(f) ((stbir_uint32) ((f)+0.5)) |
| |
| #ifdef STBIR__SATURATE_INT |
| #define STBIR__ENCODE_LINEAR8(f) stbir__saturate8 (STBIR__ROUND_INT((f) * stbir__max_uint8_as_float )) |
| #define STBIR__ENCODE_LINEAR16(f) stbir__saturate16(STBIR__ROUND_INT((f) * stbir__max_uint16_as_float)) |
| #else |
| #define STBIR__ENCODE_LINEAR8(f) (unsigned char ) STBIR__ROUND_INT(stbir__saturate(f) * stbir__max_uint8_as_float ) |
| #define STBIR__ENCODE_LINEAR16(f) (unsigned short) STBIR__ROUND_INT(stbir__saturate(f) * stbir__max_uint16_as_float) |
| #endif |
| |
| switch (decode) |
| { |
| case STBIR__DECODE(STBIR_TYPE_UINT8, STBIR_COLORSPACE_LINEAR): |
| for (x=0; x < num_pixels; ++x) |
| { |
| int pixel_index = x*channels; |
| |
| for (n = 0; n < channels; n++) |
| { |
| int index = pixel_index + n; |
| ((unsigned char*)output_buffer)[index] = STBIR__ENCODE_LINEAR8(encode_buffer[index]); |
| } |
| } |
| break; |
| |
| case STBIR__DECODE(STBIR_TYPE_UINT8, STBIR_COLORSPACE_SRGB): |
| for (x=0; x < num_pixels; ++x) |
| { |
| int pixel_index = x*channels; |
| |
| for (n = 0; n < num_nonalpha; n++) |
| { |
| int index = pixel_index + nonalpha[n]; |
| ((unsigned char*)output_buffer)[index] = stbir__linear_to_srgb_uchar(encode_buffer[index]); |
| } |
| |
| if (!(stbir_info->flags & STBIR_FLAG_ALPHA_USES_COLORSPACE)) |
| ((unsigned char *)output_buffer)[pixel_index + alpha_channel] = STBIR__ENCODE_LINEAR8(encode_buffer[pixel_index+alpha_channel]); |
| } |
| break; |
| |
| case STBIR__DECODE(STBIR_TYPE_UINT16, STBIR_COLORSPACE_LINEAR): |
| for (x=0; x < num_pixels; ++x) |
| { |
| int pixel_index = x*channels; |
| |
| for (n = 0; n < channels; n++) |
| { |
| int index = pixel_index + n; |
| ((unsigned short*)output_buffer)[index] = STBIR__ENCODE_LINEAR16(encode_buffer[index]); |
| } |
| } |
| break; |
| |
| case STBIR__DECODE(STBIR_TYPE_UINT16, STBIR_COLORSPACE_SRGB): |
| for (x=0; x < num_pixels; ++x) |
| { |
| int pixel_index = x*channels; |
| |
| for (n = 0; n < num_nonalpha; n++) |
| { |
| int index = pixel_index + nonalpha[n]; |
| ((unsigned short*)output_buffer)[index] = (unsigned short)STBIR__ROUND_INT(stbir__linear_to_srgb(stbir__saturate(encode_buffer[index])) * stbir__max_uint16_as_float); |
| } |
| |
| if (!(stbir_info->flags&STBIR_FLAG_ALPHA_USES_COLORSPACE)) |
| ((unsigned short*)output_buffer)[pixel_index + alpha_channel] = STBIR__ENCODE_LINEAR16(encode_buffer[pixel_index + alpha_channel]); |
| } |
| |
| break; |
| |
| case STBIR__DECODE(STBIR_TYPE_UINT32, STBIR_COLORSPACE_LINEAR): |
| for (x=0; x < num_pixels; ++x) |
| { |
| int pixel_index = x*channels; |
| |
| for (n = 0; n < channels; n++) |
| { |
| int index = pixel_index + n; |
| ((unsigned int*)output_buffer)[index] = (unsigned int)STBIR__ROUND_UINT(((double)stbir__saturate(encode_buffer[index])) * stbir__max_uint32_as_float); |
| } |
| } |
| break; |
| |
| case STBIR__DECODE(STBIR_TYPE_UINT32, STBIR_COLORSPACE_SRGB): |
| for (x=0; x < num_pixels; ++x) |
| { |
| int pixel_index = x*channels; |
| |
| for (n = 0; n < num_nonalpha; n++) |
| { |
| int index = pixel_index + nonalpha[n]; |
| ((unsigned int*)output_buffer)[index] = (unsigned int)STBIR__ROUND_UINT(((double)stbir__linear_to_srgb(stbir__saturate(encode_buffer[index]))) * stbir__max_uint32_as_float); |
| } |
| |
| if (!(stbir_info->flags&STBIR_FLAG_ALPHA_USES_COLORSPACE)) |
| ((unsigned int*)output_buffer)[pixel_index + alpha_channel] = (unsigned int)STBIR__ROUND_INT(((double)stbir__saturate(encode_buffer[pixel_index + alpha_channel])) * stbir__max_uint32_as_float); |
| } |
| break; |
| |
| case STBIR__DECODE(STBIR_TYPE_FLOAT, STBIR_COLORSPACE_LINEAR): |
| for (x=0; x < num_pixels; ++x) |
| { |
| int pixel_index = x*channels; |
| |
| for (n = 0; n < channels; n++) |
| { |
| int index = pixel_index + n; |
| ((float*)output_buffer)[index] = encode_buffer[index]; |
| } |
| } |
| break; |
| |
| case STBIR__DECODE(STBIR_TYPE_FLOAT, STBIR_COLORSPACE_SRGB): |
| for (x=0; x < num_pixels; ++x) |
| { |
| int pixel_index = x*channels; |
| |
| for (n = 0; n < num_nonalpha; n++) |
| { |
| int index = pixel_index + nonalpha[n]; |
| ((float*)output_buffer)[index] = stbir__linear_to_srgb(encode_buffer[index]); |
| } |
| |
| if (!(stbir_info->flags&STBIR_FLAG_ALPHA_USES_COLORSPACE)) |
| ((float*)output_buffer)[pixel_index + alpha_channel] = encode_buffer[pixel_index + alpha_channel]; |
| } |
| break; |
| |
| default: |
| STBIR_ASSERT(!"Unknown type/colorspace/channels combination."); |
| break; |
| } |
| } |
| |
| static void stbir__resample_vertical_upsample(stbir__info* stbir_info, int n) |
| { |
| int x, k; |
| int output_w = stbir_info->output_w; |
| stbir__contributors* vertical_contributors = stbir_info->vertical_contributors; |
| float* vertical_coefficients = stbir_info->vertical_coefficients; |
| int channels = stbir_info->channels; |
| int alpha_channel = stbir_info->alpha_channel; |
| int type = stbir_info->type; |
| int colorspace = stbir_info->colorspace; |
| int ring_buffer_entries = stbir_info->ring_buffer_num_entries; |
| void* output_data = stbir_info->output_data; |
| float* encode_buffer = stbir_info->encode_buffer; |
| int decode = STBIR__DECODE(type, colorspace); |
| int coefficient_width = stbir_info->vertical_coefficient_width; |
| int coefficient_counter; |
| int contributor = n; |
| |
| float* ring_buffer = stbir_info->ring_buffer; |
| int ring_buffer_begin_index = stbir_info->ring_buffer_begin_index; |
| int ring_buffer_first_scanline = stbir_info->ring_buffer_first_scanline; |
| int ring_buffer_length = stbir_info->ring_buffer_length_bytes/sizeof(float); |
| |
| int n0,n1, output_row_start; |
| int coefficient_group = coefficient_width * contributor; |
| |
| n0 = vertical_contributors[contributor].n0; |
| n1 = vertical_contributors[contributor].n1; |
| |
| output_row_start = n * stbir_info->output_stride_bytes; |
| |
| STBIR_ASSERT(stbir__use_height_upsampling(stbir_info)); |
| |
| memset(encode_buffer, 0, output_w * sizeof(float) * channels); |
| |
| // I tried reblocking this for better cache usage of encode_buffer |
| // (using x_outer, k, x_inner), but it lost speed. -- stb |
| |
| coefficient_counter = 0; |
| switch (channels) { |
| case 1: |
| for (k = n0; k <= n1; k++) |
| { |
| int coefficient_index = coefficient_counter++; |
| float* ring_buffer_entry = stbir__get_ring_buffer_scanline(k, ring_buffer, ring_buffer_begin_index, ring_buffer_first_scanline, ring_buffer_entries, ring_buffer_length); |
| float coefficient = vertical_coefficients[coefficient_group + coefficient_index]; |
| for (x = 0; x < output_w; ++x) |
| { |
| int in_pixel_index = x * 1; |
| encode_buffer[in_pixel_index + 0] += ring_buffer_entry[in_pixel_index + 0] * coefficient; |
| } |
| } |
| break; |
| case 2: |
| for (k = n0; k <= n1; k++) |
| { |
| int coefficient_index = coefficient_counter++; |
| float* ring_buffer_entry = stbir__get_ring_buffer_scanline(k, ring_buffer, ring_buffer_begin_index, ring_buffer_first_scanline, ring_buffer_entries, ring_buffer_length); |
| float coefficient = vertical_coefficients[coefficient_group + coefficient_index]; |
| for (x = 0; x < output_w; ++x) |
| { |
| int in_pixel_index = x * 2; |
| encode_buffer[in_pixel_index + 0] += ring_buffer_entry[in_pixel_index + 0] * coefficient; |
| encode_buffer[in_pixel_index + 1] += ring_buffer_entry[in_pixel_index + 1] * coefficient; |
| } |
| } |
| break; |
| case 3: |
| for (k = n0; k <= n1; k++) |
| { |
| int coefficient_index = coefficient_counter++; |
| float* ring_buffer_entry = stbir__get_ring_buffer_scanline(k, ring_buffer, ring_buffer_begin_index, ring_buffer_first_scanline, ring_buffer_entries, ring_buffer_length); |
| float coefficient = vertical_coefficients[coefficient_group + coefficient_index]; |
| for (x = 0; x < output_w; ++x) |
| { |
| int in_pixel_index = x * 3; |
| encode_buffer[in_pixel_index + 0] += ring_buffer_entry[in_pixel_index + 0] * coefficient; |
| encode_buffer[in_pixel_index + 1] += ring_buffer_entry[in_pixel_index + 1] * coefficient; |
| encode_buffer[in_pixel_index + 2] += ring_buffer_entry[in_pixel_index + 2] * coefficient; |
| } |
| } |
| break; |
| case 4: |
| for (k = n0; k <= n1; k++) |
| { |
| int coefficient_index = coefficient_counter++; |
| float* ring_buffer_entry = stbir__get_ring_buffer_scanline(k, ring_buffer, ring_buffer_begin_index, ring_buffer_first_scanline, ring_buffer_entries, ring_buffer_length); |
| float coefficient = vertical_coefficients[coefficient_group + coefficient_index]; |
| for (x = 0; x < output_w; ++x) |
| { |
| int in_pixel_index = x * 4; |
| encode_buffer[in_pixel_index + 0] += ring_buffer_entry[in_pixel_index + 0] * coefficient; |
| encode_buffer[in_pixel_index + 1] += ring_buffer_entry[in_pixel_index + 1] * coefficient; |
| encode_buffer[in_pixel_index + 2] += ring_buffer_entry[in_pixel_index + 2] * coefficient; |
| encode_buffer[in_pixel_index + 3] += ring_buffer_entry[in_pixel_index + 3] * coefficient; |
| } |
| } |
| break; |
| default: |
| for (k = n0; k <= n1; k++) |
| { |
| int coefficient_index = coefficient_counter++; |
| float* ring_buffer_entry = stbir__get_ring_buffer_scanline(k, ring_buffer, ring_buffer_begin_index, ring_buffer_first_scanline, ring_buffer_entries, ring_buffer_length); |
| float coefficient = vertical_coefficients[coefficient_group + coefficient_index]; |
| for (x = 0; x < output_w; ++x) |
| { |
| int in_pixel_index = x * channels; |
| int c; |
| for (c = 0; c < channels; c++) |
| encode_buffer[in_pixel_index + c] += ring_buffer_entry[in_pixel_index + c] * coefficient; |
| } |
| } |
| break; |
| } |
| stbir__encode_scanline(stbir_info, output_w, (char *) output_data + output_row_start, encode_buffer, channels, alpha_channel, decode); |
| } |
| |
| static void stbir__resample_vertical_downsample(stbir__info* stbir_info, int n) |
| { |
| int x, k; |
| int output_w = stbir_info->output_w; |
| stbir__contributors* vertical_contributors = stbir_info->vertical_contributors; |
| float* vertical_coefficients = stbir_info->vertical_coefficients; |
| int channels = stbir_info->channels; |
| int ring_buffer_entries = stbir_info->ring_buffer_num_entries; |
| float* horizontal_buffer = stbir_info->horizontal_buffer; |
| int coefficient_width = stbir_info->vertical_coefficient_width; |
| int contributor = n + stbir_info->vertical_filter_pixel_margin; |
| |
| float* ring_buffer = stbir_info->ring_buffer; |
| int ring_buffer_begin_index = stbir_info->ring_buffer_begin_index; |
| int ring_buffer_first_scanline = stbir_info->ring_buffer_first_scanline; |
| int ring_buffer_length = stbir_info->ring_buffer_length_bytes/sizeof(float); |
| int n0,n1; |
| |
| n0 = vertical_contributors[contributor].n0; |
| n1 = vertical_contributors[contributor].n1; |
| |
| STBIR_ASSERT(!stbir__use_height_upsampling(stbir_info)); |
| |
| for (k = n0; k <= n1; k++) |
| { |
| int coefficient_index = k - n0; |
| int coefficient_group = coefficient_width * contributor; |
| float coefficient = vertical_coefficients[coefficient_group + coefficient_index]; |
| |
| float* ring_buffer_entry = stbir__get_ring_buffer_scanline(k, ring_buffer, ring_buffer_begin_index, ring_buffer_first_scanline, ring_buffer_entries, ring_buffer_length); |
| |
| switch (channels) { |
| case 1: |
| for (x = 0; x < output_w; x++) |
| { |
| int in_pixel_index = x * 1; |
| ring_buffer_entry[in_pixel_index + 0] += horizontal_buffer[in_pixel_index + 0] * coefficient; |
| } |
| break; |
| case 2: |
| for (x = 0; x < output_w; x++) |
| { |
| int in_pixel_index = x * 2; |
| ring_buffer_entry[in_pixel_index + 0] += horizontal_buffer[in_pixel_index + 0] * coefficient; |
| ring_buffer_entry[in_pixel_index + 1] += horizontal_buffer[in_pixel_index + 1] * coefficient; |
| } |
| break; |
| case 3: |
| for (x = 0; x < output_w; x++) |
| { |
| int in_pixel_index = x * 3; |
| ring_buffer_entry[in_pixel_index + 0] += horizontal_buffer[in_pixel_index + 0] * coefficient; |
| ring_buffer_entry[in_pixel_index + 1] += horizontal_buffer[in_pixel_index + 1] * coefficient; |
| ring_buffer_entry[in_pixel_index + 2] += horizontal_buffer[in_pixel_index + 2] * coefficient; |
| } |
| break; |
| case 4: |
| for (x = 0; x < output_w; x++) |
| { |
| int in_pixel_index = x * 4; |
| ring_buffer_entry[in_pixel_index + 0] += horizontal_buffer[in_pixel_index + 0] * coefficient; |
| ring_buffer_entry[in_pixel_index + 1] += horizontal_buffer[in_pixel_index + 1] * coefficient; |
| ring_buffer_entry[in_pixel_index + 2] += horizontal_buffer[in_pixel_index + 2] * coefficient; |
| ring_buffer_entry[in_pixel_index + 3] += horizontal_buffer[in_pixel_index + 3] * coefficient; |
| } |
| break; |
| default: |
| for (x = 0; x < output_w; x++) |
| { |
| int in_pixel_index = x * channels; |
| |
| int c; |
| for (c = 0; c < channels; c++) |
| ring_buffer_entry[in_pixel_index + c] += horizontal_buffer[in_pixel_index + c] * coefficient; |
| } |
| break; |
| } |
| } |
| } |
| |
| static void stbir__buffer_loop_upsample(stbir__info* stbir_info) |
| { |
| int y; |
| float scale_ratio = stbir_info->vertical_scale; |
| float out_scanlines_radius = stbir__filter_info_table[stbir_info->vertical_filter].support(1/scale_ratio) * scale_ratio; |
| |
| STBIR_ASSERT(stbir__use_height_upsampling(stbir_info)); |
| |
| for (y = 0; y < stbir_info->output_h; y++) |
| { |
| float in_center_of_out = 0; // Center of the current out scanline in the in scanline space |
| int in_first_scanline = 0, in_last_scanline = 0; |
| |
| stbir__calculate_sample_range_upsample(y, out_scanlines_radius, scale_ratio, stbir_info->vertical_shift, &in_first_scanline, &in_last_scanline, &in_center_of_out); |
| |
| STBIR_ASSERT(in_last_scanline - in_first_scanline + 1 <= stbir_info->ring_buffer_num_entries); |
| |
| if (stbir_info->ring_buffer_begin_index >= 0) |
| { |
| // Get rid of whatever we don't need anymore. |
| while (in_first_scanline > stbir_info->ring_buffer_first_scanline) |
| { |
| if (stbir_info->ring_buffer_first_scanline == stbir_info->ring_buffer_last_scanline) |
| { |
| // We just popped the last scanline off the ring buffer. |
| // Reset it to the empty state. |
| stbir_info->ring_buffer_begin_index = -1; |
| stbir_info->ring_buffer_first_scanline = 0; |
| stbir_info->ring_buffer_last_scanline = 0; |
| break; |
| } |
| else |
| { |
| stbir_info->ring_buffer_first_scanline++; |
| stbir_info->ring_buffer_begin_index = (stbir_info->ring_buffer_begin_index + 1) % stbir_info->ring_buffer_num_entries; |
| } |
| } |
| } |
| |
| // Load in new ones. |
| if (stbir_info->ring_buffer_begin_index < 0) |
| stbir__decode_and_resample_upsample(stbir_info, in_first_scanline); |
| |
| while (in_last_scanline > stbir_info->ring_buffer_last_scanline) |
| stbir__decode_and_resample_upsample(stbir_info, stbir_info->ring_buffer_last_scanline + 1); |
| |
| // Now all buffers should be ready to write a row of vertical sampling. |
| stbir__resample_vertical_upsample(stbir_info, y); |
| |
| STBIR_PROGRESS_REPORT((float)y / stbir_info->output_h); |
| } |
| } |
| |
| static void stbir__empty_ring_buffer(stbir__info* stbir_info, int first_necessary_scanline) |
| { |
| int output_stride_bytes = stbir_info->output_stride_bytes; |
| int channels = stbir_info->channels; |
| int alpha_channel = stbir_info->alpha_channel; |
| int type = stbir_info->type; |
| int colorspace = stbir_info->colorspace; |
| int output_w = stbir_info->output_w; |
| void* output_data = stbir_info->output_data; |
| int decode = STBIR__DECODE(type, colorspace); |
| |
| float* ring_buffer = stbir_info->ring_buffer; |
| int ring_buffer_length = stbir_info->ring_buffer_length_bytes/sizeof(float); |
| |
| if (stbir_info->ring_buffer_begin_index >= 0) |
| { |
| // Get rid of whatever we don't need anymore. |
| while (first_necessary_scanline > stbir_info->ring_buffer_first_scanline) |
| { |
| if (stbir_info->ring_buffer_first_scanline >= 0 && stbir_info->ring_buffer_first_scanline < stbir_info->output_h) |
| { |
| int output_row_start = stbir_info->ring_buffer_first_scanline * output_stride_bytes; |
| float* ring_buffer_entry = stbir__get_ring_buffer_entry(ring_buffer, stbir_info->ring_buffer_begin_index, ring_buffer_length); |
| stbir__encode_scanline(stbir_info, output_w, (char *) output_data + output_row_start, ring_buffer_entry, channels, alpha_channel, decode); |
| STBIR_PROGRESS_REPORT((float)stbir_info->ring_buffer_first_scanline / stbir_info->output_h); |
| } |
| |
| if (stbir_info->ring_buffer_first_scanline == stbir_info->ring_buffer_last_scanline) |
| { |
| // We just popped the last scanline off the ring buffer. |
| // Reset it to the empty state. |
| stbir_info->ring_buffer_begin_index = -1; |
| stbir_info->ring_buffer_first_scanline = 0; |
| stbir_info->ring_buffer_last_scanline = 0; |
| break; |
| } |
| else |
| { |
| stbir_info->ring_buffer_first_scanline++; |
| stbir_info->ring_buffer_begin_index = (stbir_info->ring_buffer_begin_index + 1) % stbir_info->ring_buffer_num_entries; |
| } |
| } |
| } |
| } |
| |
| static void stbir__buffer_loop_downsample(stbir__info* stbir_info) |
| { |
| int y; |
| float scale_ratio = stbir_info->vertical_scale; |
| int output_h = stbir_info->output_h; |
| float in_pixels_radius = stbir__filter_info_table[stbir_info->vertical_filter].support(scale_ratio) / scale_ratio; |
| int pixel_margin = stbir_info->vertical_filter_pixel_margin; |
| int max_y = stbir_info->input_h + pixel_margin; |
| |
| STBIR_ASSERT(!stbir__use_height_upsampling(stbir_info)); |
| |
| for (y = -pixel_margin; y < max_y; y++) |
| { |
| float out_center_of_in; // Center of the current out scanline in the in scanline space |
| int out_first_scanline, out_last_scanline; |
| |
| stbir__calculate_sample_range_downsample(y, in_pixels_radius, scale_ratio, stbir_info->vertical_shift, &out_first_scanline, &out_last_scanline, &out_center_of_in); |
| |
| STBIR_ASSERT(out_last_scanline - out_first_scanline + 1 <= stbir_info->ring_buffer_num_entries); |
| |
| if (out_last_scanline < 0 || out_first_scanline >= output_h) |
| continue; |
| |
| stbir__empty_ring_buffer(stbir_info, out_first_scanline); |
| |
| stbir__decode_and_resample_downsample(stbir_info, y); |
| |
| // Load in new ones. |
| if (stbir_info->ring_buffer_begin_index < 0) |
| stbir__add_empty_ring_buffer_entry(stbir_info, out_first_scanline); |
| |
| while (out_last_scanline > stbir_info->ring_buffer_last_scanline) |
| stbir__add_empty_ring_buffer_entry(stbir_info, stbir_info->ring_buffer_last_scanline + 1); |
| |
| // Now the horizontal buffer is ready to write to all ring buffer rows. |
| stbir__resample_vertical_downsample(stbir_info, y); |
| } |
| |
| stbir__empty_ring_buffer(stbir_info, stbir_info->output_h); |
| } |
| |
| static void stbir__setup(stbir__info *info, int input_w, int input_h, int output_w, int output_h, int channels) |
| { |
| info->input_w = input_w; |
| info->input_h = input_h; |
| info->output_w = output_w; |
| info->output_h = output_h; |
| info->channels = channels; |
| } |
| |
| static void stbir__calculate_transform(stbir__info *info, float s0, float t0, float s1, float t1, float *transform) |
| { |
| info->s0 = s0; |
| info->t0 = t0; |
| info->s1 = s1; |
| info->t1 = t1; |
| |
| if (transform) |
| { |
| info->horizontal_scale = transform[0]; |
| info->vertical_scale = transform[1]; |
| info->horizontal_shift = transform[2]; |
| info->vertical_shift = transform[3]; |
| } |
| else |
| { |
| info->horizontal_scale = ((float)info->output_w / info->input_w) / (s1 - s0); |
| info->vertical_scale = ((float)info->output_h / info->input_h) / (t1 - t0); |
| |
| info->horizontal_shift = s0 * info->output_w / (s1 - s0); |
| info->vertical_shift = t0 * info->output_h / (t1 - t0); |
| } |
| } |
| |
| static void stbir__choose_filter(stbir__info *info, stbir_filter h_filter, stbir_filter v_filter) |
| { |
| if (h_filter == 0) |
| h_filter = stbir__use_upsampling(info->horizontal_scale) ? STBIR_DEFAULT_FILTER_UPSAMPLE : STBIR_DEFAULT_FILTER_DOWNSAMPLE; |
| if (v_filter == 0) |
| v_filter = stbir__use_upsampling(info->vertical_scale) ? STBIR_DEFAULT_FILTER_UPSAMPLE : STBIR_DEFAULT_FILTER_DOWNSAMPLE; |
| info->horizontal_filter = h_filter; |
| info->vertical_filter = v_filter; |
| } |
| |
| static stbir_uint32 stbir__calculate_memory(stbir__info *info) |
| { |
| int pixel_margin = stbir__get_filter_pixel_margin(info->horizontal_filter, info->horizontal_scale); |
| int filter_height = stbir__get_filter_pixel_width(info->vertical_filter, info->vertical_scale); |
| |
| info->horizontal_num_contributors = stbir__get_contributors(info->horizontal_scale, info->horizontal_filter, info->input_w, info->output_w); |
| info->vertical_num_contributors = stbir__get_contributors(info->vertical_scale , info->vertical_filter , info->input_h, info->output_h); |
| |
| // One extra entry because floating point precision problems sometimes cause an extra to be necessary. |
| info->ring_buffer_num_entries = filter_height + 1; |
| |
| info->horizontal_contributors_size = info->horizontal_num_contributors * sizeof(stbir__contributors); |
| info->horizontal_coefficients_size = stbir__get_total_horizontal_coefficients(info) * sizeof(float); |
| info->vertical_contributors_size = info->vertical_num_contributors * sizeof(stbir__contributors); |
| info->vertical_coefficients_size = stbir__get_total_vertical_coefficients(info) * sizeof(float); |
| info->decode_buffer_size = (info->input_w + pixel_margin * 2) * info->channels * sizeof(float); |
| info->horizontal_buffer_size = info->output_w * info->channels * sizeof(float); |
| info->ring_buffer_size = info->output_w * info->channels * info->ring_buffer_num_entries * sizeof(float); |
| info->encode_buffer_size = info->output_w * info->channels * sizeof(float); |
| |
| STBIR_ASSERT(info->horizontal_filter != 0); |
| STBIR_ASSERT(info->horizontal_filter < STBIR__ARRAY_SIZE(stbir__filter_info_table)); // this now happens too late |
| STBIR_ASSERT(info->vertical_filter != 0); |
| STBIR_ASSERT(info->vertical_filter < STBIR__ARRAY_SIZE(stbir__filter_info_table)); // this now happens too late |
| |
| if (stbir__use_height_upsampling(info)) |
| // The horizontal buffer is for when we're downsampling the height and we |
| // can't output the result of sampling the decode buffer directly into the |
| // ring buffers. |
| info->horizontal_buffer_size = 0; |
| else |
| // The encode buffer is to retain precision in the height upsampling method |
| // and isn't used when height downsampling. |
| info->encode_buffer_size = 0; |
| |
| return info->horizontal_contributors_size + info->horizontal_coefficients_size |
| + info->vertical_contributors_size + info->vertical_coefficients_size |
| + info->decode_buffer_size + info->horizontal_buffer_size |
| + info->ring_buffer_size + info->encode_buffer_size; |
| } |
| |
| static int stbir__resize_allocated(stbir__info *info, |
| const void* input_data, int input_stride_in_bytes, |
| void* output_data, int output_stride_in_bytes, |
| int alpha_channel, stbir_uint32 flags, stbir_datatype type, |
| stbir_edge edge_horizontal, stbir_edge edge_vertical, stbir_colorspace colorspace, |
| void* tempmem, size_t tempmem_size_in_bytes) |
| { |
| size_t memory_required = stbir__calculate_memory(info); |
| |
| int width_stride_input = input_stride_in_bytes ? input_stride_in_bytes : info->channels * info->input_w * stbir__type_size[type]; |
| int width_stride_output = output_stride_in_bytes ? output_stride_in_bytes : info->channels * info->output_w * stbir__type_size[type]; |
| |
| #ifdef STBIR_DEBUG_OVERWRITE_TEST |
| #define OVERWRITE_ARRAY_SIZE 8 |
| unsigned char overwrite_output_before_pre[OVERWRITE_ARRAY_SIZE]; |
| unsigned char overwrite_tempmem_before_pre[OVERWRITE_ARRAY_SIZE]; |
| unsigned char overwrite_output_after_pre[OVERWRITE_ARRAY_SIZE]; |
| unsigned char overwrite_tempmem_after_pre[OVERWRITE_ARRAY_SIZE]; |
| |
| size_t begin_forbidden = width_stride_output * (info->output_h - 1) + info->output_w * info->channels * stbir__type_size[type]; |
| memcpy(overwrite_output_before_pre, &((unsigned char*)output_data)[-OVERWRITE_ARRAY_SIZE], OVERWRITE_ARRAY_SIZE); |
| memcpy(overwrite_output_after_pre, &((unsigned char*)output_data)[begin_forbidden], OVERWRITE_ARRAY_SIZE); |
| memcpy(overwrite_tempmem_before_pre, &((unsigned char*)tempmem)[-OVERWRITE_ARRAY_SIZE], OVERWRITE_ARRAY_SIZE); |
| memcpy(overwrite_tempmem_after_pre, &((unsigned char*)tempmem)[tempmem_size_in_bytes], OVERWRITE_ARRAY_SIZE); |
| #endif |
| |
| STBIR_ASSERT(info->channels >= 0); |
| STBIR_ASSERT(info->channels <= STBIR_MAX_CHANNELS); |
| |
| if (info->channels < 0 || info->channels > STBIR_MAX_CHANNELS) |
| return 0; |
| |
| STBIR_ASSERT(info->horizontal_filter < STBIR__ARRAY_SIZE(stbir__filter_info_table)); |
| STBIR_ASSERT(info->vertical_filter < STBIR__ARRAY_SIZE(stbir__filter_info_table)); |
| |
| if (info->horizontal_filter >= STBIR__ARRAY_SIZE(stbir__filter_info_table)) |
| return 0; |
| if (info->vertical_filter >= STBIR__ARRAY_SIZE(stbir__filter_info_table)) |
| return 0; |
| |
| if (alpha_channel < 0) |
| flags |= STBIR_FLAG_ALPHA_USES_COLORSPACE | STBIR_FLAG_ALPHA_PREMULTIPLIED; |
| |
| if (!(flags&STBIR_FLAG_ALPHA_USES_COLORSPACE) || !(flags&STBIR_FLAG_ALPHA_PREMULTIPLIED)) |
| STBIR_ASSERT(alpha_channel >= 0 && alpha_channel < info->channels); |
| |
| if (alpha_channel >= info->channels) |
| return 0; |
| |
| STBIR_ASSERT(tempmem); |
| |
| if (!tempmem) |
| return 0; |
| |
| STBIR_ASSERT(tempmem_size_in_bytes >= memory_required); |
| |
| if (tempmem_size_in_bytes < memory_required) |
| return 0; |
| |
| memset(tempmem, 0, tempmem_size_in_bytes); |
| |
| info->input_data = input_data; |
| info->input_stride_bytes = width_stride_input; |
| |
| info->output_data = output_data; |
| info->output_stride_bytes = width_stride_output; |
| |
| info->alpha_channel = alpha_channel; |
| info->flags = flags; |
| info->type = type; |
| info->edge_horizontal = edge_horizontal; |
| info->edge_vertical = edge_vertical; |
| info->colorspace = colorspace; |
| |
| info->horizontal_coefficient_width = stbir__get_coefficient_width (info->horizontal_filter, info->horizontal_scale); |
| info->vertical_coefficient_width = stbir__get_coefficient_width (info->vertical_filter , info->vertical_scale ); |
| info->horizontal_filter_pixel_width = stbir__get_filter_pixel_width (info->horizontal_filter, info->horizontal_scale); |
| info->vertical_filter_pixel_width = stbir__get_filter_pixel_width (info->vertical_filter , info->vertical_scale ); |
| info->horizontal_filter_pixel_margin = stbir__get_filter_pixel_margin(info->horizontal_filter, info->horizontal_scale); |
| info->vertical_filter_pixel_margin = stbir__get_filter_pixel_margin(info->vertical_filter , info->vertical_scale ); |
| |
| info->ring_buffer_length_bytes = info->output_w * info->channels * sizeof(float); |
| info->decode_buffer_pixels = info->input_w + info->horizontal_filter_pixel_margin * 2; |
| |
| #define STBIR__NEXT_MEMPTR(current, newtype) (newtype*)(((unsigned char*)current) + current##_size) |
| |
| info->horizontal_contributors = (stbir__contributors *) tempmem; |
| info->horizontal_coefficients = STBIR__NEXT_MEMPTR(info->horizontal_contributors, float); |
| info->vertical_contributors = STBIR__NEXT_MEMPTR(info->horizontal_coefficients, stbir__contributors); |
| info->vertical_coefficients = STBIR__NEXT_MEMPTR(info->vertical_contributors, float); |
| info->decode_buffer = STBIR__NEXT_MEMPTR(info->vertical_coefficients, float); |
| |
| if (stbir__use_height_upsampling(info)) |
| { |
| info->horizontal_buffer = NULL; |
| info->ring_buffer = STBIR__NEXT_MEMPTR(info->decode_buffer, float); |
| info->encode_buffer = STBIR__NEXT_MEMPTR(info->ring_buffer, float); |
| |
| STBIR_ASSERT((size_t)STBIR__NEXT_MEMPTR(info->encode_buffer, unsigned char) == (size_t)tempmem + tempmem_size_in_bytes); |
| } |
| else |
| { |
| info->horizontal_buffer = STBIR__NEXT_MEMPTR(info->decode_buffer, float); |
| info->ring_buffer = STBIR__NEXT_MEMPTR(info->horizontal_buffer, float); |
| info->encode_buffer = NULL; |
| |
| STBIR_ASSERT((size_t)STBIR__NEXT_MEMPTR(info->ring_buffer, unsigned char) == (size_t)tempmem + tempmem_size_in_bytes); |
| } |
| |
| #undef STBIR__NEXT_MEMPTR |
| |
| // This signals that the ring buffer is empty |
| info->ring_buffer_begin_index = -1; |
| |
| stbir__calculate_filters(info->horizontal_contributors, info->horizontal_coefficients, info->horizontal_filter, info->horizontal_scale, info->horizontal_shift, info->input_w, info->output_w); |
| stbir__calculate_filters(info->vertical_contributors, info->vertical_coefficients, info->vertical_filter, info->vertical_scale, info->vertical_shift, info->input_h, info->output_h); |
| |
| STBIR_PROGRESS_REPORT(0); |
| |
| if (stbir__use_height_upsampling(info)) |
| stbir__buffer_loop_upsample(info); |
| else |
| stbir__buffer_loop_downsample(info); |
| |
| STBIR_PROGRESS_REPORT(1); |
| |
| #ifdef STBIR_DEBUG_OVERWRITE_TEST |
| STBIR_ASSERT(memcmp(overwrite_output_before_pre, &((unsigned char*)output_data)[-OVERWRITE_ARRAY_SIZE], OVERWRITE_ARRAY_SIZE) == 0); |
| STBIR_ASSERT(memcmp(overwrite_output_after_pre, &((unsigned char*)output_data)[begin_forbidden], OVERWRITE_ARRAY_SIZE) == 0); |
| STBIR_ASSERT(memcmp(overwrite_tempmem_before_pre, &((unsigned char*)tempmem)[-OVERWRITE_ARRAY_SIZE], OVERWRITE_ARRAY_SIZE) == 0); |
| STBIR_ASSERT(memcmp(overwrite_tempmem_after_pre, &((unsigned char*)tempmem)[tempmem_size_in_bytes], OVERWRITE_ARRAY_SIZE) == 0); |
| #endif |
| |
| return 1; |
| } |
| |
| |
| static int stbir__resize_arbitrary( |
| void *alloc_context, |
| const void* input_data, int input_w, int input_h, int input_stride_in_bytes, |
| void* output_data, int output_w, int output_h, int output_stride_in_bytes, |
| float s0, float t0, float s1, float t1, float *transform, |
| int channels, int alpha_channel, stbir_uint32 flags, stbir_datatype type, |
| stbir_filter h_filter, stbir_filter v_filter, |
| stbir_edge edge_horizontal, stbir_edge edge_vertical, stbir_colorspace colorspace) |
| { |
| stbir__info info; |
| int result; |
| size_t memory_required; |
| void* extra_memory; |
| |
| stbir__setup(&info, input_w, input_h, output_w, output_h, channels); |
| stbir__calculate_transform(&info, s0,t0,s1,t1,transform); |
| stbir__choose_filter(&info, h_filter, v_filter); |
| memory_required = stbir__calculate_memory(&info); |
| extra_memory = STBIR_MALLOC(memory_required, alloc_context); |
| |
| if (!extra_memory) |
| return 0; |
| |
| result = stbir__resize_allocated(&info, input_data, input_stride_in_bytes, |
| output_data, output_stride_in_bytes, |
| alpha_channel, flags, type, |
| edge_horizontal, edge_vertical, |
| colorspace, extra_memory, memory_required); |
| |
| STBIR_FREE(extra_memory, alloc_context); |
| |
| return result; |
| } |
| |
| STBIRDEF int stbir_resize_uint8( const unsigned char *input_pixels , int input_w , int input_h , int input_stride_in_bytes, |
| unsigned char *output_pixels, int output_w, int output_h, int output_stride_in_bytes, |
| int num_channels) |
| { |
| return stbir__resize_arbitrary(NULL, input_pixels, input_w, input_h, input_stride_in_bytes, |
| output_pixels, output_w, output_h, output_stride_in_bytes, |
| 0,0,1,1,NULL,num_channels,-1,0, STBIR_TYPE_UINT8, STBIR_FILTER_DEFAULT, STBIR_FILTER_DEFAULT, |
| STBIR_EDGE_CLAMP, STBIR_EDGE_CLAMP, STBIR_COLORSPACE_LINEAR); |
| } |
| |
| STBIRDEF int stbir_resize_float( const float *input_pixels , int input_w , int input_h , int input_stride_in_bytes, |
| float *output_pixels, int output_w, int output_h, int output_stride_in_bytes, |
| int num_channels) |
| { |
| return stbir__resize_arbitrary(NULL, input_pixels, input_w, input_h, input_stride_in_bytes, |
| output_pixels, output_w, output_h, output_stride_in_bytes, |
| 0,0,1,1,NULL,num_channels,-1,0, STBIR_TYPE_FLOAT, STBIR_FILTER_DEFAULT, STBIR_FILTER_DEFAULT, |
| STBIR_EDGE_CLAMP, STBIR_EDGE_CLAMP, STBIR_COLORSPACE_LINEAR); |
| } |
| |
| STBIRDEF int stbir_resize_uint8_srgb(const unsigned char *input_pixels , int input_w , int input_h , int input_stride_in_bytes, |
| unsigned char *output_pixels, int output_w, int output_h, int output_stride_in_bytes, |
| int num_channels, int alpha_channel, int flags) |
| { |
| return stbir__resize_arbitrary(NULL, input_pixels, input_w, input_h, input_stride_in_bytes, |
| output_pixels, output_w, output_h, output_stride_in_bytes, |
| 0,0,1,1,NULL,num_channels,alpha_channel,flags, STBIR_TYPE_UINT8, STBIR_FILTER_DEFAULT, STBIR_FILTER_DEFAULT, |
| STBIR_EDGE_CLAMP, STBIR_EDGE_CLAMP, STBIR_COLORSPACE_SRGB); |
| } |
| |
| STBIRDEF int stbir_resize_uint8_srgb_edgemode(const unsigned char *input_pixels , int input_w , int input_h , int input_stride_in_bytes, |
| unsigned char *output_pixels, int output_w, int output_h, int output_stride_in_bytes, |
| int num_channels, int alpha_channel, int flags, |
| stbir_edge edge_wrap_mode) |
| { |
| return stbir__resize_arbitrary(NULL, input_pixels, input_w, input_h, input_stride_in_bytes, |
| output_pixels, output_w, output_h, output_stride_in_bytes, |
| 0,0,1,1,NULL,num_channels,alpha_channel,flags, STBIR_TYPE_UINT8, STBIR_FILTER_DEFAULT, STBIR_FILTER_DEFAULT, |
| edge_wrap_mode, edge_wrap_mode, STBIR_COLORSPACE_SRGB); |
| } |
| |
| STBIRDEF int stbir_resize_uint8_generic( const unsigned char *input_pixels , int input_w , int input_h , int input_stride_in_bytes, |
| unsigned char *output_pixels, int output_w, int output_h, int output_stride_in_bytes, |
| int num_channels, int alpha_channel, int flags, |
| stbir_edge edge_wrap_mode, stbir_filter filter, stbir_colorspace space, |
| void *alloc_context) |
| { |
| return stbir__resize_arbitrary(alloc_context, input_pixels, input_w, input_h, input_stride_in_bytes, |
| output_pixels, output_w, output_h, output_stride_in_bytes, |
| 0,0,1,1,NULL,num_channels,alpha_channel,flags, STBIR_TYPE_UINT8, filter, filter, |
| edge_wrap_mode, edge_wrap_mode, space); |
| } |
| |
| STBIRDEF int stbir_resize_uint16_generic(const stbir_uint16 *input_pixels , int input_w , int input_h , int input_stride_in_bytes, |
| stbir_uint16 *output_pixels , int output_w, int output_h, int output_stride_in_bytes, |
| int num_channels, int alpha_channel, int flags, |
| stbir_edge edge_wrap_mode, stbir_filter filter, stbir_colorspace space, |
| void *alloc_context) |
| { |
| return stbir__resize_arbitrary(alloc_context, input_pixels, input_w, input_h, input_stride_in_bytes, |
| output_pixels, output_w, output_h, output_stride_in_bytes, |
| 0,0,1,1,NULL,num_channels,alpha_channel,flags, STBIR_TYPE_UINT16, filter, filter, |
| edge_wrap_mode, edge_wrap_mode, space); |
| } |
| |
| |
| STBIRDEF int stbir_resize_float_generic( const float *input_pixels , int input_w , int input_h , int input_stride_in_bytes, |
| float *output_pixels , int output_w, int output_h, int output_stride_in_bytes, |
| int num_channels, int alpha_channel, int flags, |
| stbir_edge edge_wrap_mode, stbir_filter filter, stbir_colorspace space, |
| void *alloc_context) |
| { |
| return stbir__resize_arbitrary(alloc_context, input_pixels, input_w, input_h, input_stride_in_bytes, |
| output_pixels, output_w, output_h, output_stride_in_bytes, |
| 0,0,1,1,NULL,num_channels,alpha_channel,flags, STBIR_TYPE_FLOAT, filter, filter, |
| edge_wrap_mode, edge_wrap_mode, space); |
| } |
| |
| |
| STBIRDEF int stbir_resize( const void *input_pixels , int input_w , int input_h , int input_stride_in_bytes, |
| void *output_pixels, int output_w, int output_h, int output_stride_in_bytes, |
| stbir_datatype datatype, |
| int num_channels, int alpha_channel, int flags, |
| stbir_edge edge_mode_horizontal, stbir_edge edge_mode_vertical, |
| stbir_filter filter_horizontal, stbir_filter filter_vertical, |
| stbir_colorspace space, void *alloc_context) |
| { |
| return stbir__resize_arbitrary(alloc_context, input_pixels, input_w, input_h, input_stride_in_bytes, |
| output_pixels, output_w, output_h, output_stride_in_bytes, |
| 0,0,1,1,NULL,num_channels,alpha_channel,flags, datatype, filter_horizontal, filter_vertical, |
| edge_mode_horizontal, edge_mode_vertical, space); |
| } |
| |
| |
| STBIRDEF int stbir_resize_subpixel(const void *input_pixels , int input_w , int input_h , int input_stride_in_bytes, |
| void *output_pixels, int output_w, int output_h, int output_stride_in_bytes, |
| stbir_datatype datatype, |
| int num_channels, int alpha_channel, int flags, |
| stbir_edge edge_mode_horizontal, stbir_edge edge_mode_vertical, |
| stbir_filter filter_horizontal, stbir_filter filter_vertical, |
| stbir_colorspace space, void *alloc_context, |
| float x_scale, float y_scale, |
| float x_offset, float y_offset) |
| { |
| float transform[4]; |
| transform[0] = x_scale; |
| transform[1] = y_scale; |
| transform[2] = x_offset; |
| transform[3] = y_offset; |
| return stbir__resize_arbitrary(alloc_context, input_pixels, input_w, input_h, input_stride_in_bytes, |
| output_pixels, output_w, output_h, output_stride_in_bytes, |
| 0,0,1,1,transform,num_channels,alpha_channel,flags, datatype, filter_horizontal, filter_vertical, |
| edge_mode_horizontal, edge_mode_vertical, space); |
| } |
| |
| STBIRDEF int stbir_resize_region( const void *input_pixels , int input_w , int input_h , int input_stride_in_bytes, |
| void *output_pixels, int output_w, int output_h, int output_stride_in_bytes, |
| stbir_datatype datatype, |
| int num_channels, int alpha_channel, int flags, |
| stbir_edge edge_mode_horizontal, stbir_edge edge_mode_vertical, |
| stbir_filter filter_horizontal, stbir_filter filter_vertical, |
| stbir_colorspace space, void *alloc_context, |
| float s0, float t0, float s1, float t1) |
| { |
| return stbir__resize_arbitrary(alloc_context, input_pixels, input_w, input_h, input_stride_in_bytes, |
| output_pixels, output_w, output_h, output_stride_in_bytes, |
| s0,t0,s1,t1,NULL,num_channels,alpha_channel,flags, datatype, filter_horizontal, filter_vertical, |
| edge_mode_horizontal, edge_mode_vertical, space); |
| } |
| |
| #endif // STB_IMAGE_RESIZE_IMPLEMENTATION |
| |
| /* |
| ------------------------------------------------------------------------------ |
| MIT License |
| Copyright (c) 2017 Sean Barrett |
| Permission is hereby granted, free of charge, to any person obtaining a copy of |
| this software and associated documentation files (the "Software"), to deal in |
| the Software without restriction, including without limitation the rights to |
| use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies |
| of the Software, and to permit persons to whom the Software is furnished to do |
| so, subject to the following conditions: |
| The above copyright notice and this permission notice shall be included in all |
| copies or substantial portions of the Software. |
| THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE |
| AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
| OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE |
| SOFTWARE. |
| ------------------------------------------------------------------------------ |
| */ |