mirror of https://github.com/nothings/stb.git
Update documentation and add helper functions.
This commit is contained in:
Jorge Rodriguez
parent
5b40906271
commit
68f93b72d5
207
stb_resample.h
207
stb_resample.h
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@ -1,29 +1,65 @@
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/* stb_resample - v0.1 - public domain image resampling
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no warranty implied; use at your own risk
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/* stb_resample - v0.50 - public domain image resampling
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no warranty implied; use at your own risk
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Do this:
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#define STB_RESAMPLE_IMPLEMENTATION
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before you include this file in *one* C or C++ file to create the implementation.
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Do this:
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#define STB_RESAMPLE_IMPLEMENTATION
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before you include this file in *one* C or C++ file to create the implementation.
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#define STBR_ASSERT(x) to avoid using assert.h.
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#define STBR_ASSERT(x) to avoid using assert.h.
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Latest revisions:
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#define STBR_NO_MALLOC to avoid using stdlib.h and malloc. This will remove
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all resize functions except stbr_resize_arbitrary() from the API.
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See end of file for full revision history.
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QUICK NOTES:
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Written with emphasis on usage and speed. Only the resize operation is
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currently supported, no rotations or translations.
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Initial implementation by Jorge L Rodriguez
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Supports arbitrary resize for separable filters. For a list of
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supported filters see the stbr_filter enum. To add a new filter,
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write a filter function and add it to stbr__filter_info_table.
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Latest revisions:
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0.50 (2014-07-29) first released version
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See end of file for full revision history.
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TODO:
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Installable filters
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Specify with (s0, t0) X (s1, t1) what area of the source image to use,
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at sub-pixel level
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Specify wrap and filter modes independently for each axis
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Resize that respects alpha test coverage
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(Reference code: FloatImage::alphaTestCoverage and FloatImage::scaleAlphaToCoverage:
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https://code.google.com/p/nvidia-texture-tools/source/browse/trunk/src/nvimage/FloatImage.cpp )
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Initial implementation by Jorge L Rodriguez, @VinoBS
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*/
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#ifndef STBR_INCLUDE_STB_RESAMPLE_H
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#define STBR_INCLUDE_STB_RESAMPLE_H
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// Basic usage:
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// result = stbr_resize(input_data, input_w, input_h, 0, output_data, output_w, output_h, 0, channels, alpha_channel, STBR_TYPE_UINT8, STBR_FILTER_BILINEAR, STBR_EDGE_CLAMP, STBR_COLORSPACE_SRGB);
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// result = stbr_resize_srgb_uint8(input_data, input_w, input_h, output_data, output_w, output_h, channels, STBR_FILTER_CATMULLROM, STBR_EDGE_CLAMP);
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//
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// input_data is your supplied texels.
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// output_data will be the resized texels. It should be of size output_w * output_h * input_components (or output_h * output_stride if you provided a stride.)
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// If input_stride or output_stride is 0 (as in this example) the stride will be automatically calculated as width*components.
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// Returned result is 1 for success or 0 in case of an error.
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// output_data will be the resized texels. It should be of size output_w * output_h * channels
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// Returned result is 1 for success or 0 in case of an error. Currently the only error is failure to allocate memory.
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// If you're unsure of which filter to use, Catmull-Rom is a good upsampling filter and Mitchell is a good downsampling filter.
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// Advanced usage:
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// size_t memory_required = stbr_calculate_memory(input_w, input_h, output_w, output_h, channels, STBR_FILTER_CATMULLROM);
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// void* extra_memory = malloc(memory_required); // Any memory allocation method of your choosing
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// result = stbr_resize_arbitrary(input_data, input_w, input_h, input_stride_in_bytes,
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// output_data, output_w, output_h, output_stride_in_bytes,
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// channels, STBR_TYPE_UINT8, STBR_FILTER_CATMULLROM, STBR_EDGE_CLAMP, STBR_COLORSPACE_SRGB,
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// extra_memory, memory_required);
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// free(extra_memory);
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//
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// input_stride_in_bytes and output_stride_in_bytes can be 0. If so they will be automatically calculated as width * channels.
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// Returned result is 1 for success or 0 in case of an error. Currently the only error is that the memory passed in is insufficient.
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// stbr_resize_arbitrary() will not allocate any memory, it will use the memory you pass in to do its work.
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typedef enum
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{
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@ -61,7 +97,17 @@ typedef enum
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#define STBR_MAX_TYPES 4
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typedef unsigned char stbr_uc;
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typedef unsigned char stbr_uint8;
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#ifdef _MSC_VER
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typedef unsigned short stbr_uint16;
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typedef unsigned int stbr_uint32;
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#else
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#include <stdint.h>
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typedef uint16_t stbr_uint16;
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typedef uint32_t stbr_uint32;
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#endif
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typedef unsigned int stbr_size_t; // to avoid including a header for size_t
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#ifdef __cplusplus
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@ -74,18 +120,40 @@ extern "C" {
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#define STBRDEF extern
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#endif
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#ifndef STBR_NO_MALLOC
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//////////////////////////////////////////////////////////////////////////////
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//
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// PRIMARY API - resize an image
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// PRIMARY API - sRGB type-safe image resizing.
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//
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STBRDEF stbr_size_t stbr_calculate_memory(int input_w, int input_h, int input_stride_in_bytes,
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int output_w, int output_h, int output_stride_in_bytes,
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int channels, stbr_filter filter);
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STBRDEF int stbr_resize_srgb_uint8(const stbr_uint8* input_data, int input_w, int input_h,
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stbr_uint8* output_data, int output_w, int output_h,
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int channels, stbr_filter filter, stbr_edge edge);
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STBRDEF int stbr_resize_srgb_uint16(const stbr_uint16* input_data, int input_w, int input_h,
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stbr_uint16* output_data, int output_w, int output_h,
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int channels, stbr_filter filter, stbr_edge edge);
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STBRDEF int stbr_resize_srgb_uint32(const stbr_uint32* input_data, int input_w, int input_h,
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stbr_uint32* output_data, int output_w, int output_h,
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int channels, stbr_filter filter, stbr_edge edge);
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STBRDEF int stbr_resize_srgb_float(const float* input_data, int input_w, int input_h,
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float* output_data, int output_w, int output_h,
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int channels, stbr_filter filter, stbr_edge edge);
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#endif // STBR_NO_MALLOC
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//////////////////////////////////////////////////////////////////////////////
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//
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// ADVANCED API
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//
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STBRDEF stbr_size_t stbr_calculate_memory(int input_w, int input_h, int output_w, int output_h, int channels, stbr_filter filter);
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STBRDEF int stbr_resize_arbitrary(const void* input_data, int input_w, int input_h, int input_stride_in_bytes,
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void* output_data, int output_w, int output_h, int output_stride_in_bytes,
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//int channels, int alpha_channel, stbr_type type, stbr_filter filter, stbr_edge edge, stbr_colorspace colorspace,
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int channels, stbr_type type, stbr_filter filter, stbr_edge edge, stbr_colorspace colorspace,
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void* tempmem, stbr_size_t tempmem_size_in_bytes);
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@ -119,9 +187,12 @@ extern "C" {
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// For memset
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#include <string.h>
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#include <math.h>
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#ifndef STBR_NO_MALLOC
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#include <stdlib.h>
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#endif
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#ifndef _MSC_VER
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#ifdef __cplusplus
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@ -134,21 +205,8 @@ extern "C" {
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#endif
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#ifdef _MSC_VER
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typedef unsigned short stbr__uint16;
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typedef signed short stbr__int16;
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typedef unsigned int stbr__uint32;
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typedef signed int stbr__int32;
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#else
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#include <stdint.h>
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typedef uint16_t stbr__uint16;
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typedef int16_t stbr__int16;
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typedef uint32_t stbr__uint32;
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typedef int32_t stbr__int32;
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#endif
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// should produce compiler error if size is wrong
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typedef unsigned char stbr__validate_uint32[sizeof(stbr__uint32) == 4 ? 1 : -1];
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typedef unsigned char stbr__validate_uint32[sizeof(stbr_uint32) == 4 ? 1 : -1];
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#ifdef _MSC_VER
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#define STBR_NOTUSED(v) (void)(v)
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@ -1142,7 +1200,7 @@ STBRDEF int stbr_resize_arbitrary(const void* input_data, int input_w, int input
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if (!tempmem)
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return 0;
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if (tempmem_size_in_bytes < stbr_calculate_memory(input_w, input_h, input_stride_in_bytes, output_w, output_h, output_stride_in_bytes, channels, STBR_FILTER_NEAREST))
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if (tempmem_size_in_bytes < stbr_calculate_memory(input_w, input_h, output_w, output_h, channels, filter))
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return 0;
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memset(tempmem, 0, tempmem_size_in_bytes);
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@ -1213,9 +1271,7 @@ STBRDEF int stbr_resize_arbitrary(const void* input_data, int input_w, int input
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}
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STBRDEF stbr_size_t stbr_calculate_memory(int input_w, int input_h, int input_stride_in_bytes,
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int output_w, int output_h, int output_stride_in_bytes,
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int channels, stbr_filter filter)
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STBRDEF stbr_size_t stbr_calculate_memory(int input_w, int input_h, int output_w, int output_h, int channels, stbr_filter filter)
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{
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STBR_ASSERT(filter != 0);
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STBR_ASSERT(filter < STBR_ARRAY_SIZE(stbr__filter_info_table));
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@ -1244,8 +1300,83 @@ STBRDEF stbr_size_t stbr_calculate_memory(int input_w, int input_h, int input_st
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return info_size + contributors_size + horizontal_coefficients_size + vertical_coefficients_size + decode_buffer_size + horizontal_buffer_size + ring_buffer_size + encode_buffer_size;
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}
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#ifndef STBR_NO_MALLOC
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STBRDEF int stbr_resize_srgb_uint8(const stbr_uint8* input_data, int input_w, int input_h,
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stbr_uint8* output_data, int output_w, int output_h,
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int channels, stbr_filter filter, stbr_edge edge)
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{
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size_t memory_required = stbr_calculate_memory(input_w, input_h, output_w, output_h, channels, filter);
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void* extra_memory = malloc(memory_required);
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if (!extra_memory)
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return 0;
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int result = stbr_resize_arbitrary(input_data, input_w, input_h, 0, output_data, output_w, output_h, 0, channels, STBR_TYPE_UINT8, filter, edge, STBR_COLORSPACE_SRGB, extra_memory, memory_required);
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free(extra_memory);
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return result;
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}
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STBRDEF int stbr_resize_srgb_uint16(const stbr_uint16* input_data, int input_w, int input_h,
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stbr_uint16* output_data, int output_w, int output_h,
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int channels, stbr_filter filter, stbr_edge edge)
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{
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size_t memory_required = stbr_calculate_memory(input_w, input_h, output_w, output_h, channels, filter);
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void* extra_memory = malloc(memory_required);
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if (!extra_memory)
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return 0;
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int result = stbr_resize_arbitrary(input_data, input_w, input_h, 0, output_data, output_w, output_h, 0, channels, STBR_TYPE_UINT16, filter, edge, STBR_COLORSPACE_SRGB, extra_memory, memory_required);
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free(extra_memory);
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return result;
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}
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STBRDEF int stbr_resize_srgb_uint32(const stbr_uint32* input_data, int input_w, int input_h,
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stbr_uint32* output_data, int output_w, int output_h,
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int channels, stbr_filter filter, stbr_edge edge)
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{
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size_t memory_required = stbr_calculate_memory(input_w, input_h, output_w, output_h, channels, filter);
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void* extra_memory = malloc(memory_required);
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if (!extra_memory)
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return 0;
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int result = stbr_resize_arbitrary(input_data, input_w, input_h, 0, output_data, output_w, output_h, 0, channels, STBR_TYPE_UINT32, filter, edge, STBR_COLORSPACE_SRGB, extra_memory, memory_required);
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free(extra_memory);
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return result;
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}
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STBRDEF int stbr_resize_srgb_float(const float* input_data, int input_w, int input_h,
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float* output_data, int output_w, int output_h,
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int channels, stbr_filter filter, stbr_edge edge)
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{
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size_t memory_required = stbr_calculate_memory(input_w, input_h, output_w, output_h, channels, filter);
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void* extra_memory = malloc(memory_required);
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if (!extra_memory)
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return 0;
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int result = stbr_resize_arbitrary(input_data, input_w, input_h, 0, output_data, output_w, output_h, 0, channels, STBR_TYPE_FLOAT, filter, edge, STBR_COLORSPACE_SRGB, extra_memory, memory_required);
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free(extra_memory);
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return result;
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}
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#endif // STBR_NO_MALLOC
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#endif // STB_RESAMPLE_IMPLEMENTATION
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/*
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revision history:
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0.50 (2014-07-29)
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first released version
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*/
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@ -48,7 +48,7 @@ int main(int argc, char** argv)
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int in_w = 512;
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int in_h = 512;
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size_t memory_required = stbr_calculate_memory(in_w, in_h, w*n, out_w, out_h, out_stride, n, STBR_FILTER_CATMULLROM);
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size_t memory_required = stbr_calculate_memory(in_w, in_h, out_w, out_h, n, STBR_FILTER_CATMULLROM);
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void* extra_memory = malloc(memory_required);
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// Cut out the outside 64 pixels all around to test the stride.
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