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Diffstat (limited to 'externals/stb/stb_image_resize.h')
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diff --git a/externals/stb/stb_image_resize.h b/externals/stb/stb_image_resize.h new file mode 100644 index 000000000..3107e0670 --- /dev/null +++ b/externals/stb/stb_image_resize.h @@ -0,0 +1,426 @@ +// SPDX-FileCopyrightText: Jorge L Rodriguez +// SPDX-License-Identifier: MIT + +/* stb_image_resize - v0.97 - 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 + 0.97 (2020-02-02) fixed warning + 0.96 (2019-03-04) fixed warnings + 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 + +#ifndef STBIRDEF +#ifdef STB_IMAGE_RESIZE_STATIC +#define STBIRDEF static +#else +#ifdef __cplusplus +#define STBIRDEF extern "C" +#else +#define STBIRDEF extern +#endif +#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 + +/* +------------------------------------------------------------------------------ +This software is available under 2 licenses -- choose whichever you prefer. +------------------------------------------------------------------------------ +ALTERNATIVE A - 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. +------------------------------------------------------------------------------ +ALTERNATIVE B - Public Domain (www.unlicense.org) +This is free and unencumbered software released into the public domain. +Anyone is free to copy, modify, publish, use, compile, sell, or distribute this +software, either in source code form or as a compiled binary, for any purpose, +commercial or non-commercial, and by any means. +In jurisdictions that recognize copyright laws, the author or authors of this +software dedicate any and all copyright interest in the software to the public +domain. We make this dedication for the benefit of the public at large and to +the detriment of our heirs and successors. We intend this dedication to be an +overt act of relinquishment in perpetuity of all present and future rights to +this software under copyright law. +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 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. +------------------------------------------------------------------------------ +*/ |