Updated to raylib 3.7

1 files changed, 0 insertions, 930 deletions

diff --git a/libs/raylib/src/external/rgif.h b/libs/raylib/src/external/rgif.h
deleted file mode 100644
index 2bc655b..0000000
--- a/libs/raylib/src/external/rgif.h
+++ /dev/null
@@ -1,930 +0,0 @@
-/**********************************************************************************************
-*
-*   rgif.h v0.5
-*
-*   Original implementation (gif.h) by Charlie Tangora [ctangora -at- gmail -dot- com]
-*   adapted to C99, reformatted and renamed by Ramon Santamaria (@raysan5)
-*
-*   This file offers a simple, very limited way to create animated GIFs directly in code.
-*
-*   Those looking for particular cleverness are likely to be disappointed; it's pretty 
-*   much a straight-ahead implementation of the GIF format with optional Floyd-Steinberg 
-*   dithering. (It does at least use delta encoding - only the changed portions of each 
-*   frame are saved.) 
-*
-*   So resulting files are often quite large. The hope is that it will be handy nonetheless
-*   as a quick and easily-integrated way for programs to spit out animations.
-*
-*   Only RGBA8 is currently supported as an input format. (The alpha is ignored.)
-*
-*   CONFIGURATION:
-*
-*   #define RGIF_IMPLEMENTATION
-*       Generates the implementation of the library into the included file.
-*       If not defined, the library is in header only mode and can be included in other headers
-*       or source files without problems. But only ONE file should hold the implementation.
-*
-*   USAGE:
-*       1) Create a GifWriter struct. Pass it to GifBegin() to initialize and write the header.
-*       2) Pass subsequent frames to GifWriteFrame().
-*       3) Finally, call GifEnd() to close the file handle and free memory.
-*
-*
-*   LICENSE: This software is available under 2 licenses -- choose whichever you prefer
-*
-*   ALTERNATIVE A - MIT License
-*
-*   Copyright (c) 2017-2019 Ramon Santamaria (@raysan5)
-*
-*   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.
-*
-**********************************************************************************************/
-
-#ifndef RGIF_H
-#define RGIF_H
-
-#include <stdio.h>                      // Required for: FILE
-
-//#define RGIF_STATIC
-#ifdef RGIF_STATIC
-    #define RGIFDEF static              // Functions just visible to module including this file
-#else
-    #ifdef __cplusplus
-        #define RGIFDEF extern "C"      // Functions visible from other files (no name mangling of functions in C++)
-    #else
-        #define RGIFDEF extern          // Functions visible from other files
-    #endif
-#endif
-
-//----------------------------------------------------------------------------------
-// Module Functions Declaration
-//----------------------------------------------------------------------------------
-
-// NOTE: By default use bitDepth = 8, dither = false
-RGIFDEF bool GifBegin(const char *filename, unsigned int width, unsigned int height, unsigned int delay, unsigned int bitDepth, bool dither);
-RGIFDEF bool GifWriteFrame(const unsigned char *image, unsigned int width, unsigned int height, unsigned int delay, int bitDepth, bool dither);
-RGIFDEF bool GifEnd();
-
-#endif // RGIF_H
-
-
-/***********************************************************************************
-*
- *  GIF IMPLEMENTATION
-*
-************************************************************************************/
-
-#if defined(RGIF_IMPLEMENTATION)
-
-#include <stdio.h>          // Required for: FILE, fopen(), fclose()
-#include <string.h>         // Required for: memcpy()
-
-// Check if custom malloc/free functions defined, if not, using standard ones
-// RGIF_MALLOC and RGIF_FREE are used only by GifBegin and GifEnd respectively, 
-// to allocate a buffer the size of the image, which is used to find changed pixels for delta-encoding.
-#if !defined(RGIF_MALLOC)
-    #include <stdlib.h>     // Required for: malloc(), free()
-
-    #define RGIF_MALLOC(size)  malloc(size)
-    #define RGIF_FREE(ptr)     free(ptr)
-#endif
-
-//----------------------------------------------------------------------------------
-// Defines and Macros
-//----------------------------------------------------------------------------------
-#define GIFMIN(a, b) (((a)<(b))?(a):(b))
-#define GIFMAX(a, b) (((a)>(b))?(a):(b))
-#define GIFABS(x) ((x)<0?-(x):(x))
-
-//----------------------------------------------------------------------------------
-// Types and Structures Definition
-//----------------------------------------------------------------------------------
-
-// Gif palette structure
-typedef struct GifPalette {
-    int bitDepth;
-
-    unsigned char r[256];
-    unsigned char g[256];
-    unsigned char b[256];
-    
-    // k-d tree over RGB space, organized in heap fashion
-    // i.e. left child of node i is node i*2, right child is node i*2 + 1
-    // nodes 256-511 are implicitly the leaves, containing a color
-    unsigned char treeSplitElt[255];
-    unsigned char treeSplit[255];
-} GifPalette;
-
-
-// Simple structure to write out the LZW-compressed 
-// portion of the imageone bit at a time
-typedef struct GifBitStatus {
-    unsigned char bitIndex;  // how many bits in the partial byte written so far
-    unsigned char byte;      // current partial byte
-    
-    unsigned int chunkIndex;
-    unsigned char chunk[256];   // bytes are written in here until we have 256 of them, then written to the file
-} GifBitStatus;
-
-// The LZW dictionary is a 256-ary tree constructed 
-// as the file is encoded, this is one node
-typedef struct GifLzwNode {
-    unsigned short m_next[256];
-} GifLzwNode;
-
-//----------------------------------------------------------------------------------
-// Global Variables Definition
-//----------------------------------------------------------------------------------
-const int gifTransparentIndex = 0;       // Transparent color index
-
-static FILE *gifFile = NULL;
-unsigned char *gifFrame;
-
-//----------------------------------------------------------------------------------
-// Module specific Functions Declaration
-//----------------------------------------------------------------------------------
-static void GifGetClosestPaletteColor(GifPalette *pPal, int r, int g, int b, int *bestInd, int *bestDiff, int treeRoot);
-static void GifSwapPixels(unsigned char *image, int pixA, int pixB);
-static int GifPartition(unsigned char *image, const int left, const int right, const int elt, int pivotIndex);
-static void GifPartitionByMedian(unsigned char *image, int left, int right, int com, int neededCenter);
-static void GifSplitPalette(unsigned char *image, int numPixels, int firstElt, int lastElt, int splitElt, int splitDist, int treeNode, bool buildForDither, GifPalette *pal);
-static int GifPickChangedPixels(const unsigned char *lastFrame, unsigned char *frame, int numPixels);
-static void GifMakePalette(const unsigned char *lastFrame, const unsigned char *nextFrame, unsigned int width, unsigned int height, int bitDepth, bool buildForDither, GifPalette *pPal);
-static void GifDitherImage(const unsigned char *lastFrame, const unsigned char *nextFrame, unsigned char *outFrame, unsigned int width, unsigned int height, GifPalette *pPal);
-static void GifThresholdImage(const unsigned char *lastFrame, const unsigned char *nextFrame, unsigned char *outFrame, unsigned int width, unsigned int height, GifPalette *pPal);
-static void GifWriteBit(GifBitStatus *stat, unsigned int bit);
-
-static void GifWriteChunk(FILE *f, GifBitStatus *stat);
-static void GifWritePalette(FILE *f, const GifPalette *pPal);
-static void GifWriteCode(FILE *f, GifBitStatus *stat, unsigned int code, unsigned int length);
-static void GifWriteLzwImage(FILE *f, unsigned char *image, unsigned int left, unsigned int top, unsigned int width, unsigned int height, unsigned int delay, GifPalette *pPal);
-
-//----------------------------------------------------------------------------------
-// Module Functions Definition
-//----------------------------------------------------------------------------------
-
-// Creates a gif file
-// NOTE: Initializes internal file pointer (only one gif recording at a time)
-// The delay value is the time between frames in hundredths of a second - note that not all viewers pay much attention to this value.
-RGIFDEF bool GifBegin(const char *filename, unsigned int width, unsigned int height, unsigned int delay, unsigned int bitDepth, bool dither)
-{
-#if _MSC_VER >= 1400
-	gifFile = 0;
-    fopen_s(&gifFile, filename, "wb");
-#else
-    gifFile = fopen(filename, "wb");
-#endif
-
-    if (!gifFile) return false;
-    
-    // Allocate space for one gif frame
-    gifFrame = (unsigned char *)RGIF_MALLOC(width*height*4);
-    
-    // GIF Header
-    fputs("GIF89a",gifFile);
-    
-    // Reference: http://www.onicos.com/staff/iz/formats/gif.html
-    
-    // GIF Screen Descriptor
-    fputc(width & 0xff, gifFile);
-    fputc((width >> 8) & 0xff, gifFile);      // Screen width (2 byte)
-    fputc(height & 0xff, gifFile);
-    fputc((height >> 8) & 0xff, gifFile);     // Screen height (2 byte)
-    
-    fputc(0xf0, gifFile);  // Color table flags: unsorted global color table of 2 entries (1 byte, bit-flags)
-    fputc(0, gifFile);     // Background color index
-    fputc(0, gifFile);     // Pixel Aspect Ratio (square, we need to specify this because it's 1989)
-    
-    // GIF Global Color table (just a dummy palette)
-    // Color 0: black
-    fputc(0, gifFile);
-    fputc(0, gifFile); 
-    fputc(0, gifFile);
-    // Color 1: also black
-    fputc(0, gifFile);
-    fputc(0, gifFile);
-    fputc(0, gifFile);
-    
-    if (delay != 0)
-    {
-        // Application Extension Block (19 bytes long)
-        fputc(0x21, gifFile);     // GIF Extension code
-        fputc(0xff, gifFile);     // Application Extension Label
-        fputc(11, gifFile);       // Length of Application Block (11 byte)
-        fputs("NETSCAPE2.0", gifFile); // Application Identifier (Netscape 2.0 block)
-        
-        fputc(0x03, gifFile);     // Length of Data Sub-Block (3 bytes)
-        fputc(0x01, gifFile);     // 0x01
-        fputc(0x00, gifFile);     // This specifies the number of times,  
-        fputc(0x00, gifFile);     // the loop should be executed (infinitely)
-        
-        fputc(0x00, gifFile);     // Data Sub-Block Terminator.
-    }
-    
-    return true;
-}
-
-// Writes out a new frame to a GIF in progress.
-// NOTE: gifFile should have been initialized with GifBegin()
-// AFAIK, it is legal to use different bit depths for different frames of an image -
-// this may be handy to save bits in animations that don't change much.
-RGIFDEF bool GifWriteFrame(const unsigned char *image, unsigned int width, unsigned int height, unsigned int delay, int bitDepth, bool dither)
-{
-    if (!gifFile) return false;
-    
-    const unsigned char *oldImage = gifFrame;
-    
-    GifPalette pal;
-    GifMakePalette((dither ? NULL : oldImage), image, width, height, bitDepth, dither, &pal);
-    
-    if (dither) GifDitherImage(oldImage, image, gifFrame, width, height, &pal);
-    else GifThresholdImage(oldImage, image, gifFrame, width, height, &pal);
-    
-    GifWriteLzwImage(gifFile, gifFrame, 0, 0, width, height, delay, &pal);
-    
-    return true;
-}
-
-// Writes the EOF code, closes the file handle, and frees temp memory used by a GIF.
-// Many if not most viewers will still display a GIF properly if the EOF code is missing,
-// but it's still a good idea to write it out.
-RGIFDEF bool GifEnd()
-{
-    if (!gifFile) return false;
-    
-    fputc(0x3b, gifFile);     // Trailer (end of file)
-    fclose(gifFile);
-    
-    RGIF_FREE(gifFrame);
-    
-    gifFile = NULL;
-    gifFrame = NULL;
-    
-    return true;
-}
-
-//----------------------------------------------------------------------------------
-// Module specific Functions Definition
-//----------------------------------------------------------------------------------
-// walks the k-d tree to pick the palette entry for a desired color.
-// Takes as in/out parameters the current best color and its error -
-// only changes them if it finds a better color in its subtree.
-// this is the major hotspot in the code at the moment.
-static void GifGetClosestPaletteColor(GifPalette *pPal, int r, int g, int b, int *bestInd, int *bestDiff, int treeRoot)
-{
-    // base case, reached the bottom of the tree
-    if (treeRoot > (1<<pPal->bitDepth)-1)
-    {
-        int ind = treeRoot-(1<<pPal->bitDepth);
-        if (ind == gifTransparentIndex) return;
-        
-        // check whether this color is better than the current winner
-        int r_err = r - ((int)pPal->r[ind]);
-        int g_err = g - ((int)pPal->g[ind]);
-        int b_err = b - ((int)pPal->b[ind]);
-        int diff = GIFABS(r_err)+GIFABS(g_err)+GIFABS(b_err);
-        
-        if (diff < *bestDiff)
-        {
-            *bestInd = ind;
-            *bestDiff = diff;
-        }
-        
-        return;
-    }
-    
-    // take the appropriate color (r, g, or b) for this node of the k-d tree
-    int comps[3]; comps[0] = r; comps[1] = g; comps[2] = b;
-    int splitComp = comps[pPal->treeSplitElt[treeRoot]];
-    
-    int splitPos = pPal->treeSplit[treeRoot];
-    if (splitPos > splitComp)
-    {
-        // check the left subtree
-        GifGetClosestPaletteColor(pPal, r, g, b, bestInd, bestDiff, treeRoot*2);
-        
-        if (*bestDiff > (splitPos - splitComp))
-        {
-            // cannot prove there's not a better value in the right subtree, check that too
-            GifGetClosestPaletteColor(pPal, r, g, b, bestInd, bestDiff, treeRoot*2 + 1);
-        }
-    }
-    else
-    {
-        GifGetClosestPaletteColor(pPal, r, g, b, bestInd, bestDiff, treeRoot*2 + 1);
-        
-        if (*bestDiff > splitComp - splitPos)
-        {
-            GifGetClosestPaletteColor(pPal, r, g, b, bestInd, bestDiff, treeRoot*2);
-        }
-    }
-}
-
-static void GifSwapPixels(unsigned char *image, int pixA, int pixB)
-{
-    unsigned char rA = image[pixA*4];
-    unsigned char gA = image[pixA*4 + 1];
-    unsigned char bA = image[pixA*4+2];
-    unsigned char aA = image[pixA*4+3];
-    
-    unsigned char rB = image[pixB*4];
-    unsigned char gB = image[pixB*4 + 1];
-    unsigned char bB = image[pixB*4+2];
-    unsigned char aB = image[pixA*4+3];
-    
-    image[pixA*4] = rB;
-    image[pixA*4 + 1] = gB;
-    image[pixA*4+2] = bB;
-    image[pixA*4+3] = aB;
-    
-    image[pixB*4] = rA;
-    image[pixB*4 + 1] = gA;
-    image[pixB*4+2] = bA;
-    image[pixB*4+3] = aA;
-}
-
-// just the partition operation from quicksort
-static int GifPartition(unsigned char *image, const int left, const int right, const int elt, int pivotIndex)
-{
-    const int pivotValue = image[(pivotIndex)*4+elt];
-    GifSwapPixels(image, pivotIndex, right-1);
-    int storeIndex = left;
-    bool split = 0;
-    for (int ii=left; ii<right-1; ++ii)
-    {
-        int arrayVal = image[ii*4+elt];
-        if (arrayVal < pivotValue)
-        {
-            GifSwapPixels(image, ii, storeIndex);
-            ++storeIndex;
-        }
-        else if (arrayVal == pivotValue)
-        {
-            if (split)
-            {
-                GifSwapPixels(image, ii, storeIndex);
-                ++storeIndex;
-            }
-            split = !split;
-        }
-    }
-    GifSwapPixels(image, storeIndex, right-1);
-    return storeIndex;
-}
-
-// Perform an incomplete sort, finding all elements above and below the desired median
-static void GifPartitionByMedian(unsigned char *image, int left, int right, int com, int neededCenter)
-{
-    if (left < right-1)
-    {
-        int pivotIndex = left + (right-left)/2;
-    
-        pivotIndex = GifPartition(image, left, right, com, pivotIndex);
-        
-        // Only "sort" the section of the array that contains the median
-        if (pivotIndex > neededCenter)
-            GifPartitionByMedian(image, left, pivotIndex, com, neededCenter);
-        
-        if (pivotIndex < neededCenter)
-            GifPartitionByMedian(image, pivotIndex + 1, right, com, neededCenter);
-    }
-}
-
-// Builds a palette by creating a balanced k-d tree of all pixels in the image
-static void GifSplitPalette(unsigned char *image, int numPixels, int firstElt, int lastElt, int splitElt, int splitDist, 
-                            int treeNode, bool buildForDither, GifPalette *pal)
-{
-    if (lastElt <= firstElt || numPixels == 0)
-        return;
-    
-    // base case, bottom of the tree
-    if (lastElt == firstElt + 1)
-    {
-        if (buildForDither)
-        {
-            // Dithering needs at least one color as dark as anything
-            // in the image and at least one brightest color -
-            // otherwise it builds up error and produces strange artifacts
-            if (firstElt == 1)
-            {
-                // special case: the darkest color in the image
-                unsigned int r=255, g=255, b=255;
-                for (int ii=0; ii<numPixels; ++ii)
-                {
-                    r = GIFMIN(r, image[ii*4+0]);
-                    g = GIFMIN(g, image[ii*4 + 1]);
-                    b = GIFMIN(b, image[ii*4+2]);
-                }
-                
-                pal->r[firstElt] = r;
-                pal->g[firstElt] = g;
-                pal->b[firstElt] = b;
-                
-                return;
-            }
-            
-            if (firstElt == (1 << pal->bitDepth)-1)
-            {
-                // special case: the lightest color in the image
-                unsigned int r=0, g=0, b=0;
-                for (int ii=0; ii<numPixels; ++ii)
-                {
-                    r = GIFMAX(r, image[ii*4+0]);
-                    g = GIFMAX(g, image[ii*4 + 1]);
-                    b = GIFMAX(b, image[ii*4+2]);
-                }
-                
-                pal->r[firstElt] = r;
-                pal->g[firstElt] = g;
-                pal->b[firstElt] = b;
-                
-                return;
-            }
-        }
-        
-        // otherwise, take the average of all colors in this subcube
-        unsigned long long r=0, g=0, b=0;
-        for (int ii=0; ii<numPixels; ++ii)
-        {
-            r += image[ii*4+0];
-            g += image[ii*4 + 1];
-            b += image[ii*4+2];
-        }
-        
-        r += numPixels / 2;  // round to nearest
-        g += numPixels / 2;
-        b += numPixels / 2;
-        
-        r /= numPixels;
-        g /= numPixels;
-        b /= numPixels;
-        
-        pal->r[firstElt] = (unsigned char)r;
-        pal->g[firstElt] = (unsigned char)g;
-        pal->b[firstElt] = (unsigned char)b;
-        
-        return;
-    }
-    
-    // Find the axis with the largest range
-    int minR = 255, maxR = 0;
-    int minG = 255, maxG = 0;
-    int minB = 255, maxB = 0;
-    for (int ii=0; ii<numPixels; ++ii)
-    {
-        int r = image[ii*4+0];
-        int g = image[ii*4 + 1];
-        int b = image[ii*4+2];
-        
-        if (r > maxR) maxR = r;
-        if (r < minR) minR = r;
-        
-        if (g > maxG) maxG = g;
-        if (g < minG) minG = g;
-        
-        if (b > maxB) maxB = b;
-        if (b < minB) minB = b;
-    }
-    
-    int rRange = maxR - minR;
-    int gRange = maxG - minG;
-    int bRange = maxB - minB;
-    
-    // and split along that axis. (incidentally, this means this isn't a "proper" k-d tree but I don't know what else to call it)
-    int splitCom = 1;
-    if (bRange > gRange) splitCom = 2;
-    if (rRange > bRange && rRange > gRange) splitCom = 0;
-    
-    int subPixelsA = numPixels  *(splitElt - firstElt) / (lastElt - firstElt);
-    int subPixelsB = numPixels-subPixelsA;
-    
-    GifPartitionByMedian(image, 0, numPixels, splitCom, subPixelsA);
-    
-    pal->treeSplitElt[treeNode] = splitCom;
-    pal->treeSplit[treeNode] = image[subPixelsA*4+splitCom];
-    
-    GifSplitPalette(image,              subPixelsA, firstElt, splitElt, splitElt-splitDist, splitDist/2, treeNode*2,   buildForDither, pal);
-    GifSplitPalette(image+subPixelsA*4, subPixelsB, splitElt, lastElt,  splitElt+splitDist, splitDist/2, treeNode*2 + 1, buildForDither, pal);
-}
-
-// Finds all pixels that have changed from the previous image and
-// moves them to the fromt of th buffer.
-// This allows us to build a palette optimized for the colors of the
-// changed pixels only.
-static int GifPickChangedPixels(const unsigned char *lastFrame, unsigned char *frame, int numPixels)
-{
-    int numChanged = 0;
-    unsigned char *writeIter = frame;
-    
-    for (int ii=0; ii<numPixels; ++ii)
-    {
-        if (lastFrame[0] != frame[0] ||
-           lastFrame[1] != frame[1] ||
-           lastFrame[2] != frame[2])
-        {
-            writeIter[0] = frame[0];
-            writeIter[1] = frame[1];
-            writeIter[2] = frame[2];
-            ++numChanged;
-            writeIter += 4;
-        }
-        lastFrame += 4;
-        frame += 4;
-    }
-    
-    return numChanged;
-}
-
-// Creates a palette by placing all the image pixels in a k-d tree and then averaging the blocks at the bottom.
-// This is known as the "modified median split" technique
-static void GifMakePalette(const unsigned char *lastFrame, const unsigned char *nextFrame, unsigned int width, unsigned int height, int bitDepth, bool buildForDither, GifPalette *pPal)
-{
-    pPal->bitDepth = bitDepth;
-    
-    // SplitPalette is destructive (it sorts the pixels by color) so
-    // we must create a copy of the image for it to destroy
-    int imageSize = width*height*4*sizeof(unsigned char);
-    unsigned char *destroyableImage = (unsigned char*)RGIF_MALLOC(imageSize);
-    memcpy(destroyableImage, nextFrame, imageSize);
-    
-    int numPixels = width*height;
-    if (lastFrame)
-        numPixels = GifPickChangedPixels(lastFrame, destroyableImage, numPixels);
-    
-    const int lastElt = 1 << bitDepth;
-    const int splitElt = lastElt/2;
-    const int splitDist = splitElt/2;
-    
-    GifSplitPalette(destroyableImage, numPixels, 1, lastElt, splitElt, splitDist, 1, buildForDither, pPal);
-    
-    RGIF_FREE(destroyableImage);
-    
-    // add the bottom node for the transparency index
-    pPal->treeSplit[1 << (bitDepth-1)] = 0;
-    pPal->treeSplitElt[1 << (bitDepth-1)] = 0;
-    
-    pPal->r[0] = pPal->g[0] = pPal->b[0] = 0;
-}
-
-// Implements Floyd-Steinberg dithering, writes palette value to alpha
-static void GifDitherImage(const unsigned char *lastFrame, const unsigned char *nextFrame, unsigned char *outFrame, unsigned int width, unsigned int height, GifPalette *pPal)
-{
-    int numPixels = width*height;
-    
-    // quantPixels initially holds color*256 for all pixels
-    // The extra 8 bits of precision allow for sub-single-color error values
-    // to be propagated
-    int *quantPixels = (int*)RGIF_MALLOC(sizeof(int)*numPixels*4);
-    
-    for (int ii=0; ii<numPixels*4; ++ii)
-    {
-        unsigned char pix = nextFrame[ii];
-        int pix16 = (int)pix*256;
-        quantPixels[ii] = pix16;
-    }
-    
-    for (unsigned int yy=0; yy<height; ++yy)
-    {
-        for (unsigned int xx=0; xx<width; ++xx)
-        {
-            int *nextPix = quantPixels + 4*(yy*width+xx);
-            const unsigned char *lastPix = lastFrame? lastFrame + 4*(yy*width+xx) : NULL;
-            
-            // Compute the colors we want (rounding to nearest)
-            int rr = (nextPix[0] + 127) / 256;
-            int gg = (nextPix[1] + 127) / 256;
-            int bb = (nextPix[2] + 127) / 256;
-            
-            // if it happens that we want the color from last frame, then just write out
-            // a transparent pixel
-            if (lastFrame &&
-               lastPix[0] == rr &&
-               lastPix[1] == gg &&
-               lastPix[2] == bb)
-            {
-                nextPix[0] = rr;
-                nextPix[1] = gg;
-                nextPix[2] = bb;
-                nextPix[3] = gifTransparentIndex;
-                continue;
-            }
-            
-            int bestDiff = 1000000;
-            int bestInd = gifTransparentIndex;
-            
-            // Search the palete
-            GifGetClosestPaletteColor(pPal, rr, gg, bb, &bestInd, &bestDiff, 1);
-            
-            // Write the result to the temp buffer
-            int r_err = nextPix[0] - (int)(pPal->r[bestInd])*256;
-            int g_err = nextPix[1] - (int)(pPal->g[bestInd])*256;
-            int b_err = nextPix[2] - (int)(pPal->b[bestInd])*256;
-            
-            nextPix[0] = pPal->r[bestInd];
-            nextPix[1] = pPal->g[bestInd];
-            nextPix[2] = pPal->b[bestInd];
-            nextPix[3] = bestInd;
-            
-            // Propagate the error to the four adjacent locations
-            // that we haven't touched yet
-            int quantloc_7 = (yy*width+xx + 1);
-            int quantloc_3 = (yy*width+width+xx-1);
-            int quantloc_5 = (yy*width+width+xx);
-            int quantloc_1 = (yy*width+width+xx + 1);
-            
-            if (quantloc_7 < numPixels)
-            {
-                int *pix7 = quantPixels+4*quantloc_7;
-                pix7[0] += GIFMAX(-pix7[0], r_err*7 / 16);
-                pix7[1] += GIFMAX(-pix7[1], g_err*7 / 16);
-                pix7[2] += GIFMAX(-pix7[2], b_err*7 / 16);
-            }
-            
-            if (quantloc_3 < numPixels)
-            {
-                int *pix3 = quantPixels+4*quantloc_3;
-                pix3[0] += GIFMAX(-pix3[0], r_err*3 / 16);
-                pix3[1] += GIFMAX(-pix3[1], g_err*3 / 16);
-                pix3[2] += GIFMAX(-pix3[2], b_err*3 / 16);
-            }
-            
-            if (quantloc_5 < numPixels)
-            {
-                int *pix5 = quantPixels+4*quantloc_5;
-                pix5[0] += GIFMAX(-pix5[0], r_err*5 / 16);
-                pix5[1] += GIFMAX(-pix5[1], g_err*5 / 16);
-                pix5[2] += GIFMAX(-pix5[2], b_err*5 / 16);
-            }
-            
-            if (quantloc_1 < numPixels)
-            {
-                int *pix1 = quantPixels+4*quantloc_1;
-                pix1[0] += GIFMAX(-pix1[0], r_err / 16);
-                pix1[1] += GIFMAX(-pix1[1], g_err / 16);
-                pix1[2] += GIFMAX(-pix1[2], b_err / 16);
-            }
-        }
-    }
-    
-    // Copy the palettized result to the output buffer
-    for (int ii=0; ii<numPixels*4; ++ii)
-    {
-        outFrame[ii] = quantPixels[ii];
-    }
-    
-    RGIF_FREE(quantPixels);
-}
-
-// Picks palette colors for the image using simple thresholding, no dithering
-static void GifThresholdImage(const unsigned char *lastFrame, const unsigned char *nextFrame, unsigned char *outFrame, unsigned int width, unsigned int height, GifPalette *pPal)
-{
-    unsigned int numPixels = width*height;
-    for (unsigned int ii=0; ii<numPixels; ++ii)
-    {
-        // if a previous color is available, and it matches the current color,
-        // set the pixel to transparent
-        if (lastFrame &&
-           lastFrame[0] == nextFrame[0] &&
-           lastFrame[1] == nextFrame[1] &&
-           lastFrame[2] == nextFrame[2])
-        {
-            outFrame[0] = lastFrame[0];
-            outFrame[1] = lastFrame[1];
-            outFrame[2] = lastFrame[2];
-            outFrame[3] = gifTransparentIndex;
-        }
-        else
-        {
-            // palettize the pixel
-            int bestDiff = 1000000;
-            int bestInd = 1;
-            GifGetClosestPaletteColor(pPal, nextFrame[0], nextFrame[1], nextFrame[2], &bestInd, &bestDiff, 1);
-            
-            // Write the resulting color to the output buffer
-            outFrame[0] = pPal->r[bestInd];
-            outFrame[1] = pPal->g[bestInd];
-            outFrame[2] = pPal->b[bestInd];
-            outFrame[3] = bestInd;
-        }
-        
-        if (lastFrame) lastFrame += 4;
-        outFrame += 4;
-        nextFrame += 4;
-    }
-}
-
-
-// insert a single bit
-static void GifWriteBit(GifBitStatus *stat, unsigned int bit)
-{
-    bit = bit & 1;
-    bit = bit << stat->bitIndex;
-    stat->byte |= bit;
-    
-    ++stat->bitIndex;
-    if (stat->bitIndex > 7)
-    {
-        // move the newly-finished byte to the chunk buffer 
-        stat->chunk[stat->chunkIndex++] = stat->byte;
-        // and start a new byte
-        stat->bitIndex = 0;
-        stat->byte = 0;
-    }
-}
-
-// write all bytes so far to the file
-static void GifWriteChunk(FILE *f, GifBitStatus *stat)
-{
-    fputc(stat->chunkIndex, f);
-    fwrite(stat->chunk, 1, stat->chunkIndex, f);
-    
-    stat->bitIndex = 0;
-    stat->byte = 0;
-    stat->chunkIndex = 0;
-}
-
-static void GifWriteCode(FILE *f, GifBitStatus *stat, unsigned int code, unsigned int length)
-{
-    for (unsigned int ii=0; ii<length; ++ii)
-    {
-        GifWriteBit(stat, code);
-        code = code >> 1;
-        
-        if (stat->chunkIndex == 255)
-        {
-            GifWriteChunk(f, stat);
-        }
-    }
-}
-
-// write a 256-color (8-bit) image palette to the file
-static void GifWritePalette(FILE *f, const GifPalette *pPal)
-{
-    fputc(0, f);  // first color: transparency
-    fputc(0, f);
-    fputc(0, f);
-    
-    for (int ii=1; ii<(1 << pPal->bitDepth); ++ii)
-    {
-        unsigned int r = pPal->r[ii];
-        unsigned int g = pPal->g[ii];
-        unsigned int b = pPal->b[ii];
-        
-        fputc(r, f);
-        fputc(g, f);
-        fputc(b, f);
-    }
-}
-
-// write the image header, LZW-compress and write out the image
-static void GifWriteLzwImage(FILE *f, unsigned char *image, unsigned int left, unsigned int top, unsigned int width, unsigned int height, unsigned int delay, GifPalette *pPal)
-{
-    // graphics control extension
-    fputc(0x21, f);
-    fputc(0xf9, f);
-    fputc(0x04, f);
-    fputc(0x05, f); // leave prev frame in place, this frame has transparency
-    fputc(delay & 0xff, f);
-    fputc((delay >> 8) & 0xff, f);
-    fputc(gifTransparentIndex, f); // transparent color index
-    fputc(0, f);
-    
-    fputc(0x2c, f); // image descriptor block
-    
-    fputc(left & 0xff, f);           // corner of image in canvas space
-    fputc((left >> 8) & 0xff, f);
-    fputc(top & 0xff, f);
-    fputc((top >> 8) & 0xff, f);
-    
-    fputc(width & 0xff, f);          // width and height of image
-    fputc((width >> 8) & 0xff, f);
-    fputc(height & 0xff, f);
-    fputc((height >> 8) & 0xff, f);
-    
-    //fputc(0, f); // no local color table, no transparency
-    //fputc(0x80, f); // no local color table, but transparency
-    
-    fputc(0x80 + pPal->bitDepth-1, f); // local color table present, 2 ^ bitDepth entries
-    GifWritePalette(f, pPal);
-    
-    const int minCodeSize = pPal->bitDepth;
-    const unsigned int clearCode = 1 << pPal->bitDepth;
-    
-    fputc(minCodeSize, f); // min code size 8 bits
-    
-    GifLzwNode *codetree = (GifLzwNode *)RGIF_MALLOC(sizeof(GifLzwNode)*4096);
-    
-    memset(codetree, 0, sizeof(GifLzwNode)*4096);
-    int curCode = -1;
-    unsigned int codeSize = minCodeSize + 1;
-    unsigned int maxCode = clearCode + 1;
-    
-    GifBitStatus stat;
-    stat.byte = 0;
-    stat.bitIndex = 0;
-    stat.chunkIndex = 0;
-    
-    GifWriteCode(f, &stat, clearCode, codeSize);  // start with a fresh LZW dictionary
-    
-    for (unsigned int yy=0; yy<height; ++yy)
-    {
-        for (unsigned int xx=0; xx<width; ++xx)
-        {
-            unsigned char nextValue = image[(yy*width+xx)*4+3];
-            
-            // "loser mode" - no compression, every single code is followed immediately by a clear
-            //WriteCode(f, stat, nextValue, codeSize);
-            //WriteCode(f, stat, 256, codeSize);
-            
-            if (curCode < 0)
-            {
-                // first value in a new run
-                curCode = nextValue;
-            }
-            else if (codetree[curCode].m_next[nextValue])
-            {
-                // current run already in the dictionary
-                curCode = codetree[curCode].m_next[nextValue];
-            }
-            else
-            {
-                // finish the current run, write a code
-                GifWriteCode(f, &stat, curCode, codeSize);
-                
-                // insert the new run into the dictionary
-                codetree[curCode].m_next[nextValue] = ++maxCode;
-                
-                if (maxCode >= (1ul << codeSize))
-                {
-                    // dictionary entry count has broken a size barrier,
-                    // we need more bits for codes
-                    codeSize++;
-                }
-                if (maxCode == 4095)
-                {
-                    // the dictionary is full, clear it out and begin anew
-                    GifWriteCode(f, &stat, clearCode, codeSize); // clear tree
-                    
-                    memset(codetree, 0, sizeof(GifLzwNode)*4096);
-                    codeSize = minCodeSize + 1;
-                    maxCode = clearCode + 1;
-                }
-                
-                curCode = nextValue;
-            }
-        }
-    }
-    
-    // compression footer
-    GifWriteCode(f, &stat, curCode, codeSize);
-    GifWriteCode(f, &stat, clearCode, codeSize);
-    GifWriteCode(f, &stat, clearCode + 1, minCodeSize + 1);
-    
-    // write out the last partial chunk
-    while (stat.bitIndex) GifWriteBit(&stat, 0);
-    if (stat.chunkIndex) GifWriteChunk(f, &stat);
-    
-    fputc(0, f); // image block terminator
-    
-    RGIF_FREE(codetree);
-}
-
-#endif // RGIF_IMPLEMENTATION