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Add support for saving animated icons 

Add support for exporting animated DSi icons as GIF using the
header-only gif.h library.
This commit is contained in:
Rayyan Ansari 2023-11-23 18:48:05 +00:00
parent 544fefa27f
commit 679c37ddce
No known key found for this signature in database
GPG Key ID: 46A8D18E5BC49D84
6 changed files with 942 additions and 29 deletions
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39
src/frontend/qt_sdl/ROMInfoDialog.cpp
View File

@ -21,6 +21,8 @@
#include <QFileDialog>
#include "gif-h/gif.h"
#include "NDS.h"
#include "NDSCart.h"
#include "Platform.h"
@ -45,23 +47,24 @@ ROMInfoDialog::ROMInfoDialog(QWidget* parent) : QDialog(parent), ui(new Ui::ROMI
const NDSBanner* banner = NDS::NDSCartSlot->GetCart()->Banner();
const NDSHeader& header = NDS::NDSCartSlot->GetCart()->GetHeader();
u32 iconData[32 * 32];
ROMManager::ROMIcon(banner->Icon, banner->Palette, iconData);
iconImage = QImage(reinterpret_cast<unsigned char*>(iconData), 32, 32, QImage::Format_ARGB32).copy();
iconImage = QImage(reinterpret_cast<u8*>(iconData), 32, 32, QImage::Format_RGBA8888).copy();
ui->iconImage->setPixmap(QPixmap::fromImage(iconImage));
if (banner->Version == 0x103)
{
u32 animatedIconData[32 * 32 * 64] = {0};
ui->saveAnimatedIconButton->setEnabled(true);
ROMManager::AnimatedROMIcon(banner->DSiIcon, banner->DSiPalette, banner->DSiSequence, animatedIconData, animatedSequence);
for (int i = 0; i < 64; i++)
for (u32* image: animatedIconData)
{
if (animatedIconData[32 * 32 * i] == 0)
if (!image)
break;
animatedIconImages.push_back(QPixmap::fromImage(QImage(reinterpret_cast<unsigned char*>(&animatedIconData[32 * 32 * i]), 32, 32, QImage::Format_ARGB32).copy()));
animatedIconImages.push_back(QPixmap::fromImage(QImage(reinterpret_cast<u8*>(image), 32, 32, QImage::Format_RGBA8888).copy()));
}
iconTimeline = new QTimeLine(animatedSequence.size() / 60 * 1000, this);
iconTimeline->setFrameRange(0, animatedSequence.size() - 1);
iconTimeline->setLoopCount(0);
@ -139,6 +142,30 @@ void ROMInfoDialog::on_saveIconButton_clicked()
iconImage.save(filename, "PNG");
}
void ROMInfoDialog::on_saveAnimatedIconButton_clicked()
{
QString filename = QFileDialog::getSaveFileName(this,
"Save Animated Icon",
QString::fromStdString(Config::LastROMFolder),
"GIF Images (*.gif)");
if (filename.isEmpty())
return;
GifWriter writer;
// The GIF format only supports delays of 0.01 seconds, so 0.0166... (60fps)
// is rounded up to 0.02 (50fps)
GifBegin(&writer, filename.toStdString().c_str(), 32, 32, 2);
for (int i: animatedSequence)
{
if (animatedIconData[i] == 0)
break;
GifWriteFrame(&writer, reinterpret_cast<u8*>(animatedIconData[i]), 32, 32, 2);
}
GifEnd(&writer);
}
void ROMInfoDialog::iconSetFrame(int frame)
{
ui->dsiIconImage->setPixmap(animatedIconImages[animatedSequence[frame]]);

2
src/frontend/qt_sdl/ROMInfoDialog.h
View File

@ -60,6 +60,7 @@ private slots:
void done(int r);
void on_saveIconButton_clicked();
void on_saveAnimatedIconButton_clicked();
void iconSetFrame(int frame);
@ -68,6 +69,7 @@ private:
QImage iconImage;
QTimeLine* iconTimeline;
u32 animatedIconData[64][32*32] = {0};
std::vector<QPixmap> animatedIconImages;
std::vector<int> animatedSequence;
};

88
src/frontend/qt_sdl/ROMInfoDialog.ui
View File

@ -6,8 +6,8 @@
<rect>
<x>0</x>
<y>0</y>
<width>559</width>
<height>532</height>
<width>557</width>
<height>547</height>
</rect>
</property>
<property name="sizePolicy">
@ -525,10 +525,17 @@
<item row="0" column="0" colspan="2">
<widget class="QGroupBox" name="groupBox_2">
<layout class="QGridLayout" name="gridLayout_9">
<item row="1" column="1">
<widget class="QPushButton" name="saveIconButton">
<property name="text">
<string>Save icon</string>
</property>
</widget>
</item>
<item row="0" column="1">
<widget class="QGroupBox" name="iconBox">
<property name="sizePolicy">
<sizepolicy hsizetype="Preferred" vsizetype="Preferred">
<sizepolicy hsizetype="Preferred" vsizetype="Fixed">
<horstretch>0</horstretch>
<verstretch>0</verstretch>
</sizepolicy>
@ -619,7 +626,7 @@
<property name="bottomMargin">
<number>1</number>
</property>
<item row="0" column="0">
<item row="0" column="1">
<widget class="QLabel" name="iconTitle">
<property name="sizePolicy">
<sizepolicy hsizetype="MinimumExpanding" vsizetype="MinimumExpanding">
@ -644,16 +651,42 @@
</property>
</widget>
</item>
</layout>
</widget>
</item>
</layout>
</widget>
</item>
<item row="0" column="2">
<spacer name="horizontalSpacer_2">
<property name="orientation">
<enum>Qt::Horizontal</enum>
</property>
<property name="sizeHint" stdset="0">
<size>
<width>20</width>
<height>20</height>
</size>
</property>
</spacer>
</item>
<item row="0" column="0">
<spacer name="horizontalSpacer_4">
<property name="orientation">
<enum>Qt::Horizontal</enum>
</property>
<property name="sizeHint" stdset="0">
<size>
<width>20</width>
<height>20</height>
</size>
</property>
</spacer>
</item>
</layout>
</widget>
</item>
</layout>
</widget>
</item>
<item row="0" column="2" alignment="Qt::AlignHCenter">
<widget class="QGroupBox" name="dsiIconBox">
<property name="sizePolicy">
<sizepolicy hsizetype="Minimum" vsizetype="Minimum">
<sizepolicy hsizetype="Fixed" vsizetype="Fixed">
<horstretch>0</horstretch>
<verstretch>0</verstretch>
</sizepolicy>
@ -724,25 +757,40 @@
</layout>
</widget>
</item>
<item row="0" column="3">
<item row="1" column="2">
<widget class="QPushButton" name="saveAnimatedIconButton">
<property name="enabled">
<bool>false</bool>
</property>
<property name="text">
<string>Save animated icon</string>
</property>
</widget>
</item>
<item row="0" column="3" rowspan="2">
<spacer name="horizontalSpacer_3">
<property name="orientation">
<enum>Qt::Horizontal</enum>
</property>
<property name="sizeHint" stdset="0">
<size>
<width>0</width>
<height>0</height>
</size>
</property>
</spacer>
</item>
<item row="1" column="1">
<widget class="QPushButton" name="saveIconButton">
<property name="text">
<string>Save icon</string>
</property>
</widget>
</item>
<item row="0" column="0">
<item row="0" column="0" rowspan="2">
<spacer name="horizontalSpacer">
<property name="orientation">
<enum>Qt::Horizontal</enum>
</property>
<property name="sizeHint" stdset="0">
<size>
<width>0</width>
<height>0</height>
</size>
</property>
</spacer>
</item>
</layout>

11
src/frontend/qt_sdl/ROMManager.cpp
View File

@ -1478,7 +1478,7 @@ QString GBACartLabel()
}
void ROMIcon(const u8 (&data)[512], const u16 (&palette)[16], u32* iconRef)
void ROMIcon(const u8 (&data)[512], const u16 (&palette)[16], u32 (&iconRef)[32*32])
{
int index = 0;
for (int i = 0; i < 4; i++)
@ -1495,7 +1495,7 @@ void ROMIcon(const u8 (&data)[512], const u16 (&palette)[16], u32* iconRef)
u8 b = ((palette[pal_index] >> 10) & 0x1F) * 255 / 31;
u8 a = pal_index ? 255: 0;
u32* row = &iconRef[256 * i + 32 * k + 8 * j];
row[l] = (a << 24) | (r << 16) | (g << 8) | b;
row[l] = r | (g << 8) | (b << 16) | (a << 24);
index++;
}
}
@ -1509,14 +1509,15 @@ void ROMIcon(const u8 (&data)[512], const u16 (&palette)[16], u32* iconRef)
#define SEQ_BMP(i) ((i & 0b0000011100000000) >> 8)
#define SEQ_DUR(i) ((i & 0b0000000011111111) >> 0)
void AnimatedROMIcon(const u8 (&data)[8][512], const u16 (&palette)[8][16], const u16 (&sequence)[64], u32 (&animatedTexRef)[32 * 32 * 64], std::vector<int> &animatedSequenceRef)
void AnimatedROMIcon(const u8 (&data)[8][512], const u16 (&palette)[8][16], const u16 (&sequence)[64], u32 (&animatedIconRef)[64][32*32], std::vector<int> &animatedSequenceRef)
{
for (int i = 0; i < 64; i++)
{
if (!sequence[i])
break;
u32* frame = &animatedTexRef[32 * 32 * i];
ROMIcon(data[SEQ_BMP(sequence[i])], palette[SEQ_PAL(sequence[i])], frame);
ROMIcon(data[SEQ_BMP(sequence[i])], palette[SEQ_PAL(sequence[i])], animatedIconRef[i]);
u32* frame = animatedIconRef[i];
if (SEQ_FLIPH(sequence[i]))
{

5
src/frontend/qt_sdl/ROMManager.h
View File

@ -62,11 +62,10 @@ void UndoStateLoad();
void EnableCheats(bool enable);
ARCodeFile* GetCheatFile();
void ROMIcon(const u8 (&data)[512], const u16 (&palette)[16], u32* iconRef);
void ROMIcon(const u8 (&data)[512], const u16 (&palette)[16], u32 (&iconRef)[32*32]);
void AnimatedROMIcon(const u8 (&data)[8][512], const u16 (&palette)[8][16],
const u16 (&sequence)[64], u32 (&animatedTexRef)[32 * 32 * 64],
const u16 (&sequence)[64], u32 (&animatedIconRef)[64][32*32],
std::vector<int> &animatedSequenceRef);
}
#endif // ROMMANAGER_H

836
src/frontend/qt_sdl/gif-h/gif.h Normal file
View File

@ -0,0 +1,836 @@
//
// gif.h
// by Charlie Tangora
// Public domain.
// Email me : ctangora -at- gmail -dot- com
//
// 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.)
//
// If capturing a buffer with a bottom-left origin (such as OpenGL), define GIF_FLIP_VERT
// to automatically flip the buffer data when writing the image (the buffer itself is
// unchanged.
//
// USAGE:
// Create a GifWriter struct. Pass it to GifBegin() to initialize and write the header.
// Pass subsequent frames to GifWriteFrame().
// Finally, call GifEnd() to close the file handle and free memory.
//
#ifndef gif_h
#define gif_h
#include <stdio.h> // for FILE*
#include <string.h> // for memcpy and bzero
#include <stdint.h> // for integer typedefs
#include <stdbool.h> // for bool macros
// Define these macros to hook into a custom memory allocator.
// TEMP_MALLOC and TEMP_FREE will only be called in stack fashion - frees in the reverse order of mallocs
// and any temp memory allocated by a function will be freed before it exits.
// MALLOC and 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.)
#ifndef GIF_TEMP_MALLOC
#include <stdlib.h>
#define GIF_TEMP_MALLOC malloc
#endif
#ifndef GIF_TEMP_FREE
#include <stdlib.h>
#define GIF_TEMP_FREE free
#endif
#ifndef GIF_MALLOC
#include <stdlib.h>
#define GIF_MALLOC malloc
#endif
#ifndef GIF_FREE
#include <stdlib.h>
#define GIF_FREE free
#endif
const int kGifTransIndex = 0;
typedef struct
{
int bitDepth;
uint8_t r[256];
uint8_t g[256];
uint8_t 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
uint8_t treeSplitElt[256];
uint8_t treeSplit[256];
} GifPalette;
// max, min, and abs functions
int GifIMax(int l, int r) { return l>r?l:r; }
int GifIMin(int l, int r) { return l<r?l:r; }
int GifIAbs(int i) { return i<0?-i:i; }
// 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.
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 == kGifTransIndex) return;
// check whether this color is better than the current winner
int r_err = r - ((int32_t)pPal->r[ind]);
int g_err = g - ((int32_t)pPal->g[ind]);
int b_err = b - ((int32_t)pPal->b[ind]);
int diff = GifIAbs(r_err)+GifIAbs(g_err)+GifIAbs(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);
}
}
}
void GifSwapPixels(uint8_t* image, int pixA, int pixB)
{
uint8_t rA = image[pixA*4];
uint8_t gA = image[pixA*4+1];
uint8_t bA = image[pixA*4+2];
uint8_t aA = image[pixA*4+3];
uint8_t rB = image[pixB*4];
uint8_t gB = image[pixB*4+1];
uint8_t bB = image[pixB*4+2];
uint8_t 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
int GifPartition(uint8_t* 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
void GifPartitionByMedian(uint8_t* 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
void GifSplitPalette(uint8_t* 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
uint32_t r=255, g=255, b=255;
for(int ii=0; ii<numPixels; ++ii)
{
r = (uint32_t)GifIMin((int32_t)r, image[ii * 4 + 0]);
g = (uint32_t)GifIMin((int32_t)g, image[ii * 4 + 1]);
b = (uint32_t)GifIMin((int32_t)b, image[ii * 4 + 2]);
}
pal->r[firstElt] = (uint8_t)r;
pal->g[firstElt] = (uint8_t)g;
pal->b[firstElt] = (uint8_t)b;
return;
}
if( firstElt == (1 << pal->bitDepth)-1 )
{
// special case: the lightest color in the image
uint32_t r=0, g=0, b=0;
for(int ii=0; ii<numPixels; ++ii)
{
r = (uint32_t)GifIMax((int32_t)r, image[ii * 4 + 0]);
g = (uint32_t)GifIMax((int32_t)g, image[ii * 4 + 1]);
b = (uint32_t)GifIMax((int32_t)b, image[ii * 4 + 2]);
}
pal->r[firstElt] = (uint8_t)r;
pal->g[firstElt] = (uint8_t)g;
pal->b[firstElt] = (uint8_t)b;
return;
}
}
// otherwise, take the average of all colors in this subcube
uint64_t 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 += (uint64_t)numPixels / 2; // round to nearest
g += (uint64_t)numPixels / 2;
b += (uint64_t)numPixels / 2;
r /= (uint64_t)numPixels;
g /= (uint64_t)numPixels;
b /= (uint64_t)numPixels;
pal->r[firstElt] = (uint8_t)r;
pal->g[firstElt] = (uint8_t)g;
pal->b[firstElt] = (uint8_t)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] = (uint8_t)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.
int GifPickChangedPixels( const uint8_t* lastFrame, uint8_t* frame, int numPixels )
{
int numChanged = 0;
uint8_t* 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
void GifMakePalette( const uint8_t* lastFrame, const uint8_t* nextFrame, uint32_t width, uint32_t 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
size_t imageSize = (size_t)(width * height * 4 * sizeof(uint8_t));
uint8_t* destroyableImage = (uint8_t*)GIF_TEMP_MALLOC(imageSize);
memcpy(destroyableImage, nextFrame, imageSize);
int numPixels = (int)(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);
GIF_TEMP_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
void GifDitherImage( const uint8_t* lastFrame, const uint8_t* nextFrame, uint8_t* outFrame, uint32_t width, uint32_t height, GifPalette* pPal )
{
int numPixels = (int)(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
int32_t *quantPixels = (int32_t *)GIF_TEMP_MALLOC(sizeof(int32_t) * (size_t)numPixels * 4);
for( int ii=0; ii<numPixels*4; ++ii )
{
uint8_t pix = nextFrame[ii];
int32_t pix16 = (int32_t)(pix) * 256;
quantPixels[ii] = pix16;
}
for( uint32_t yy=0; yy<height; ++yy )
{
for( uint32_t xx=0; xx<width; ++xx )
{
int32_t* nextPix = quantPixels + 4*(yy*width+xx);
const uint8_t* lastPix = lastFrame? lastFrame + 4*(yy*width+xx) : NULL;
// Compute the colors we want (rounding to nearest)
int32_t rr = (nextPix[0] + 127) / 256;
int32_t gg = (nextPix[1] + 127) / 256;
int32_t 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] = kGifTransIndex;
continue;
}
int32_t bestDiff = 1000000;
int32_t bestInd = kGifTransIndex;
// Search the palete
GifGetClosestPaletteColor(pPal, rr, gg, bb, &bestInd, &bestDiff, 1);
// Write the result to the temp buffer
int32_t r_err = nextPix[0] - (int32_t)(pPal->r[bestInd]) * 256;
int32_t g_err = nextPix[1] - (int32_t)(pPal->g[bestInd]) * 256;
int32_t b_err = nextPix[2] - (int32_t)(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 = (int)(yy * width + xx + 1);
int quantloc_3 = (int)(yy * width + width + xx - 1);
int quantloc_5 = (int)(yy * width + width + xx);
int quantloc_1 = (int)(yy * width + width + xx + 1);
if(quantloc_7 < numPixels)
{
int32_t* pix7 = quantPixels+4*quantloc_7;
pix7[0] += GifIMax( -pix7[0], r_err * 7 / 16 );
pix7[1] += GifIMax( -pix7[1], g_err * 7 / 16 );
pix7[2] += GifIMax( -pix7[2], b_err * 7 / 16 );
}
if(quantloc_3 < numPixels)
{
int32_t* pix3 = quantPixels+4*quantloc_3;
pix3[0] += GifIMax( -pix3[0], r_err * 3 / 16 );
pix3[1] += GifIMax( -pix3[1], g_err * 3 / 16 );
pix3[2] += GifIMax( -pix3[2], b_err * 3 / 16 );
}
if(quantloc_5 < numPixels)
{
int32_t* pix5 = quantPixels+4*quantloc_5;
pix5[0] += GifIMax( -pix5[0], r_err * 5 / 16 );
pix5[1] += GifIMax( -pix5[1], g_err * 5 / 16 );
pix5[2] += GifIMax( -pix5[2], b_err * 5 / 16 );
}
if(quantloc_1 < numPixels)
{
int32_t* pix1 = quantPixels+4*quantloc_1;
pix1[0] += GifIMax( -pix1[0], r_err / 16 );
pix1[1] += GifIMax( -pix1[1], g_err / 16 );
pix1[2] += GifIMax( -pix1[2], b_err / 16 );
}
}
}
// Copy the palettized result to the output buffer
for( int ii=0; ii<numPixels*4; ++ii )
{
outFrame[ii] = (uint8_t)quantPixels[ii];
}
GIF_TEMP_FREE(quantPixels);
}
// Picks palette colors for the image using simple thresholding, no dithering
void GifThresholdImage( const uint8_t* lastFrame, const uint8_t* nextFrame, uint8_t* outFrame, uint32_t width, uint32_t height, GifPalette* pPal )
{
uint32_t numPixels = width*height;
for( uint32_t 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] = kGifTransIndex;
}
else
{
// palettize the pixel
int32_t bestDiff = 1000000;
int32_t 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] = (uint8_t)bestInd;
}
if(lastFrame) lastFrame += 4;
outFrame += 4;
nextFrame += 4;
}
}
// Simple structure to write out the LZW-compressed portion of the image
// one bit at a time
typedef struct
{
uint8_t bitIndex; // how many bits in the partial byte written so far
uint8_t byte; // current partial byte
uint32_t chunkIndex;
uint8_t chunk[256]; // bytes are written in here until we have 256 of them, then written to the file
} GifBitStatus;
// insert a single bit
void GifWriteBit( GifBitStatus* stat, uint32_t 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
void GifWriteChunk( FILE* f, GifBitStatus* stat )
{
fputc((int)stat->chunkIndex, f);
fwrite(stat->chunk, 1, stat->chunkIndex, f);
stat->bitIndex = 0;
stat->byte = 0;
stat->chunkIndex = 0;
}
void GifWriteCode( FILE* f, GifBitStatus* stat, uint32_t code, uint32_t length )
{
for( uint32_t ii=0; ii<length; ++ii )
{
GifWriteBit(stat, code);
code = code >> 1;
if( stat->chunkIndex == 255 )
{
GifWriteChunk(f, stat);
}
}
}
// The LZW dictionary is a 256-ary tree constructed as the file is encoded,
// this is one node
typedef struct
{
uint16_t m_next[256];
} GifLzwNode;
// write a 256-color (8-bit) image palette to the file
void GifWritePalette( const GifPalette* pPal, FILE* f )
{
fputc(0, f); // first color: transparency
fputc(0, f);
fputc(0, f);
for(int ii=1; ii<(1 << pPal->bitDepth); ++ii)
{
uint32_t r = pPal->r[ii];
uint32_t g = pPal->g[ii];
uint32_t b = pPal->b[ii];
fputc((int)r, f);
fputc((int)g, f);
fputc((int)b, f);
}
}
// write the image header, LZW-compress and write out the image
void GifWriteLzwImage(FILE* f, uint8_t* image, uint32_t left, uint32_t top, uint32_t width, uint32_t height, uint32_t 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(kGifTransIndex, 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(pPal, f);
const int minCodeSize = pPal->bitDepth;
const uint32_t clearCode = 1 << pPal->bitDepth;
fputc(minCodeSize, f); // min code size 8 bits
GifLzwNode* codetree = (GifLzwNode*)GIF_TEMP_MALLOC(sizeof(GifLzwNode)*4096);
memset(codetree, 0, sizeof(GifLzwNode)*4096);
int32_t curCode = -1;
uint32_t codeSize = (uint32_t)minCodeSize + 1;
uint32_t 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(uint32_t yy=0; yy<height; ++yy)
{
for(uint32_t xx=0; xx<width; ++xx)
{
#ifdef GIF_FLIP_VERT
// bottom-left origin image (such as an OpenGL capture)
uint8_t nextValue = image[((height-1-yy)*width+xx)*4+3];
#else
// top-left origin
uint8_t nextValue = image[(yy*width+xx)*4+3];
#endif
// "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, (uint32_t)curCode, codeSize);
// insert the new run into the dictionary
codetree[curCode].m_next[nextValue] = (uint16_t)++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 = (uint32_t)(minCodeSize + 1);
maxCode = clearCode+1;
}
curCode = nextValue;
}
}
}
// compression footer
GifWriteCode(f, &stat, (uint32_t)curCode, codeSize);
GifWriteCode(f, &stat, clearCode, codeSize);
GifWriteCode(f, &stat, clearCode + 1, (uint32_t)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
GIF_TEMP_FREE(codetree);
}
typedef struct
{
FILE* f;
uint8_t* oldImage;
bool firstFrame;
} GifWriter;
// Creates a gif file.
// The input GIFWriter is assumed to be uninitialized.
// The delay value is the time between frames in hundredths of a second - note that not all viewers pay much attention to this value.
bool GifBegin( GifWriter* writer, const char* filename, uint32_t width, uint32_t height, uint32_t delay, int32_t bitDepth = 8, bool dither = false )
{
(void)bitDepth; (void)dither; // Mute "Unused argument" warnings
#if defined(_MSC_VER) && (_MSC_VER >= 1400)
writer->f = 0;
fopen_s(&writer->f, filename, "wb");
#else
writer->f = fopen(filename, "wb");
#endif
if(!writer->f) return false;
writer->firstFrame = true;
// allocate
writer->oldImage = (uint8_t*)GIF_MALLOC(width*height*4);
fputs("GIF89a", writer->f);
// screen descriptor
fputc(width & 0xff, writer->f);
fputc((width >> 8) & 0xff, writer->f);
fputc(height & 0xff, writer->f);
fputc((height >> 8) & 0xff, writer->f);
fputc(0xf0, writer->f); // there is an unsorted global color table of 2 entries
fputc(0, writer->f); // background color
fputc(0, writer->f); // pixels are square (we need to specify this because it's 1989)
// now the "global" palette (really just a dummy palette)
// color 0: black
fputc(0, writer->f);
fputc(0, writer->f);
fputc(0, writer->f);
// color 1: also black
fputc(0, writer->f);
fputc(0, writer->f);
fputc(0, writer->f);
if( delay != 0 )
{
// animation header
fputc(0x21, writer->f); // extension
fputc(0xff, writer->f); // application specific
fputc(11, writer->f); // length 11
fputs("NETSCAPE2.0", writer->f); // yes, really
fputc(3, writer->f); // 3 bytes of NETSCAPE2.0 data
fputc(1, writer->f); // JUST BECAUSE
fputc(0, writer->f); // loop infinitely (byte 0)
fputc(0, writer->f); // loop infinitely (byte 1)
fputc(0, writer->f); // block terminator
}
return true;
}
// Writes out a new frame to a GIF in progress.
// The GIFWriter should have been created by 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.
bool GifWriteFrame( GifWriter* writer, const uint8_t* image, uint32_t width, uint32_t height, uint32_t delay, int bitDepth = 8, bool dither = false )
{
if(!writer->f) return false;
const uint8_t* oldImage = writer->firstFrame? NULL : writer->oldImage;
writer->firstFrame = false;
GifPalette pal;
GifMakePalette((dither? NULL : oldImage), image, width, height, bitDepth, dither, &pal);
if(dither)
GifDitherImage(oldImage, image, writer->oldImage, width, height, &pal);
else
GifThresholdImage(oldImage, image, writer->oldImage, width, height, &pal);
GifWriteLzwImage(writer->f, writer->oldImage, 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.
bool GifEnd( GifWriter* writer )
{
if(!writer->f) return false;
fputc(0x3b, writer->f); // end of file
fclose(writer->f);
GIF_FREE(writer->oldImage);
writer->f = NULL;
writer->oldImage = NULL;
return true;
}
#endif