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gif-lib basic example.
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#include <iostream> | |
#include <sstream> | |
#include <string> | |
#include <string.h> | |
#include <gif_lib.h> | |
bool gif_write(const char* fileName) | |
{ | |
int error; | |
GifFileType* gifFile = EGifOpenFileName(fileName, false, &error); | |
if (!gifFile) { | |
std::cout << "EGifOpenFileName() failed - " << error << std::endl; | |
return false; | |
} | |
GifColorType colors[64]; | |
GifColorType* c = colors; | |
int level[4] = { 0, 85, 170, 255 }; | |
for (int r = 0; r < 4; ++r) { | |
for (int g = 0; g < 4; ++g) { | |
for (int b = 0; b < 4; ++b, ++c) { | |
c->Red = level[r]; | |
c->Green = level[g]; | |
c->Blue = level[b]; | |
} | |
} | |
} | |
GifByteType pix[16] = { | |
0, 1, 2, 3, // B | |
0, 4, 8, 12, // G | |
0, 16, 32, 48, // R | |
0, 21, 42, 63, // BK | |
}; | |
gifFile->SWidth = 4; | |
gifFile->SHeight = 4; | |
gifFile->SColorResolution = 8; | |
gifFile->SBackGroundColor = 0; | |
gifFile->SColorMap = GifMakeMapObject(64, colors); | |
SavedImage gifImage; | |
gifImage.ImageDesc.Left = 0; | |
gifImage.ImageDesc.Top = 0; | |
gifImage.ImageDesc.Width = 4; | |
gifImage.ImageDesc.Height = 4; | |
gifImage.ImageDesc.Interlace = false; | |
gifImage.ImageDesc.ColorMap = nullptr; | |
gifImage.RasterBits = (GifByteType*)malloc(16); | |
gifImage.ExtensionBlockCount = 0; | |
gifImage.ExtensionBlocks = nullptr; | |
memcpy(gifImage.RasterBits, pix, 16); | |
GifMakeSavedImage(gifFile, &gifImage); | |
if (EGifSpew(gifFile) == GIF_ERROR) { | |
std::cout << "EGifSpew() failed - " << gifFile->Error << std::endl; | |
EGifCloseFile(gifFile, &error); | |
return false; | |
} | |
EGifCloseFile(gifFile, &error); | |
return true; | |
} | |
bool gif_read(const char* fileName) | |
{ | |
int error; | |
GifFileType* gifFile = DGifOpenFileName(fileName, &error); | |
if (!gifFile) { | |
std::cout << "DGifOpenFileName() failed - " << error << std::endl; | |
return false; | |
} | |
if (DGifSlurp(gifFile) == GIF_ERROR) { | |
std::cout << "DGifSlurp() failed - " << gifFile->Error << std::endl; | |
DGifCloseFile(gifFile, &error); | |
return false; | |
} | |
ColorMapObject* commonMap = gifFile->SColorMap; | |
std::cout << fileName << ": " << gifFile->SWidth << "x" << gifFile->SHeight << std::endl; | |
for (int i = 0; i < gifFile->ImageCount; ++i) { | |
const SavedImage& saved = gifFile->SavedImages[i]; | |
const GifImageDesc& desc = saved.ImageDesc; | |
const ColorMapObject* colorMap = desc.ColorMap ? desc.ColorMap : commonMap; | |
std::cout << "[" << i << "] " | |
<< desc.Width << "x" << desc.Height << "+" << desc.Left << "," << desc.Top | |
<< ", has local colorMap: " << (desc.ColorMap ? "Yes" : "No") << std::endl; | |
std::stringstream ss; | |
for (int v = 0; v < desc.Height; ++v) { | |
for (int u = 0; u < desc.Width; ++u) { | |
int c = saved.RasterBits[v * desc.Width + u]; | |
printf(" %02X", c); | |
if (colorMap) { | |
GifColorType rgb = colorMap->Colors[c]; | |
ss << " [" << (int)rgb.Red << "," << (int)rgb.Green << "," << (int)rgb.Blue << "]"; | |
} | |
} | |
std::cout << ":" << ss.str() << std::endl; | |
} | |
} | |
DGifCloseFile(gifFile, &error); | |
return true; | |
} | |
int main(int argc, char **argv) | |
{ | |
return (gif_write("test.gif") && gif_read("test.gif")) ? 0 : 1; | |
} |
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