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#include "../include/dchat/Gif.hpp"
#include "../include/dchat/FileUtil.hpp"
using namespace std;
namespace dchat
{
static void* bitmapCreate(int width, int height)
{
return calloc(width * height, 4);
}
static void bitmapDestroy(void *bitmap)
{
free(bitmap);
}
static unsigned char* bitmapGetBuffer(void *bitmap)
{
return (unsigned char*)bitmap;
}
static void bitmapSetOpaque(void *bitmap, bool opaque)
{
}
static bool bitmapTestOpaque(void *bitmap)
{
return false;
}
static void bitmapModified(void *bitmap)
{
}
static const char* gifResultToString(gif_result code)
{
switch(code)
{
case GIF_INSUFFICIENT_FRAME_DATA:
return "GIF_INSUFFICIENT_FRAME_DATA";
case GIF_FRAME_DATA_ERROR:
return "GIF_FRAME_DATA_ERROR";
case GIF_INSUFFICIENT_DATA:
return "GIF_INSUFFICIENT_DATA";
case GIF_DATA_ERROR:
return "GIF_DATA_ERROR";
case GIF_INSUFFICIENT_MEMORY:
return "GIF_INSUFFICIENT_MEMORY";
default:
return "Unknown gif result code";
}
}
Gif::Gif(const boost::filesystem::path &filepath) :
currentFrame(0),
timeElapsedCs(0.0)
{
try
{
fileContent = getFileContent(filepath);
}
catch(FileException &e)
{
throw GifLoadException(e.what());
}
try
{
init();
}
catch(GifLoadException &e)
{
delete[] fileContent.data;
throw e;
}
}
Gif::Gif(StringView _fileContent) :
fileContent(move(_fileContent)),
currentFrame(0),
timeElapsedCs(0.0)
{
try
{
init();
}
catch(GifLoadException &e)
{
delete[] fileContent.data;
throw e;
}
}
void Gif::init()
{
gif_bitmap_callback_vt bitmapCallbacks =
{
bitmapCreate,
bitmapDestroy,
bitmapGetBuffer,
bitmapSetOpaque,
bitmapTestOpaque,
bitmapModified
};
gif_create(&gif, &bitmapCallbacks);
gif_result code;
do
{
code = gif_initialise(&gif, fileContent.size, (unsigned char*)fileContent.data);
if(code != GIF_OK && code != GIF_WORKING)
{
string errMsg = "Failed to initialize gif, reason: ";
errMsg += gifResultToString(code);
throw GifLoadException(errMsg);
}
}
while(code != GIF_OK);
if(!createTexture(gif.width, gif.height))
throw GifLoadException("Failed to create texture for gif");
}
Gif::~Gif()
{
gif_finalise(&gif);
delete[] fileContent.data;
}
Vec2u Gif::getSize() const
{
return { gif.width, gif.height };
}
void Gif::update()
{
double timeElapsedMilli = (double)frameTimer.getElapsedTimeMillis();
// If gif is not redrawn for a while, then we reset timer (gif is paused). This happens when gif is not visible and then appears visible
// (because it's visible in window). The reason this is done is to prevent too much time between rendering gif frames, as processing a gif
// requires to process all frames between two points in time, if elapsed frame time is too high, then we would require to process several
// frames of gif in one application render frame.
if(timeElapsedMilli > 1000.0)
timeElapsedMilli = 0.0;
double frameDeltaCs = timeElapsedMilli * 0.1; // Centisecond
frameTimer.restart();
timeElapsedCs += frameDeltaCs;
unsigned char *image = nullptr;
u32 startFrame = currentFrame;
while(true)
{
u32 i = currentFrame % gif.frame_count;
gif_result code = gif_decode_frame(&gif, i);
if(code != GIF_OK)
{
printf("Warning: gif_decode_frame: %s\n", gifResultToString(code));
break;
}
gif_frame &frame = gif.frames[i];
// frame_delay is in centiseconds
unsigned int frameDelay = frame.frame_delay;
if(frameDelay == 0)
frameDelay = 7;
double fFrameDelay = (double)frameDelay;
if(timeElapsedCs >= fFrameDelay)
timeElapsedCs -= fFrameDelay;
else
break;
image = (unsigned char*)gif.frame_image;
++currentFrame;
}
if(currentFrame != startFrame)
{
updateTexture(image);
}
}
bool Gif::isDataGif(const StringView &data)
{
return data.size >= 6 && (memcmp(data.data, "GIF87a", 6) == 0 || memcmp(data.data, "GIF89a", 6) == 0);
}
}
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