1 files changed, 169 insertions, 0 deletions
diff --git a/src/Gif.cpp b/src/Gif.cpp
new file mode 100644
index 0000000..3f7216e
--- /dev/null
+++ b/src/Gif.cpp
@@ -0,0 +1,169 @@
+#include "../include/Gif.hpp"
+#include "../include/FileUtil.hpp"
+
+using namespace std;
+
+namespace dchat
+{
+    void* bitmapCreate(int width, int height)
+    {
+        return calloc(width * height, 4);
+    }
+    
+    void bitmapDestroy(void *bitmap)
+    {
+        free(bitmap);
+    }
+    
+    unsigned char* bitmapGetBuffer(void *bitmap)
+    {
+        return (unsigned char*)bitmap;
+    }
+    
+    void bitmapSetOpaque(void *bitmap, bool opaque)
+    {
+        
+    }
+    
+    bool bitmapTestOpaque(void *bitmap)
+    {
+        return false;
+    }
+    
+    void bitmapModified(void *bitmap)
+    {
+        
+    }
+    
+    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());
+        }
+        init();
+    }
+    
+    Gif::Gif(StringView &&_fileContent) : 
+        fileContent(move(_fileContent)),
+        currentFrame(0),
+        timeElapsedCs(0.0)
+    {
+        init();
+    }
+    
+    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(!texture.create(gif.width, gif.height))
+            throw GifLoadException("Failed to create texture for gif");
+        
+        sprite.setTexture(texture, true);
+    }
+    
+    Gif::~Gif()
+    {
+        gif_finalise(&gif);
+        delete fileContent.data;
+    }
+    
+    void Gif::setPosition(const sf::Vector2f &position)
+    {
+        sprite.setPosition(position);
+    }
+    
+    void Gif::setSize(const sf::Vector2f &size)
+    {
+        sf::Vector2u textureSize = sprite.getTexture()->getSize();
+        sprite.setScale(size.x / (float)textureSize.x, size.y / (float)textureSize.y);
+    }
+    
+    void Gif::draw(sf::RenderWindow &window)
+    {
+        double frameDeltaCs = (double)frameTimer.getElapsedTime().asMilliseconds() * 0.1; // Centisecond
+        frameTimer.restart();
+        timeElapsedCs += frameDeltaCs;
+        
+        unsigned char *image = nullptr;
+        u32 startFrame = currentFrame;
+        while(true)
+        {
+            int 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));
+            
+            gif_frame &frame = gif.frames[i];
+            // frame_delay is in centiseconds
+            double frameDelay = (double)frame.frame_delay;
+            if(timeElapsedCs >= frameDelay)
+                timeElapsedCs -= frameDelay;
+            else
+                break;
+            
+            image = (unsigned char*)gif.frame_image;
+            ++currentFrame;
+        }
+        
+        if(currentFrame != startFrame)
+        {
+            texture.update(image);
+            sprite.setTexture(texture, true); 
+        }
+        window.draw(sprite);
+    }
+    
+    bool Gif::isDataGif(const StringView &data)
+    {
+        return data.size >= 6 && (memcmp(data.data, "GIF87a", 6) == 0 || memcmp(data.data, "GIF89a", 6) == 0);
+    }
+}