public void Load(Reader reader)
{
// Read the header:
reader.ReadString(6);
Width = reader.ReadInt16();
Height = reader.ReadInt16();
if (HostSPA == null)
{
// Create the host SPA (default 100fps):
HostSPA = new SPA(Width, Height, 100);
}
// Apply parent:
HostSPA.ParentGif = this;
byte packed = (byte)reader.ReadByte();
bool colorTableFlag = ((packed & 0x80) >> 7) == 1;
ColorResolution = (byte)((packed & 0x60) >> 5);
SortFlags = ((byte)(packed & 0x10)) >> 4;
// Background index (unused):
byte bgIndex = (byte)reader.ReadByte();
PixelAspect = (byte)reader.ReadByte();
Color32[] globalColorTable = null;
BackgroundColour = new Color32(0, 0, 0, 0);
if (colorTableFlag)
{
int colorTableSize = ((int)2) << (packed & 7);
globalColorTable = LoadPalette(reader.ReadBytes(colorTableSize * 3));
if (bgIndex < globalColorTable.Length)
{
BackgroundColour = globalColorTable[bgIndex];
}
}
byte nextFlag = (byte)reader.ReadByte();
int frameCount = 0;
int gcbCount = 0;
Color32[] previousFrame = null;
List <SPASprite> spaFrames = new List <SPASprite>();
List <GifFrame> frames = new List <GifFrame>();
while (nextFlag != GifBlocks.Terminator)
{
if (nextFlag == GifBlocks.ImageLabel)
{
GifFrame frame;
if (frames.Count <= frameCount)
{
// Create the frame now:
frame = new GifFrame(this, frameCount);
frames.Add(frame);
}
else
{
// Load it:
frame = frames[frameCount];
}
// Drop zero-delay frames from the output.
// - This makes "full colour" GIFs work.
if (frame.Delay != 0f || spaFrames.Count == 0)
{
spaFrames.Add(frame);
}
previousFrame = ReadFrame(previousFrame, frame, reader, globalColorTable);
frameCount++;
}
else if (nextFlag == GifBlocks.ExtensionIntroducer)
{
int gcl = reader.ReadByte();
switch (gcl)
{
case GifBlocks.GraphicControlLabel:
int blockSize = reader.ReadByte();
if (blockSize != 4)
{
throw new Exception("A graphic extension block had the wrong size in a GIF stream.");
}
byte gPacked = (byte)reader.ReadByte();
bool transparencyFlag = (gPacked & 0x01) == 1;
int disposalMethod = (gPacked & 0x1C) >> 2;
// Frame delay in seconds:
float delay = (float)reader.ReadInt16() / 100f;
byte transparencyIndex = (byte)reader.ReadByte();
// Terminal 0:
reader.ReadByte();
GifFrame frame;
if (frames.Count <= gcbCount)
{
// Create the frame now:
frame = new GifFrame(this, gcbCount);
frames.Add(frame);
}
else
{
// Load it:
frame = frames[gcbCount];
}
// Apply delay:
frame.Delay = delay;
frame.DisposalMethod = disposalMethod;
if (transparencyFlag)
{
frame.TransparencyIndex = transparencyIndex;
}
else
{
frame.TransparencyIndex = -1;
}
gcbCount++;
break;
case GifBlocks.CommentLabel:
CommentBlock commentBlock = new CommentBlock();
commentBlock.Load(reader);
Blocks.Add(commentBlock);
break;
case GifBlocks.ApplicationExtensionLabel:
ApplicationExtensionBlock appBlock = new ApplicationExtensionBlock();
appBlock.Load(reader);
Blocks.Add(appBlock);
break;
case GifBlocks.PlainTextLabel:
PlainTextBlock texBlock = new PlainTextBlock();
texBlock.Load(reader);
Blocks.Add(texBlock);
break;
}
}
else if (nextFlag == GifBlocks.EndIntroducer)
{
break;
}
nextFlag = reader.ReadByte();
}
Frames = frames.ToArray();
// Apply the frames to the host SPA:
HostSPA.Sprites = spaFrames.ToArray();
}
public static Color32[] LoadFramePixels(Color32[] prevImage, byte[] pixels, Color32[] colorTable, bool interlaceFlag, GifFrame frame)
{
Gif gif = frame.Gif;
int fw = frame.Width;
int iw = gif.Width;
int ih = gif.Height;
// Get transparency index:
int transIndex = frame.TransparencyIndex;
// Based on disposal method, we may actually be using prevImage.
Color32[] fullImage = prevImage;
int disposal = frame.DisposalMethod;
int maxY = ih - 1;
bool drawTransparent = (disposal == 2);
/*
* if(disposal==0){
* // Undefined - do nothing.
* // - Safe to reuse prevImage here.
* }else if(disposal==1){
* // Don't dispose. Return the frame from this function.
* // - Safe to reuse prevImage here.
* }else if(disposal==2){
* // Restore to background.
* // - Safe to reuse prevImage here.
* }
*/
if (disposal == 3)
{
// Restore to previous. Return prevImage.
// - Can't reuse prevImage here.
fullImage = null;
}
// Create the image area if one is needed:
if (fullImage == null)
{
fullImage = new Color32[iw * ih];
}
// Got a previous image?
if (prevImage != null && prevImage != fullImage)
{
// Blit previous into fullImage:
Array.Copy(prevImage, 0, fullImage, 0, fullImage.Length);
}
int startRowPoint = ((maxY - frame.OffsetY) * iw);
int offSet = 0;
if (interlaceFlag)
{
int i = 0;
int row = 0;
int rowPoint = startRowPoint;
int pass = 0;
while (pass < 4)
{
if (pass == 1)
{
rowPoint = startRowPoint - (4 * iw);
offSet += 4 * fw;
}
else if (pass == 2)
{
rowPoint = startRowPoint - (2 * iw);
offSet += 2 * fw;
}
else if (pass == 3)
{
rowPoint = startRowPoint - (1 * iw);
offSet += 1 * fw;
}
int rate = 1;
if (pass == 0 | pass == 1)
{
rate = 7;
}
else if (pass == 2)
{
rate = 3;
}
while (i < pixels.Length)
{
int colIndex = pixels[i++];
if (colIndex == transIndex)
{
if (drawTransparent)
{
fullImage[rowPoint + row + frame.OffsetX] = new Color32(0, 0, 0, 0);
}
}
else
{
fullImage[rowPoint + row + frame.OffsetX] = colorTable[colIndex];
}
row++;
offSet++;
if (row == fw)
{
// End of the row
row = 0;
rowPoint -= (rate + 1) * iw;
offSet += (fw * rate);
if (offSet >= pixels.Length)
{
pass++;
offSet = 0;
break;
}
}
}
}
}
else
{
int row = 0;
int rowPoint = startRowPoint;
for (int i = 0; i < pixels.Length; i++)
{
int colIndex = pixels[i];
if (colIndex == transIndex)
{
if (drawTransparent)
{
fullImage[rowPoint + row + frame.OffsetX] = new Color32(0, 0, 0, 0);
}
}
else
{
fullImage[rowPoint + row + frame.OffsetX] = colorTable[colIndex];
}
row++;
if (row == fw)
{
row = 0;
rowPoint -= iw;
}
}
}
// Create frame texture:
Texture2D tex = new Texture2D(frame.Gif.Width, frame.Gif.Height);
tex.SetPixels32(fullImage);
// Make sure it filters correctly.
// This is so we don't see parts of other frames around the edge of the image onscreen:
tex.filterMode = FilterMode.Point;
tex.Apply();
frame.Sprite = tex;
if (disposal == 3)
{
return(prevImage);
}
if (disposal == 2)
{
// Restore to background.
int graphicSize = fw * frame.Height;
int row = 0;
int rowPoint = startRowPoint;
Color32 background = gif.BackgroundColour;
for (int i = 0; i < graphicSize; i++)
{
fullImage[rowPoint + row + frame.OffsetX] = background;
row++;
if (row == fw)
{
// End of the row
row = 0;
rowPoint -= iw;
}
}
}
return(fullImage);
}
