private static void CopyFromZYXW <TColor, TPacked>(Image <TColor, TPacked> image)
where TColor : struct, IPackedPixel <TPacked>
where TPacked : struct
{
using (PixelAccessor <TColor, TPacked> pixels = image.Lock())
{
byte red = 1;
byte green = 2;
byte blue = 3;
byte alpha = 4;
using (PixelRow <TColor, TPacked> row = new PixelRow <TColor, TPacked>(1, ComponentOrder.ZYXW))
{
row.Bytes[0] = blue;
row.Bytes[1] = green;
row.Bytes[2] = red;
row.Bytes[3] = alpha;
pixels.CopyFrom(row, 0);
Color color = (Color)(object)pixels[0, 0];
Assert.Equal(red, color.R);
Assert.Equal(green, color.G);
Assert.Equal(blue, color.B);
Assert.Equal(alpha, color.A);
}
}
}
private void RestoreToBackground(ImageBase <TColor, TPacked> frame)
{
if (this.restoreArea == null)
{
return;
}
// Optimization for when the size of the frame is the same as the image size.
if (this.restoreArea.Value.Width == this.decodedImage.Width &&
this.restoreArea.Value.Height == this.decodedImage.Height)
{
using (PixelAccessor <TColor, TPacked> pixelAccessor = frame.Lock())
{
pixelAccessor.Reset();
}
}
else
{
using (PixelRow <TColor, TPacked> emptyRow = new PixelRow <TColor, TPacked>(this.restoreArea.Value.Width, ComponentOrder.XYZW))
{
using (PixelAccessor <TColor, TPacked> pixelAccessor = frame.Lock())
{
for (int y = this.restoreArea.Value.Top; y < this.restoreArea.Value.Top + this.restoreArea.Value.Height; y++)
{
pixelAccessor.CopyFrom(emptyRow, y, this.restoreArea.Value.Left);
}
}
}
}
this.restoreArea = null;
}
/// <summary>
/// Reads the 16 bit color palette from the stream
/// </summary>
/// <typeparam name="TColor">The pixel format.</typeparam>
/// <typeparam name="TPacked">The packed format. <example>uint, long, float.</example></typeparam>
/// <param name="pixels">The <see cref="PixelAccessor{TColor, TPacked}"/> to assign the palette to.</param>
/// <param name="width">The width of the bitmap.</param>
/// <param name="height">The height of the bitmap.</param>
/// <param name="inverted">Whether the bitmap is inverted.</param>
private void ReadRgb16 <TColor, TPacked>(PixelAccessor <TColor, TPacked> pixels, int width, int height, bool inverted)
where TColor : struct, IPackedPixel <TPacked>
where TPacked : struct
{
// We divide here as we will store the colors in our floating point format.
const int ScaleR = 8; // 256/32
const int ScaleG = 4; // 256/64
const int ComponentCount = 2;
TColor color = default(TColor);
using (PixelRow <TColor, TPacked> row = new PixelRow <TColor, TPacked>(width, ComponentOrder.XYZ))
{
for (int y = 0; y < height; y++)
{
row.Read(this.currentStream);
int newY = Invert(y, height, inverted);
int offset = 0;
for (int x = 0; x < width; x++)
{
short temp = BitConverter.ToInt16(row.Bytes, offset);
byte r = (byte)(((temp & Rgb16RMask) >> 11) * ScaleR);
byte g = (byte)(((temp & Rgb16GMask) >> 5) * ScaleG);
byte b = (byte)((temp & Rgb16BMask) * ScaleR);
color.PackFromBytes(r, g, b, 255);
pixels[x, newY] = color;
offset += ComponentCount;
}
}
}
}
/// <summary>
/// Collects a row of true color pixel data.
/// </summary>
/// <typeparam name="TColor">The pixel format.</typeparam>
/// <typeparam name="TPacked">The packed format. <example>uint, long, float.</example></typeparam>
/// <param name="pixels">The image pixel accessor.</param>
/// <param name="row">The row index.</param>
/// <param name="rawScanline">The raw scanline.</param>
private void CollectColorBytes <TColor, TPacked>(PixelAccessor <TColor, TPacked> pixels, int row, byte[] rawScanline)
where TColor : struct, IPackedPixel <TPacked>
where TPacked : struct
{
// We can use the optimized PixelAccessor here and copy the bytes in unmanaged memory.
using (PixelRow <TColor, TPacked> pixelRow = new PixelRow <TColor, TPacked>(this.width, rawScanline, this.bytesPerPixel == 4 ? ComponentOrder.XYZW : ComponentOrder.XYZ))
{
pixels.CopyTo(pixelRow, row);
}
}
/// <summary>
/// Writes the 24bit color palette to the stream.
/// </summary>
/// <typeparam name="TColor">The pixel format.</typeparam>
/// <typeparam name="TPacked">The packed format. <example>uint, long, float.</example></typeparam>
/// <param name="writer">The <see cref="EndianBinaryWriter"/> containing the stream to write to.</param>
/// <param name="pixels">The <see cref="PixelAccessor{TColor,TPacked}"/> containing pixel data.</param>
private void Write24Bit <TColor, TPacked>(EndianBinaryWriter writer, PixelAccessor <TColor, TPacked> pixels)
where TColor : struct, IPackedPixel <TPacked>
where TPacked : struct
{
using (PixelRow <TColor, TPacked> row = new PixelRow <TColor, TPacked>(pixels.Width, ComponentOrder.ZYX, this.padding))
{
for (int y = pixels.Height - 1; y >= 0; y--)
{
pixels.CopyTo(row, y);
writer.Write(row.Bytes);
}
}
}
/// <summary>
/// Reads the 32 bit color palette from the stream
/// </summary>
/// <typeparam name="TColor">The pixel format.</typeparam>
/// <typeparam name="TPacked">The packed format. <example>uint, long, float.</example></typeparam>
/// <param name="pixels">The <see cref="PixelAccessor{TColor, TPacked}"/> to assign the palette to.</param>
/// <param name="width">The width of the bitmap.</param>
/// <param name="height">The height of the bitmap.</param>
/// <param name="inverted">Whether the bitmap is inverted.</param>
private void ReadRgb32 <TColor, TPacked>(PixelAccessor <TColor, TPacked> pixels, int width, int height, bool inverted)
where TColor : struct, IPackedPixel <TPacked>
where TPacked : struct
{
int padding = CalculatePadding(width, 4);
using (PixelRow <TColor, TPacked> row = new PixelRow <TColor, TPacked>(width, ComponentOrder.ZYXW, padding))
{
for (int y = 0; y < height; y++)
{
row.Read(this.currentStream);
int newY = Invert(y, height, inverted);
pixels.CopyFrom(row, newY);
}
}
}
private static void CopyToZYX <TColor, TPacked>(Image <TColor, TPacked> image)
where TColor : struct, IPackedPixel <TPacked>
where TPacked : struct
{
using (PixelAccessor <TColor, TPacked> pixels = image.Lock())
{
byte red = 1;
byte green = 2;
byte blue = 3;
using (PixelRow <TColor, TPacked> row = new PixelRow <TColor, TPacked>(1, ComponentOrder.ZYX))
{
pixels[0, 0] = (TColor)(object)new Color(red, green, blue);
pixels.CopyTo(row, 0);
Assert.Equal(blue, row.Bytes[0]);
Assert.Equal(green, row.Bytes[1]);
Assert.Equal(red, row.Bytes[2]);
}
}
}
/// <summary>
/// Reads the frames colors, mapping indices to colors.
/// </summary>
/// <param name="indices">The indexed pixels.</param>
/// <param name="colorTable">The color table containing the available colors.</param>
/// <param name="descriptor">The <see cref="GifImageDescriptor"/></param>
private unsafe void ReadFrameColors(byte[] indices, byte[] colorTable, GifImageDescriptor descriptor)
{
int imageWidth = this.logicalScreenDescriptor.Width;
int imageHeight = this.logicalScreenDescriptor.Height;
ImageFrame <TColor, TPacked> previousFrame = null;
ImageFrame <TColor, TPacked> currentFrame = null;
ImageBase <TColor, TPacked> image;
if (this.nextFrame == null)
{
image = this.decodedImage;
image.Quality = colorTable.Length / 3;
// This initializes the image to become fully transparent because the alpha channel is zero.
image.InitPixels(imageWidth, imageHeight);
}
else
{
if (this.graphicsControlExtension != null &&
this.graphicsControlExtension.DisposalMethod == DisposalMethod.RestoreToPrevious)
{
previousFrame = this.nextFrame;
}
currentFrame = this.nextFrame.Clone();
image = currentFrame;
this.RestoreToBackground(image);
this.decodedImage.Frames.Add(currentFrame);
}
if (this.graphicsControlExtension != null && this.graphicsControlExtension.DelayTime > 0)
{
image.FrameDelay = this.graphicsControlExtension.DelayTime;
}
int i = 0;
int interlacePass = 0; // The interlace pass
int interlaceIncrement = 8; // The interlacing line increment
int interlaceY = 0; // The current interlaced line
using (PixelAccessor <TColor, TPacked> pixelAccessor = image.Lock())
{
using (PixelRow <TColor, TPacked> pixelRow = new PixelRow <TColor, TPacked>(imageWidth, ComponentOrder.XYZW))
{
for (int y = descriptor.Top; y < descriptor.Top + descriptor.Height; y++)
{
// Check if this image is interlaced.
int writeY; // the target y offset to write to
if (descriptor.InterlaceFlag)
{
// If so then we read lines at predetermined offsets.
// When an entire image height worth of offset lines has been read we consider this a pass.
// With each pass the number of offset lines changes and the starting line changes.
if (interlaceY >= descriptor.Height)
{
interlacePass++;
switch (interlacePass)
{
case 1:
interlaceY = 4;
break;
case 2:
interlaceY = 2;
interlaceIncrement = 4;
break;
case 3:
interlaceY = 1;
interlaceIncrement = 2;
break;
}
}
writeY = interlaceY + descriptor.Top;
interlaceY += interlaceIncrement;
}
else
{
writeY = y;
}
pixelRow.Reset();
byte *pixelBase = pixelRow.PixelBase;
for (int x = 0; x < descriptor.Width; x++)
{
int index = indices[i];
if (this.graphicsControlExtension == null ||
this.graphicsControlExtension.TransparencyFlag == false ||
this.graphicsControlExtension.TransparencyIndex != index)
{
int indexOffset = index * 3;
*(pixelBase + 0) = colorTable[indexOffset];
*(pixelBase + 1) = colorTable[indexOffset + 1];
*(pixelBase + 2) = colorTable[indexOffset + 2];
*(pixelBase + 3) = 255;
}
i++;
pixelBase += 4;
}
pixelAccessor.CopyFrom(pixelRow, writeY, descriptor.Left);
}
}
}
if (previousFrame != null)
{
this.nextFrame = previousFrame;
return;
}
if (currentFrame == null)
{
this.nextFrame = this.decodedImage.ToFrame();
}
else
{
this.nextFrame = currentFrame.Clone();
}
if (this.graphicsControlExtension != null &&
this.graphicsControlExtension.DisposalMethod == DisposalMethod.RestoreToBackground)
{
this.restoreArea = new Rectangle(descriptor.Left, descriptor.Top, descriptor.Width, descriptor.Height);
}
}
