/// <summary>
/// Copies a rectangular block of pixel data from a source image to a this image (Blt = BlockTransfer).
/// </summary>
/// <param name="xDst">The x destination coordinate (where to place the block within dst).</param>
/// <param name="yDst">The y destination coordinate (where to place the block within dst).</param>
/// <param name="src">The source image.</param>
/// <param name="xSrc">The x source coordinate (where to start copying from within src).</param>
/// <param name="ySrc">The y source coordinate (where to start copying from within src).</param>
/// <param name="width">The width of the block to copy. (default is src.Width).</param>
/// <param name="height">The height of the block to copy (default is src.Height).</param>
/// <remarks>
/// All specified parameters are clipped to avoid out-of-bounds indices. No warnings or exceptions are issued
/// in case clipping results in a smaller or an empty block.
/// </remarks>
public void Blt(int xDst, int yDst, IImageData src, int xSrc = 0, int ySrc = 0, int width = 0, int height = 0)
{
if (width == 0)
{
width = src.Width;
}
if (height == 0)
{
height = src.Height;
}
ClipBlt(ref xDst, Width, ref xSrc, src.Width, ref width);
ClipBlt(ref yDst, Height, ref ySrc, src.Height, ref height);
if (width <= 0 || height <= 0)
{
return;
}
CopyFunc copyLine;
if (PixelFormat.ColorFormat.Equals(src.PixelFormat.ColorFormat))
{
// Case: same color space, just loop over scanlines from src and copy line-wise into this ImageData
copyLine = delegate(byte[] srcScanLineBytes, int destinationIndex)
{
Array.Copy(srcScanLineBytes, 0, PixelData, destinationIndex, srcScanLineBytes.Length);
};
}
else
{
// Wee need to perform pixel-conversion while copying. -> still GetLineBytes and then perform pixel conversion
switch (PixelFormat.ColorFormat)
{
case ColorFormat.RGBA:
switch (src.PixelFormat.ColorFormat)
{
case ColorFormat.RGB:
copyLine = delegate(byte[] srcLineBytes, int destinationIndex)
{
for (int i = 0; i < srcLineBytes.Length; i += 3) // jump 3 units per loop because we want to copy src RGB to dst RGBA
{
PixelData[destinationIndex + i + 0] = srcLineBytes[i + 0];
PixelData[destinationIndex + i + 1] = srcLineBytes[i + 1];
PixelData[destinationIndex + i + 2] = srcLineBytes[i + 2];
PixelData[destinationIndex + i + 3] = byte.MaxValue;
}
};
break;
case ColorFormat.Intensity:
copyLine = delegate(byte[] srcLineBytes, int destinationIndex)
{
for (int i = 0; i < srcLineBytes.Length; i++) // jump 1 unit per loop because we want to copy src Intensity to dst RGBA
{
PixelData[destinationIndex + i + 0] = srcLineBytes[i];
PixelData[destinationIndex + i + 1] = srcLineBytes[i];
PixelData[destinationIndex + i + 2] = srcLineBytes[i];
PixelData[destinationIndex + i + 3] = byte.MaxValue;
}
};
break;
default:
throw new ArgumentOutOfRangeException(nameof(src), "Unknown source pixel format to copy to RGBA");
}
break;
case ColorFormat.RGB:
switch (src.PixelFormat.ColorFormat)
{
case ColorFormat.RGBA:
copyLine = delegate(byte[] srcLineBytes, int destinationIndex)
{
for (int i = 0; i < srcLineBytes.Length; i += 4) // jump 4 units per loop because we want to copy src RGBA to dst RGB
{
PixelData[destinationIndex + i + 0] = srcLineBytes[i + 0];
PixelData[destinationIndex + i + 1] = srcLineBytes[i + 1];
PixelData[destinationIndex + i + 2] = srcLineBytes[i + 2];
// skip source alpha
}
};
break;
case ColorFormat.Intensity:
copyLine = delegate(byte[] srcLineBytes, int destinationIndex)
{
for (int i = 0; i < srcLineBytes.Length; i++) // jump 1 unit per loop because we want to copy src Intensity to dst RGB
{
PixelData[destinationIndex + i + 0] = srcLineBytes[i];
PixelData[destinationIndex + i + 1] = srcLineBytes[i];
PixelData[destinationIndex + i + 2] = srcLineBytes[i];
}
};
break;
default:
throw new ArgumentOutOfRangeException(nameof(src), "Unknown source pixel format to copy to RGB");
}
break;
case ColorFormat.Intensity:
switch (src.PixelFormat.ColorFormat)
{
case ColorFormat.RGB:
copyLine = delegate(byte[] srcLineBytes, int destinationIndex)
{
for (int i = 0; i < srcLineBytes.Length; i += 3) // jump 3 units per loop because we want to copy src RGB to dst Intensity
{
// Quick integer Luma conversion (not accurate)
// See http://stackoverflow.com/questions/596216/formula-to-determine-brightness-of-rgb-color
int r = srcLineBytes[destinationIndex + i + 0];
int g = srcLineBytes[destinationIndex + i + 1];
int b = srcLineBytes[destinationIndex + i + 2];
PixelData[destinationIndex + i] = (byte)((r + r + b + g + g + g) / 6);
}
};
break;
case ColorFormat.RGBA:
copyLine = delegate(byte[] srcLineBytes, int destinationIndex)
{
for (int i = 0; i < srcLineBytes.Length; i += 4) // jump 4 units per loop because we want to copy src RGBA to dst Intensity
{
// Quick integer Luma conversion (not accurate)
// See http://stackoverflow.com/questions/596216/formula-to-determine-brightness-of-rgb-color
int r = srcLineBytes[destinationIndex + i + 0];
int g = srcLineBytes[destinationIndex + i + 1];
int b = srcLineBytes[destinationIndex + i + 2];
PixelData[destinationIndex + i] = (byte)((r + r + b + g + g + g) / 6);
}
};
break;
default:
throw new ArgumentOutOfRangeException(nameof(src), "Unknown source pixel format to copy to RGB");
}
break;
default:
throw new ArgumentOutOfRangeException(ToString(), "Unknown destination pixel format");
} // end switch
} // end else block
// loop over the ScanLineEnumerator and call CopyLine delegate
var srcEnumerator = src.ScanLines(xSrc, ySrc, width, height);
while (srcEnumerator.MoveNext())
{
var srcScanLine = srcEnumerator.Current;
if (srcScanLine != null)
{
byte[] srcScanLineBytes = srcScanLine.GetScanLineBytes();
int destinationIndex = yDst * PixelFormat.BytesPerPixel * Width + xDst * PixelFormat.BytesPerPixel; // move down by yDst and add (move right) xDst
copyLine(srcScanLineBytes, destinationIndex);
yDst++; // increment yDst == move to the next line
}
}
}