As an experiment, I tried using a Vector4 format instead of the NormalizedByte4 format which is causing me all this trouble.
However, I got an exception in SpritePacker Copy:
System.InvalidOperationException: Could not copy between Vector4 and Vector4
PixelBitmapContent<Vector4>.Copy(source, new Rectangle(0, 0, w, h),
output, new Rectangle(x + 1, y + 1, w, h));
This is the framework code that throws the exception:
/// <summary>
/// Copies one bitmap into another.
/// The destination bitmap can be in any format and size. If the destination is larger or smaller, the source bitmap is scaled accordingly.
/// </summary>
/// <param name="sourceBitmap">BitmapContent being copied.</param>
/// <param name="sourceRegion">Region of sourceBitmap.</param>
/// <param name="destinationBitmap">BitmapContent being overwritten.</param>
/// <param name="destinationRegion">Region of bitmap to be overwritten.</param>
public static void Copy(BitmapContent sourceBitmap, Rectangle sourceRegion, BitmapContent destinationBitmap, Rectangle destinationRegion)
{
ValidateCopyArguments(sourceBitmap, sourceRegion, destinationBitmap, destinationRegion);
SurfaceFormat sourceFormat;
if (!sourceBitmap.TryGetFormat(out sourceFormat))
throw new InvalidOperationException("Could not retrieve surface format of source bitmap");
SurfaceFormat destinationFormat;
if (!destinationBitmap.TryGetFormat(out destinationFormat))
throw new InvalidOperationException("Could not retrieve surface format of destination bitmap");
// If the formats are the same and the regions are the full bounds of the bitmaps and they are the same size, do a simpler copy
if (sourceFormat == destinationFormat && sourceRegion == destinationRegion
&& sourceRegion == new Rectangle(0, 0, sourceBitmap.Width, sourceBitmap.Height)
&& destinationRegion == new Rectangle(0, 0, destinationBitmap.Width, destinationBitmap.Height))
{
destinationBitmap.SetPixelData(sourceBitmap.GetPixelData());
return;
}
// The basic process is
// 1. Copy from source bitmap region to a new PixelBitmapContent<Vector4> using sourceBitmap.TryCopyTo()
// 2. If source and destination regions are a different size, resize Vector4 version
// 3. Copy from Vector4 to destination region using destinationBitmap.TryCopyFrom()
// Copy from the source to the intermediate Vector4 format
var intermediate = new PixelBitmapContent<Vector4>(sourceRegion.Width, sourceRegion.Height);
var intermediateRegion = new Rectangle(0, 0, intermediate.Width, intermediate.Height);
if (sourceBitmap.TryCopyTo(intermediate, sourceRegion, intermediateRegion))
{
// Resize the intermediate if required
if (intermediate.Width != destinationRegion.Width || intermediate.Height != destinationRegion.Height)
intermediate = intermediate.Resize(destinationRegion.Width, destinationRegion.Height) as PixelBitmapContent<Vector4>;
// Copy from the intermediate to the destination
if (destinationBitmap.TryCopyFrom(intermediate, new Rectangle(0, 0, intermediate.Width, intermediate.Height), destinationRegion))
return;
}
// If we got here, one of the above steps didn't work
throw new InvalidOperationException("Could not copy between " + sourceFormat + " and " + destinationFormat);
}
XNA does not throw this exception, so I will create a separate post for it.
