/**
* Writes the data for a single mip-level into a destination buffer.
* @param FaceIndex The index of the face of the mip-level to read.
* @param MipIndex The index of the mip-level to read.
* @param Dest The address of the destination buffer to receive the mip-level's data.
* @param DestPitch Number of bytes per row
*/
void GetData( int32 FaceIndex, int32 MipIndex, void* Dest, uint32 DestPitch )
{
check( MipData[FaceIndex][MipIndex] );
// for platforms that returned 0 pitch from Lock, we need to just use the bulk data directly, never do
// runtime block size checking, conversion, or the like
if (DestPitch == 0)
{
FMemory::Memcpy(Dest, MipData[FaceIndex][MipIndex], Owner->PlatformData->Mips[MipIndex].BulkData.GetBulkDataSize() / 6);
}
else
{
EPixelFormat PixelFormat = Owner->GetPixelFormat();
uint32 NumRows = 0;
uint32 SrcPitch = 0;
uint32 BlockSizeX = GPixelFormats[PixelFormat].BlockSizeX; // Block width in pixels
uint32 BlockSizeY = GPixelFormats[PixelFormat].BlockSizeY; // Block height in pixels
uint32 BlockBytes = GPixelFormats[PixelFormat].BlockBytes;
FIntPoint MipExtent = CalcMipMapExtent(Owner->GetSizeX(), Owner->GetSizeY(), PixelFormat, MipIndex);
uint32 NumColumns = (MipExtent.X + BlockSizeX - 1) / BlockSizeX; // Num-of columns in the source data (in blocks)
NumRows = (MipExtent.Y + BlockSizeY - 1) / BlockSizeY; // Num-of rows in the source data (in blocks)
SrcPitch = NumColumns * BlockBytes; // Num-of bytes per row in the source data
SIZE_T MipSizeInBytes = CalcTextureMipMapSize(MipExtent.X, MipExtent.Y, PixelFormat, 0);
if (SrcPitch == DestPitch)
{
// Copy data, not taking into account stride!
FMemory::Memcpy(Dest, MipData[FaceIndex][MipIndex], MipSizeInBytes);
}
else
{
// Copy data, taking the stride into account!
uint8 *Src = (uint8*) MipData[FaceIndex][MipIndex];
uint8 *Dst = (uint8*) Dest;
for ( uint32 Row=0; Row < NumRows; ++Row )
{
FMemory::Memcpy( Dst, Src, SrcPitch );
Src += SrcPitch;
Dst += DestPitch;
}
check( (PTRINT(Src) - PTRINT(MipData[FaceIndex][MipIndex])) == PTRINT(MipSizeInBytes) );
}
}
FMemory::Free( MipData[FaceIndex][MipIndex] );
MipData[FaceIndex][MipIndex] = NULL;
}
