private RobAndSliceSizes GetRobAndSliceSizes(int width, int height, GobBlockSizes gbSizes)
{
int widthInGobs = BitUtils.DivRoundUp(width * _texBpp, GobWidth);
int robSize = GobSize * gbSizes.Height * gbSizes.Depth * widthInGobs;
int sliceSize = BitUtils.DivRoundUp(height, gbSizes.Height * GobHeight) * robSize;
return(new RobAndSliceSizes(robSize, sliceSize));
}
public int GetMipOffset(int level)
{
int totalSize = 0;
for (int index = 0; index < level; index++)
{
int width = Math.Max(1, _texWidth >> index);
int height = Math.Max(1, _texHeight >> index);
int depth = Math.Max(1, _texDepth >> index);
GobBlockSizes gbSizes = AdjustGobBlockSizes(height, depth);
RobAndSliceSizes rsSizes = GetRobAndSliceSizes(width, height, gbSizes);
totalSize += BitUtils.DivRoundUp(depth, gbSizes.Depth) * rsSizes.SliceSize;
}
return(totalSize);
}
public void SetMipLevel(int level)
{
_baseOffset = GetMipOffset(level);
int width = Math.Max(1, _texWidth >> level);
int height = Math.Max(1, _texHeight >> level);
int depth = Math.Max(1, _texDepth >> level);
GobBlockSizes gbSizes = AdjustGobBlockSizes(height, depth);
_bhMask = gbSizes.Height - 1;
_bdMask = gbSizes.Depth - 1;
_bhShift = BitUtils.CountTrailingZeros32(gbSizes.Height);
_bdShift = BitUtils.CountTrailingZeros32(gbSizes.Depth);
_xShift = BitUtils.CountTrailingZeros32(GobSize * gbSizes.Height * gbSizes.Depth);
RobAndSliceSizes gsSizes = GetRobAndSliceSizes(width, height, gbSizes);
_robSize = gsSizes.RobSize;
_sliceSize = gsSizes.SliceSize;
}