/// <summary>
/// Computes pitch information about an image given its DXGI format and uncompressed dimensions.
/// </summary>
/// <param name="format">Format of the image data.</param>
/// <param name="width">Uncompressed width, in texels.</param>
/// <param name="height">Uncompressed height, in texels.</param>
/// <param name="rowPitch">Total # of bytes per scanline.</param>
/// <param name="slicePitch">Total # of bytes per slice (if 3D texture).</param>
/// <param name="widthCount">Compressed width, if the format is a compressed image format, otherwise the given width.</param>
/// <param name="heightCount">Compressed height, if the format is a compressed image format, otherwise the given height.</param>
/// <param name="bytesPerPixel">Gets the size of the format.</param>
/// <param name="legacyDword">True if need to use workaround computation for some incorrectly created DDS files based on legacy DirectDraw assumptions about pitch alignment.</param>
public static void ComputePitch(DDS.DXGIFormat format, int width, int height, out int rowPitch, out int slicePitch, out int widthCount, out int heightCount, out int bytesPerPixel, bool legacyDword = false)
{
widthCount = width;
heightCount = height;
if (DDS.FormatConverter.IsCompressed(format))
{
int blockSize = DDS.FormatConverter.GetCompressedBlockSize(format);
widthCount = Math.Max(1, (width + 3) / 4);
heightCount = Math.Max(1, (height + 3) / 4);
rowPitch = widthCount * blockSize;
slicePitch = rowPitch * heightCount;
bytesPerPixel = blockSize;
}
else if (DDS.FormatConverter.IsPacked(format))
{
rowPitch = ((width + 1) >> 1) * 4;
slicePitch = rowPitch * height;
int bitsPerPixel = DDS.FormatConverter.GetBitsPerPixel(format);
bytesPerPixel = Math.Max(1, bitsPerPixel / 8);
}
else
{
int bitsPerPixel = DDS.FormatConverter.GetBitsPerPixel(format);
bytesPerPixel = Math.Max(1, bitsPerPixel / 8);
if (legacyDword)
{
//Allow for old DDS files that based pitch on certain assumptions
rowPitch = ((width * bitsPerPixel + 31) / 32) * sizeof(int);
slicePitch = rowPitch * height;
}
else
{
rowPitch = (width * bitsPerPixel + 7) / 8;
slicePitch = rowPitch * height;
}
}
}
/// <summary>
/// Computes pitch information about an image given its DXGI format and uncompressed dimensions.
/// </summary>
/// <param name="format">Format of the image data.</param>
/// <param name="width">Uncompressed width, in texels.</param>
/// <param name="height">Uncompressed height, in texels.</param>
/// <param name="rowPitch">Total # of bytes per scanline.</param>
/// <param name="slicePitch">Total # of bytes per slice (if 3D texture).</param>
/// <param name="widthCount">Compressed width, if the format is a compressed image format, otherwise the given width.</param>
/// <param name="heightCount">Compressed height, if the format is a compressed image format, otherwise the given height.</param>
/// <param name="legacyDword">True if need to use workaround computation for some incorrectly created DDS files based on legacy DirectDraw assumptions about pitch alignment.</param>
public static void ComputePitch(DDS.DXGIFormat format, int width, int height, out int rowPitch, out int slicePitch, out int widthCount, out int heightCount, bool legacyDword = false)
{
int bytesPerPixel;
ComputePitch(format, width, height, out rowPitch, out slicePitch, out widthCount, out heightCount, out bytesPerPixel, legacyDword);
}
