internal static void TestDDSMipSize(List <MipMap> newMips, ImageFormats.ImageEngineFormatDetails destFormatDetails, int width, int height, out double fixXScale, out double fixYScale, MipHandling mipChoice)
{
fixXScale = 0;
fixYScale = 0;
if (destFormatDetails.IsBlockCompressed && (!UsefulThings.General.IsPowerOfTwo(width) || !UsefulThings.General.IsPowerOfTwo(height)))
{
// If only keeping top mip, and that mip is divisible by 4, it's ok.
if ((mipChoice == MipHandling.KeepTopOnly || mipChoice == MipHandling.KeepExisting) &&
DDSGeneral.CheckSize_DXT(width, height))
{
return;
}
double newWidth = 0;
double newHeight = 0;
// Takes into account aspect ratio (a little bit)
double aspect = width / height;
if (aspect > 1)
{
newWidth = UsefulThings.General.RoundToNearestPowerOfTwo(width);
var tempScale = newWidth / width;
newHeight = UsefulThings.General.RoundToNearestPowerOfTwo((int)(height * tempScale));
}
else
{
newHeight = UsefulThings.General.RoundToNearestPowerOfTwo(height);
var tempScale = newHeight / height;
newWidth = UsefulThings.General.RoundToNearestPowerOfTwo((int)(width * tempScale));
}
// Little extra bit to allow integer cast from Double with the correct answer. Occasionally dimensions * scale would be 511.99999999998 instead of 512, so adding a little allows the integer cast to return correct value.
fixXScale = 1d * newWidth / width + 0.001;
fixYScale = 1d * newHeight / height + 0.001;
newMips[0] = Resize(newMips[0], fixXScale, fixYScale);
}
}
