/// <summary>
/// Create the mipmaps by downsampling using a filter.
/// </summary>
public void GenerateMipmaps(Filter filter)
{
for (int i = 1; i < Levels; i++)
{
TextureData2D src = Data[i - 1];
TextureData2D dst = Data[i];
int srcWidth = src.GetWidth();
int srcHeight = src.GetHeight();
int dstWidth = dst.GetWidth();
int dstHeight = dst.GetHeight();
float[] tmp = new float[dstWidth * srcHeight * Channels];
PolyphaseKernel xKernel = new PolyphaseKernel(filter, srcWidth, dstWidth, 32);
PolyphaseKernel yKernel = new PolyphaseKernel(filter, srcHeight, dstHeight, 32);
for (int y = 0; y < srcHeight; y++)
{
xKernel.ApplyHorizontal(y, src, tmp, dstWidth);
}
for (int x = 0; x < dstWidth; x++)
{
yKernel.ApplyVertical(x, tmp, dstWidth, srcHeight, Channels, dst);
}
}
}
/// <summary>
/// Create a new mipmap with the data all set to 0.
/// </summary>
public Mipmap2D(int width, int height, int channels, int bitDepth, TEXTURE_MIPMAP mode = TEXTURE_MIPMAP.BOX, int minLevel = -1)
: base(width, height, channels, bitDepth)
{
MipmapMode = mode;
int min = Math.Min(width, height);
Levels = (int)(Math.Log(min) / Math.Log(2)) + 1;
if (minLevel > -1 && Levels > minLevel)
{
Levels = minLevel;
}
Data = new List <TextureData2D>(Levels);
int w = Width;
int h = Height;
for (int i = 0; i < Levels; i++)
{
Data.Add(TextureData2D.CreateData(w, h, channels, bitDepth));
w /= 2;
h /= 2;
}
}
public static TextureData2D CreateData(int width, int height, int channels, int bitDepth)
{
TextureData2D data = null;
switch (bitDepth)
{
case 32:
data = new TextureData2D32(width, height, channels);
break;
case 16:
data = new TextureData2D16(width, height, channels);
break;
case 8:
data = new TextureData2D8(width, height, channels);
break;
default:
throw new ArgumentException("Bit depth " + bitDepth + " is invalid");
}
return(data);
}
