private void InitTextures()
{
var i = byte.MaxValue + 1;
var perm2 = new byte[i, i, 4];
for (var y = 0; y < i; y++)
{
for (var x = 0; x < i; x++)
{
var a = _perm[x] + y;
perm2[y, x, 0] = (byte)_perm[a];
perm2[y, x, 1] = (byte)_perm[a + 1];
var b = _perm[x + 1] + y;
perm2[y, x, 2] = (byte)_perm[b];
perm2[y, x, 3] = (byte)_perm[b + 1];
}
}
_perm2D = new Texture2D(i, i, 4, typeof(byte));
_perm2D.Activate();
GL.TexSubImage2D(TextureTarget.Texture2D, 0, 0, 0, i, i, PixelFormat.Rgba, PixelType.Byte, perm2);
GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureMinFilter, (int)TextureMinFilter.Nearest);
GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureMagFilter, (int)TextureMagFilter.Nearest);
GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureWrapS, (int)TextureWrapMode.Repeat);
GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureWrapT, (int)TextureWrapMode.Repeat);
_permGrad3 = new Texture1D(i, 3, typeof(OpenTK.Half));
var pg3 = _perm.SelectMany(x => new[]
{
(float)_grad3[x % 16, 0],
(float)_grad3[x % 16, 1],
(float)_grad3[x % 16, 2],
}).ToArray();
_permGrad3.Activate();
GL.TexSubImage1D(TextureTarget.Texture1D, 0, 0, i, PixelFormat.Rgb, PixelType.Float, pg3);
GL.TexParameter(TextureTarget.Texture1D, TextureParameterName.TextureMinFilter, (int)TextureMinFilter.Nearest);
GL.TexParameter(TextureTarget.Texture1D, TextureParameterName.TextureMagFilter, (int)TextureMagFilter.Nearest);
GL.TexParameter(TextureTarget.Texture1D, TextureParameterName.TextureWrapS, (int)TextureWrapMode.Repeat);
}
