/// <summary>
/// Creates a cached texture for the specifed texture, using the specified path
/// as a lookup key.
/// </summary>
public int CreateCachedTexture(BLP texture, string texturePath, TextureWrapMode textureWrapMode = TextureWrapMode.Repeat)
{
if (texture == null)
{
throw new ArgumentNullException(nameof(texture));
}
int textureID = GL.GenTexture();
if (texture.GetCompressionType() == TextureCompressionType.DXTC)
{
try
{
LoadDXTTexture(textureID, texture);
}
catch (GraphicsErrorException gex)
{
Log.Warn($"GraphicsErrorException in CreateCachedTexture (failed to create DXT texture): {gex.Message}\n" +
"The texture will be loaded as a bitmap instead.");
}
finally
{
// Load a fallback bitmap instead
using (Bitmap mipZero = texture.GetMipMap(0))
{
LoadBitmapTexture(textureID, mipZero);
}
}
}
else
{
using (Bitmap mipZero = texture.GetMipMap(0))
{
LoadBitmapTexture(textureID, mipZero);
}
}
// Use linear mipmapped filtering
GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureMagFilter, (int)TextureMagFilter.Linear);
GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureMinFilter, (int)TextureMinFilter.LinearMipmapLinear);
GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureWrapS, (int)textureWrapMode);
GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureWrapT, (int)textureWrapMode);
int maximalMipLevel = texture.GetMipMapCount() == 0 ? 0 : texture.GetMipMapCount() - 1;
GL.TexParameterI(TextureTarget.Texture2D, TextureParameterName.TextureMaxLevel, ref maximalMipLevel);
GL.TexParameter(TextureTarget.Texture2D, TextureParameterName.TextureBaseLevel, 0);
this.GLTextureCache.Add(texturePath.ConvertPathSeparatorsToCurrentNativeSeparator().ToUpperInvariant(), textureID);
return(textureID);
}
/// <summary>
/// Loads the specified compressed image (in <see cref="BLP"/> format) into a native OpenGL texture.
/// </summary>
/// <param name="textureID">The ID of the texture to load the image into.</param>
/// <param name="compressedImage">The compressed image to load.</param>
/// <exception cref="ArgumentException">
/// Thrown if the image format does not match the pixel format.
/// </exception>
/// <exception cref="ArgumentNullException">
/// Thrown if the input image is null.
/// </exception>
private static void LoadDXTTexture(int textureID, BLP compressedImage)
{
if (compressedImage == null)
{
throw new ArgumentNullException(nameof(compressedImage));
}
GL.BindTexture(TextureTarget.Texture2D, textureID);
// Load the set of raw compressed mipmaps
for (uint i = 0; i < compressedImage.GetMipMapCount(); ++i)
{
byte[] compressedMipMap = compressedImage.GetRawMipMap(i);
Resolution mipResolution = compressedImage.GetMipLevelResolution(i);
PixelInternalFormat compressionFormat;
switch (compressedImage.GetPixelFormat())
{
case BLPPixelFormat.DXT1:
{
compressionFormat = PixelInternalFormat.CompressedRgbaS3tcDxt1Ext;
break;
}
case BLPPixelFormat.DXT3:
{
compressionFormat = PixelInternalFormat.CompressedRgbaS3tcDxt3Ext;
break;
}
case BLPPixelFormat.DXT5:
{
compressionFormat = PixelInternalFormat.CompressedRgbaS3tcDxt5Ext;
break;
}
default:
{
throw new ArgumentException($"Image format (DXTC) did not match pixel format: {compressedImage.GetPixelFormat()}", nameof(Image));
}
}
// Load the mipmap into the texture
GL.CompressedTexImage2D(TextureTarget.Texture2D, (int)i,
compressionFormat,
(int)mipResolution.X,
(int)mipResolution.Y,
0,
compressedMipMap.Length,
compressedMipMap);
}
}