+ LUMINANCE8 = GL_LUMINANCE8,
+ LUMINANCE16F = GL_LUMINANCE16F_ARB,
+ LUMINANCE32F = GL_LUMINANCE32F_ARB,
+ LUMINANCE_ALPHA = GL_LUMINANCE_ALPHA,
+ LUMINANCE_ALPHA8 = GL_LUMINANCE8_ALPHA8,
+ LUMINANCE_ALPHA16F = GL_LUMINANCE_ALPHA16F_ARB,
+ LUMINANCE_ALPHA32F = GL_LUMINANCE_ALPHA32F_ARB