private void InitializeOpenGlBlendMode()
{
//These are copied from GameEngine2d. I only have a vague idea what they do.
NoBlendFunc = new BlendFunc(BlendFuncMode.Add, BlendFuncFactor.One, BlendFuncFactor.One);
NormalBlendFunc = new BlendFunc(BlendFuncMode.Add, BlendFuncFactor.SrcAlpha, BlendFuncFactor.OneMinusSrcAlpha);
AdditiveBlendFunc = new BlendFunc(BlendFuncMode.Add, BlendFuncFactor.One, BlendFuncFactor.One);
MultiplicativeBlendFunc = new BlendFunc(BlendFuncMode.Add, BlendFuncFactor.DstColor, BlendFuncFactor.Zero);
PremultipliedAlphaBlendFunc = new BlendFunc(BlendFuncMode.Add, BlendFuncFactor.One, BlendFuncFactor.OneMinusSrcAlpha);
}