I am not familiar with Blitz3D. But in BlitzMax,
`Alpha` is SetBlend ALPHABLEND
`Add` is SetBlend LIGHTBLEND
`Multiply` is SetBlend SHADEBLEND
I don't know what the Dot3 or Modulate 2X do. You might look at setting up your own modes with glBlendFunc() and glEnable(GL_BLEND). You might be able to use glBlendFunc(SRC_ALPHA_SATURATE,GL_ONE) to achieve something like a `2x` modulation, but I have no idea if thats the same thing.
`Alpha` is SetBlend ALPHABLEND
`Add` is SetBlend LIGHTBLEND
`Multiply` is SetBlend SHADEBLEND
I don't know what the Dot3 or Modulate 2X do. You might look at setting up your own modes with glBlendFunc() and glEnable(GL_BLEND). You might be able to use glBlendFunc(SRC_ALPHA_SATURATE,GL_ONE) to achieve something like a `2x` modulation, but I have no idea if thats the same thing.