data formatting
format
Returns OpenGL constants:
format("L") returns GL_LUMINANCE (6409)
format("R") returns GL_RED (6403)
format("G") returns GL_GREEN (6404)
format("B") returns GL_BLUE (6405)
format("A") returns GL_ALPHA (6406)
format("LA") returns GL_LUMINANCE_ALPHA (6410)
format("RGB") returns GL_RGB (6407)
format("RGBA") returns GL_RGBA (6408)