GL_OES_blend_equation_separate
https://www.khronos.org/registry/OpenGL/extensions/OES/OES_blend_equation_separate.txt
GL_OES_blend_equation_separate

	GL_BLEND_EQUATION_RGB_OES 0x8009
	GL_BLEND_EQUATION_ALPHA_OES 0x883D
	void glBlendEquationSeparateOES (GLenum modeRGB, GLenum modeAlpha)