https://developer.apple.com/library/mac/documentation/GraphicsImaging/Conceptual/OpenGLShaderBuilderUserGuide/Introduction/Introduction.html

https://www.opengl.org/wiki/Debugging_Tools

http://blog.nobel-joergensen.com/2013/03/10/debugging-opengl-part-3-using-tools/

GLSL Debugger的姿势