How to make Grayscale Sprite?

How to make Grayscale Sprite?
0.0 0



I want to create a grayscale sprite.

I found the Sample ‘GLImageProcessing’ From Apple Developer Homepage,
but this sample is too complicated for me.

Is there an easier way to grayscale from OpenGL-based?

I wonder if I can do grayscale.

Thank you.


Does this thread on stackoverflow helps


Thank you for link!
but this sample is based OpenGL 3.0( It is higher than cocos2d-x based OpenGL ES 1.1 )