First thx for your attention.
Recently i came up with a question that when use glReadPixel in my code, and run it on a mobile with PowerVR 580 chip, it will crash when calling glReadPixel. I have tried many ways to test and the conclution is: when the left down point of the rect assigned to the rect is at (0,0), the result is OK! But if it’s not (0,0), it will insult crashing here.
Please give me some suggestion and thx very much!