Why does SurfaceFlinger render layers upside down

Question

Recently, when digging into the SurfaceFlinger code, I discovered it renders its layers upside down, using the method like 1.0f minus vertex Y coordinate. I feel confused. Why do they do this?

score 1 · Accepted Answer · answered Sep 02 '15 at 17:16

1

Could be because OpenGL's (0,0) point is at the bottom-left of the screen.. whereas the higher-level windowing API assumes (0,0) is the top-left.

answered Sep 02 '15 at 17:16

Buddy

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Thanks. I think that's the answer. – linzuojian Sep 03 '15 at 02:38

Why does SurfaceFlinger render layers upside down

1 Answers1