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87bc1fb552
The only place angle is activated and causes effect is RenderCopyEx. All other methods which use vertex shader, leave angle disabled and cause useless sin/cos calculation in shader. To get around shader's interface is changed to a vector that contains results of sin and cos. To behave properly when disabled, cos value is set with offset -1.0 making 0.0 default when deactivated. As nice side effect it simplifies GLES2_UpdateVertexBuffer: All attributes are vectors now. Additional background: * On RaspberryPi it gives a performace win for operations. Tested with [1] numbers go down for 5-10% (not easy to estimate due to huge variation). * SDL_RenderCopyEx was tested with [2] * It works around left rotated display caused by low accuracy sin implemetation in RaspberryPi/VC4 [3] [1] https://github.com/schnitzeltony/sdl2box [2] https://github.com/schnitzeltony/sdl2rendercopyex [3] https://github.com/anholt/mesa/issues/110 Signed-off-by: Andreas M?ller <schnitzeltony@gmail.com>
Simple DirectMedia Layer
(SDL)
Version 2.0
---
https://www.libsdl.org/
Simple DirectMedia Layer is a cross-platform development library designed
to provide low level access to audio, keyboard, mouse, joystick, and graphics
hardware via OpenGL and Direct3D. It is used by video playback software,
emulators, and popular games including Valve's award winning catalog
and many Humble Bundle games.
More extensive documentation is available in the docs directory, starting
with README.md
Enjoy!
Sam Lantinga (slouken@libsdl.org)