tree 2fd8899cf3e88213c1ca112ef7c46da3b6fa8727
parent e830ef3458a3ee623866ce0bf1be96d5dc477fb8
author Sam Lantinga <slouken@libsdl.org> 1508584857 -0700
committer Sam Lantinga <slouken@libsdl.org> 1508584857 -0700

Fixed bug 3901 - Fix vsync-ed pageflips on the KMSDRM video driver

Manuel

I noticed that, at least on Intel GPU hardware, passing SDL_RENDERER_PRESENTVSYNC would result on a static console instead of the program graphics.
That was due to the fact that calling drmModePageFlip() only works if we have previously set up CRTC to one of the GBM buffers with a drmModeSetCrtc() call, so now it's done and things work as expected.

The KMSDRM_GLES_SetupCrtc() call is done only one time, only when needed (when egl_swapinterval is not 0: when it's 0, there's no need for it because we flip by calling drmModePageFlip() anyway).
The place where KMSDRM_GLES_SetupCrtc() call is done may look strange, but it's right: it needs EGL completely ready because it needs to call eglSwapBuffers() internally to work (see more comments about it in the code).