sdl2 modesetting example

gistfile1.txt

diff --git a/src/video/kmsdrm/SDL_kmsdrmvideo.c b/src/video/kmsdrm/SDL_kmsdrmvideo.c
index 3fe4dfb..f1d35fb 100644
--- a/src/video/kmsdrm/SDL_kmsdrmvideo.c
+++ b/src/video/kmsdrm/SDL_kmsdrmvideo.c
@@ -350,6 +350,7 @@ KMSDRM_VideoInit(_THIS)
     SDL_bool found;
     int ret = 0;
     char *devname;
+    const char *mode_override;
     SDL_VideoData *vdata = ((SDL_VideoData *)_this->driverdata);
     drmModeRes *resources = NULL;
     drmModeConnector *connector = NULL;
@@ -473,7 +474,11 @@ KMSDRM_VideoInit(_THIS)
                  vdata->saved_crtc->crtc_id, vdata->saved_crtc->buffer_id, vdata->saved_crtc->x,
                  vdata->saved_crtc->y, vdata->saved_crtc->width, vdata->saved_crtc->height);
     data->crtc_id = encoder->crtc_id;
-    data->cur_mode = vdata->saved_crtc->mode;
+    mode_override = SDL_getenv("SDL_VIDEO_KMSDRM_MODE");
+    if (mode_override)
+        data->cur_mode = connector->modes[SDL_atoi(mode_override)];
+    else
+        data->cur_mode = vdata->saved_crtc->mode;
     vdata->crtc_id = encoder->crtc_id;
 
     // select default mode if this one is not valid