/* Sets up an OpenGL ES 2 context. Returnes NULL if it succeeds, or
* an error message on failure.
*/
char *egl_init(int interval) {
SDL_SysWMinfo wminfo;
EGLint major, minor;
EGLint num_config;
const EGLint attrs[] = {
EGL_RENDERABLE_TYPE, EGL_OPENGL_ES2_BIT,
EGL_ALPHA_SIZE, 8,
EGL_NONE
};
const EGLint context_attrs[] = {
EGL_CONTEXT_CLIENT_VERSION, 2,
EGL_NONE
};
SDL_VERSION(&wminfo.version);
SDL_GetWMInfo(&wminfo);
if (! initialized) {
display = eglGetDisplay(GetDC(wminfo.window));
egl_check("getting display");
eglInitialize(display, &major, &minor);
egl_check("initializing EGL");
eglBindAPI(EGL_OPENGL_ES_API);
egl_check("binding OpenGL ES");
eglChooseConfig(display, attrs, &config, 1, &num_config);
egl_check("choosing EGL config");
context = eglCreateContext(display, config, EGL_NO_CONTEXT, context_attrs);
egl_check("creating EGL context");
surface = eglCreateWindowSurface(display, config, wminfo.window, NULL);
egl_check("creating EGL surface");
} else if (window != wminfo.window) {
eglDestroySurface(display, surface);
egl_check("destroying existing EGL surface")
surface = eglCreateWindowSurface(display, config, wminfo.window, NULL);
egl_check("creating EGL surface");
}
eglMakeCurrent(display, surface, surface, context);
egl_check("making EGL context current");
eglSwapInterval(display, interval);
egl_check("setting swap interval")
initialized = 1;
window = wminfo.window;
return NULL;
}
static int atomic_run(const struct gbm *gbm, const struct egl *egl)
{
struct gbm_bo *bo = NULL;
struct drm_fb *fb;
uint32_t i = 0;
uint32_t flags = DRM_MODE_ATOMIC_NONBLOCK;
struct timeval timeout;
fd_set fds;
int ret;
if (egl_check(egl, eglDupNativeFenceFDANDROID) ||
egl_check(egl, eglCreateSyncKHR) ||
egl_check(egl, eglDestroySyncKHR) ||
egl_check(egl, eglWaitSyncKHR) ||
egl_check(egl, eglClientWaitSyncKHR))
return -1;
/* Allow a modeset change for the first commit only. */
flags |= DRM_MODE_ATOMIC_ALLOW_MODESET;
while (1) {
struct gbm_bo *next_bo;
EGLSyncKHR gpu_fence = NULL; /* out-fence from gpu, in-fence to kms */
EGLSyncKHR kms_fence = NULL; /* in-fence to gpu, out-fence from kms */
if (drm.kms_out_fence_fd != -1) {
kms_fence = create_fence(egl, drm.kms_out_fence_fd);
assert(kms_fence);
/* driver now has ownership of the fence fd: */
drm.kms_out_fence_fd = -1;
/* wait "on the gpu" (ie. this won't necessarily block, but
* will block the rendering until fence is signaled), until
* the previous pageflip completes so we don't render into
* the buffer that is still on screen.
*/
egl->eglWaitSyncKHR(egl->display, kms_fence, 0);
}
egl->draw(i++);
/* insert fence to be singled in cmdstream.. this fence will be
* signaled when gpu rendering done
*/
gpu_fence = create_fence(egl, EGL_NO_NATIVE_FENCE_FD_ANDROID);
assert(gpu_fence);
eglSwapBuffers(egl->display, egl->surface);
/* after swapbuffers, gpu_fence should be flushed, so safe
* to get fd:
*/
drm.kms_in_fence_fd = egl->eglDupNativeFenceFDANDROID(egl->display, gpu_fence);
egl->eglDestroySyncKHR(egl->display, gpu_fence);
assert(drm.kms_in_fence_fd != -1);
next_bo = gbm_surface_lock_front_buffer(gbm->surface);
if (!next_bo) {
printf("Failed to lock frontbuffer\n");
return -1;
}
fb = drm_fb_get_from_bo(next_bo);
if (!fb) {
printf("Failed to get a new framebuffer BO\n");
return -1;
}
if (kms_fence) {
EGLint status;
/* Wait on the CPU side for the _previous_ commit to
* complete before we post the flip through KMS, as
* atomic will reject the commit if we post a new one
* whilst the previous one is still pending.
*/
do {
status = egl->eglClientWaitSyncKHR(egl->display,
kms_fence,
0,
EGL_FOREVER_KHR);
} while (status != EGL_CONDITION_SATISFIED_KHR);
egl->eglDestroySyncKHR(egl->display, kms_fence);
}
/*
* Here you could also update drm plane layers if you want
* hw composition
*/
ret = drm_atomic_commit(fb->fb_id, flags);
if (ret) {
printf("failed to commit: %s\n", strerror(errno));
return -1;
}
/* release last buffer to render on again: */
if (bo)
gbm_surface_release_buffer(gbm->surface, bo);
bo = next_bo;
/* Allow a modeset change for the first commit only. */
flags &= ~(DRM_MODE_ATOMIC_ALLOW_MODESET);
/* watch for user interruption */
FD_ZERO(&fds);
FD_SET(0, &fds);
memset(&timeout, 0, sizeof(timeout));
ret = select(1, &fds, NULL, NULL, &timeout);
if (ret < 0) {
printf("select() failed: %s\n", strerror(errno));
break;
}
/*
* select() will immediately timeout if there was no user
* interrupt because of the 0 timeout. However, that's an
* expected situation, not an error, so we just ignore it
* here.
*/
if (FD_ISSET(0, &fds)) {
printf("user interrupted!\n");
break;
}
}
return ret;
}
