| /* |
| Simple DirectMedia Layer |
| Copyright (C) 1997-2020 Sam Lantinga <slouken@libsdl.org> |
| |
| This software is provided 'as-is', without any express or implied |
| warranty. In no event will the authors be held liable for any damages |
| arising from the use of this software. |
| |
| Permission is granted to anyone to use this software for any purpose, |
| including commercial applications, and to alter it and redistribute it |
| freely, subject to the following restrictions: |
| |
| 1. The origin of this software must not be misrepresented; you must not |
| claim that you wrote the original software. If you use this software |
| in a product, an acknowledgment in the product documentation would be |
| appreciated but is not required. |
| 2. Altered source versions must be plainly marked as such, and must not be |
| misrepresented as being the original software. |
| 3. This notice may not be removed or altered from any source distribution. |
| */ |
| |
| #include "../../SDL_internal.h" |
| |
| #if SDL_VIDEO_DRIVER_KMSDRM && SDL_VIDEO_OPENGL_EGL |
| |
| #include "SDL_kmsdrmvideo.h" |
| #include "SDL_kmsdrmopengles.h" |
| #include "SDL_kmsdrmdyn.h" |
| |
| #ifndef EGL_PLATFORM_GBM_MESA |
| #define EGL_PLATFORM_GBM_MESA 0x31D7 |
| #endif |
| |
| /* EGL implementation of SDL OpenGL support */ |
| |
| int |
| KMSDRM_GLES_LoadLibrary(_THIS, const char *path) { |
| NativeDisplayType display = (NativeDisplayType)((SDL_VideoData *)_this->driverdata)->gbm; |
| return SDL_EGL_LoadLibrary(_this, path, display, EGL_PLATFORM_GBM_MESA); |
| } |
| |
| SDL_EGL_CreateContext_impl(KMSDRM) |
| |
| int KMSDRM_GLES_SetSwapInterval(_THIS, int interval) { |
| if (!_this->egl_data) { |
| return SDL_SetError("EGL not initialized"); |
| } |
| |
| if (interval == 0 || interval == 1) { |
| _this->egl_data->egl_swapinterval = interval; |
| } else { |
| return SDL_SetError("Only swap intervals of 0 or 1 are supported"); |
| } |
| |
| return 0; |
| } |
| |
| int |
| KMSDRM_GLES_SwapWindow(_THIS, SDL_Window * window) { |
| SDL_WindowData *windata = ((SDL_WindowData *) window->driverdata); |
| SDL_DisplayData *dispdata = (SDL_DisplayData *) SDL_GetDisplayForWindow(window)->driverdata; |
| SDL_VideoData *viddata = ((SDL_VideoData *)_this->driverdata); |
| KMSDRM_FBInfo *fb_info; |
| |
| /* ALWAYS wait for each pageflip to complete before issuing another, vsync or not, |
| or drmModePageFlip() will start returning EBUSY if there are pending pageflips. |
| |
| To disable vsync in games, it would be needed to issue async pageflips, |
| and then wait for each pageflip to complete. Since async pageflips complete ASAP |
| instead of VBLANK, thats how non-vsync screen updates should wok. |
| |
| BUT Async pageflips do not work right now because calling drmModePageFlip() with the |
| DRM_MODE_PAGE_FLIP_ASYNC flag returns error on every driver I have tried. |
| |
| So, for now, only do vsynced updates: _this->egl_data->egl_swapinterval is |
| ignored for now, it makes no sense to use it until async pageflips work on drm drivers. */ |
| |
| /* Recreate the GBM / EGL surfaces if the display mode has changed */ |
| if (windata->egl_surface_dirty) { |
| KMSDRM_CreateSurfaces(_this, window); |
| } |
| |
| if (windata->double_buffer) { |
| /* Use a double buffering scheme, independently of the number of buffers that the GBM surface has, |
| (number of buffers on the GBM surface depends on the implementation). |
| Double buffering (instead of triple) is achieved by waiting for synchronous pageflip to complete |
| inmediately after the pageflip is issued. That way, in the end of this function only two buffers |
| are needed: a buffer that is available to be picked again by EGL as a backbuffer to draw on it, |
| and the new front buffer that has just been set up. |
| |
| Since programmer has no control over the number of buffers of the GBM surface, wait for pageflip |
| is done inmediately after issuing pageflip, and so a double-buffer scheme is achieved. */ |
| |
| /* Ask EGL to mark the current back buffer to become the next front buffer. |
| That will happen when a pageflip is issued, and the next vsync arrives (sync flip) |
| or ASAP (async flip). */ |
| if (!(_this->egl_data->eglSwapBuffers(_this->egl_data->egl_display, windata->egl_surface))) { |
| SDL_LogError(SDL_LOG_CATEGORY_VIDEO, "eglSwapBuffers failed."); |
| return 0; |
| } |
| |
| /* Get a handler to the buffer that is marked to become the next front buffer, and lock it |
| so it can not be chosen by EGL as a back buffer. */ |
| windata->next_bo = KMSDRM_gbm_surface_lock_front_buffer(windata->gs); |
| if (!windata->next_bo) { |
| SDL_LogError(SDL_LOG_CATEGORY_VIDEO, "Could not lock GBM surface front buffer"); |
| return 0; |
| /* } else { |
| SDL_LogDebug(SDL_LOG_CATEGORY_VIDEO, "Locked GBM surface %p", (void *)windata->next_bo); */ |
| } |
| |
| /* Issue synchronous pageflip: drmModePageFlip() NEVER blocks, synchronous here means that it |
| will be done on next VBLANK, not ASAP. And return to program loop inmediately. */ |
| |
| fb_info = KMSDRM_FBFromBO(_this, windata->next_bo); |
| if (!fb_info) { |
| return 0; |
| } |
| |
| /* When needed, this is done once we have the needed fb_id, not before. */ |
| if (windata->crtc_setup_pending) { |
| if (KMSDRM_drmModeSetCrtc(viddata->drm_fd, dispdata->crtc_id, fb_info->fb_id, 0, |
| 0, &dispdata->conn->connector_id, 1, &dispdata->mode)) { |
| SDL_LogError(SDL_LOG_CATEGORY_VIDEO, "Could not configure CRTC on video mode setting."); |
| } |
| windata->crtc_setup_pending = SDL_FALSE; |
| } |
| |
| if (!KMSDRM_drmModePageFlip(viddata->drm_fd, dispdata->crtc_id, fb_info->fb_id, |
| DRM_MODE_PAGE_FLIP_EVENT, &windata->waiting_for_flip)) { |
| windata->waiting_for_flip = SDL_TRUE; |
| } else { |
| SDL_LogError(SDL_LOG_CATEGORY_VIDEO, "Could not issue pageflip"); |
| } |
| |
| /* Since issued pageflips are always synchronous (ASYNC dont currently work), these pageflips |
| will happen at next vsync, so in practice waiting for vsync is being done here. */ |
| if (!KMSDRM_WaitPageFlip(_this, windata, -1)) { |
| SDL_LogError(SDL_LOG_CATEGORY_VIDEO, "Error waiting for pageflip event"); |
| return 0; |
| } |
| |
| /* Return the previous front buffer to the available buffer pool of the GBM surface, |
| so it can be chosen again by EGL as the back buffer for drawing into it. */ |
| if (windata->curr_bo) { |
| KMSDRM_gbm_surface_release_buffer(windata->gs, windata->curr_bo); |
| /* SDL_LogDebug(SDL_LOG_CATEGORY_VIDEO, "Released GBM surface buffer %p", (void *)windata->curr_bo); */ |
| windata->curr_bo = NULL; |
| } |
| |
| /* Take note of the current front buffer, so it can be freed next time this function is called. */ |
| windata->curr_bo = windata->next_bo; |
| } else { |
| /* Triple buffering requires waiting for last pageflip upon entering instead of waiting at the end, |
| and issuing the next pageflip at the end, thus allowing the program loop to run |
| while the issued pageflip arrives (at next VBLANK, since ONLY synchronous pageflips are possible). |
| In a game context, this means that the player can be doing inputs before seeing the last |
| completed frame, causing "input lag" that is known to plage other APIs and backends. |
| Triple buffering requires the use of three different buffers at the end of this function: |
| 1- the front buffer which is on screen, |
| 2- the back buffer wich is ready to be flipped (a pageflip has been issued on it, which has yet to complete) |
| 3- a third buffer that can be used by EGL to draw while the previously issued pageflip arrives |
| (should not put back the previous front buffer into the free buffers pool of the |
| GBM surface until that happens). |
| If the implementation only has two buffers for the GBM surface, this would behave like a double buffer. |
| */ |
| |
| /* Wait for previously issued pageflip to complete. */ |
| if (!KMSDRM_WaitPageFlip(_this, windata, -1)) { |
| SDL_LogError(SDL_LOG_CATEGORY_VIDEO, "Error waiting for pageflip event"); |
| return 0; |
| } |
| |
| /* Free the previous front buffer so EGL can pick it again as back buffer.*/ |
| if (windata->curr_bo) { |
| KMSDRM_gbm_surface_release_buffer(windata->gs, windata->curr_bo); |
| /* SDL_LogDebug(SDL_LOG_CATEGORY_VIDEO, "Released GBM surface buffer %p", (void *)windata->curr_bo); */ |
| windata->curr_bo = NULL; |
| } |
| |
| /* Ask EGL to mark the current back buffer to become the next front buffer. |
| That will happen when a pageflip is issued, and the next vsync arrives (sync flip) |
| or ASAP (async flip). */ |
| if (!(_this->egl_data->eglSwapBuffers(_this->egl_data->egl_display, windata->egl_surface))) { |
| SDL_LogError(SDL_LOG_CATEGORY_VIDEO, "eglSwapBuffers failed."); |
| return 0; |
| } |
| |
| /* Take note of the current front buffer, so it can be freed next time this function is called. */ |
| windata->curr_bo = windata->next_bo; |
| |
| /* Get a handler to the buffer that is marked to become the next front buffer, and lock it |
| so it can not be chosen by EGL as a back buffer. */ |
| windata->next_bo = KMSDRM_gbm_surface_lock_front_buffer(windata->gs); |
| if (!windata->next_bo) { |
| SDL_LogError(SDL_LOG_CATEGORY_VIDEO, "Could not lock GBM surface front buffer"); |
| return 0; |
| /* } else { |
| SDL_LogDebug(SDL_LOG_CATEGORY_VIDEO, "Locked GBM surface %p", (void *)windata->next_bo); */ |
| } |
| |
| /* Issue synchronous pageflip: drmModePageFlip() NEVER blocks, synchronous here means that it |
| will be done on next VBLANK, not ASAP. And return to program loop inmediately. */ |
| fb_info = KMSDRM_FBFromBO(_this, windata->next_bo); |
| if (!fb_info) { |
| return 0; |
| } |
| |
| /* When needed, this is done once we have the needed fb_id, not before. */ |
| if (windata->crtc_setup_pending) { |
| if (KMSDRM_drmModeSetCrtc(viddata->drm_fd, dispdata->crtc_id, fb_info->fb_id, 0, |
| 0, &dispdata->conn->connector_id, 1, &dispdata->mode)) { |
| SDL_LogError(SDL_LOG_CATEGORY_VIDEO, "Could not configure CRTC on video mode setting."); |
| } |
| windata->crtc_setup_pending = SDL_FALSE; |
| } |
| |
| |
| if (!KMSDRM_drmModePageFlip(viddata->drm_fd, dispdata->crtc_id, fb_info->fb_id, |
| DRM_MODE_PAGE_FLIP_EVENT, &windata->waiting_for_flip)) { |
| windata->waiting_for_flip = SDL_TRUE; |
| } else { |
| SDL_LogError(SDL_LOG_CATEGORY_VIDEO, "Could not issue pageflip"); |
| } |
| } |
| |
| return 0; |
| } |
| |
| SDL_EGL_MakeCurrent_impl(KMSDRM) |
| |
| #endif /* SDL_VIDEO_DRIVER_KMSDRM && SDL_VIDEO_OPENGL_EGL */ |
| |
| /* vi: set ts=4 sw=4 expandtab: */ |
