1 files changed, 203 insertions, 0 deletions

diff --git a/contrib/SDL-3.2.8/src/video/kmsdrm/SDL_kmsdrmopengles.c b/contrib/SDL-3.2.8/src/video/kmsdrm/SDL_kmsdrmopengles.c
new file mode 100644
index 0000000..cc93cde
--- /dev/null
+++ b/contrib/SDL-3.2.8/src/video/kmsdrm/SDL_kmsdrmopengles.c
@@ -0,0 +1,203 @@
+/*
+  Simple DirectMedia Layer
+  Copyright (C) 1997-2025 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"
+
+#ifdef SDL_VIDEO_DRIVER_KMSDRM
+
+#include "SDL_kmsdrmvideo.h"
+#include "SDL_kmsdrmopengles.h"
+#include "SDL_kmsdrmdyn.h"
+#include <errno.h>
+
+#ifndef EGL_PLATFORM_GBM_MESA
+#define EGL_PLATFORM_GBM_MESA 0x31D7
+#endif
+
+// EGL implementation of SDL OpenGL support
+
+void KMSDRM_GLES_DefaultProfileConfig(SDL_VideoDevice *_this, int *mask, int *major, int *minor)
+{
+    /* if SDL was _also_ built with the Raspberry Pi driver (so we're
+       definitely a Pi device) or with the ROCKCHIP video driver
+       (it's a ROCKCHIP device),  default to GLES2. */
+#if defined(SDL_VIDEO_DRIVER_RPI) || defined(SDL_VIDEO_DRIVER_ROCKCHIP)
+    *mask = SDL_GL_CONTEXT_PROFILE_ES;
+    *major = 2;
+    *minor = 0;
+#endif
+}
+
+bool KMSDRM_GLES_LoadLibrary(SDL_VideoDevice *_this, const char *path)
+{
+    /* Just pretend you do this here, but don't do it until KMSDRM_CreateWindow(),
+       where we do the same library load we would normally do here.
+       because this gets called by SDL_CreateWindow() before KMSDR_CreateWindow(),
+       so gbm dev isn't yet created when this is called, AND we can't alter the
+       call order in SDL_CreateWindow(). */
+#if 0
+    NativeDisplayType display = (NativeDisplayType)_this->internal->gbm_dev;
+    return SDL_EGL_LoadLibrary(_this, path, display, EGL_PLATFORM_GBM_MESA);
+#endif
+    return true;
+}
+
+void KMSDRM_GLES_UnloadLibrary(SDL_VideoDevice *_this)
+{
+    /* As with KMSDRM_GLES_LoadLibrary(), we define our own "dummy" unloading function
+       so we manually unload the library whenever we want. */
+}
+
+SDL_EGL_CreateContext_impl(KMSDRM)
+
+bool KMSDRM_GLES_SetSwapInterval(SDL_VideoDevice *_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 true;
+}
+
+bool KMSDRM_GLES_SwapWindow(SDL_VideoDevice *_this, SDL_Window *window)
+{
+    SDL_WindowData *windata = window->internal;
+    SDL_DisplayData *dispdata = SDL_GetDisplayDriverDataForWindow(window);
+    SDL_VideoData *viddata = _this->internal;
+    KMSDRM_FBInfo *fb_info;
+    int ret = 0;
+
+    /* Always wait for the previous issued flip before issuing a new one,
+       even if you do async flips. */
+    uint32_t flip_flags = DRM_MODE_PAGE_FLIP_EVENT;
+
+    // Skip the swap if we've switched away to another VT
+    if (windata->egl_surface == EGL_NO_SURFACE) {
+        // Wait a bit, throttling to ~100 FPS
+        SDL_Delay(10);
+        return true;
+    }
+
+    // Recreate the GBM / EGL surfaces if the display mode has changed
+    if (windata->egl_surface_dirty) {
+        KMSDRM_CreateSurfaces(_this, window);
+    }
+
+    /* Wait for confirmation that the next front buffer has been flipped, at which
+       point the previous front buffer can be released */
+    if (!KMSDRM_WaitPageflip(_this, windata)) {
+        return SDL_SetError("Wait for previous pageflip failed");
+    }
+
+    // Release the previous front buffer
+    if (windata->bo) {
+        KMSDRM_gbm_surface_release_buffer(windata->gs, windata->bo);
+        windata->bo = NULL;
+    }
+
+    windata->bo = windata->next_bo;
+
+    /* Mark a buffer to become the next front buffer.
+       This won't happen until pagelip completes. */
+    if (!(_this->egl_data->eglSwapBuffers(_this->egl_data->egl_display,
+                                          windata->egl_surface))) {
+        return SDL_SetError("eglSwapBuffers failed");
+    }
+
+    /* From the GBM surface, get the next BO to become the next front buffer,
+       and lock it so it can't be allocated as a back buffer (to prevent EGL
+       from drawing into it!) */
+    windata->next_bo = KMSDRM_gbm_surface_lock_front_buffer(windata->gs);
+    if (!windata->next_bo) {
+        return SDL_SetError("Could not lock front buffer on GBM surface");
+    }
+
+    // Get an actual usable fb for the next front buffer.
+    fb_info = KMSDRM_FBFromBO(_this, windata->next_bo);
+    if (!fb_info) {
+        return SDL_SetError("Could not get a framebuffer");
+    }
+
+    if (!windata->bo) {
+        /* On the first swap, immediately present the new front buffer. Before
+           drmModePageFlip can be used the CRTC has to be configured to use
+           the current connector and mode with drmModeSetCrtc */
+        ret = KMSDRM_drmModeSetCrtc(viddata->drm_fd,
+                                    dispdata->crtc->crtc_id, fb_info->fb_id, 0, 0,
+                                    &dispdata->connector->connector_id, 1, &dispdata->mode);
+
+        if (ret) {
+            return SDL_SetError("Could not set videomode on CRTC.");
+        }
+    } else {
+        /* On subsequent swaps, queue the new front buffer to be flipped during
+           the next vertical blank
+
+           Remember: drmModePageFlip() never blocks, it just issues the flip,
+           which will be done during the next vblank, or immediately if
+           we pass the DRM_MODE_PAGE_FLIP_ASYNC flag.
+           Since calling drmModePageFlip() will return EBUSY if we call it
+           without having completed the last issued flip, we must pass the
+           DRM_MODE_PAGE_FLIP_ASYNC if we don't block on EGL (egl_swapinterval = 0).
+           That makes it flip immediately, without waiting for the next vblank
+           to do so, so even if we don't block on EGL, the flip will have completed
+           when we get here again. */
+        if (_this->egl_data->egl_swapinterval == 0 && viddata->async_pageflip_support) {
+            flip_flags |= DRM_MODE_PAGE_FLIP_ASYNC;
+        }
+
+        ret = KMSDRM_drmModePageFlip(viddata->drm_fd, dispdata->crtc->crtc_id,
+                                     fb_info->fb_id, flip_flags, &windata->waiting_for_flip);
+
+        if (ret == 0) {
+            windata->waiting_for_flip = true;
+        } else {
+            SDL_LogError(SDL_LOG_CATEGORY_VIDEO, "Could not queue pageflip: %d", ret);
+        }
+
+        /* Wait immediately for vsync (as if we only had two buffers).
+           Even if we are already doing a WaitPageflip at the beginning of this
+           function, this is NOT redundant because here we wait immediately
+           after submitting the image to the screen, reducing lag, and if
+           we have waited here, there won't be a pending pageflip so the
+           WaitPageflip at the beginning of this function will be a no-op.
+           Just leave it here and don't worry.
+           Run your SDL program with "SDL_VIDEO_DOUBLE_BUFFER=1 <program_name>"
+           to enable this. */
+        if (windata->double_buffer) {
+            if (!KMSDRM_WaitPageflip(_this, windata)) {
+                return SDL_SetError("Immediate wait for previous pageflip failed");
+            }
+        }
+    }
+
+    return true;
+}
+
+SDL_EGL_MakeCurrent_impl(KMSDRM)
+
+#endif // SDL_VIDEO_DRIVER_KMSDRM