From ec7137e693f8663db7afb4d92e86f69599e5127c Mon Sep 17 00:00:00 2001
From: Cameron Gutman <aicommander@gmail.com>
Date: Sun, 9 Jun 2024 14:26:26 -0500
Subject: [PATCH] Flush window events in MMAL and DRM renderers

---
 app/streaming/video/ffmpeg-renderers/drm.cpp  | 17 +++++++++++++++++
 app/streaming/video/ffmpeg-renderers/mmal.cpp | 17 +++++++++++++++++
 2 files changed, 34 insertions(+)

diff --git a/app/streaming/video/ffmpeg-renderers/drm.cpp b/app/streaming/video/ffmpeg-renderers/drm.cpp
index 15d575d4..f3f202b8 100644
--- a/app/streaming/video/ffmpeg-renderers/drm.cpp
+++ b/app/streaming/video/ffmpeg-renderers/drm.cpp
@@ -317,6 +317,23 @@ bool DrmRenderer::initialize(PDECODER_PARAMETERS params)
         // CRTC modes below.
         SDL_Renderer* renderer = SDL_CreateRenderer(params->window, -1, SDL_RENDERER_SOFTWARE);
         if (renderer != nullptr) {
+            // SDL_CreateRenderer() can end up having to recreate our window (SDL_RecreateWindow())
+            // to ensure it's compatible with the renderer's OpenGL context. If that happens, we
+            // can get spurious SDL_WINDOWEVENT events that will cause us to (again) recreate our
+            // renderer. This can lead to an infinite to renderer recreation, so discard all
+            // SDL_WINDOWEVENT events after SDL_CreateRenderer().
+            Session* session = Session::get();
+            if (session != nullptr) {
+                // If we get here during a session, we need to synchronize with the event loop
+                // to ensure we don't drop any important events.
+                session->flushWindowEvents();
+            }
+            else {
+                // If we get here prior to the start of a session, just pump and flush ourselves.
+                SDL_PumpEvents();
+                SDL_FlushEvent(SDL_WINDOWEVENT);
+            }
+
             SDL_SetRenderDrawColor(renderer, 0, 0, 0, SDL_ALPHA_OPAQUE);
             SDL_RenderClear(renderer);
             SDL_RenderPresent(renderer);
diff --git a/app/streaming/video/ffmpeg-renderers/mmal.cpp b/app/streaming/video/ffmpeg-renderers/mmal.cpp
index 98cf663d..bd733fbe 100644
--- a/app/streaming/video/ffmpeg-renderers/mmal.cpp
+++ b/app/streaming/video/ffmpeg-renderers/mmal.cpp
@@ -230,6 +230,23 @@ void MmalRenderer::setupBackground(PDECODER_PARAMETERS params)
             return;
         }
 
+        // SDL_CreateRenderer() can end up having to recreate our window (SDL_RecreateWindow())
+        // to ensure it's compatible with the renderer's OpenGL context. If that happens, we
+        // can get spurious SDL_WINDOWEVENT events that will cause us to (again) recreate our
+        // renderer. This can lead to an infinite to renderer recreation, so discard all
+        // SDL_WINDOWEVENT events after SDL_CreateRenderer().
+        Session* session = Session::get();
+        if (session != nullptr) {
+            // If we get here during a session, we need to synchronize with the event loop
+            // to ensure we don't drop any important events.
+            session->flushWindowEvents();
+        }
+        else {
+            // If we get here prior to the start of a session, just pump and flush ourselves.
+            SDL_PumpEvents();
+            SDL_FlushEvent(SDL_WINDOWEVENT);
+        }
+
         SDL_SetRenderDrawColor(m_BackgroundRenderer, 0, 0, 0, SDL_ALPHA_OPAQUE);
         SDL_RenderClear(m_BackgroundRenderer);
         SDL_RenderPresent(m_BackgroundRenderer);