Perform window creation in eventthread

Astrabit-ST · Jul 6, 2024 · 027c7a0 · 027c7a0
1 parent b8cfec5
commit 027c7a0
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Showing 4 changed files with 65 additions and 18 deletions.
diff --git a/binding/osfm-screen-binding.cpp b/binding/osfm-screen-binding.cpp
@@ -1,5 +1,6 @@
 #include <SDL2/SDL.h>
 #include "etc-internal.h"
+#include "eventthread.h"
 #include "gl-fun.h"
 #include "gl-util.h"
 #include "gl-meta.h"
@@ -286,31 +287,31 @@ struct MonitorWindow {
   WindowScene scene;
 
   MonitorWindow(int x, int y, int w, int h, unsigned int flags, const char* name) : scene(w, h) {
-    window = SDL_CreateWindow(name, x, y, w, h, flags);
+    EventThread::CreateWindowArgs args = {x, y, w, h, flags, name};
+    window = shState->eThread().requestNewWindow(&args);
     shState->monitorWindows.insert(this);
   }
   ~MonitorWindow() {
     shState->monitorWindows.erase(this);
-    if (window)
-      SDL_DestroyWindow(window);
+    shState->eThread().destroySDLWindow(window); // do it on the event thread
   }
 
-  void draw();
+  // renders to ping pong buffer
+  void renderScene();
+  // present the ping pong buffer
+  void present();
   Scene* getScene();
 };
 // so we can use this from outside this file
 Scene* MonitorWindow::getScene() {
   return &scene;
 }
-void MonitorWindow::draw() {
-  SDL_GLContext ctx = shState->graphics().context();
-  int err = SDL_GL_MakeCurrent(window, ctx);
-  if (err != 0) {
-    GFX_UNLOCK;
-    rb_raise(rb_eRuntimeError, "Failed to make window current: %s", SDL_GetError());
-  }
-
+void MonitorWindow::renderScene() {
   scene.composite();
+}
+void MonitorWindow::present() {
+  SDL_GLContext ctx = shState->graphics().context();
+  SDL_GL_MakeCurrent(window, ctx);
   auto geo = scene.getGeometry();
   int w = geo.rect.w;
   int h = geo.rect.h;

diff --git a/src/display/graphics.cpp b/src/display/graphics.cpp
@@ -79,7 +79,8 @@
 #define AUDIO_BUFFER_LEN_MS 2000
 
 struct MonitorWindow {
-    void draw();
+    void renderScene();
+    void present();
 };
 
 typedef struct AudioQueue
@@ -1185,6 +1186,9 @@ struct GraphicsPrivate {
             shState->oneshot().obscuredDirty = false;
         }
         screen.composite();
+        for (auto window : shState->monitorWindows) {
+            window->renderScene(); // renders to an offscreen fbo so we dont need to switch contexts
+        }
 
         // maybe unspaghetti this later
         if (integerScaleStepApplicable() && !integerLastMileScaling)
@@ -1248,8 +1252,11 @@ struct GraphicsPrivate {
 
         GLMeta::blitEnd();
 
+        // perform presents here to avoid constant context switching
         swapGLBuffer();
-
+        for (auto window : shState->monitorWindows) {
+            window->present();
+        }
         updateAvgFPS();
     }
 
@@ -1370,10 +1377,6 @@ void Graphics::update(bool checkForShutdown) {
 
     p->checkResize();
     p->redrawScreen();
-
-    for (auto window : shState->monitorWindows) {
-        window->draw();
-    }
 }
 
 void Graphics::freeze() {

diff --git a/src/eventthread.cpp b/src/eventthread.cpp
@@ -20,6 +20,7 @@
  */
 
 #include "eventthread.h"
+#include "SDL_video.h"
 
 #include <SDL_events.h>
 #include <SDL_messagebox.h>
@@ -109,12 +110,15 @@ enum
     REQUEST_TEXTMODE,
 
     REQUEST_SETTINGS,
+    REQUEST_NEW_WINDOW,
+    REQUEST_DESTROY_WINDOW,
 
     UPDATE_FPS,
     UPDATE_SCREEN_RECT,
 
     EVENT_COUNT
 };
+volatile SDL_Window *new_window;
 
 static uint32_t usrIdStart;
 
@@ -594,6 +598,20 @@ void EventThread::process(RGSSThreadData &rtData)
                         openSettingsWindow();
 #endif
                         break;
+                    case REQUEST_NEW_WINDOW:
+                    {
+                        const CreateWindowArgs *args = static_cast<const CreateWindowArgs*>(event.user.data1);
+                        new_window = SDL_CreateWindow(args->name,
+                                                   args->x, args->y,
+                                                   args->w, args->h,
+                                                   args->flags);
+                        break;
+                    }
+                    case REQUEST_DESTROY_WINDOW:
+                    {
+                        SDL_DestroyWindow(static_cast<SDL_Window*>(event.user.data1));
+                        break;
+                    }
 
                     case UPDATE_FPS :
                         if (rtData.config.printFPS)
@@ -833,6 +851,25 @@ void EventThread::requestSettingsMenu()
     SDL_PushEvent(&event);
 }
 
+SDL_Window *EventThread::requestNewWindow(const CreateWindowArgs *args)
+{
+    SDL_Event event;
+    event.type = usrIdStart + REQUEST_NEW_WINDOW;
+    event.user.data1 = (void*)args;
+    new_window = nullptr; // reset 
+    SDL_PushEvent(&event);
+    while (!new_window)
+        SDL_Delay(1);
+    return (SDL_Window*) new_window;
+}
+void EventThread::destroySDLWindow(SDL_Window *window)
+{
+    SDL_Event event;
+    event.type = usrIdStart + REQUEST_DESTROY_WINDOW;
+    event.user.data1 = window;
+    SDL_PushEvent(&event);
+}
+
 void EventThread::showMessageBox(const char *body, int flags)
 {
     msgBoxDone.clear();

diff --git a/src/eventthread.h b/src/eventthread.h
@@ -32,6 +32,7 @@
 
 #include <stdint.h>
 
+#include "SDL_video.h"
 #include "config.h"
 #include "etc-internal.h"
 #include "sdl-util.h"
@@ -98,6 +99,11 @@ class EventThread
     void requestWindowCenter();
     void requestWindowRename(const char *title);
 	void requestShowCursor(bool mode);
+
+	struct CreateWindowArgs { int x; int y; int w; int h; unsigned int flags; const char* name; };
+	// get random freezes without doing this on the event thread
+	SDL_Window* requestNewWindow(const CreateWindowArgs *args);
+	void destroySDLWindow(SDL_Window *window);
 
     void requestTextInputMode(bool mode);