Implement overlay support on Emscripten

lanodan · Dec 31, 2023 · 5a2389d · 5a2389d
1 parent 27e7fcf
commit 5a2389d
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Showing 3 changed files with 34 additions and 8 deletions.
diff --git a/src/she/sdl2/sdl2_display.cpp b/src/she/sdl2/sdl2_display.cpp
@@ -93,6 +93,8 @@ namespace she {
     if (m_window) {
       sdl::windowIdToDisplay.erase(SDL_GetWindowID(m_window));
       m_surface->dispose();
+      if (m_doublebuffer)
+	  m_doublebuffer->dispose();
       if (m_renderer)
         SDL_DestroyRenderer(m_renderer);
       SDL_DestroyWindow(m_window);
@@ -182,6 +184,15 @@ namespace she {
     m_dirty = true;
     m_surface = newSurface;
     she::sdl::screen = newSurface;
+
+    #ifdef EMSCRIPTEN
+    newSurface = new SDL2Surface(width() / m_scale, height() / m_scale, SDL2Surface::DeleteAndDestroy);
+    if (m_doublebuffer) {
+      m_doublebuffer->blitTo(newSurface, 0, 0, 0, 0, width(), height());
+      m_doublebuffer->dispose();
+    }
+    m_doublebuffer = newSurface;
+    #endif
   }
 
   Surface* SDL2Display::getSurface()
@@ -197,7 +208,7 @@ namespace she {
 
     if (m_renderer) {
       #ifdef EMSCRIPTEN
-      auto texture = static_cast<SDL2Surface*>(m_surface)->getTexture(nullptr);
+      auto texture = static_cast<SDL2Surface*>(m_doublebuffer)->getTexture(nullptr);
       #else
       SDL_Rect empty{0, 0, 0, 0};
       auto texture = static_cast<SDL2Surface*>(m_surface)->getTexture(&empty);
@@ -211,8 +222,13 @@ namespace she {
   void SDL2Display::flip(const gfx::Rect& bounds)
   {
     m_dirty = true;
-    if (!she::instance()->isGfxThread())
+    if (!she::instance()->isGfxThread()) {
+      SDL_Rect rect {bounds.x, bounds.y, bounds.w, bounds.h};
+      SDL_Rect dst { rect.x, rect.y, rect.w, rect.h };
+      SDL_BlitScaled((SDL_Surface*)m_surface->nativeHandle(), &rect,
+		     (SDL_Surface*)m_doublebuffer->nativeHandle(), &dst);
       return;
+    }
 
     SDL_Rect rect {bounds.x, bounds.y, bounds.w, bounds.h};
     if (m_renderer) {

diff --git a/src/she/sdl2/sdl2_display.h b/src/she/sdl2/sdl2_display.h
@@ -60,7 +60,8 @@ namespace she {
     private:
         SDL_Window* m_window;
         SDL_Renderer* m_renderer;
-        Surface* m_surface;
+        Surface* m_surface{};
+        Surface* m_doublebuffer{};
         int m_scale;
         int m_width;
         int m_height;

diff --git a/src/she/sdl2/she.cpp b/src/she/sdl2/she.cpp
@@ -37,7 +37,7 @@
 #include <chrono>
 #include <thread>
 
-#ifdef EMSCRIPTEN
+#ifdef __EMSCRIPTEN__
 #include <emscripten/emscripten.h>
 #endif
 
@@ -216,7 +216,7 @@ she::KeyModifiers getSheModifiers() {
   return (she::KeyModifiers) mod;
 }
 
-#ifdef EMSCRIPTEN
+#ifdef __EMSCRIPTEN__
 EM_JS(int, get_canvas_width, (), { return canvas.clientWidth; });
 EM_JS(int, get_canvas_height, (), { return canvas.clientHeight; });
 static int oldWidth, oldHeight;
@@ -319,7 +319,7 @@ namespace she {
             continue;
 
           case SDL_WINDOWEVENT_RESIZED: {
-	    #ifdef EMSCRIPTEN
+	    #ifdef __EMSCRIPTEN__
 	    continue;
 	    #else
             auto display = sdl::windowIdToDisplay[sdlEvent.window.windowID];
@@ -584,6 +584,15 @@ namespace she {
       #ifndef EMSCRIPTEN
       mainThreadId = gfxThreadId;
       return func();
+      #elif defined(EMSCRIPTEN) && !defined(__EMSCRIPTEN__)
+      // like emscripten, but not really
+      mainThread = std::thread{[this, func = std::move(func)]{
+        mainThreadId = std::this_thread::get_id();
+	func();
+      }};
+      while (!shutdown)(
+	refresh();
+      }
       #else
       mainThread = std::thread{[this, func = std::move(func)]{
         mainThreadId = std::this_thread::get_id();
@@ -592,16 +601,16 @@ namespace she {
       emscripten_set_main_loop([]{
 	static_cast<SDL2System*>(g_instance)->refresh();
       }, 0, true);
-      return 0;
       #endif
+      return 0;
     }
 
     void refresh() {
       if (!sleeping) {
 	static_cast<SDL2EventQueue*>(EventQueue::instance())->refresh();
 	return;
       }
-      #ifdef EMSCRIPTEN
+      #ifdef __EMSCRIPTEN__
       auto width = get_canvas_width();
       auto height = get_canvas_height();
       if (width && height && (oldWidth != width || oldHeight != height) && !sdl::windowIdToDisplay.empty()) {