Added the mask sprite layer

This layer is below the normal sprite layer. Sprites on it are only rendered within the area of a zone that is defined per-map.

1 files changed, 30 insertions, 0 deletions

@@ -178,6 +178,36 @@ void Renderer::render(Game& game) {
     SDL_RenderCopy(ren_.get(), mapSwapTex_.get(), nullptr, nullptr);
   }
 
+  // Render mask sprite layer
+  if (!game.getMap().getMaskZone().empty()) {
+    texture_ptr spritesTex(
+      SDL_CreateTexture(
+        ren_.get(),
+        SDL_PIXELFORMAT_RGBA8888,
+        SDL_TEXTUREACCESS_TARGET,
+        mapBounds.w(),
+        mapBounds.h()));
+
+    if (!spritesTex) {
+      throw sdl_error();
+    }
+
+    SDL_SetRenderTarget(ren_.get(), spritesTex.get());
+    SDL_SetRenderDrawColor(ren_.get(), 0, 0, 0, 0);
+    SDL_RenderClear(ren_.get());
+
+    for (const Sprite& sprite : game.getSystem<TransformSystem>().getSpritesByY(SpriteLayer::Mask) | game.spriteView()) {
+      renderSprite(sprite);
+    }
+
+    const Zone& zone = game.getMap().getZone(game.getMap().getMaskZone());
+    SDL_Rect zoneArea { zone.ul.x(), zone.ul.y(), zone.dr.x() - zone.ul.x(), zone.dr.y() - zone.ul.y() };
+
+    SDL_SetRenderTarget(ren_.get(), canvas.get());
+    SDL_SetTextureBlendMode(spritesTex.get(), SDL_BLENDMODE_BLEND);
+    SDL_RenderCopy(ren_.get(), spritesTex.get(), &zoneArea, &zoneArea);
+  }
+
   // Render normal sprite layer
   for (const Sprite& sprite : game.getSystem<TransformSystem>().getSpritesByY(SpriteLayer::Normal) | game.spriteView()) {
     renderSprite(sprite);