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.

7 files changed, 49 insertions, 5 deletions

@@ -12,6 +12,4 @@ const int PARTY_FRAME_DELAY = 20; // true delay is this divided by movement spee
 
 const int MESSAGE_TEXT_WIDTH = 196;
 
-const int NUM_SPRITE_LAYERS = 2;
-
 #endif /* end of include guard: CONSTS_H_9561E49C */
@@ -56,7 +56,7 @@ void Game::loadMap(std::string filename) {
     if (spritesByAlias_.count(p.name)) continue;
 
     int spriteId = emplaceSprite(p.name);
-    getSystem<TransformSystem>().initSprite(spriteId, p.pos);
+    getSystem<TransformSystem>().initSprite(spriteId, p.pos, p.masked ? SpriteLayer::Mask : SpriteLayer::Normal);
     getSystem<TransformSystem>().setUpCollision(spriteId, p.collisionOffset, p.collisionSize, true);
     if (!p.animationFilename.empty()) {
       getSystem<AnimationSystem>().initSprite(spriteId, p.animationFilename);
@@ -71,12 +71,20 @@ Map::Map(std::string_view name) : name_(name) {
     } else if (layer->getType() == tmx::Layer::Type::Object) {
       const auto& objectLayer = layer->getLayerAs<tmx::ObjectGroup>();
 
+      bool masked = false;
+      for (const tmx::Property& property : objectLayer.getProperties()) {
+        if (property.getName() == "masked" && property.getBoolValue()) {
+          masked = true;
+        }
+      }
+
       for (const tmx::Object& object : objectLayer.getObjects()) {
         if (object.getType() == "sprite") {
           Prototype p;
           p.name = object.getName();
           p.pos.x() = object.getPosition().x;
           p.pos.y() = object.getPosition().y;
+          p.masked = masked;
 
           for (const tmx::Property& property : object.getProperties()) {
             if (property.getName() == "collisionOffsetX") {
@@ -159,6 +167,8 @@ Map::Map(std::string_view name) : name_(name) {
   for (const tmx::Property& property : mapfile.getProperties()) {
     if (property.getName() == "music") {
       music_ = property.getStringValue();
+    } else if (property.getName() == "maskZone") {
+      maskZone_ = property.getStringValue();
     }
   }
 }
@@ -31,6 +31,7 @@ struct Prototype {
   bool wander = false;
   int movementSpeed = -1;
   std::string enclosureZone;
+  bool masked = false;
 };
 
 struct Trigger {
@@ -82,6 +83,8 @@ public:
 
   const std::string& getMusic() const { return music_; }
 
+  const std::string& getMaskZone() const { return maskZone_; }
+
 private:
 
   std::string name_;
@@ -96,6 +99,7 @@ private:
   std::vector<Trigger> triggers_;
   std::map<std::string, Zone> zones_;
   std::string music_;
+  std::string maskZone_;
 };
 
 #endif /* end of include guard: MAP_H_D95D6D47 */
@@ -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);
@@ -11,8 +11,10 @@
 #include "step_type.h"
 
 enum class SpriteLayer {
+  Mask,
   Normal,
-  Above
+  Above,
+  NUM_SPRITE_LAYERS // do not use
 };
 
 struct SpriteFrame {
@@ -54,7 +54,7 @@ public:
 private:
 
   Game& game_;
-  std::set<std::tuple<int, int>> spritesByY_[NUM_SPRITE_LAYERS];
+  std::set<std::tuple<int, int>> spritesByY_[static_cast<int>(SpriteLayer::NUM_SPRITE_LAYERS)];
 
   struct Collidable {
     int lower;