Moved World::checkDelete into World::step, made checks debug only.

source/Game.cpp

@@ -86,7 +86,6 @@ Game::loop() {
 		}
 
 		Character::think(elapsed);
-		mWorld.checkDelete();
 
 		mWorld.step(elapsed);
 

source/World.cpp

@@ -18,11 +18,12 @@
  */
 void
 World::insert(std::shared_ptr<Sprite> drawable) {
+#ifndef NDEBUG
 	Sprite::Category cat = drawable->getCategory();
 	auto item = std::find(mDrawables[cat].begin(), mDrawables[cat].end(), drawable);
-	if (item == mDrawables[cat].end()) {
-		mDrawables[cat].push_back(drawable);
-	}
+	assert(item == mDrawables[cat].end());
+#endif
+		mDrawables[drawable->getCategory()].push_back(drawable);
 }
 
 /**
@@ -38,10 +39,23 @@ World::remove(std::shared_ptr<Sprite> drawable) {
 	}
 }
 
+/**
+ * Checks for collisions and applies movement, also removes sprites if
+ * Sprite::getDelete returns true.
+ *
+ * This method can be improved by only testing each pair of sprites once,
+ * and using the result for both. Applying movement should be done in
+ * testCollision, always applying the part that causes no collision.
+ */
 void
 World::step(int elapsed) {
 	for (auto v = mDrawables.begin(); v != mDrawables.end(); v++) {
-		for (auto spriteA : v->second) {
+		for (auto it = v->second.begin(); it != v->second.end(); ) {
+			auto spriteA = *it;
+			if (spriteA->getDelete()) {
+				remove(spriteA);
+			}
+			else {
 				sf::Vector2f speed = spriteA->getSpeed();
 				speed *= elapsed / 1000.0f;
 				bool overlap = false;
@@ -50,7 +64,9 @@ World::step(int elapsed) {
 						if (spriteA == spriteB) {
 							continue;
 						}
-					if (!spriteA->collisionEnabled(spriteB->getCategory()) || !spriteB->collisionEnabled(spriteA->getCategory())) {
+						// Ignore anything that is filtered by masks.
+						if (!spriteA->collisionEnabled(spriteB->getCategory()) ||
+								!spriteB->collisionEnabled(spriteA->getCategory())) {
 							continue;
 						}
 						if (testCollision(spriteA, spriteB, elapsed)) {
@@ -62,6 +78,8 @@ World::step(int elapsed) {
 				if (!overlap) {
 					spriteA->setPosition(spriteA->getPosition() + speed);
 				}
+				it++;
+			}
 		}
 	}
 }
@@ -132,23 +150,6 @@ World::testCollision(std::shared_ptr<Sprite> spriteA,
 	return false;
 }
 
-/**
- * Deletes any sprites which return true for getDelete().
- */
-void
-World::checkDelete() {
-	for (auto v = mDrawables.begin(); v != mDrawables.end(); v++) {
-		for (auto item = v->second.begin(); item != v->second.end(); ) {
-			if ((*item)->getDelete()) {
-				item = v->second.erase(item);
-			}
-			else {
-				item++;
-			}
-		}
-	}
-}
-
 /**
  * Draws all elements in the group.
  */

source/World.h

@@ -30,9 +30,8 @@ public:
 	void insert(std::shared_ptr<Sprite> drawable);
 	void remove(std::shared_ptr<Sprite> drawable);
 	void step(int elapsed);
-	void checkDelete();
 
-// Private functions.
+// Private types.
 private:
 	class Interval {
 	public:
@@ -43,6 +42,8 @@ private:
 		float getLength();
 	};
 
+// Private functions.
+private:
     void draw(sf::RenderTarget& target, sf::RenderStates states) const;
     bool testCollision(std::shared_ptr<Sprite> spriteA, std::shared_ptr<Sprite> spriteB, int elapsed) const;