make xSpriteGroup render all if not animated, and only the current frame in the other case

xSDL/xSpriteGroup.cpp

@@ -25,11 +25,19 @@ void xSpriteGroup::remove(xSprite* sprite){
 	_mutex.unlock();
 }
 
-/** set absolute move for each sprite */
+/** set relative move for each sprite */
-void xSpriteGroup::moveTo(int x, int y){
+void xSpriteGroup::displace(int x, int y, int w, int h){
 	_mutex.lock();
-	_move.x = x;
+	_displace.x = x;
-	_move.y = y;
+	_displace.y = y;
+	_displace.w = w;
+	_displace.h = h;
+	_mutex.unlock();
+}
+/** set relative move for each sprite */
+void xSpriteGroup::displace(SDL_Rect displace){
+	_mutex.lock();
+	_displace = displace;
 	_mutex.unlock();
 }
 
@@ -37,9 +45,23 @@ void xSpriteGroup::moveTo(int x, int y){
 void xSpriteGroup::draw(SDL_Renderer* renderer){
 	_mutex.lock();
 
+	// only draw active sprite if animated
+	if( _animated ){
+		set<xSprite*>::iterator at_index = _sprites.begin();
+		advance(at_index, _active_sprite);
+		if( at_index == _sprites.end() ){
+			_mutex.unlock();
+			return;
+		}
+		draw_sprite(renderer, *at_index);
+		_mutex.unlock();
+		return;
+	}
+
+	// else draw every sprite
 	set<xSprite*>::iterator it;
 	for( it = _sprites.begin() ; it != _sprites.end() ; it++ ){
-		(*it)->draw(renderer);
+		draw_sprite(renderer, *it);
 	}
 	_mutex.unlock();
 }
@@ -47,18 +69,46 @@ void xSpriteGroup::draw(SDL_Renderer* renderer){
 /** animation process */
 void xSpriteGroup::tick(const uint32_t ticks){
 	_mutex.lock();
-	uint32_t time_index  = ticks / _animation_interval;
+	const uint32_t time_index  = ticks / _animation_interval;
 	_active_sprite = time_index % _sprites.size();
 	_mutex.unlock();
 }
 
 /** orchestrate the animation */
 void xSpriteGroup::animate(uint32_t interval){
+	_mutex.lock();
+	_animated = true;
 	_animation_interval = interval;
 	xApplication::get()->addOrchestrable(this);
+	_mutex.unlock();
 }
 
 /** stops orchestrating the animation */
 void xSpriteGroup::freeze(){
+	_mutex.lock();
 	xApplication::get()->removeOrchestrable(this);
+	_mutex.unlock();
+}
+
+
+
+/* draws a sprite using the relative displace */
+void xSpriteGroup::draw_sprite(SDL_Renderer* renderer, xSprite* sprite) {
+	const SDL_Rect projection = sprite->projection();
+	const SDL_Rect clip       = sprite->clip();
+
+	// displace sprite projection with group move
+	const SDL_Rect displace {
+		projection.x + _displace.x,
+		projection.y + _displace.y,
+		projection.w + _displace.w,
+		projection.h + _displace.h
+	};
+
+	SDL_RenderCopy(
+		renderer,
+		SDL_CreateTextureFromSurface(renderer, sprite->surface()),
+		&clip,
+		&displace
+	);
 }

xSDL/xSpriteGroup.h

@@ -24,7 +24,8 @@
 			void clear();
 
 			// set absolute move for each sprite
-			void moveTo(int x, int y);
+			void displace(SDL_Rect displace);
+			void displace(int x, int y, int w, int h);
 
 			// implement xDrawable
 			virtual void draw(SDL_Renderer* renderer) override;
@@ -37,13 +38,17 @@
 			void freeze();
 
 		protected:
-			SDL_Rect      _move;
+			void draw_sprite(SDL_Renderer* renderer, xSprite* sprite);
+
+			SDL_Rect      _displace;
 
 			set<xSprite*> _sprites;
 
-			// active sprite for animation ; equal to 0 if not an animated sprite
+			// if not animated, draw all sprites, else draw one at a time
+			bool          _animated = false;
+			// active sprite for animation
 			size_t        _active_sprite = 0;
-			uint32_t      _animation_interval;
+			uint32_t      _animation_interval = 0;
 
 			mutex         _mutex;