From cb1a862b6f5dd4808182b8e922c7d5a32197c2df Mon Sep 17 00:00:00 2001
From: xdrm-brackets <xdrm.brackets.dev@gmail.com>
Date: Tue, 4 Feb 2020 20:22:17 +0100
Subject: [PATCH] make xSpriteGroup displace() actually update sprites with
 relative displace

---
 xSDL/xSpriteGroup.cpp | 62 +++++++++++++++++++------------------------
 xSDL/xSpriteGroup.h   |  8 ++----
 2 files changed, 29 insertions(+), 41 deletions(-)

diff --git a/xSDL/xSpriteGroup.cpp b/xSDL/xSpriteGroup.cpp
index 5930bad..40c0345 100644
--- a/xSDL/xSpriteGroup.cpp
+++ b/xSDL/xSpriteGroup.cpp
@@ -25,19 +25,24 @@ void xSpriteGroup::remove(xSprite* sprite){
 	_mutex.unlock();
 }
 
-/** set relative move for each sprite */
+/** apply relative displace for each sprite */
 void xSpriteGroup::displace(int x, int y, int w, int h){
-	_mutex.lock();
-	_displace.x = x;
-	_displace.y = y;
-	_displace.w = w;
-	_displace.h = h;
-	_mutex.unlock();
+	displace( (SDL_Rect){x,y,w,h} );
 }
-/** set relative move for each sprite */
-void xSpriteGroup::displace(SDL_Rect displace){
+void xSpriteGroup::displace(SDL_Rect relative_displace){
 	_mutex.lock();
-	_displace = displace;
+
+	for( set<xSprite*>::iterator it = _sprites.begin() ; it != _sprites.end() ; it++ ) {
+		xSprite* sprite = (*it);
+		const SDL_Rect actual_projection = sprite->projection();
+
+		sprite->project(
+			actual_projection.x + relative_displace.x,
+			actual_projection.y + relative_displace.y,
+			actual_projection.w + relative_displace.w,
+			actual_projection.h + relative_displace.h
+		);
+	}
 	_mutex.unlock();
 }
 
@@ -47,13 +52,22 @@ void xSpriteGroup::draw(SDL_Renderer* renderer){
 
 	// only draw active sprite if animated
 	if( _animated ){
+
+		// invalid active index
+		if( _active_sprite >= _sprites.size() ) {
+			_active_sprite = 0;
+			_mutex.unlock();
+			return;
+		}
+
 		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);
+		(*at_index)->draw(renderer);
+
 		_mutex.unlock();
 		return;
 	}
@@ -61,7 +75,7 @@ void xSpriteGroup::draw(SDL_Renderer* renderer){
 	// else draw every sprite
 	set<xSprite*>::iterator it;
 	for( it = _sprites.begin() ; it != _sprites.end() ; it++ ){
-		draw_sprite(renderer, *it);
+		(*it)->draw(renderer);
 	}
 	_mutex.unlock();
 }
@@ -79,6 +93,7 @@ void xSpriteGroup::animate(uint32_t interval){
 	_mutex.lock();
 	_animated = true;
 	_animation_interval = interval;
+	_active_sprite = 0;
 	xApplication::get()->addOrchestrable(this);
 	_mutex.unlock();
 }
@@ -88,27 +103,4 @@ 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
-	);
 }
\ No newline at end of file
diff --git a/xSDL/xSpriteGroup.h b/xSDL/xSpriteGroup.h
index 26a90a0..702d287 100644
--- a/xSDL/xSpriteGroup.h
+++ b/xSDL/xSpriteGroup.h
@@ -23,8 +23,8 @@
 			void remove(xSprite* sprite);
 			void clear();
 
-			// set absolute move for each sprite
-			void displace(SDL_Rect displace);
+			// apply relative displace for each sprite
+			void displace(SDL_Rect relative_displace);
 			void displace(int x, int y, int w, int h);
 
 			// implement xDrawable
@@ -38,10 +38,6 @@
 			void freeze();
 
 		protected:
-			void draw_sprite(SDL_Renderer* renderer, xSprite* sprite);
-
-			SDL_Rect      _displace;
-
 			set<xSprite*> _sprites;
 
 			// if not animated, draw all sprites, else draw one at a time