Improve collision testing performance, checking only with at least one moving entity

GameLib/Entity.c

@@ -357,6 +357,24 @@ void CollisionInfo_Add(CollisionInfo *collInfoRef,
 }
 
 
+/////////////////////////////
+// CollisionInfo_CheckRepetition
+//
+//
+int CollisionInfo_CheckRepetition(CollisionInfo collInfo,Entity ent1,Entity ent2)
+{
+	while(collInfo!=NULL){
+		if((collInfo->ent1==ent1 && collInfo->ent2==ent2) ||
+			(collInfo->ent1==ent2 && collInfo->ent2==ent1))
+		{
+			return(1);
+		}
+		collInfo=collInfo->next;
+	}
+	return(0);
+}
+
+
 /////////////////////////////
 // Entity_CheckCollisions
 //

GameLib/Entity.h

@@ -166,6 +166,13 @@ void CollisionInfo_Add(CollisionInfo *collInfo,
 	int responseType,Entity ent1,Entity ent2,float t,vec2 n,int applyFriction);
 
 
+/////////////////////////////
+// CollisionInfo_CheckRepetition
+//
+//
+int CollisionInfo_CheckRepetition(CollisionInfo collInfo,Entity ent1,Entity ent2);
+
+
 /////////////////////////////
 // Entity_CheckCollision
 //

GameLib/GameLib.c

@@ -215,14 +215,21 @@ int GameLib_ProcLoop(){
 	do{
 		repeat=0;
 		CollisionInfo collInfo=NULL;
-		for(i=0;i<(_n_entities-1);i++){
+		for(i=0;i<_n_entities;i++){
 			if(!(_entity[i]->flags&EntityFlag_Collision) || _entity[i]->mass<0.0f)
 				continue;
-			for(j=i;j<_n_entities;j++){
+			if(_entity[i]->vel[0]<=0.0f && _entity[i]->vel[0]>=-0.0f &&
-				if(!(_entity[j]->flags&EntityFlag_Collision))
+				_entity[i]->vel[1]<=0.0f && _entity[i]->vel[1]>=-0.0f)
-					continue;
+			{
-				if(!Entity_BBoxIntersect(_entity[i],_entity[j]))
+				continue;
+			}
+			for(j=0;j<_n_entities;j++){
+				if(!(_entity[j]->flags&EntityFlag_Collision) ||
+					!Entity_BBoxIntersect(_entity[i],_entity[j]) ||
+					CollisionInfo_CheckRepetition(collInfo,_entity[i],_entity[j]))
+				{
 					continue;
+				}
 				Entity_CheckCollision(_entity[i],_entity[j],&collInfo);
 			}
 		}