Parallax backgrounds

Game/GameEnts.c

@@ -90,7 +90,6 @@ void player_proc(Entity e,int ft){
 
 
 	// Scroll View
-	//GameLib_MoveToPosH(e->pos,0.6f);
 	GameLib_MoveToPos(e->pos,0.6f);
 }
 

Game/main.c

@@ -14,23 +14,33 @@ extern int gamelib_debug;
 
 
 DrawFnt font;
-DrawFnt font_shad;
+DrawImg imgBackground;
+
+void MainGame_Text(int x, int y, char *text){
+	Draw_SetColor(0.0f, 0.0f, 0.0f, 0.5f);
+	Draw_DrawText(font, text, x+1, y+1);
+	Draw_SetColor(1.0f, 1.0f, 1.0f, 1.0f);
+	Draw_DrawText(font, text, x, y);
+}
 
 void ProcGame(){
 
 }
-
 void PostProcGame(){
 	// Apply gravity to every entity
 	GameLib_ForEachEnt(EntityApplyGravity);
 }
-
+void PreDrawGame(float f){
+	
+}
+void DrawGame(float f){
+	MainGame_Text(8,8,"Hello world!");
+}
 
 int main(int argc,char *argv[]){
 	int i,j;
 	Entity *e;
 
-
 	srand(time(NULL));
 
 	if (argc>1) {
@@ -42,30 +52,26 @@ int main(int argc,char *argv[]){
 
 	GameLib_Init(640,480,"Game",20,60);
 
-
-
 	/////////////////////////////
 	// Load and initialize media.
 	//
 	font=Draw_DefaultFont(255,255,255,255);
-	font_shad=Draw_DefaultFont(0,0,0,127);
-
+	imgBackground=Draw_LoadImage("data/background.png");
+	Draw_SetOffset(imgBackground,0,0);
 	GameEnts_Init();
 
-
 	/////////////////////////
 	// Initialize world.
 	//
 	GameLib_DelEnts();
 	GameMap_LoadLevel("data/level_01.txt",64);
 
-
 	/////////////////////////
 	// Run the world.
 	//
-
-	GameLib_Loop(ProcGame,PostProcGame,NULL,NULL);
-
+	GameLib_CleanParallaxBackgrounds();
+	GameLib_AddParallaxBackground(imgBackground, (int[2]){512, 512}, (int[2]){0, 0}, (float[2]){0.5f, 0.0f});
+	GameLib_Loop(ProcGame,PostProcGame,PreDrawGame,DrawGame);
 
 	return(0);
 }

GameLib/Draw.c

@@ -929,6 +929,35 @@ void Draw_DrawImgPartHoriz(DrawImg img,int x,int y,int w,int i){
 }
 
 
+/////////////////////////////
+// Draw_ImgParallax
+//
+//
+void Draw_ImgParallax(DrawImg img, int imgSize[2], int imgOffset[2], float parallaxFactor[2], int gamePos[2], int gameSize[2]){
+	int paralaxPos[2];
+	int mult[2];
+	int x, y;
+	
+	paralaxPos[0] = (gamePos[0] * parallaxFactor[0]) + imgOffset[0];
+	paralaxPos[1] = (gamePos[1] * parallaxFactor[1]) + imgOffset[1];
+	
+	mult[0] = floor(paralaxPos[0] / imgSize[0]);
+	if(paralaxPos[0] < 0 ){ mult[0]--; }
+	mult[1] = floor(paralaxPos[1] / imgSize[1]);
+	if(paralaxPos[1] < 0 ){ mult[1]--; }
+	
+	y = (mult[1] * imgSize[1]) - paralaxPos[1];
+	while(y < gameSize[1]){
+		x = (mult[0] * imgSize[0]) - paralaxPos[0];
+		while(x < gameSize[0]){
+			Draw_DrawImgResized(img, x, y, imgSize[0], imgSize[1]);
+			x += imgSize[0];
+		}
+		y += imgSize[1];
+	}
+}
+
+
 /////////////////////////////
 // Draw_SetColor
 //

GameLib/Draw.h

@@ -125,6 +125,13 @@ void Draw_DrawImgPart(DrawImg img,int x,int y,int w,int h,int i,int j);
 void Draw_DrawImgPartHoriz(DrawImg img,int x,int y,int w,int i);
 
 
+/////////////////////////////
+// Draw_ImgParallax
+//
+//
+void Draw_ImgParallax(DrawImg img, int imgSize[2], int imgOffset[2], float parallaxFactor[2], int gamePos[2], int gameSize[2]);
+
+
 /////////////////////////////
 // Draw_SetColor
 //

GameLib/GameLib.c

@@ -40,6 +40,17 @@ long long t_draw;
 int fproc_count;
 int fdraw_count;
 
+typedef struct TParallaxBackground TParallaxBackground, *ParallaxBackground;
+struct TParallaxBackground {
+	DrawImg img;
+	int imgSize[2];
+	int imgOffset[2];
+	float parallaxFactor[2];
+};
+#define MaxParallaxBackgrounds 10
+TParallaxBackground _parallaxBackground[MaxParallaxBackgrounds];
+int _nParallaxBackgrounds=0;
+
 int gamelib_debug=0;
 
 
@@ -351,17 +362,29 @@ void GameLib_DrawLoop(void *data, float f){
 	int i;
 	int game_pos[2];
 
-	game_pos[0]=_game_pos0[0]+f*(_game_pos1[0]-_game_pos0[0]);
-	game_pos[1]=_game_pos0[1]+f*(_game_pos1[1]-_game_pos0[1]);
+	GameLib_GetPosInstant(game_pos,f);
 
 	time=Time_GetTime();
 
-	// Predibujado
+	// PreDraw
 	if(_gamepredraw){
 		_gamepredraw(f);
 	}else{
-		// Limpiar pantalla
-		Draw_Clean(0,0,0);
+		if(_nParallaxBackgrounds==0){
+			// Clean screen
+			Draw_Clean(0,0,0);
+		}
+	}
+	
+	// Draw parallax backgrounds
+	for(i=0;i<_nParallaxBackgrounds;i++){
+		Draw_ImgParallax(
+			_parallaxBackground[i].img,
+			_parallaxBackground[i].imgSize,
+			_parallaxBackground[i].imgOffset,
+			_parallaxBackground[i].parallaxFactor,
+			game_pos,
+			_game_size);
 	}
 	
 	// Draw entities
@@ -446,6 +469,7 @@ void GameLib_Loop(
 // GameLib_SetPos
 // GameLib_UpdatePos
 // GameLib_SetPos
+// GameLib_GetPosInstant
 //
 //
 void GameLib_GetPos(int pos[2]){
@@ -466,6 +490,10 @@ void GameLib_GetSize(int size[2]){
 	size[0]=_game_size[0];
 	size[1]=_game_size[1];
 }
+void GameLib_GetPosInstant(int pos[2],float f){
+	pos[0]=_game_pos0[0]+f*(_game_pos1[0]-_game_pos0[0]);
+	pos[1]=_game_pos0[1]+f*(_game_pos1[1]-_game_pos0[1]);
+}
 
 
 
@@ -659,3 +687,33 @@ void GameLib_ConvertScreenPositionToGamePosition(
 	gamePos[1]=(screenPos[1]*_game_size[1])+game_pos[1];
 }
 
+
+/////////////////////////////
+// GameLib_AddParallaxBackground
+//
+//
+void GameLib_AddParallaxBackground(DrawImg img, int imgSize[2], int imgOffset[2], float parallaxFactor[2]){
+	int idx = _nParallaxBackgrounds;
+	if((idx+1)>=MaxParallaxBackgrounds){
+		Print("GameLib: Can't add parallaxBackground, limit reached.");
+		return;
+	}
+	_parallaxBackground[idx].img=img;
+	_parallaxBackground[idx].imgSize[0]=imgSize[0];
+	_parallaxBackground[idx].imgSize[1]=imgSize[1];
+	_parallaxBackground[idx].imgOffset[0]=imgOffset[0];
+	_parallaxBackground[idx].imgOffset[1]=imgOffset[1];
+	_parallaxBackground[idx].parallaxFactor[0]=parallaxFactor[0];
+	_parallaxBackground[idx].parallaxFactor[1]=parallaxFactor[1];
+	_nParallaxBackgrounds++;
+}
+
+
+/////////////////////////////
+// GameLib_CleanParallaxBackgrounds
+//
+//
+void GameLib_CleanParallaxBackgrounds(){
+	_nParallaxBackgrounds=0;
+}
+

GameLib/GameLib.h

@@ -56,12 +56,14 @@ void GameLib_Loop(
 // GameLib_SetPos
 // GameLib_UpdatePos
 // GameLib_SetPos
+// GameLib_GetPosInstant
 //
 //
 void GameLib_GetPos(int pos[2]);
 void GameLib_SetPos(int pos[2]);
 void GameLib_UpdatePos(int pos[2]);
 void GameLib_GetSize(int size[2]);
+void GameLib_GetPosInstant(int pos[2],float f);
 
 
 /////////////////////////////
@@ -132,4 +134,17 @@ void GameLib_ConvertScreenPositionToGamePosition(
 	vec2 screenPos, vec2 gamePos);
 
 
+/////////////////////////////
+// GameLib_AddParallaxBackground
+//
+//
+void GameLib_AddParallaxBackground(DrawImg img, int imgSize[2], int imgOffset[2], float parallaxFactor[2]);
+
+
+/////////////////////////////
+// GameLib_CleanParallaxBackgrounds
+//
+//
+void GameLib_CleanParallaxBackgrounds();
+
 #endif