Something

void DrawTile(BITMAP * dest,byte x,byte y,int dest_x,int dest_y) {
	blit(tileset,dest,x*32,y*32,dest_x,dest_y,32,32);
}

void DrawLevel(BITMAP * dest,int _x,int _y,int x_size,int y_size) {
	x_size/=32;
	y_size/=32;
	for(byte i=0;i<layers.size();i++) {
		for(int y=(_y);y<(y_size+_y);y++) {
			if(y==layers[i]->y_size)
				break;
			for(int x=(_x);x<(x_size+_x);x++) {
				if(x==layers[i]->x_size)
					break;
				tileset->DrawTile(dest,layers[i]->tiles[y][x].x,layers[i]->tiles[y][x].y,x*32,y*32);
			}
		}
	}
}