Setup game camera and player transformed view following/offset.

src/Hamster.cpp

@@ -42,14 +42,16 @@ All rights reserved.
 #include <ranges>
 
 std::vector<Hamster>Hamster::HAMSTER_LIST;
+const uint8_t Hamster::MAX_HAMSTER_COUNT{100U};
 const uint8_t Hamster::NPC_HAMSTER_COUNT{5U};
 const std::vector<std::string>Hamster::NPC_HAMSTER_IMAGES{
 	"hamster.png",
 };
 const std::string Hamster::PLAYER_HAMSTER_IMAGE{"hamster.png"};
+std::optional<Hamster*>Hamster::playerHamster;
 
-Hamster::Hamster(const vf2d spawnPos,const std::string_view img,const PlayerControlled playerControlled)
-:pos(spawnPos),playerControlled(playerControlled){
+Hamster::Hamster(const vf2d spawnPos,const std::string_view img,const PlayerControlled IsPlayerControlled)
+:pos(spawnPos),IsPlayerControlled(IsPlayerControlled){
 	animations=HamsterGame::GetAnimations(img);
 	animations.ChangeState(internalAnimState,HamsterGame::DEFAULT);
 }
@@ -62,7 +64,10 @@ void Hamster::UpdateHamsters(const float fElapsedTime){
 
 void Hamster::LoadHamsters(const vf2d startingLoc){
 	HAMSTER_LIST.clear();
-	HAMSTER_LIST.emplace_back(startingLoc,PLAYER_HAMSTER_IMAGE,PLAYER_CONTROLLED);
+	playerHamster.reset();
+	HAMSTER_LIST.reserve(MAX_HAMSTER_COUNT);
+	if(NPC_HAMSTER_COUNT+1>MAX_HAMSTER_COUNT)throw std::runtime_error{std::format("WARNING! Max hamster count is too high! Please expand the MAX_HAMSTER_COUNT if you want more hamsters. Requested {} hamsters.",MAX_HAMSTER_COUNT)};
+	playerHamster=&HAMSTER_LIST.emplace_back(startingLoc,PLAYER_HAMSTER_IMAGE,PLAYER_CONTROLLED);
 	for(int i:std::ranges::iota_view(0U,NPC_HAMSTER_COUNT)){
 		HAMSTER_LIST.emplace_back(startingLoc,NPC_HAMSTER_IMAGES.at(util::random()%NPC_HAMSTER_IMAGES.size()),NPC);
 	}
@@ -77,4 +82,13 @@ void Hamster::DrawHamsters(TransformedView&tv){
 
 const Animate2D::Frame&Hamster::GetCurrentAnimation()const{
 	return animations.GetFrame(internalAnimState);
+}
+
+const Hamster&Hamster::GetPlayer(){
+	if(!playerHamster.has_value())throw std::runtime_error{std::format("WARNING! Player is not created at this time! There should not be any code referencing the player at this moment!")};
+	return *playerHamster.value();
+}
+
+const vf2d&Hamster::GetPos()const{
+	return pos;
 }

src/Hamster.h

@@ -49,6 +49,7 @@ class Hamster{
 
 	static std::vector<Hamster>HAMSTER_LIST;
 
+	static const uint8_t MAX_HAMSTER_COUNT;
 	static const uint8_t NPC_HAMSTER_COUNT;
 
 	static const std::vector<std::string>NPC_HAMSTER_IMAGES;
@@ -60,11 +61,14 @@ class Hamster{
 	std::string img;
 	Animate2D::Animation<HamsterGame::AnimationState>animations;
 	Animate2D::AnimationState internalAnimState;
-	PlayerControlled playerControlled;
+	PlayerControlled IsPlayerControlled;
+	static std::optional<Hamster*>playerHamster;
 public:
-	Hamster(const vf2d spawnPos,const std::string_view img,const PlayerControlled playerControlled=NPC);
+	Hamster(const vf2d spawnPos,const std::string_view img,const PlayerControlled IsPlayerControlled=NPC);
+	static const Hamster&GetPlayer();
 	static void UpdateHamsters(const float fElapsedTime);
 	static void LoadHamsters(const vf2d startingLoc);
 	static void DrawHamsters(TransformedView&tv);
 	const Animate2D::Frame&GetCurrentAnimation()const;
+	const vf2d&GetPos()const;
 };

src/HamsterGame.cpp

@@ -13,7 +13,9 @@ HamsterGame::HamsterGame()
 }
 
 bool HamsterGame::OnUserCreate(){
-	tv.Initialise({320,288},{1,1});
+	camera=Camera2D{SCREEN_FRAME.size};
+	camera.SetMode(Camera2D::Mode::LazyFollow);
+	tv.Initialise(SCREEN_FRAME.size,{1,1});
 	tv.SetWorldOffset(-SCREEN_FRAME.pos);
 	LoadGraphics();
 	LoadAnimations();
@@ -54,9 +56,12 @@ void HamsterGame::LoadAnimations(){
 void HamsterGame::LoadLevel(){
 	const vf2d levelSpawnLoc{50,50}; //TEMPORARY
 	Hamster::LoadHamsters(levelSpawnLoc);
+	camera.SetTarget(Hamster::GetPlayer().GetPos());
 }
 
 void HamsterGame::UpdateGame(const float fElapsedTime){
+	camera.Update(fElapsedTime);
+	tv.SetWorldOffset(-SCREEN_FRAME.pos+camera.GetViewPosition());
 	Hamster::UpdateHamsters(fElapsedTime);
 }
 

src/olcUTIL_Camera2D.h

@@ -116,7 +116,7 @@ namespace olc::utils
 		}
 
 		// Set tracked point via pointer
-		inline void SetTarget(olc::vf2d& vTarget)
+		inline void SetTarget(const olc::vf2d& vTarget)
 		{
 			m_pTarget = &vTarget;
 		}
@@ -242,7 +242,7 @@ namespace olc::utils
 		Mode m_nMode = Mode::Simple;
 
 		// Target Vector2D object camera should follow (either ref or ptr)
-		olc::vf2d* m_pTarget = nullptr;
+		const olc::vf2d* m_pTarget = nullptr;
 		olc::vf2d m_vLocalTarget;
 
 		// World Boundary