SmarterPointerExample/SmartPointerExample/SmartPointerExample.cpp

#define OLC_PGE_APPLICATION
#include "olcPixelGameEngine.h"

using namespace olc;

#define PI 3.14159

// Override base class with your custom functionality
class SmartPointerExample : public olc::PixelGameEngine
{

	struct DamageNumber{
		vf2d pos;
		int dmg;
		float timer=0;
		bool dead=false;
		float stopTimer=0;
		void Update(SmartPointerExample*pge, float fElapsedTime){
			if(stopTimer>0){
				stopTimer-=fElapsedTime;
			} else {
				timer-=fElapsedTime;
				pos.y-=12*fElapsedTime;
			}
			if(timer<=0){
				dead=true;
			}
		}
	};

	std::shared_ptr<DamageNumber> CreateDamageNumber(vf2d pos,int dmg){
		std::shared_ptr<DamageNumber> ptr=std::make_shared<DamageNumber>(pos,dmg,2);
		damageNumbers.push_back(ptr);
		return ptr;
	};

	struct Object{
		vf2d pos;
		Renderable&r;
		Pixel col;
		float radius;
		float dir;
		vf2d spd;
		bool friendly=false;
		bool dead=false;
		int health=100;
		float invulnTimer=0;
		const float friction=100;
		std::shared_ptr<DamageNumber>ptrDamageNumber=nullptr;
		Object(vf2d pos,Renderable&r,Pixel col,float radius,float dir)
			:pos(pos),r(r),col(col),radius(radius),dir(dir){};
		virtual void Collision(SmartPointerExample*pge,Object&collisionObj){};
		void InternalUpdate(SmartPointerExample*pge,float fElapsedTime){
			pos+=spd*fElapsedTime;
			pos.x=std::max(0.f,std::min(float(pge->ScreenWidth()),pos.x));
			pos.y=std::max(0.f,std::min(float(pge->ScreenHeight()),pos.y));
			if(spd.x>0){
				spd.x=std::max(0.f,spd.x-friction*fElapsedTime);
			} else {
				spd.x=std::min(0.f,spd.x+friction*fElapsedTime);
			}
			if(spd.y>0){
				spd.y=std::max(0.f,spd.y-friction*fElapsedTime);
			} else {
				spd.y=std::min(0.f,spd.y+friction*fElapsedTime);
			}
			if(spd.x!=0||spd.y!=0){
				vf2d normSpd = spd.norm();
				dir=atan2(normSpd.y,normSpd.x);
			}
			if(health<=0){
				dead=true;
			}
			invulnTimer=std::max(0.f,invulnTimer-fElapsedTime);
		}
		virtual void Update(SmartPointerExample * pge, float fElapsedTime){}
		virtual void Draw(SmartPointerExample*pge){
			pge->DrawRotatedDecal(pos,r.Decal(),dir,r.Sprite()->Size()/2,{1,1},col);	
		};
	};
	struct Player:Object{
		Player(vf2d pos,Renderable&r,Pixel col,float radius,float dir)
			:Object(pos,r,col,radius,dir){
			friendly=true;
		}
		void Collision(SmartPointerExample*pge,Object&collisionObj)override{
			if(!collisionObj.friendly&&collisionObj.invulnTimer==0){
				collisionObj.health-=10;
				collisionObj.invulnTimer=0.5;
				if(collisionObj.ptrDamageNumber!=nullptr){
					if(collisionObj.ptrDamageNumber->stopTimer>0||collisionObj.ptrDamageNumber->timer>=1.0){
						collisionObj.ptrDamageNumber->dmg+=10;
						collisionObj.ptrDamageNumber->stopTimer=0.5;
					} else {
						std::shared_ptr ptrDamageNumber = pge->CreateDamageNumber(collisionObj.pos,10);
						collisionObj.ptrDamageNumber=ptrDamageNumber;
					}
				} else {
					std::shared_ptr ptrDamageNumber = pge->CreateDamageNumber(collisionObj.pos,10);
					collisionObj.ptrDamageNumber=ptrDamageNumber;
				}
			}
		}
		void Update(SmartPointerExample*pge,float fElapsedTime)override{
			if(pge->GetKey(UP).bHeld){
				spd.y=-32;
			}
			if(pge->GetKey(DOWN).bHeld){
				spd.y=32;
			}
			if(pge->GetKey(RIGHT).bHeld){
				spd.x=32;
			}
			if(pge->GetKey(LEFT).bHeld){
				spd.x=-32;
			}
		}
	};
	struct Enemy:Object{
		Enemy(vf2d pos,Renderable&r,Pixel col,float radius,float dir)
			:Object(pos,r,col,radius,dir){
			friendly=false;
		}
	};


	std::vector<std::unique_ptr<Object>>objects;
	std::vector<std::shared_ptr<DamageNumber>>damageNumbers;

public:
	SmartPointerExample()
	{
		// Name your application
		sAppName = "Smart Pointer Example";
	}

	Renderable player_img;

public:
	bool OnUserCreate() override
	{
		player_img.Load("assets/player.png");
		// Called once at the start, so create things here
		objects.push_back(std::make_unique<Player>(vf2d{32,32},player_img,GREEN,8,0));
		objects.push_back(std::make_unique<Enemy>(vf2d{64,128},player_img,DARK_RED,8,PI/2));
		objects.push_back(std::make_unique<Enemy>(vf2d{96,164},player_img,DARK_RED,8,1.75*PI));
		objects.push_back(std::make_unique<Enemy>(vf2d{32,196},player_img,DARK_RED,8,1.25*PI));
		objects.push_back(std::make_unique<Enemy>(vf2d{72,220},player_img,DARK_RED,8,PI/8));
		return true;
	}

	bool OnUserUpdate(float fElapsedTime) override
	{
		for(auto&ptrO:objects){
			Object*o=ptrO.get();
			for(auto&ptrO2:objects){
				Object*o2=ptrO2.get();
				if(o!=o2){
					auto dist = [&](vf2d pos1,vf2d pos2){return sqrt(pow(pos1.x-pos2.x,2)+pow(pos1.y-pos2.y,2));};
					if(dist(o->pos,o2->pos)<o->radius+o2->radius){
						o->Collision(this,*o2);
						o2->Collision(this,*o);
					}
				}
			}
			o->Update(this,fElapsedTime);
			o->InternalUpdate(this,fElapsedTime);
			o->Draw(this);
		}

		for(auto&ptrDamageNumber:damageNumbers){
			ptrDamageNumber->Update(this,fElapsedTime);
			DrawStringDecal(ptrDamageNumber->pos,std::to_string(ptrDamageNumber->dmg),RED);
		}

		std::erase_if(objects,[&](auto&ptrO){return ptrO->dead;});
		std::erase_if(damageNumbers,[&](auto&ptrDamageNumber){return ptrDamageNumber->dead;});
		return true;
	}
};

int main()
{
	SmartPointerExample demo;
	if (demo.Construct(256, 240, 4, 4))
		demo.Start();
	return 0;
}