CPlusPlusProjectTemplate/main.cpp

#define OLC_PGE_APPLICATION
#include "pixelGameEngine.h"

using namespace olc;

class Circles : public olc::PixelGameEngine
{
public:
	Circles()
	{
		sAppName = "Circles";
	}

public:

	int CIRCLE_PRECISION=32;

	void DrawCircleDecal(vf2d pos,float radius,Pixel col=WHITE) {
		std::vector<vf2d> poly;
		std::vector<vf2d> uvs;
		for (int i=0;i<CIRCLE_PRECISION;i++) {
			poly.push_back({pos.x+sinf(2*M_PI/CIRCLE_PRECISION*i)*radius,pos.y+cosf(2*M_PI/CIRCLE_PRECISION*i)*radius});
			uvs.push_back({0,0});
		}
		poly.push_back(poly[0]);
		uvs.push_back({0,0});
		SetDecalStructure(DecalStructure::LINE);
		SetDecalMode(DecalMode::WIREFRAME);
		DrawPolygonDecal(nullptr,poly,uvs,col);
		SetDecalMode(DecalMode::NORMAL);
		SetDecalStructure(DecalStructure::FAN);
	}
	void FillCircleDecal(vf2d pos,float radius,Pixel col=WHITE) {
		std::vector<vf2d> poly;
		std::vector<vf2d> uvs;
		poly.push_back(pos);
		uvs.push_back({0,0});
		for (int i=0;i<CIRCLE_PRECISION;i++) {
			poly.push_back({pos.x+sinf(2*M_PI/CIRCLE_PRECISION*i)*radius,pos.y+cosf(2*M_PI/CIRCLE_PRECISION*i)*radius});
			uvs.push_back({0,0});
		}
		poly.push_back(poly[1]);
		uvs.push_back({0,0});
		DrawPolygonDecal(nullptr,poly,uvs,col);
	}

	bool OnUserCreate() override
	{
		// Called once at the start, so create things here
		return true;
	}

	bool OnUserUpdate(float fElapsedTime) override
	{
		// called once per frame
		DrawCircleDecal({50,50},10,BLUE);
		FillCircleDecal({100,100},20,GREEN);
		return true;
	}
};


int main()
{
	Circles demo;
	if (demo.Construct(256, 240, 4, 4))
		demo.Start();

	return 0;
}