Examples/Matrices.cpp at master · defGameEngine/Examples · GitHub

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#include"../Include/defGameEngine.hpp"

structmat2x2
{
float* operator[](size_t i) { return m[i]; }

float m[2][2]{ 0 };
};

voidMat_MultiplyMat(mat2x2& matA, mat2x2& matB, mat2x2& matResult)
{
for (size_t i = 0; i < 2; i++)
for (size_t j = 0; j < 2; j++)
 {
for (size_t k = 0; k < 2; k++)
 matResult[i][j] += matA[i][k] * matB[k][j];
 }
}

voidMat_MultiplyVec(mat2x2& matA, def::Vector2f& vecB, def::Vector2f& vResult)
{
	vResult.x = matA[0][0] * vecB.x + matA[0][1] * vecB.y;
	vResult.y = matA[1][0] * vecB.x + matA[1][1] * vecB.y;
}

voidMat_MakeRotation(mat2x2& matA, constfloatfAngle)
{
float s = sin(fAngle), c = cos(fAngle);
	matA[0][0] = c;
	matA[0][1] = s;
	matA[1][0] = -s;
	matA[1][1] = c;
}

voidMat_MakeScale(mat2x2& matA, const def::Vector2f& vScale)
{
	matA[0][0] = vScale.x;
	matA[0][1] = 0.0f;
	matA[1][0] = 0.0f;
	matA[1][1] = vScale.y;
}

classSample : publicdef::GameEngine
{
public:
Sample()
	{
Window().SetTitle("Sample");
	}

protected:
boolOnUserCreate() override
	{
 sprDemo = newdef::Sprite("assets/road.jpg");
returntrue;
	}

boolOnUserUpdate(floatfDeltaTime) override
	{
 mat2x2 matRotated, matScaled;

Mat_MakeRotation(matRotated, fTheta);
Mat_MakeScale(matScaled, { 0.5f, 0.5f });

Clear(def::BLACK);

 def::Vector2f vPos;
for (vPos.y = 0; vPos.y < sprDemo->size.y; vPos.y++)
for (vPos.x = 0; vPos.x < sprDemo->size.x; vPos.x++)
 {
 def::Vector2f vScaled;
Mat_MultiplyVec(matScaled, vPos, vScaled);

 def::Vector2f vRotated;
Mat_MultiplyVec(matRotated, vScaled, vRotated);

 def::Vector2f vTranslated;
 vTranslated = vRotated + def::Vector2f(Window().GetScreenWidth() * 0.5f, Window().GetScreenHeight() * 0.5f);

Draw(vTranslated, sprDemo->GetPixel(vPos.x, vPos.y));
 }

fTheta += fDeltaTime;
returntrue;
	}

private:
	def::Sprite* sprDemo = nullptr;
floatfTheta = 0.0f;

};

intmain()
{
	Sample demo;

	demo.Construct(1280, 720, 1, 1);
	demo.Run();

return0;
}