スポットライト

https://scrapbox.io/files/64dd9943a9f898001c19a211.png

code:スポットライト.cpp

# include <Siv3D.hpp>

class Spotlight {

public:

const MSRenderTexture renderTexture;

Spotlight(const Size&size=Scene::Size()):renderTexture{ size }{}

void draw()const {

const ScopedRenderStates2D blend{ BlendState::Multiplicative };

Graphics2D::Flush();

renderTexture.resolve();

renderTexture.draw();

}

};

class ScopedSpotlight {

public:

ScopedSpotlight(const Spotlight& spotlight,const ColorF& color=ColorF{0}) :target{spotlight.renderTexture.clear(color)} {}

private:

const ScopedRenderTarget2D target;

const ScopedRenderStates2D blend{ BlendState::Additive };

};

void Main()

{

Scene::SetBackground(ColorF{ 0.8 });

Spotlight light;

const int32 cellSize = 20;

Texture emoji1{ U"🐦"_emoji };

Texture emoji2{ U"🐣"_emoji };

Texture emoji3{ U"🦜"_emoji };

while (System::Update())

{

for (int32 y = 0; y < (Scene::Height() / cellSize); ++y)

{

for (int32 x = 0; x < (Scene::Width() / cellSize); ++x)

{

if (IsEven(y + x))

{

Rect{ (x * cellSize), (y * cellSize), cellSize }.draw(ColorF{ 0.75 });

}

}

}

emoji1.drawAt(200, 300);

emoji2.drawAt(400, 300);

emoji3.drawAt(600, 300);

{

//ライトを描く

ScopedSpotlight target{ light,ColorF{0.3} };

Circle{ Scene::Size() - Cursor::Pos(),100 }.draw(ColorF{0.5});

Circle{ Cursor::Pos(),100 }.draw(ColorF{0.5});

}

light.draw();

}

}

追記

2023/11/14：コードを変更しました。