レンダーテクスチャとガウスぼかしを使ったブルーム効果

https://gyazo.com/f5b64bd399f868defc39fdee12942f03

code:cpp

# include <Siv3D.hpp> // OpenSiv3D v0.6.11

void drawBg()

{

Scene::Rect().draw(Arg::top = ColorF(0.08), Arg::bottom = ColorF(0.25));

}

void drawScene()

{

TextureAsset(U"cat").resized(128).rotated(Scene::Time() * 2).drawAt(Scene::CenterF() + Circular(150, Scene::Time()));

TextureAsset(U"ghost").resized(128).rotated(Scene::Time() * 2.3).drawAt(Scene::CenterF() + Circular(150, Scene::Time() + Math::HalfPiF));

TextureAsset(U"alien").resized(128).rotated(Scene::Time() * 2.7).drawAt(Scene::CenterF() + Circular(150, Scene::Time() + Math::PiF));

TextureAsset(U"nko").resized(128).rotated(Scene::Time() * 3.5).drawAt(Scene::CenterF() + Circular(150, Scene::Time() - Math::HalfPiF));

}

void Main()

{

Scene::SetBackground(Palette::Black);

TextureAsset::Register(U"cat", Emoji(U"🐈"));

TextureAsset::Register(U"ghost", Emoji(U"👻"));

TextureAsset::Register(U"alien", Emoji(U"👾"));

TextureAsset::Register(U"nko", Emoji(U"💩"));

// シーン

RenderTexture rtScene(Scene::Size(), Palette::Black);

// Bloom用

RenderTexture rtBlurA(Scene::Size()), rtBlurB(Scene::Size());

RenderTexture rtBlur4A(Scene::Size() / 4), rtBlur4B(Scene::Size() / 4);

RenderTexture rtBlur8A(Scene::Size() / 8), rtBlur8B(Scene::Size() / 8);

// GUI

double sliderA = 0.2, sliderB = 0.25, sliderC = 0.37;

bool useGrayscale = false;

bool use = false;

// カスタムシェーダ

const PixelShader psDefault = HLSL{ U"example/shader/hlsl/default2d.hlsl", U"PS" };

const PixelShader psGrayscale = HLSL{ U"example/shader/hlsl/grayscale.hlsl", U"PS" };

while (System::Update())

{

drawBg();

{

ScopedCustomShader2D shader(useGrayscale ? psGrayscale : psDefault);

drawScene();

{

ScopedRenderTarget2D target(rtScene);

ScopedRenderStates2D state(BlendState::Additive);

rtScene.clear(Palette::Black);

drawScene();

}

if (use)

{

Shader::GaussianBlur(rtScene, rtBlurB, rtBlurA);

Shader::Downsample(rtBlurA, rtBlur4A);

Shader::GaussianBlur(rtBlur4A, rtBlur4B, rtBlur4A);

Shader::Downsample(rtBlur4A, rtBlur8A);

Shader::GaussianBlur(rtBlur8A, rtBlur8B, rtBlur8A);

{

ScopedRenderStates2D state(BlendState::Additive);

rtBlurA.draw(ColorF(sliderA));

rtBlur4A.resized(Scene::Size()).draw(ColorF(sliderB));

rtBlur8A.resized(Scene::Size()).draw(ColorF(sliderC));

}

}

}

{

const Transformer2D t{ Mat3x2::Scale(0.75, Vec2(0, 0)), TransformCursor::Yes };

SimpleGUI::Slider(Format(sliderA), sliderA, 0.0, 2.0, Vec2(20, 20));

SimpleGUI::Slider(Format(sliderB), sliderB, 0.0, 2.0, Vec2(20, 60));

SimpleGUI::Slider(Format(sliderC), sliderC, 0.0, 2.0, Vec2(20, 100));

SimpleGUI::CheckBox(useGrayscale, U"grayscale", Vec2(20, 140));

SimpleGUI::CheckBox(use, U"use", Vec2(20, 180));

}

}

}