モクモク

https://gyazo.com/fbf87f29f5b41aa9aa3086b3a563a66d

Emoji を使って煙のようなエフェクト

code:cpp

# include <Siv3D.hpp> // OpenSiv3D v0.3.2

struct Smoke : IEffect

{

const Vec2 m_pos;

const double m_size;

const double m_speed;

const double m_time;

const double m_delay;

Smoke(const Vec2& pos)

:

m_pos(pos + RandomVec2(Random(20, 70))),

m_size(Random(0.8, 2.0)),

m_speed(Random(30, 100)),

m_time(Random(0.3, 0.7)),

m_delay(Random(0.0, 0.3))

{

}

virtual bool update(double timeSec) override

{

const double time = timeSec - m_delay;

if (time < 0) return true;

const double t = 1.0 - time / m_time; // 1.0 ～ 0.0

const auto scale = Vec2(80, 120) * m_size * (0.5 + t * 0.5);

TextureAsset(U"smoke").resized(scale).rotated((628 * Random(8) / 8) / 100.0).drawAt(m_pos + Vec2(0, -m_speed * (1.0 - t)), ColorF(Palette::White, 0.8 * t));

return time < m_time;

}

};

void Main()

{

Graphics::SetBackground(ColorF(0.1, 0.1, 0.2));

TextureAsset::Register(U"smoke", Emoji(U"☁"), TextureDesc::Mipped);

Effect effect;

while (System::Update())

{

if (MouseL.down())

{

for (int i : step(8))

{

effect.add(std::unique_ptr<IEffect>(new Smoke(Cursor::PosF())));

}

}

effect.update();

}

}