夜空

https://gyazo.com/b213f42b4fdeb0cb37d102d99260f424

説明

星がいっぱいの夜空です．

流れない星

code:Star.hpp

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

class Star {

//星の数

int32 starCount;

//星の大きさ

double minSize, maxSize;

//double 星の色

ColorF starCol;

//星の生成エリア

Rect starArea;

//☆

Array<Circle> stars;

public:

Star(Rect _starArea = Scene::Rect(), int32 _starCount = 30)

:starArea(_starArea), starCount(_starCount), minSize(1.0), maxSize(2.0), starCol(Palette::White)

{

//星をランダムに配置

stars.clear();

for (int i : step(starCount))stars.push_back(Circle(RandomVec2(starArea), Random(minSize, maxSize)));

}

void update() {}

void draw() const{

for (const auto& s : stars)s.draw(ColorF{ starCol,Random(0.5,0.85) });

}

Star& setStarCount(int32 _starCount) { starCount = _starCount; return *this; }

Star& setMinSize(double _minSize) { minSize = _minSize; return *this; }

Star& setMaxSize(double _maxSize) { maxSize = _maxSize; return *this; }

Star& setStarCol(ColorF _starCol) { starCol = _starCol; return *this; }

Star& setStarArea(Rect _starArea) { starArea = _starArea; return *this; }

void create() {

stars.clear();

for (int i : step(starCount))stars.push_back(Circle(RandomVec2(starArea), Random(minSize, maxSize)));

};

};

流れる星

code:ShootingStar.hpp

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

class ShootingStar

{

struct ShootingStarobj

{

Vec2 pos;

double size;

Trail trail;

};

//最大の流れ星の数

int32 maxStars = 20;

//流れ星生成の間隔

double interval = 0.6;

//流れ星の速度

Vec2 speed{ -200,300 };

//流れ星が消える座標

double endPos;

//流れ星

Array<ShootingStarobj> shootingStars;

Stopwatch sw;

public:

ShootingStar(Vec2 _speed = { -200,300 }, double _interval = 0.6, int32 maxStars = 20)

:speed(_speed), interval(_interval), maxStars(maxStars), endPos{ (double)Scene::Height() * 2 / 3 }

{

sw.start();

}

void update() {

//流れ星の軌跡を更新

for (auto& s : shootingStars)s.trail.update();

//流れ星を生成

if (sw.sF() > interval and shootingStars.size() < maxStars) {

sw.restart();

double x = Random(Scene::Width() / 2, Scene::Width() + 200);

double y = Random(-500, -10);

double size = Random(1, 3);

const Trail trail{ Random(1.0, 3.0) };

shootingStars.push_back(ShootingStarobj{ {x,y},size,trail });

}

//流れ星を移動

const double t = Scene::DeltaTime();

for (int i : step(shootingStars.size())) {

}

}

//流れ星の軌跡が消えたら削除

shootingStars.remove_if([](const ShootingStarobj& s) {return s.trail.num_points() == 0; });

}

void draw() const {

// 星,流れ星

for (const auto& s : shootingStars)s.trail.draw();

}

ShootingStar& setSpeed(Vec2 _speed) { speed = _speed; return *this; }

ShootingStar& setInterval(double _interval) { interval = _interval; return *this; }

ShootingStar& setMaxStars(int32 _maxStars) { maxStars = _maxStars; return *this; }

ShootingStar& setEndPos(double _endPos) { endPos = _endPos; return *this; }

};

code:main.cpp

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

void Main()

{

ShootingStar shootingStar;

shootingStar.setSpeed({ -200,300 })

.setInterval(0.6)

.setMaxStars(20)

.setEndPos(Scene::Height() * 2 / 3);

Star stars;

stars.setStarArea(Rect{ 0,0,Scene::Width(),Scene::Height() * 2 / 3 })

.setStarCol(Palette::Aqua)

.setStarCount(50);

stars.create();

while (System::Update())

{

shootingStar.update();

//背景

Scene::Rect().draw(Arg::top = ColorF(0.0, 0.0, 0.2), Arg::bottom = ColorF(0.2, 0.2, 0.4));

shootingStar.draw();

stars.draw();

}

}

作者

BetAmoto