Coding Style¶

This page explains Siv3D's coding style.

Variables¶

Variables use camelCase

# include <Siv3D.hpp>

void Main()
{
	int32 count = 0;

	const Texture texture{ U"example/windmill.png" };

	while (System::Update())
	{

	}
}

constexpr constants use PascalCase

# include <Siv3D.hpp>

void Main()
{
	constexpr Size SceneSize{ 640, 480 };

	constexpr ColorF BackgroundColor{ 0.8, 0.9, 1.0 };

	while (System::Update())
	{

	}
}

Functions¶

Function names use PascalCase

# include <Siv3D.hpp>

[[nodiscard]]
constexpr int32 Add(const int32 a, const int32 b) noexcept
{
	return (a + b);
}

void Main()
{
	Print << Add(10, 20);

	while (System::Update())
	{

	}
}

Classes¶

Class names use PascalCase
Use struct if it only has public members, otherwise use class
For class, write in the order public: → protected: → private: unless necessary
Non-static private member variables start with m_ and continue with camelCase
Non-static member functions use camelCase
Static member functions use PascalCase
Static member constants use PascalCase

# include <Siv3D.hpp>

class Button
{
public:

	Button() = default;

	Button(const String& label, const Vec2& pos, const Font& font, double fontSize = 20.0)
		: m_label{ label }
		, m_pos{ pos }
		, m_font{ font }
		, m_fontSize{ fontSize }
		, m_width{ m_font(label).region(fontSize).w + Padding * 2 } {}

	[[nodiscard]]
	RectF getRect() const noexcept
	{
		if (isEmpty())
		{
			return Rect::Empty();
		}

		return{ m_pos, m_width, ButtonHeight };
	}

	[[nodiscard]]
	bool pushed() const noexcept
	{
		if (isEmpty())
		{
			return false;
		}

		return getRect().leftClicked();
	}

	void draw() const
	{
		if (isEmpty())
		{
			return;
		}

		const RectF rect = getRect();

		const bool mouseOver = rect.mouseOver();

		rect.rounded(ButtonRadius).draw(mouseOver ? ButtonMouseOverColor : ButtonColor);

		m_font(m_label).drawAt(m_fontSize, rect.center(), ButtonLabelColor);

		if (mouseOver)
		{
			Cursor::RequestStyle(CursorStyle::Hand);
		}
	}

	[[nodiscard]]
	bool isEmpty() const noexcept
	{
		return (m_width == EmptyWidth);
	}

private:

	String m_label;

	Vec2 m_pos{ 0, 0 };

	Font m_font;

	double m_fontSize = 0.0;

	double m_width = EmptyWidth;

	static constexpr double EmptyWidth = 0.0;

	static constexpr double Padding = 20.0;

	static constexpr double ButtonRadius = 4.0;

	static constexpr int32 ButtonHeight = 40;

	static constexpr ColorF ButtonColor{ 0.8, 0.9, 1.0 };

	static constexpr ColorF ButtonMouseOverColor{ 0.9, 0.95, 1.0 };

	static constexpr ColorF ButtonLabelColor{ 0.11 };
};

void Main()
{
	const Font font{ FontMethod::MSDF, 48, Typeface::Bold };

	const Button button{ U"OK", Vec2{ 100, 100 }, font };

	while (System::Update())
	{
		if (button.pushed())
		{
			Print << U"OK";
		}

		button.draw();
	}
}

Enums¶

Enum names use PascalCase
Enumerators use PascalCase
Use enum class rather than enum

Indentation¶

Use tab characters

Brace Style¶

Use Allman style

# include <Siv3D.hpp>

void Main()
{
	while (System::Update())
	{
		if (MouseL.down())
		{
			Print << U"MouseL.down()";
		}
	}
}

Comparison Operators¶

Don't use > and >= unless there's a specific reason

Floating-Point Literals¶

Always write digits before and after the decimal point

double x = 1.0; // OK
double y = 1.; // NG
double z = .1; // NG

Parentheses¶

Use them actively

Alternative Tokens¶

Replace the logical NOT operator ! with not

# include <Siv3D.hpp>

void Main()
{
	const Texture texture{ U"example/windmill.png" };

	if (not texture)
	{
		return;
	}

	while (System::Update())
	{

	}
}

Increment/Decrement Operators¶

Use prefix operators unless there's a specific reason

Array Names¶

Use plural forms
For words without plural forms, use ~List

include¶

# include <...>
# include "..."

Include Guards¶

# pragma once

Source File Names¶

PascalCase
Source files use .cpp
Header files use .hpp
Header files for detailed implementation included by header files use .ipp