leadline.cpp

#include <Siv3D.hpp>

enum class LeadLineTextHAlign
{
	Left,
	Right,
};

enum class LeadLineTextVAlign
{
	Top,
	Middle,
	Bottom,
};

void drawLeadLine(const Vec2& from, const Circular& lead1, const double lead2, const String text, const LeadLineTextHAlign halign, const LeadLineTextVAlign valign, const Font& font)
{
	const Vec2 p1 = from;
	const Vec2 p2 = p1 + lead1;
	const Vec2 p3 = p2 + Circular(lead2, halign == LeadLineTextHAlign::Left ? 270_deg : 90_deg);

	const Rect region = font(text).region();

	Vec2 pText;
	pText.x = halign == LeadLineTextHAlign::Left ? p3.x : p3.x - region.w;

	switch (valign)
	{
	case LeadLineTextVAlign::Top: pText.y = p3.y - region.h; break;
	case LeadLineTextVAlign::Middle: pText.y = p3.y - region.h / 2; break;
	case LeadLineTextVAlign::Bottom: pText.y = p3.y; break;
	}

	Line(p1, p2).draw(Palette::White);
	Line(p2, p3).draw(Palette::White);
	font(text).draw(pText, Palette::White);
}


void Main()
{
	Graphics::SetBackground(Palette::Black);

	const Font font(12);

	while (System::Update())
	{
		Circle(Window::Center(), 50.0).draw(Palette::Darkorange);

		drawLeadLine(Window::Center(), Circular(100.0, 60_deg), 150.0, L"引き出し線", LeadLineTextHAlign::Right, LeadLineTextVAlign::Top, font);
		drawLeadLine(Window::Center() + Circular(50.0, -45_deg), Circular(100.0, -45_deg), 150.0, L"左にも引ける", LeadLineTextHAlign::Left, LeadLineTextVAlign::Top, font);
	}
}