/*
arrow.cpp
© Andrey Bushman, 18 Jun 2013
Chapter 13, exercise 3.
*/
//---------------------------------------------------------------------------
#include "arrow.h"
//*****************************************************************************
namespace Bushman{
	// Point get_offset_point(Point,double,double);
//---------------------------------------------------------------------------
	Arrow::Arrow(Point p0, double angle, double length, Arrow_style style): 
		ang(angle), len(length), s(style){

			Point Bushman::get_offset_point(Point,double,double);

			Point p1 = Bushman::get_offset_point(p0,angle,length);
			Point p2 = Bushman::get_offset_point(p0,angle+10,length/2);
			Point p3 = Bushman::get_offset_point(p0,angle-10,length/2);

			// стрелка указывает:			
			add(p0); // куда
			add(p1); // откуда
			// засечки
			add(p2);
			add(p3);
	}
//---------------------------------------------------------------------------
	Point get_offset_point(Point p0, double angle, double length){

		if(length < 0) 
			throw runtime_error("Invalid length value: " + to_string(length));

		if(angle > 360 || angle < -360) 
			throw runtime_error("Invalid angle value: " + to_string(angle));

		if(angle < 0) angle = 360 - abs(angle);

		// если угол не прямой, то переводим его в радианы.
		if(angle != 0 && angle != 90 && angle != 180 && angle != 270) 
			angle *= 3.14159265/180;

		// Определяю начало стрелки	(точка p1)	
		Point p1;
		if(angle == 0 || angle == 360){
			p1.x = p0.x + length;
			p1.y = p0.y;
		}
		else if(angle < 90){
			p1.x = p0.x + length * cos(angle);
			p1.y = p0.y - length * sin(angle);
		}
		else if(angle == 90){
			p1.y = p0.y - length;
			p1.x = p0.x;
		}
		else if(angle < 180){
			p1.x = p0.x - length * cos(180 - angle);
			p1.y = p0.y - length * sin(180 - angle);
		}
		else if(angle == 180){
			p1.x = p0.x - length;
			p1.y = p0.y;
		}
		else if(angle < 270){
			p1.x = p0.x - length * cos(270 - angle);
			p1.y = p0.y + length * sin(270 - angle);
		}
		else if(angle == 270){
			p1.x = p0.x;
			p1.y = p0.y + length;
		}		
		else if(angle < 360){
			p1.x = p0.x + length * cos(360 - angle);
			p1.y = p0.y + length * sin(360 - angle);
		}
		return p1;
	}
}

/*
arrow.h
© Andrey Bushman, 18 Jun 2013
Chapter 13, exercise 3.
*/
//---------------------------------------------------------------------------
#ifndef BUSH_ARROW_H
#define BUSH_ARROW_H
#include "../Point.h"
#include "../Graph.h"
//*****************************************************************************
namespace Bushman{
//---------------------------------------------------------------------------
	struct Arrow_style{
		enum Arrow_style_type{ none, lines, filled, unfilled};
		Arrow_style(Arrow_style_type style): s(style) {}
		Arrow_style_type style() const { return s; }
	private:
		Arrow_style_type s;
	};
//---------------------------------------------------------------------------
	class Arrow: public Graph_lib::Shape 
	// Arrow
	{
	public:
		Arrow(Point p0, double angle, double length, Arrow_style style);
		void draw_lines() const;
		double angle() const { return ang; }
		double length() const { return len; }
		void set_angle(double val) { ang = val; }
		void set_length(double val) { len = val; }
		Arrow_style style() const { return s; }
		void set_style(Arrow_style val) { s = val; }
	private:		
		double ang,len;
		Arrow_style s; 
	};
}
#endif