// 名稱: veh_inh.cc
// 作者: 洪朝貴 http://www.cyut.edu.tw/~ckhung/
// 功能: 示範繼承相關問題
// 日期: 11-1999
// 編譯方式:
//	1. 一併取得 ../c/sitio.c 與 ../c/sitio.h
//	2. gcc -Wall sitio.c veh_inh.cc

extern "C" {
#include <stdio.h>
#include "sitio.h"
}

class object {
public:
    int x, y;
    void draw() const {}
    void clear() const {}
    void move(int dx, int dy);
};

class wheel : public object {
public:
    wheel(int x0, int y0) { x = x0; y = y0; }
    void draw() const;
    void clear() const;
};

class vehicle : public object {
public:
    const char style;
    wheel front_wh, rear_wh;
    vehicle(int x0, int y0, char st = '-') :
	style(st), front_wh(x0-5, y0), rear_wh(x0+5, y0)
	{ x = x0; y = y0; }
    void draw() const;
    void clear() const;
    void move(int dx, int dy);
};

class ambulance : public vehicle {
public:
    ambulance(int x0, int y0, char st = '*') : vehicle(x0, y0, st) {}
    void draw() const;
};

class jet_ambulance : public ambulance {
public:
    jet_ambulance(int x0, int y0, char st = '@') : ambulance(x0, y0, st) {}
    void draw() const;
};

inline void gotoxy(int x, int y) { gotorc(25-y, x); }

void object::move(int dx, int dy)
{
    x += dx;
    y += dy;
}

void wheel::draw() const
{
    gotoxy(x-1,y+1);	printf("/-\\");
    gotoxy(x-1,y);	printf("|o|");
    gotoxy(x-1,y-1);	printf("\\-/");
}

void wheel::clear() const
{
    gotoxy(x-1,y+1);	printf("   ");
    gotoxy(x-1,y);	printf("   ");
    gotoxy(x-1,y-1);	printf("   ");
}

void vehicle::draw() const
{
    int k;
    front_wh.draw();
    rear_wh.draw();
    gotoxy(x-6, y+5);
    for (k=-6; k<=6; ++k) putchar(style);
    gotoxy(x-3, y);
    for (k=-3; k<=3; ++k) putchar(style);
    for (k=0; k<=5; ++k) {
	gotoxy(x-7, y+k);	putchar('|');
	gotoxy(x+7, y+k);	putchar('|');
    }
}

void vehicle::clear() const
{
    front_wh.clear();
    rear_wh.clear();
    for (int k=0; k<=5; ++k) {
	gotoxy(x-7, y+k);	printf("%15s", "");
    }
}

void vehicle::move(int dx, int dy)
{
    object::move(dx, dy);
    front_wh.move(dx, dy);
    rear_wh.move(dx, dy);
}

void ambulance::draw() const
{
    vehicle::draw();
    gotoxy(x-4, y+6);	printf("O");
}

void jet_ambulance::draw() const
{
    ambulance::draw();
    gotoxy(x+8, y);	printf("<<");
    gotoxy(x-4, y+3);	printf("j-a");
}

#include <stdlib.h>

void race(vehicle * a, vehicle * b)
{
    int k;
    a->draw();
    b->draw();
    while (a->x > 10 || b->x > 10) {
	getkey();
	k = (a->x<=10) ? 1 : (b->x<=10) ? 0 : rand()%2;
	if (k) {
	    b->clear(); b->move(-1, 0); b->draw();
	} else {
	    a->clear(); a->move(-1, 0); a->draw();
	}
    }
}

int main(void)
{
    initsitio();
    {
	clearscr();
	vehicle v0(10,10);
	ambulance v1(30, 10);
	jet_ambulance v2(50, 10);
	v0.draw();	getkey();
	v1.draw();	getkey();
	v2.draw();	getkey();
	v0.clear();	getkey();
	v1.clear();	getkey();
	v2.clear();	getkey();
    }
    {
	clearscr();
	jet_ambulance v0(70, 5);
	ambulance v1(70, 15);
	race(&v0, &v1);
    }
    gotoxy(1,1);
    return 0;
}