Chapter14_exercise5_PPPC++

c14_ex5.cpp

/* 14章 練習問題5 */

#include "Simple_window.h"
#include "Graph.h"

struct Striped_rectangle : Shape {

    Striped_rectangle(Point xy, int ww, int hh) : w(ww), h(hh)
    {
        add(xy);
        if (h<=0 || w<=0) error("Bad rectangle: non-positive side");
    }

    Striped_rectangle(Point x, Point y) : w(y.x-x.x), h(y.y-x.y)
    {
        add(x);
        if (h<=0 || w<=0) error("Bad rectangle: non-positive width or height");
    }
    void draw_lines() const;

    int height() const { return h; }
    int width() const { return w; }
private:
    int h;    // height
    int w;    // width
};

void Striped_rectangle::draw_lines()const
{
    if (fill_color().visibility()) {    // fill        
        fl_color(fill_color().as_int());
        
        int const padding = 3;    // 余白
        int const line_height = 5;  // ライン間の長さ

        int x_begin = point(0).x + padding;
        int x_end = x_begin + width() - padding;
        int y_begin = point(0).y + padding;
        int y_end = y_begin + height() - padding;
        for(int y = y_begin; y < y_end; y += line_height){
            fl_line(x_begin, y, x_end, y);
        }
        
        fl_color(color().as_int());    // reset color
    }

    if (color().visibility()) {    // lines on top of fill
        fl_color(color().as_int());
        fl_rect(point(0).x,point(0).y,w,h);
    }
}

int main()
{
    Simple_window win1(Point(50, 50), 800, 600, "Chapter14 Ex.5");

    Striped_rectangle sr(Point(50, 50), 200, 100);
    sr.set_color(Color::white);   // 白枠
    sr.set_fill_color(Color::blue); // 青の縞で塗りつぶし
    win1.attach(sr);

    win1.wait_for_button();
}