065.c

// 【程序65】
// 题目：一个最优美的图案。
// 1.程序分析：
// 2.程序源代码：
#include "graphics.h"
#include "math.h"
#include "dos.h"
#include "conio.h"
#include "stdlib.h"
#include "stdio.h"
#include "stdarg.h"
#define MAXPTS 15
#define PI 3.1415926
struct PTS {
	int x, y;
};
double AspectRatio = 0.85;
void LineToDemo(void) {
	struct viewporttype vp;
	struct PTS points[MAXPTS];
	int i, j, h, w, xcenter, ycenter;
	int radius, angle, step;
	double rads;
	printf(" MoveTo / LineTo Demonstration" );
	getviewsettings( &vp );
	h = vp.bottom - vp.top;
	w = vp.right - vp.left;
	xcenter = w / 2; /* Determine the center of circle */
	ycenter = h / 2;
	radius = (h - 30) / (AspectRatio * 2);
	step = 360 / MAXPTS; /* Determine # of increments */
	angle = 0; /* Begin at zero degrees */
	for ( i = 0 ; i < MAXPTS ; ++i ) { /* Determine circle intercepts */
		rads = (double)angle * PI / 180.0; /* Convert angle to radians */
		points[i].x = xcenter + (int)( cos(rads) * radius );
		points[i].y = ycenter - (int)( sin(rads) * radius * AspectRatio );
		angle += step; /* Move to next increment */
	}
	circle( xcenter, ycenter, radius ); /* Draw bounding circle */
	for ( i = 0 ; i < MAXPTS ; ++i ) { /* Draw the cords to the circle */
		for ( j = i ; j < MAXPTS ; ++j ) { /* For each remaining intersect */
			moveto(points[i].x, points[i].y); /* Move to beginning of cord */
			lineto(points[j].x, points[j].y); /* Draw the cord */
		}
	}
}
main() {
	int driver, mode;
	driver = CGA; mode = CGAC0;
	initgraph(&driver, &mode, "");
	setcolor(3);
	setbkcolor(GREEN);
	LineToDemo();
}