C语言经典100例题（62-65）--学习putpixel画点；画椭圆ellipse；利用ellipse and rectangle 画图；一个最优美的图案

目录

题目【62】：学习putpixel画点

题目【63】：画椭圆ellipse

题目【64】：利用ellipse and rectangle 画图

题目【65】：一个最优美的图案

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以下题目的代码均可在VS上运行。注意源文件的后缀要为“.cpp”

题目【62】：学习putpixel画点

 

#include "stdio.h"
#include "graphics.h"
#include "conio.h"
int main()
{
	int i, j;
	initgraph(640, 680);
	setbkcolor(YELLOW);
	cleardevice();
	for (i = 50;i <= 230;i += 20)
		for (j = 50;j <= 230;j++)
			putpixel(i, j, 1);
	for (j = 50;j <= 230;j += 20)
		for (i = 50;i <= 230;i++)
			putpixel(i, j, 1);
	_getch();
}

题目【63】：画椭圆ellipse

 

#include "stdio.h"
#include "graphics.h"
#include "conio.h"
int main()
{
	int x = 360, y = 160;
	int num = 20, i;
	int top, bottom;
	initgraph(640,680);
	top = y - 30;
	bottom = y - 30;
	for (i = 0;i < num;i++)
	{
		ellipse(250, 250, 0, 360);
		top -= 5;
		bottom += 5;
	}
	_getch();
}

题目【64】：利用ellipse and rectangle 画图

 

#include "stdio.h"
#include "graphics.h"
#include "conio.h"
int main()
{
	int i, num = 15, top = 50;
	int left = 20, right = 50;
	initgraph(640, 680);
	for (i = 0;i < num;i++)
	{
		ellipse(250, 250, 0, 360);
		ellipse(250, 250, 0, 360);
		rectangle(20 - 2 * i, 20 - 2 * i, 10 * (i + 2), 10 * (i + 2));
		right += 5;
		left += 5;
		top += 10;
	}
	_getch();
}

题目【65】：一个最优美的图案

 

#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;
	h = 400;w = 600;
	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 */
		}
	}
}
int main()
{
	initgraph(640, 580);
	setcolor(3);
	setbkcolor(GREEN);
	cleardevice();
	LineToDemo();
	system("pause");
	return 0;
}