C语言经典100例题（56-60）--画圆；画方；画线

目录

【程序56】题目：画图，学用circle画圆形

【程序57】题目：画图，学用line画直线。

【程序58】题目：画图，学用rectangle画方形。

【程序59】题目：画图，综合例子。

【程序60】题目：画图，综合例子。　　　

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【程序56】

题目：画图，学用circle画圆形

#include "graphics.h"
#include<conio.h>
int main()
{
    int  i;
    float j = 1, k = 1;
    initgraph(640, 480);
    setbkcolor(YELLOW);
    cleardevice();
    for (i = 0;i <= 25;i++)
    {
        setlinestyle(PS_SOLID, 4);
        setlinecolor(BLUE);
        circle(310, 250, k);
        k = k + j;
        j = j + 0.3;
    }
    _getch();
    closegraph();//关闭窗口
}

【程序57】

题目：画图，学用line画直线。

#include "graphics.h"
#include<conio.h>
int main()
{
    int i;
    float x0, y0, y1, x1;
    float j = 12, k;
    initgraph(640, 480);
    setbkcolor(GREEN);
    cleardevice();
    x0 = 263;y0 = 263;y1 = 275;x1 = 275;
    for (i = 0;i <= 18;i++)
    {
        setlinestyle(PS_SOLID, 4);
        setlinecolor(BLUE);
        line(x0, y0, x0, y1);
        x0 = x0 - 5;
        y0 = y0 - 5;
        x1 = x1 + 5;
        y1 = y1 + 5;
        j = j + 10;
    }
    x0 = 263;y1 = 275;y0 = 263;
    for (i = 0;i <= 20;i++)
    {
        setlinestyle(PS_SOLID, 4);
        setlinecolor(BLUE);
        line(x0, y0, x0, y1);
        x0 = x0 + 5;
        y0 = y0 + 5;
        y1 = y1 - 5;
    }
    _getch();
    closegraph();//关闭窗口
}

【程序58】

题目：画图，学用rectangle画方形。

程序分析：利用for循环控制100 - 999个数，每个数分解出个位，十位，百位。

#include <graphics.h>
#include<conio.h>
int main()
{
    int x0, y0, y1, x1, i;
    initgraph(640, 480);
    setbkcolor(YELLOW);
    cleardevice();
    x0 = 263;y0 = 263;y1 = 275;x1 = 275;
    for (i = 0;i <= 18;i++)
    {
        setlinestyle(PS_SOLID, 4);
        setlinecolor(BLUE);
        rectangle(x0, y0, x1, y1);
        x0 = x0 - 5;
        y0 = y0 - 5;
        x1 = x1 + 5;
        y1 = y1 + 5;
    }
    setcolor(2);
    circle(269, 269, 137);
    _getch();
    closegraph();//关闭窗口
}

【程序59】

题目：画图，综合例子。

# define PAI 3.1415926
# define B 0.809
# include "graphics.h"
#include "math.h"
#include<conio.h>
int main()
{
    int i, j, k, x0, y0, x, y;
    float a;
    initgraph(640, 480);
    setlinestyle(PS_SOLID, 3);
    setlinecolor(BLUE);
    setbkcolor(GREEN);
    cleardevice();
    x0 = 150;y0 = 100;
    circle(x0, y0, 10);
    circle(x0, y0, 20);
    circle(x0, y0, 50);
    for (i = 0;i < 16;i++)
    {
        a = (2 * PAI / 16) * i;
        x = ceil(x0 + 48 * cos(a));
        y = ceil(y0 + 48 * sin(a) * B);
        setlinestyle(PS_SOLID, 3);
        setlinecolor(BLUE);
        line(x0, y0, x, y);
    }
    setcolor(3);circle(x0, y0, 60);
    /* Make 0 time normal size letters */
    _getch();
    setfillstyle(10, YELLOW);
    floodfill(202, 100, WHITE);
    _getch();
    for (k = 0;k <= 500;k++)
    {
        setlinestyle(PS_SOLID, 4);
        setlinecolor(BLUE);
        for (i = 0;i <= 16;i++)
        {
            a = (2 * PAI / 16) * i + (2 * PAI / 180) * k;
            x = ceil(x0 + 48 * cos(a));
            y = ceil(y0 + 48 + sin(a) * B);
            setlinestyle(PS_SOLID, 3);
            setlinecolor(BLUE);
            line(x0, y0, x, y);
        }
        for (j = 1;j <= 50;j++)
        {
            a = (2 * PAI / 16) * i + (2 * PAI / 180) * k - 1;
            x = ceil(x0 + 48 * cos(a));
            y = ceil(y0 + 48 * sin(a) * B);
            line(x0, y0, x, y);
        }
    }
    restorecrtmode();
    _getch();
    closegraph();//关闭窗口
}

【程序60】

题目：画图，综合例子。

#include "graphics.h"
#include<conio.h>
#define LEFT 0
#define TOP 0
#define RIGHT 639
#define BOTTOM 479
#define LINES 400
#define MAXCOLOR 15
int main()
{
    int error=0;
    int x1, y1;
    int x2, y2;
    int dx1, dy1, dx2, dy2, i = 1;
    int count = 0;
    int color = 0;
    initgraph(640, 480);
    x1 = x2 = y1 = y2 = 10;
    dx1 = dy1 = 2;
    dx2 = dy2 = 3;
    while (!_kbhit())
    {
        line(x1, y1, x2, y2);
        x1 += dx1;y1 += dy1;
        x2 += dx2;y2 + dy2;
        if (x1 <= LEFT || x1 >= RIGHT)
            dx1 = -dx1;
        if (y1 <= TOP || y1 >= BOTTOM)
            dy1 = -dy1;
        if (x2 <= LEFT || x2 >= RIGHT)
            dx2 = -dx2;
        if (y2 <= TOP || y2 >= BOTTOM)
            dy2 = -dy2;
        if (++count > LINES)
        {
            setlinestyle(PS_SOLID, 0);
            setlinecolor(BLUE);
            color = (color >= MAXCOLOR) ? 0 : ++color;
        }
    }
    closegraph();
    _getch();
    closegraph();//关闭窗口
}