drawpoly

函式drawpoly() 用當前繪圖色、線型及線寬，畫一個給定若干點所定義的多邊形·

基本介紹

• 中文名：drawpoly
• 實質：函式
• 第一個參數：是多邊形的頂點數
• 使用：當前繪圖色、線型及線寬
• 功 能：畫多邊形

簡介

函式名: drawpoly

第一個參數，是多邊形的頂點數

第二個參數，該數組存放著多邊形所有頂點(x,y)坐標值,即一系列整數對

用 法: void far drawpoly(int numpoints, int far *polypoints);

程式例:

#include <graphics.h>

#include <stdlib.h>

#include <stdio.h>

#include <conio.h>

int main(void)

{

/* request auto detection */

int gdriver = DETECT, gmode, errorcode;

int maxx, maxy;

/* our polygon array */

int poly[10];

/* initialize graphics and local

variables */

initgraph(&gdriver, &gmode, "");

/* read result of initialization */

errorcode = graphresult();

if (errorcode != grOk)

/* an error occurred */

{

printf("Graphics error: %s\n", \

grapherrormsg(errorcode));

printf("Press any key to halt:");

getch();

/* terminate with an error code */

exit(1);

}

maxx = getmaxx();

maxy = getmaxy();

poly[0] = 20; /* 1st vertext */

poly[1] = maxy / 2;

poly[2] = maxx - 20; /* 2nd */

poly[3] = 20;

poly[4] = maxx - 50; /* 3rd */

poly[5] = maxy - 20;

poly[6] = maxx / 2; /* 4th */

poly[7] = maxy / 2;

/*

drawpoly doesn't automatically close

the polygon, so we close it.

*/

poly[8] = poly[0];

poly[9] = poly[1];

/* draw the polygon */

drawpoly(5, poly);

/* clean up */

getch();

closegraph();

return 0;

}