函式名: putpixel
功 能: 在指定位置畫一像素
用 法: void far putpixel (int x, int y, int pixelcolor);
程式例:
#include <graphics.h>
#include <stdlib.h>
#include <stdio.h>
#include <conio.h>
#include <dos.h>
#define PIXEL_COUNT 1000
#define DELAY_TIME 100 /* in milliseconds */
int main(void)
{
/* request autodetection */
int gdriver = DETECT, gmode, errorcode;
int i, x, y, color, maxx, maxy, maxcolor, seed;
/* 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();
exit(1); /* terminate with an error code */
}
maxx = getmaxx() + 1;
maxy = getmaxy() + 1;
maxcolor = getmaxcolor() + 1;
while (!kbhit())
{
/* seed the random number generator */
seed = random(32767);
srand(seed);
for (i=0; i<PIXEL_COUNT; i++)
{
x = random(maxx);
y = random(maxy);
color = random(maxcolor);
putpixel(x, y, color);
}
delay(DELAY_TIME);
srand(seed);
for (i=0; i<PIXEL_COUNT; i++)
{
x = random(maxx);
y = random(maxy);
color = random(maxcolor);
if (color == getpixel(x, y))
putpixel(x, y, 0);
}
}
/* clean up */
getch();
closegraph();
return 0;
}
需要注意的是，如果沒有專門添加頭檔案和庫檔案，該函式並不能夠在vc中使用。
