在指定位置画一像素

[c]代码库

#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; 
}