从当前位置点(CP)到与CP有一给定相对距离的点画一直线

[c]代码库

#include <graphics.h> 
#include <stdlib.h> 
#include <stdio.h> 
#include <conio.h> 

int main(void) 
{ 
   /* request auto detection */ 
   int gdriver = DETECT, gmode, errorcode; 
   char msg[80]; 

   /* initialize graphics and local variables */ 
   initgraph(&gdriver, &gmode, ""); 

   /* read result of initialization */ 
   errorcode = graphresult(); 
   if (errorcode != grOk) 
   { 
      printf("Graphics error: %s\n", 
  grapherrormsg(errorcode)); 
      printf("Press any key to halt:"); 
      getch(); 
      exit(1); 
   } 

   /* move the C.P. to location (20, 30) */ 
   moveto(20, 30); 

   /* create and output a 
      message at (20, 30) */ 
   sprintf(msg, " (%d, %d)", getx(), gety()); 
   outtextxy(20, 30, msg); 

   /* draw a line to a point a relative 
      distance away from the current 
      value of C.P.   */ 
   linerel(100, 100); 

   /* create and output a message at C.P. */ 
   sprintf(msg, " (%d, %d)", getx(), gety()); 
   outtext(msg); 

   /* clean up */ 
   getch(); 
   closegraph(); 
   return 0; 
}