#include <graphics.h>

int GraphInit=0;
double rate_x=0;
double extremox=0;
double extremoy=0;
double rate_y=0;


int InitGraficos(void);
void Ejes( double,double,double,double);
void FinGraficos(void);
void Punto( double, double);

int  InitGraficos()
{
   int gdriver = 9, gmode=2;

   if(GraphInit != 1)
     initgraph(&gdriver, &gmode, "A:\BGI");
   if (graphresult() != grOk)
      return -1;
   else
   {
      GraphInit = 1;
      return 0;
   }
}


void Ejes( double x1, double x2, double y1, double y2)
{
  extremox=x1;
  extremoy=y1;

  rate_x=640.0 / (double) (x2-x1);
  rate_y=480.0 / (double) (y2-y1);

  moveto(0,240);
  lineto(640,240);
  moveto(320,0);
  lineto(320,480);
}

void Punto( double x, double y)
{
 putpixel( (x-extremox)*rate_x, 480 - (y-extremoy)*rate_y,15 );
}

void FinGraficos()
{
   closegraph();
}