/*
 * File: trygraphics2.c
 * -------------
 *  Eric Siegel testing graphics some more
 */

#include <stdio.h>
#include <math.h>
#include "genlib.h"
#include "simpio.h"
#include "graphics.h"

#define PI 3.14159

/*  This function draws a line from (x1,y1) to (x2,y2) */
void
AbsLine(double x1, double y1, double x2, double y2)
{
    MovePen(x1,y1);
    DrawLine(x2-x1,y2-y1);
}

main()
{
    double cx, cy;     /* center of window */
    double height, width;
    double i, dy;

    InitGraphics();

    width = GetWindowWidth();       /* window width */
    cx = width / 2;                 /* center of x-axis */
    height = GetWindowHeight();     /* window height */
    cy = height / 2;                /* center of y-axis */

    /* Funky grid pattern */
    SetPenColor("Red");
    for(i=0; i < height; i += .1) {
      AbsLine(0,i,height-i,0);
    }

    /* Parabolic arc, dude */    
    SetPenColor("Blue");
    for(dy=0; dy < 1; dy += .1) {
      DrawLine(.5,dy);
    }

    /* Crave the Sine Wave */
    SetPenColor("Dark Gray");
    SetPenColor("Green");
    for(i=0; i < 2*PI ; i+=.01) {
      AbsLine(i,cy+sin(i),i,cy+sin(i));
    }
}

email: evs at cs dot columbia dot edu