//open a display window
//and generate a sine curve

//www.timestocome.com

//to compile in OSX
//gcc sine.c -o sine -framework OpenGL -framework GLUT

#include <stdlib.h>
#include <stdio.h>
#include <math.h>
#include <GLUT/glut.h>



void display (void){

	typedef GLfloat point2[2];			//define a point array
	long int k;
	point2 p = {0.0, 0.0};				//start somewhere
	glClear(GL_COLOR_BUFFER_BIT);		//clear window



	for( k=0; k<2500; k++){
										//compute point

		p[0] += 500.0/2500.0;
		p[1] = (sin(p[0])*10.0)+125;

										//plot point

		glBegin(GL_POINTS);

			glVertex2fv(p);

		glEnd();

	}

	glFlush();							//plot quickly..  only benefit if on a network

}





void myinit (void){

//attributes

	glClearColor(1.0, 1.0, 1.0, 0.0);	//backround
	glColor3f(1.0, 0.0, 0.0);			//draw color



//set up viewing

	glMatrixMode(GL_PROJECTION);
	gluOrtho2D(0.0, 500.0, 0.0, 250.0);	//2d coordinate sys lower left corner 0,0
	glMatrixMode(GL_MODELVIEW);

}





void main(int argc, char **argv)

{

	glutInit(&argc, argv);
    glutInitWindowSize(500, 250);
   	glutInitDisplayMode(GLUT_RGB|GLUT_SINGLE);
    (void)glutCreateWindow("2d Sine Curve");
    glutDisplayFunc(display);
	myinit();
	glutMainLoop();

}