# PyFunc.py
# Plotting functions

from OpenGL.GL import *
from OpenGL.GLU import *
from OpenGL.GLUT import *
from numpy import *
import sys

def init():
	glClearColor(1.0, 1.0, 1.0, 1.0)
	gluOrtho2D(-2.0, 2.0, -2.0, 2.0)

def plotfunc():
	glClear(GL_COLOR_BUFFER_BIT)
	glColor3f(0.0, 0.0, 0.0)
	glPointSize(1.0)
	
	# Plot the coordinate axes
	glBegin(GL_LINES)
	glVertex2f(-2.0, 0.0)
	glVertex2f(2.0, 0.0)
	glVertex2f(0.0, 2.0)
	glVertex2f(0.0, -2.0)
	glEnd()

	# Plot the parametric equations
	glBegin(GL_POINTS)
	for t in arange(0.0,6.28, 0.001):
		x = sin(t)
		y = cos(t)
		glVertex2f(x, y)
	glEnd()
	glFlush()


def main():
	glutInit(sys.argv)
	glutInitDisplayMode(GLUT_SINGLE|GLUT_RGB)
	glutInitWindowPosition(50,50)
	glutInitWindowSize(250,250)
	glutCreateWindow("Parametric Plotter")
	glutDisplayFunc(plotfunc)
	
	init()
	glutMainLoop()

main()