opengl02.py

#!/usr/bin/python3
# ===================================================================
# pip3 install PyOpenGL PyOpenGL_acclerate
# sudo apt-get install python-opengl
#
# Example From: stackabuse.com/
#       brief-introduction-to-opengl-in-python-with-pyopengl/
# ===================================================================

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

import sys

# -------------------------------------------------------------------
# we have to declare the points in this instance:
# bottom left, bottom right, top right, top left
def square():
    glBegin(GL_QUADS)
    glVertex2f(100,100)  # bottom left
    glVertex2f(200,100)  # bottom right
    glVertex2f(200,200)  # top right
    glVertex2f(100,200)  # top left
    glEnd()

# -------------------------------------------------------------------
def iterate():
    glViewport(0,0,500,500)
    glMatrixMode(GL_PROJECTION)
    glLoadIdentity()
    glOrtho(0.0,500,0.0,500,0.0,1.0)
    glMatrixMode(GL_MODELVIEW)
    glLoadIdentity()

#--------------------------------------------------------------------
def showScreen():
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT)
    glLoadIdentity()
    iterate()
    glColor3f(1.0,0.0,3.0)
    square()
    glutSwapBuffers()

glutInit()
glutInitDisplayMode(GLUT_RGBA)
glutInitWindowSize(500,500)
glutInitWindowPosition(0,0)
wind = glutCreateWindow("OpenGL Coding Practice")
glutDisplayFunc(showScreen)
glutIdleFunc(showScreen)
glutMainLoop()