#!/usr/bin/env pythonw

# This is statement is required by the build system to query build info
from __future__ import print_function
if __name__ == '__build__':
    raise Exception

__version__ = '$Revision: 1.8 $'.split()[1]
__date__ = ' '.join('$Date: 2002/12/31 04:13:56 $'.split()[1:3])
__author__ = 'Tarn Weisner Burton <twburton@users.sourceforge.net>'

#
# Ported to PyOpenGL 2.0 by Tarn Weisner Burton 10May2001
#
# This code was created by Richard Campbell '99 (ported to Python/PyOpenGL by John Ferguson and Tony Colston 2000)
# To be honst I stole all of John Ferguson's code and just added the changed stuff for lesson 5. So he did most
# of the hard work.
#
# The port was based on the PyOpenGL tutorial module: dots.py
#
# If you've found this code useful, please let me know (email John Ferguson at hakuin@voicenet.com).
# or Tony Colston (tonetheman@hotmail.com)
#
# See original source and C based tutorial at http:#nehe.gamedev.net
#
# Note:
# -----
# This code is not a good example of Python and using OO techniques.  It is a simple and direct
# exposition of how to use the Open GL API in Python via the PyOpenGL package.  It also uses GLUT,
# which in my opinion is a high quality library in that it makes my work simpler.  Due to using
# these APIs, this code is more like a C program using function based programming (which Python
# is in fact based upon, note the use of closures and lambda) than a "good" OO program.
#
# To run this code get and install OpenGL, GLUT, PyOpenGL (see http:#www.python.org), and NumPy.
# Installing PyNumeric means having a C compiler that is configured properly, or so I found.  For
# Win32 this assumes VC++, I poked through the setup.py for Numeric, and chased through disutils code
# and noticed what seemed to be hard coded preferences for VC++ in the case of a Win32 OS.  However,
# I am new to Python and know little about disutils, so I may just be not using it right.
#
# NumPy is not a hard requirement, as I am led to believe (based on skimming PyOpenGL sources) that
# PyOpenGL could run without it. However preformance may be impacted since NumPy provides an efficient
# multi-dimensional array type and a linear algebra library.
#
# BTW, since this is Python make sure you use tabs or spaces to indent, I had numerous problems since I
# was using editors that were not sensitive to Python.
#
from OpenGL.GL import *
from OpenGL.GLUT import *
from OpenGL.GLU import *
import sys

# Some api in the chain is translating the keystrokes to this octal string
# so instead of saying: ESCAPE = 27, we use the following.
ESCAPE = '\033'

# Number of the glut window.
window = 0

# Rotation angle for the triangle.
rtri = 0.0

# Rotation angle for the quadrilateral.
rquad = 0.0

# A general OpenGL initialization function.  Sets all of the initial parameters.
def InitGL(Width, Height):                # We call this right after our OpenGL window is created.
    glClearColor(0.0, 0.0, 0.0, 0.0)    # This Will Clear The Background Color To Black
    glClearDepth(1.0)                    # Enables Clearing Of The Depth Buffer
    glDepthFunc(GL_LESS)                # The Type Of Depth Test To Do
    glEnable(GL_DEPTH_TEST)                # Enables Depth Testing
    glShadeModel(GL_SMOOTH)                # Enables Smooth Color Shading

    glMatrixMode(GL_PROJECTION)
    glLoadIdentity()                    # Reset The Projection Matrix
                                        # Calculate The Aspect Ratio Of The Window
    gluPerspective(45.0, float(Width)/float(Height), 0.1, 100.0)

    glMatrixMode(GL_MODELVIEW)

# The function called when our window is resized (which shouldn't happen if you enable fullscreen, below)
def ReSizeGLScene(Width, Height):
    if Height == 0:                        # Prevent A Divide By Zero If The Window Is Too Small
        Height = 1

    glViewport(0, 0, Width, Height)        # Reset The Current Viewport And Perspective Transformation
    glMatrixMode(GL_PROJECTION)
    glLoadIdentity()
    gluPerspective(45.0, float(Width)/float(Height), 0.1, 100.0)
    glMatrixMode(GL_MODELVIEW)

# The main drawing function.
def DrawGLScene():
    global rtri, rquad

    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT)    # Clear The Screen And The Depth Buffer
    glLoadIdentity()                    # Reset The View
    glTranslatef(-1.5,0.0,-6.0)                # Move Left And Into The Screen

    glRotatef(rtri,0.0,1.0,0.0)                # Rotate The Pyramid On It's Y Axis

    glBegin(GL_TRIANGLES)                    # Start Drawing The Pyramid

    glColor3f(1.0,0.0,0.0)            # Red
    glVertex3f( 0.0, 1.0, 0.0)        # Top Of Triangle (Front)
    glColor3f(0.0,1.0,0.0)            # Green
    glVertex3f(-1.0,-1.0, 1.0)        # Left Of Triangle (Front)
    glColor3f(0.0,0.0,1.0)            # Blue
    glVertex3f( 1.0,-1.0, 1.0)

    glColor3f(1.0,0.0,0.0)            # Red
    glVertex3f( 0.0, 1.0, 0.0)        # Top Of Triangle (Right)
    glColor3f(0.0,0.0,1.0)            # Blue
    glVertex3f( 1.0,-1.0, 1.0)        # Left Of Triangle (Right)
    glColor3f(0.0,1.0,0.0)            # Green
    glVertex3f( 1.0,-1.0, -1.0)        # Right

    glColor3f(1.0,0.0,0.0)            # Red
    glVertex3f( 0.0, 1.0, 0.0)        # Top Of Triangle (Back)
    glColor3f(0.0,1.0,0.0)            # Green
    glVertex3f( 1.0,-1.0, -1.0)        # Left Of Triangle (Back)
    glColor3f(0.0,0.0,1.0)            # Blue
    glVertex3f(-1.0,-1.0, -1.0)        # Right Of


    glColor3f(1.0,0.0,0.0)            # Red
    glVertex3f( 0.0, 1.0, 0.0)        # Top Of Triangle (Left)
    glColor3f(0.0,0.0,1.0)            # Blue
    glVertex3f(-1.0,-1.0,-1.0)        # Left Of Triangle (Left)
    glColor3f(0.0,1.0,0.0)            # Green
    glVertex3f(-1.0,-1.0, 1.0)        # Right Of Triangle (Left)
    glEnd()


    glLoadIdentity()
    glTranslatef(1.5,0.0,-7.0)        # Move Right And Into The Screen
    glRotatef(rquad,1.0,1.0,1.0)        # Rotate The Cube On X, Y & Z
    glBegin(GL_QUADS)            # Start Drawing The Cube


    glColor3f(0.0,1.0,0.0)            # Set The Color To Blue
    glVertex3f( 1.0, 1.0,-1.0)        # Top Right Of The Quad (Top)
    glVertex3f(-1.0, 1.0,-1.0)        # Top Left Of The Quad (Top)
    glVertex3f(-1.0, 1.0, 1.0)        # Bottom Left Of The Quad (Top)
    glVertex3f( 1.0, 1.0, 1.0)        # Bottom Right Of The Quad (Top)

    glColor3f(1.0,0.5,0.0)            # Set The Color To Orange
    glVertex3f( 1.0,-1.0, 1.0)        # Top Right Of The Quad (Bottom)
    glVertex3f(-1.0,-1.0, 1.0)        # Top Left Of The Quad (Bottom)
    glVertex3f(-1.0,-1.0,-1.0)        # Bottom Left Of The Quad (Bottom)
    glVertex3f( 1.0,-1.0,-1.0)        # Bottom Right Of The Quad (Bottom)

    glColor3f(1.0,0.0,0.0)            # Set The Color To Red
    glVertex3f( 1.0, 1.0, 1.0)        # Top Right Of The Quad (Front)
    glVertex3f(-1.0, 1.0, 1.0)        # Top Left Of The Quad (Front)
    glVertex3f(-1.0,-1.0, 1.0)        # Bottom Left Of The Quad (Front)
    glVertex3f( 1.0,-1.0, 1.0)        # Bottom Right Of The Quad (Front)

    glColor3f(1.0,1.0,0.0)            # Set The Color To Yellow
    glVertex3f( 1.0,-1.0,-1.0)        # Bottom Left Of The Quad (Back)
    glVertex3f(-1.0,-1.0,-1.0)        # Bottom Right Of The Quad (Back)
    glVertex3f(-1.0, 1.0,-1.0)        # Top Right Of The Quad (Back)
    glVertex3f( 1.0, 1.0,-1.0)        # Top Left Of The Quad (Back)

    glColor3f(0.0,0.0,1.0)            # Set The Color To Blue
    glVertex3f(-1.0, 1.0, 1.0)        # Top Right Of The Quad (Left)
    glVertex3f(-1.0, 1.0,-1.0)        # Top Left Of The Quad (Left)
    glVertex3f(-1.0,-1.0,-1.0)        # Bottom Left Of The Quad (Left)
    glVertex3f(-1.0,-1.0, 1.0)        # Bottom Right Of The Quad (Left)

    glColor3f(1.0,0.0,1.0)            # Set The Color To Violet
    glVertex3f( 1.0, 1.0,-1.0)        # Top Right Of The Quad (Right)
    glVertex3f( 1.0, 1.0, 1.0)        # Top Left Of The Quad (Right)
    glVertex3f( 1.0,-1.0, 1.0)        # Bottom Left Of The Quad (Right)
    glVertex3f( 1.0,-1.0,-1.0)        # Bottom Right Of The Quad (Right)
    glEnd()                # Done Drawing The Quad

    # What values to use?  Well, if you have a FAST machine and a FAST 3D Card, then
    # large values make an unpleasant display with flickering and tearing.  I found that
    # smaller values work better, but this was based on my experience.
    rtri  = rtri + 0.2                  # Increase The Rotation Variable For The Triangle
    rquad = rquad - 0.15                 # Decrease The Rotation Variable For The Quad


    #  since this is double buffered, swap the buffers to display what just got drawn.
    glutSwapBuffers()

# The function called whenever a key is pressed. Note the use of Python tuples to pass in: (key, x, y)
def keyPressed(*args):
    # If escape is pressed, kill everything.
    if args[0] == ESCAPE:
        sys.exit()

def main():
    global window
    glutInit(sys.argv)

    # Select type of Display mode:
    #  Double buffer
    #  RGBA color
    # Alpha components supported
    # Depth buffer
    glutInitDisplayMode(GLUT_RGBA | GLUT_DOUBLE | GLUT_DEPTH)

    # get a 640 x 480 window
    glutInitWindowSize(640, 480)

    # the window starts at the upper left corner of the screen
    glutInitWindowPosition(0, 0)

    # Okay, like the C version we retain the window id to use when closing, but for those of you new
    # to Python (like myself), remember this assignment would make the variable local and not global
    # if it weren't for the global declaration at the start of main.
    window = glutCreateWindow("Jeff Molofee's GL Code Tutorial ... NeHe '99")

       # Register the drawing function with glut, BUT in Python land, at least using PyOpenGL, we need to
    # set the function pointer and invoke a function to actually register the callback, otherwise it
    # would be very much like the C version of the code.
    glutDisplayFunc(DrawGLScene)

    # Uncomment this line to get full screen.
    # glutFullScreen()

    # When we are doing nothing, redraw the scene.
    glutIdleFunc(DrawGLScene)

    # Register the function called when our window is resized.
    glutReshapeFunc(ReSizeGLScene)

    # Register the function called when the keyboard is pressed.
    glutKeyboardFunc(keyPressed)

    # Initialize our window.
    InitGL(640, 480)

    # Start Event Processing Engine
    glutMainLoop()

# Print message to console, and kick off the main to get it rolling.
print("Hit ESC key to quit.")
main()
