User:Crond/sandbox/openglExample

Written for CEGUI 0.7

---

Works with versions 0.7.x (obsolete)

Requires at least version
0.7.5

Introduction

This presents a minimal PyCEGUI application, using OpenGL as the renderer. The goal is to familiarize the reader with the basics of how to get PyCEGUI up and running, and to provide a few pointers along the way.

Requirements

• Python 2.6 (untested on Python 3.+)
• PyCEGUI
• PyOpenGL (GLU and GLUT, as well)

Source

#!/usr/bin/env python
#
#
# example.py
 
 
# Import: std
import sys
 
# Import: PyOpenGL
from OpenGL.GL import *
from OpenGL.GLU import *
from OpenGL.GLUT import *
 
# Import: PyCEGUI
import PyCEGUI
from PyCEGUIOpenGLRenderer import OpenGLRenderer as Renderer
 
# Constants
PATH_RESOURCES = './'
 
 
# Application
class Application(object):
 
  # Constructor
  def __init__(self):
    super(Application, self).__init__()
    self.lastFrameTime = 0
    self.updateFPS = 0
    return
 
  # Initialize: OpenGL
  # - A full list of values for `glutInitDisplayMode` can be found in the GLUT
  #   documentation.
  def initializeOpenGL(self):
    glutInit()
    glutInitDisplayMode(GLUT_DEPTH | GLUT_DOUBLE | GLUT_RGBA)
    glutInitWindowSize(1024, 768)
    glutInitWindowPosition(-1, -1) # Let the windowing system figure it out
    glutCreateWindow("Crazy Eddie's GUI Mk-2 - glut Base Application")
    glutSetCursor(GLUT_CURSOR_NONE)
    return
 
  # Initialize: Handlers
  # - Setup the methods which will be called when events happen.
  def initializeHandlers(self):
    glutDisplayFunc(self.handlerDisplay)
    glutReshapeFunc(self.handlerResize)
    glutMouseFunc(self.handlerMouse)
    glutMotionFunc(self.handlerMouseMotion)
    glutPassiveMotionFunc(self.handlerMouseMotion)
    return
 
  # Initialize: PyCEGUI
  # - Store some components; saves a lot of typing.
  def initializePyCEGUI(self):
    Renderer.bootstrapSystem()
    self.sys = PyCEGUI.System.getSingleton()
    self.rp = self.sys.getResourceProvider()
    self.scheme = PyCEGUI.SchemeManager.getSingleton()
    self.wm = PyCEGUI.WindowManager.getSingleton()
    return
 
  # Initialize: Defaults
  # - Resource locations.
  def initializeDefaults(self):
    self.rp.setResourceGroupDirectory('schemes', './datafiles/schemes')
    self.rp.setResourceGroupDirectory('imagesets', './datafiles/imagesets')
    self.rp.setResourceGroupDirectory('fonts', './datafiles/fonts')
    self.rp.setResourceGroupDirectory('layouts', './datafiles/layouts')
    self.rp.setResourceGroupDirectory('looknfeels', './datafiles/looknfeel')
    self.rp.setResourceGroupDirectory('schemas', './datafiles/xml_schemas')
    PyCEGUI.Imageset.setDefaultResourceGroup('imagesets')
    PyCEGUI.Font.setDefaultResourceGroup('fonts')
    PyCEGUI.Scheme.setDefaultResourceGroup('schemes')
    PyCEGUI.WidgetLookManager.setDefaultResourceGroup('looknfeels')
    PyCEGUI.WindowManager.setDefaultResourceGroup('layouts')
    parser = self.sys.getXMLParser()
    if parser.isPropertyPresent('SchemaDefaultResourceGroup'):
      parser.setProperty('SchemaDefaultResourceGroup', 'schemas')
    return
 
  # Initialize: GUI
  # - This is where we are actually setting up the windows we will see.
  def initializeGUI(self):
    self.scheme.create('VanillaSkin.scheme')
    self.scheme.create('TaharezLook.scheme')
 
    # GUISheet
    self.rootWindow = self.wm.loadWindowLayout('VanillaWindows.layout')
    self.sys.setGUISheet(self.rootWindow)
 
    # Cursor
    self.sys.setDefaultMouseCursor('Vanilla-Images', 'MouseArrow')
 
    # An extra window
    w = self.wm.createWindow('TaharezLook/FrameWindow', 'Demo window')
    self.rootWindow.addChildWindow(w)
    return
 
  # Initialize
  def Initialize(self):
    self.initializeOpenGL()
    self.initializeHandlers()
    self.initializePyCEGUI()
    self.initializeDefaults()
    self.initializeGUI()
    return
 
  # Handler: Display
  def handlerDisplay(self):
 
    # Injecting the time allows CEGUI to know how much time has passed, and
    # use that to coordinate certain activities - fading, animation, tooltips,
    # etc.
    now = glutGet(GLUT_ELAPSED_TIME)
    elapsed = (now - self.lastFrameTime) / 1000.0
    self.lastFrameTime = now
    self.updateFPS = self.updateFPS - elapsed
    self.sys.injectTimePulse(elapsed)
 
    # Actual rendering
    # - `renderGUI` updates CEGUI's picture of the GUI.
    # - `glutPostRedisplay` is what actually marks the window as needing to
    #   be redrawn by OpenGL.
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT)
    self.sys.renderGUI()
    glutPostRedisplay()
    glutSwapBuffers()
    return
 
  # Handler: Resize
  # - `glViewport` modifies the OpenGL viewport to whatever the window size is.
  def handlerResize(self, width, height):
    glViewport(0, 0, width, height)
    self.sys.notifyDisplaySizeChanged(PyCEGUI.Size(width, height))
    return
 
  # Handler: Mouse buttons
  def handlerMouse(self, button, state, x, y):
    if button == GLUT_LEFT_BUTTON:
      if state == GLUT_UP:
        self.sys.injectMouseButtonUp(PyCEGUI.LeftButton)
      else:
        self.sys.injectMouseButtonDown(PyCEGUI.LeftButton)
    elif button == GLUT_RIGHT_BUTTON:
      if state == GLUT_UP:
        self.sys.injectMouseButtonUp(PyCEGUI.RightButton)
      else:
        self.sys.injectMouseButtonDown(PyCEGUI.RightButton)
    return
 
  # Handler: Mouse motion
  def handlerMouseMotion(self, x, y):
    self.sys.injectMousePosition(x, y)
    return
 
  # Run
  def Run(self):
    self.lastFrameTime = glutGet(GLUT_ELAPSED_TIME)
    glutMainLoop()
    return
 
# Main
def main():
  app = Application()
  app.Initialize()
  app.Run()
  return 0
 
 
# Guard
if __name__ == '__main__':
  sys.exit(main())