[Pyobjc-dev] PyObjC and NSOpenGLView

[Tobias W. <t.w...@im...>]

Hello,
First off, sorry if this is the wrong place to post this - I couldn't find a PyObjC users list. If there's a better place to post please let me know and I'll send it there.

I've been trying to rewrite a game of mine using PyObjC - it's currently a horrible mess of Objective-C and C++ and I think PyObjC will be a much better infrastructure. Unfortunately I'm failing at the first hurdle - implementing a subclass of NSOpenGLView working by reimplementing my Objective-C version line-by-line in PyObjC. I've got two problems with it:
1) The NSOpenGLView seems to interfere with the drawing of the Window it's in. When I don't have the NSOpenGLView instantiated in Interface Builder, I'll get the standard grey/silver background in the window. Once I add the NSOpenGLView, the Window is suddenly filled in white (The OpenGLView is drawn correctly on top).
2) If I try to use the GLU function gluPerspective I get the following unexpected error (My subclass is called WorldView, code is at the end of this message):
ValueError: NSInvalidArgumentException - Unlocking Focus on wrong view (<NSThemeFrame:0x2c11580>), expected <WorldView: 0x4e7850>)
Should I not be subclassing NSOpenGLView? Should I be subclassing something else? I've included my current sub-class below.

On a different note, when I started this project I was intending to write the interface mainly in Objective-C and the game engine in Python. However the PyObjC examples all seem to be geared towards writing everything in Python. Is there a recommended way to call Python-implemented objects from Objective-C code? The only way I could find to do it is something along the lines of:

id someObject;
Class PythonClass = NSClassFromString(@"PythonName");
someObject = [PythonClass new];

but I was wondering if there was any other way?

Thanks in advance for any help,
Toby Wood

WorldView.py:

from objc import YES, NO, IBAction, IBOutlet
from Foundation import *
from AppKit import *
from OpenGL.GL import *
from OpenGL.GLU import *

class WorldView(NSOpenGLView):
   def awakeFromNib(self):
       NSLog(u'Awoke')

   def initWithFrame_(self, frame):
       self = super(WorldView, self).initWithFrame_(frame)
       if self:
           # initialization code here
           pass
       NSLog(u'init')
       return self

   def prepareOpenGL(self):
       NSLog(u'Prep')
       glClearColor(1.0,0.0,0.0,1.0)

   def reshape(self):
       NSLog(u'Reshape')
       rect = self.bounds()
       glViewport(0, 0, int(rect.size.width), int(rect.size.height))

       if (rect.size.height == 0.0):
           rect.size.height == 1.0

       aspect = rect.size.width/rect.size.height
       glMatrixMode(GL_PROJECTION)
       glLoadIdentity()
       gluPerspective(45.0, fAspect, 1., 1000.)    # Fails on this line
       glMatrixMode(GL_MODELVIEW)
       glLoadIdentity()

   def drawRect_(self, rect):
       # drawing code here
       NSLog(u'Drawing')
       glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT)
       glFlush()