Question

This question repeats my earlier one but my earlier one was a failure because I didn’t copy some vital information correctly, so I have to redo it.

I’m getting an error with a call to an OpenGL function. Maybe pyglet isn’t initialising OpenGL correctly? The error happens with a simple function that worked before:

 def setup_framebuffer(surface):
   #Create texture if not done already
   if surface.texture is None:
      create_texture(surface)
   #Render child to parent
   if surface.frame_buffer is None:
      surface.frame_buffer =  glGenFramebuffersEXT(1)
   glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, surface.frame_buffer)
   glFramebufferTexture2DEXT(GL_FRAMEBUFFER_EXT, GL_COLOR_ATTACHMENT0_EXT, GL_TEXTURE_2D, surface.texture, 0)
   glPushAttrib(GL_VIEWPORT_BIT)
   glViewport(0,0,surface._scale[0],surface._scale[1])
   glMatrixMode(GL_PROJECTION)
   glLoadIdentity() #Load the projection matrix
   gluOrtho2D(0,surface._scale[0],0,surface._scale[1])

The error is:

glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, surface.frame_buffer)
ctypes.ArgumentError: argument 2: : wrong type

Wrong type? Then is glGenFramebuffersEXT(1) giving the wrong type now? Why would that be?

Before that function is called I initialise a class instance which manages my game. Here’s the init method:

pyglet.options['audio'] = ('alsa','openal','directsound','silent')
  self.keys = [False] * 323
  self.events = []
  self.title = title
  self.game_size = game_size
  self.first_screen = (1280,720) #Take 120 pixels from the height because the menu bar, window bar and dock takes space
  config = pyglet.gl.Config(alpha_size=8,double_buffer=True,sample_buffers=1,samples=4)
  self.window = pyglet.window.Window(game_size[0],game_size[1],title,True,config=config)
  self.window.set_handler('on_draw',self.game_loop)
  self.window.set_handler('on_resize',self.reshaped)
  self.window.set_handler('on_key_press',self.keydown)
  self.window.set_handler('on_key_release',self.keyup)
  self.window.set_handler('on_mouse_press',self.mouse_func)
  glViewport(0,0,self.first_screen[0],self.first_screen[1]) #Creates the viewport which is mapped to the window
  glEnable(GL_BLEND) #Enable alpha blending
  glEnable(GL_TEXTURE_2D) #Enable 2D Textures
  glEnable(GL_MULTISAMPLE) #Enable Multisampling anti-aliasing
  glEnable(GL_POLYGON_SMOOTH) #Enable antialiased polygons
  glHint(GL_POLYGON_SMOOTH_HINT, GL_NICEST)
  glHint(GL_LINE_SMOOTH_HINT, GL_NICEST)
  glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA)
  glMatrixMode(GL_PROJECTION)
  glLoadIdentity() #Load the projection matrix
  gluOrtho2D(0,1280,720,0) #Set an orthorgraphic view
  self.game_gap = (0,0)
  self.on_exit = on_exit
  self.mod_key = 1024 if sys.platform == "darwin" else 64
  Surface.__init__(self,game_size)
  self.screen_change = True
  self.frames = [time.time()]
  self.fps = 60
  self.last_time = 0
  self.fade_surface = Surface([1280,720])
  pyglet.font.add_file(os.path.dirname(sys.argv[0]) + "/NEUROPOL.ttf")
  pyglet.font.load('NEUROPOL')

Surface is a class that I made which acts a bit like the pygame.Surface class but uses OpenGL textures.

That method sets up the Window and OpenGL (Probably not properly which is the problem?) and after calling it I set-up some things for my game which uses the setup_framebuffer function for rendering to textures. Then pyglet.app.run() is called which should hopefully run my game_loop method since I did self.window.set_handler(‘on_draw,self.game_loop) but my game crashes before it gets there.

This is the first time I’ve use pyglet. The documentation doesn’t explain to me what I’m doing wrong. Can anyone help?

Thank you.

Answer 1

glBindFramebufferEXT expects pointer to a buffer. AFAIK, you have to use ctypes in this case.

from pyglet.gl import *
from ctypes import c_uint, byref

fb = c_uint()
glGenFramebuffersEXT(1, byref(fb))
glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, fb) 

Search pyglet mailing list for better examples. And BTW:

>> glGenFramebuffersEXT(1)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: this function takes at least 2 arguments (1 given)

Edit:
I should have guessed that you are using pyOpenGL:

fb = int(glGenFramebuffersEXT(1))
glBindFramebufferEXT(GL_FRAMEBUFFER_EXT, fb)