PyOpenGL, wxPython weird behaviour

[kyosohma at gmail.com]

On Jan 3, 11:50 am, Adeola Bannis <theCodeMai... at gmail.com> wrote:
> Hi everyone,
>
> I'm doing a project using wxPython and pyopengl, and I seem to have a
> problem rendering textures. This is code that worked before my hard
> drive had a meltdown, but not since I re-installed everything.
>
> I've determined the problem is in the OpenGL part of my program. I do
> some calculations to generate a 2D numpy array that holds the image
> data, and pylab.imshow() shows me the image as it is meant to be. I
> used the same algorithm in Octave and MATLAB, and all are giving me
> the right picture.
>
> However, using pyOpenGL and the numpyhandler functions (http://cours-
> info.iut-bm.univ-fcomte.fr/docs/python/OpenGL/
> OpenGL.arrays.numpymodule.NumpyHandler-class.html) doesn't seem to
> work. I get a garbled screen pocked with black pixels. I am including
> my openGL code below. What am I doing wrong?
>
> And yes, I did make the dtype of my array 'float32'.
>
> -------code snippets------
>
> import wx
> from wx.glcanvas import GLCanvas
>
> from OpenGL.GLU import *
> from OpenGL.GL import *
> from OpenGL.arrays.numpymodule import NumpyHandler
>
> PC = 1
> RI = 0
>
> class myGLCanvas(GLCanvas):
>         def __init__(self, parent):
>                 GLCanvas.__init__(self, parent,-1)
>                 wx.EVT_PAINT(self, self.OnPaint)
>                 self.init = 0
>                 self.mode = -1
>                 # making a texture for the range image
>                 self.texture = glGenTextures(1)
>                 # making a spot for the point cloud points
>                 self.cloud = None
>                 return
>
>         def OnPaint(self,event):
>                 dc = wx.PaintDC(self)
>                 self.SetCurrent()
>                 if not self.init:
>                         self.InitGL()
>                         self.init = 1
>                 self.OnDraw()
>                 return
>
>         def OnDraw(self):
>                 glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT)
>                 if self.mode == RI:
>                         self.drawRange()
>                 elif self.mode == PC:
>                         self.drawCloud()
>
>         def InitGL(self):
>                 glClearColor(0.0, 0.0, 0.0, 0.0);
>                 glClearDepth(1.0)
>                 glEnable(GL_DEPTH_TEST)
>                 glDepthFunc(GL_LEQUAL)
>                 glClear(GL_COLOR_BUFFER_BIT)
>
>                 glPixelStorei(GL_UNPACK_ALIGNMENT, 1)
>                 glPixelStorei(GL_PACK_ALIGNMENT, 1)
>
>                 #NTSC colour scales...
>                 glPixelTransferf(GL_RED_SCALE, 0.299);
>                 glPixelTransferf(GL_GREEN_SCALE, 0.587);
>                 glPixelTransferf(GL_BLUE_SCALE, 0.114);
>
>                 glMatrixMode(GL_PROJECTION)
>                 glLoadIdentity()
>                 glOrtho(0.0,1.0,0,1.0,-1.0,1.0)
>                 glMatrixMode(GL_MODELVIEW)
>                 glLoadIdentity()
>
>                 return
>
>         def rangeImage(self, image):
>
>                 glBindTexture(GL_TEXTURE_2D, self.texture)
>                 glTexEnvf( GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE )
>
>                 glTexParameterf (GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER,
>                                                 GL_LINEAR)
>                 glTexParameterf (GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR)
>                 glTexParameterf (GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT)
>                 glTexParameterf (GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT)
>
>                 # flatten it into a list so the OpenGL calls work
>                 n = NumpyHandler()
>                 fI = image.flatten()
>                 flatImage = n.dataPointer(n.contiguous(fI))
>
>                 print n.contiguous(fI)
>
>                 gluBuild2DMipmaps(GL_TEXTURE_2D, 1, image.shape[0]+1,
> image.shape[1]+1,
>                                                         GL_LUMINANCE, GL_FLOAT, flatImage)
>                 self.mode = RI
>                 self.OnDraw()
>
>         def drawRange(self):
>                 ''' Controls the actual drawing of the range image'''
>
>                 glMatrixMode(GL_MODELVIEW)
>                 glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT)
>
>                 glColor3f(1.0,1.0,1.0)
>                 glEnable(GL_TEXTURE_2D)
>                 glBindTexture(GL_TEXTURE_2D, self.texture)
>                 glBegin(GL_TRIANGLE_FAN)
>                 glTexCoord2d(1,1); glVertex3f(0.0, 0.0, 0.0)
>                 glTexCoord2d(1,0); glVertex3f(0.0, 1.0, 0.0)
>                 glTexCoord2d(0,0); glVertex3f(1.0, 1.0, 0.0)
>                 glTexCoord2d(0,1); glVertex3f(1.0, 0.0, 0.0)
>                 glEnd()
>                 self.SwapBuffers()
>
> --------end snippet-----------

I've never messed with pyOpenGL, but it seems that they have their own
user's group, which would probably be better at answering your
question:

http://sourceforge.net/mail/?group_id=5988

Of course, it could be that you upgraded your wxPython to the latest
version and as I recall, they were discussing some subtle differences
in DCs, blitting, paint events and other things that I just don't
understand at this point in my "Pythoneering". You might ask them at
their group, which is usually very helpful: wxPython.org

Mike