Re: [PyOpenGL-Users] get Translation inside matrix stack
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mcfletch
From: Black <py...@bl...> - 2008-07-22 16:54:23
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Two quick things to check: a) Is the MODELVIEW matrix the current matrix (i.e., the one being affected by the glTranslates)? If not, well, it should be b) Are you doing this while constructing a display list with glNewList(GL_COMPILE)? If so, the matrix isn't being updated and this won't work On Jul 22, 2008, at 12:32 PM, Prashant Saxena wrote: > I am sorry but I didn't get any success with your code. I tried this: > > glPushMatrix() > glTranslate(5,0,0) > glTranslate(10,0,0) > glTranslate(5,0,0) > # To get total increment of x axis(which is 5+10+5=20) > modelview = glGetFloatv( GL_MODELVIEW_MATRIX ) > print modelview > glPopMatrix() > > but I am getting this: > [[1.0, 0.0, 0.0, 0.0], [0.0, 1.0, 0.0, 0.0], [0.0, 0.0, 1.0, 0.0], > [0.0, 0.0, 0.0, 1.0]] > Which does,'t solve my problem. > > ----- Original Message ---- > From: Prashant Saxena <ani...@ya...> > To: Gary Herron <gh...@is...> > Sent: Tuesday, July 22, 2008 9:59:38 PM > Subject: Re: [PyOpenGL-Users] get Translation inside matrix stack > > I am sorry but I didn't get any success with your code. I tried this: > > glPushMatrix() > glTranslate(5,0,0) > glTranslate(10,0,0) > glTranslate(5,0,0) > # To get total increment of x axis(which is 5+10+5=20) > modelview = glGetFloatv( GL_MODELVIEW_MATRIX ) > print modelview > glPopMatrix() > > but I am getting this: > [[1.0, 0.0, 0.0, 0.0], [0.0, 1.0, 0.0, 0.0], [0.0, 0.0, 1.0, 0.0], > [0.0, 0.0, 0.0, 1.0]] > Which does,'t solve my problem. > > > ----- Original Message ---- > From: Gary Herron <gh...@is...> > Cc: pyo...@li... > Sent: Tuesday, July 22, 2008 8:48:24 PM > Subject: Re: [PyOpenGL-Users] get Translation inside matrix stack > > Shantytown Saxena wrote: > > > > glPushMatrix() > > glTranslate(5,0,0) > > glTranslate(10,0,0) > > glTranslate(5,0,0) > > # How do I get here total increment of x axis(which is 5+10+5=20) > > before I Pop up. > > glPopMatrix() > > All the transformations are recorded by OpenGL in a 4x4 matrix. > You can recover that matrix like this: > > buff = (ctypes.c_double*16)() > pyglet.gl.glGetDoublev(stack, buff) > > If you started with the identity and did no other transformations > you'll > find the 20 in that 4x4 array. > > In either the [0,3] or [3,0] element. (I've forgotten which way > Opengl > stores the array now.) > > Gary Herron > > > > > > > ------------------------------------------------------------------------ > > > > > ------------------------------------------------------------------------- > > This SF.Net email is sponsored by the Moblin Your Move Developer's > challenge > > Build the coolest Linux based applications with Moblin SDK & win > great prizes > > Grand prize is a trip for two to an Open Source event anywhere in > the world > > http://moblin-contest.org/redirect.php?banner_id=100&url=/ > > > ------------------------------------------------------------------------ > > > > _______________________________________________ > > PyOpenGL Homepage > > http://pyopengl.sourceforge.net > > _______________________________________________ > > PyOpenGL-Users mailing list > > PyO...@li... > > https://lists.sourceforge.net/lists/listinfo/pyopengl-users > > > > > ------------------------------------------------------------------------- > This SF.Net email is sponsored by the Moblin Your Move Developer's > challenge > Build the coolest Linux based applications with Moblin SDK & win > great prizes > Grand prize is a trip for two to an Open Source event anywhere in > the world > http://moblin-contest.org/redirect.php?banner_id=100&url=/ > _______________________________________________ > PyOpenGL Homepage > http://pyopengl.sourceforge.net > _______________________________________________ > PyOpenGL-Users mailing list > PyO...@li... > https://lists.sourceforge.net/lists/listinfo/pyopengl-users > > > ------------------------------------------------------------------------- > This SF.Net email is sponsored by the Moblin Your Move Developer's > challenge > Build the coolest Linux based applications with Moblin SDK & win > great prizes > Grand prize is a trip for two to an Open Source event anywhere in > the world > http://moblin-contest.org/redirect.php?banner_id=100&url=/_______________________________________________ > PyOpenGL Homepage > http://pyopengl.sourceforge.net > _______________________________________________ > PyOpenGL-Users mailing list > PyO...@li... > https://lists.sourceforge.net/lists/listinfo/pyopengl-users |