Re: [sdljava-users] Incorrect behaviour of glTranslatef() on Linux?

[Raffael H. <her...@ra...>]

Ivan Z. Ganza schrieb:
> I would have to gamble that glTranslatef() is working correctly.  The
> reason is that sdljava only delegates the call to the OpenGL layer
> and does nothing special itself.

Yes, I actually thought so too, but the behaviour was so funny ... ;)

Yesterday I managed to figure out what was going wrong by looking at a=20
C/SDL 'port' of the tutorial code. This code did some more OpenGL=20
initialization before the 1:1 port of the tutorial:

  gl.glEnable(GL.GL_TEXTURE_2D);
  gl.glShadeModel(GL.GL_SMOOTH);
  gl.glClearColor(0f, 0f, 0f, 0f);
  gl.glClearDepth(1);
  gl.glEnable(GL.GL_DEPTH_TEST);
  gl.glDepthFunc(GL.GL_LEQUAL);

  gl.glMatrixMode(GL.GL_PROJECTION);
  gl.glLoadIdentity();
  gl.gluPerspective(45f, (float)width/(float)height, .1f, 100f);

  gl.glMatrixMode(GL.GL_MODELVIEW);
  gl.glHint(GL.GL_PERSPECTIVE_CORRECTION_HINT, GL.GL_NICEST);

By experiments I found that the call to gluPerspective() while in matrix=20
mode GL_PROJECTION is the important action here which makes things=20
working as they should. I'm sure, some time I'll even understand=20
why. ;)

cu & thanks,
   Raffi

=2D-=20
The difference between theory and practice is that in theory, there is
no difference, but in practice, there is.

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