Okay, after much head scratching the OpenGL problems on the
MAC are making more sense.
In jzopengl_darwin.ijs, I replaced line 37 which was:
r=. CGLChoosePixelFormat 53 8 32 0;(,2);,2
with:
r=. CGLChoosePixelFormat 53 8 32 12 8 0;(,2);,2
which (I think) adds an 8 bit depth buffer to the render context.
(Well it could be adding just 8 levels - ie 3 bits).
After that all the demos worked great!!
I'm very much an OpenGL newbie, so comments are welcome!
Regards,
Carl.
Well, I finally started getting some sensible results by using
1) glEnable GL_CULL_FACES
2) including a glNormal call for each polygon.
which resulted in a 3d cube that looked perfect.
I tried extending the test by drawing a second translatred cube - which
resulted
in other rendering problems.
It seems that in the original what is happening is that the polygons are
being
literally drawn in the order in which they are fed into the OpenGL buffer.
The
result of this is that the back faces take priority over the front faces -
sort of.
That's about as good as my explanation can get at the moment. It's as if
the depth
sorting/culling routine is not working correctly.
Unfortunately, I'm not enough of an OpenGL expert to know where to go from
this point.
Regards,
Carl.
Mike, Oleg,
My graphics card is also an ATI Radeon, but different model 9200.
I also downloaded the XCode development environment from the Apple site.
It includes a fairly comprehensive set of OpenGL demos, so I'll see if
I'm
able to notice anything that's different in what they're doing. BTW, the
apple demos work quite nicely.
Regards,
Carl.
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