This is a reply to both posts: I've been working with OpenGL for the past decade, and I have yet to find a bug-free OpenGL driver... ATI, nVidia makes no difference. The litmus test is to disable hardware acceleration completely, and if the scene draws correctly, then you know the problem is not your code nor the underlying toolkit (FLTK).
Re. > > For example yesterday I ported some code from my desktop to a laptop. Laptop drivers are the worst. You get maybe one or two driver updates before the manufacturer discontinues support. Re. > > and resorted to using fonts modeled out of polygons. Much more reliable, however they tend to suck at small font sizes. Re. > gl_draw() does seem to be extremely sensitive to the current OpenGL state > which makes it difficult to figure out what what is going on. I ended up > drawing all my text first, at the front of the viewing volume with the > depth buffer enabled, then drawing the rest of the scene to go behind it. > This was the best way I could figure to isolate gl_draw() from the state > changes that followed. > > Also, turns out I needed to explicitely disable GL_TEXTURE2D before my > calls to gl_draw() or it would either display with the wrong color, or not > draw at all, but the exact behavior seemed to be random. > GL_TEXTURE2D is off by default. If it isn't, then the driver is in error, or your program forgot to reset it at some point. Make good use of glPush/PopAttrib() to maintain the default state. It is possible that FLTK fails to manage state properly in some cases... never looked into it. A catchall solution would be to create a glDefaultState() function that ensures that critical states are as you expect. Cheers, Don. PS. A solution I found, after years of conditional compilation and glGetString() etc. to enable work-arounds for driver-specific bugs, was to add an option to create a software-only OpenGL context to my applications. FLTK does not provide this when creating contexts, but I can post my modifications if anyone wants. _______________________________________________ fltk-opengl mailing list [email protected] http://lists.easysw.com/mailman/listinfo/fltk-opengl
