December 2006 - cl-opengl-devel - mailman3.common-lisp.net

[cl-opengl-devel] generating function bindings, extension loading
by Bart Botta 11 Mar '07

11 Mar '07

I've been working on generating bindings from the .spec files on opengl.org, and it seems to be to the point where it could be turned into a patch... Before that though, I wanted to get some feedback about changing the naming for the bindings: First suggestion is moving the function bindings to a separate package, and giving them lisp style names, so people like me who want to use them directly have supported access to them. Second is changing the GLenums from cffi:defcenums to defconstants. Advantages I can think of from doing that: *Easier for users to add enums from a new extension without modifying library code (unless cffi allows adding to an enum after it is defined, not sure about that) *Easier to add offsets to them, for example a loop to disable all lights could use (+ index gl:+light0+) instead of having to convert from enum and back, or store a list of the light enums or whatever. *being able to add offsets also solves the problem of some values (light in particular) potentially having more valid values than are enums. (The .spec files name 8 lights, but leaves room for 4096, I'm pretty sure there has been hardware supporting at least 32.) *compatibility with other bindings (glx and cl-sdl both use +foo+ style for enums if I remember correctly) *possibly speed. If cffi can remap values at compile time it probably isn't too bad, but it probably wouldn't be too hard to find code with a lot of enums specified at runtime. (Alternately, is it possible to tell cffi to allow using either the constants or the keywords?) Also, a small patch: someone in #lisp was having problems with OpenMCL objecting to compute-applicable-methods being called with extra arguments in glut/interface.lisp, which was fixed by the following patch to define-glut-event: diff -rN old-pct/glut/interface.lisp new-pct/glut/interface.lisp 130c130 < :func ',event-func :arg-count ,(length args)) --- > :func ',event-func :arg-count ,(length arg-names))

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[cl-opengl-devel] Vertex Arrays
by Charlie McMackin 26 Dec '06

26 Dec '06

Hello, To begin, as it's my first post, I'd like to thank all the developers who started and maintain this project. As a hobbiest beginner, this package allows me to play with the two things that I'm interested in most these days, Lisp and OpenGL. With that said, I was working my way through OpenGL Distilled by Paul Martz, I noticed that section 2.8 on Vertex Arrays of the OpenGL spec was missing. I wasn't quite sure if this was on purpose or not, in favor of a more "Lispy" way but since I couldn't find any equivalent functionality I decided it was a big TODO. So I've after researching and playing with the system, I believe I've made a mostly function patch to add Vertex Arrays to cl-opengl. Of course this has caveats. The biggest caveat is I am still new to OpenGL and Lisp however my patch does produce nearly accurate results of rb-varray in the cl-glut-examples and I have hope that many of the other Vertex Array functions that aren't tested in the rb-varray example work as well. The "nearly accurate" results is why I've decided to mail in my patch. For the there is something odd about how OpenGL is getting one vertex and I can't for the life of me pinpoint it (hopefully due to my green-thumbedness). I /think/ it's either with CFFI itself or the 'with-opengl-array' / 'with-opengl-sequence' macros or maybe even my ATI mobitlity chip :( I'd be interested to hear if rb-varray works for anyone else. Sorry for the long explanation. Here's a short change summary followed by the patch attachment generated by 'darcs whatsnew' gl/package.lisp, funcs.lisp, opengl.lisp added the code for Vertex Arrays through CFFI and the export symbols necessary gl/util.lisp probably my more "dangerous" code as I modified slightly with-opengl-sequence to get rid of the eval quick hack and modified with-opengl-array to look like with-opengl-sequence with out the extra gynsym for array. I hope I did it right and didn't shoot myself in the foot... examples/rb-varray.lisp adjusted until if gave me output using rb-cube.lisp as a reference Thanks again and I hope this code is useful. Charlie Mac

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[cl-opengl-devel] cl-opengl on Windows
by Gilbert Wong 18 Dec '06

18 Dec '06

Hello, sorry if this isnt the right place for these issues since i'm fairly a novice to lisp. I am currently playing around with sbcl 9.17 on Windows and am having problems compiling cl-opengl. It seems that it has trouble finding all the gl functions, specifically anything above gl 1.1. Has this been adressed? Is there an easy way to utilize something like wglGetProc to address this problem? -- gilbert

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