[MIT-Scheme-devel] Callbacks in GLFW bindings via FFI; multiple C-includes

[craven]

Hello fellow Schemers!

I'm playing around with OpenGL bindings in MIT/GNU Scheme. I'm using
GLFW as the toolkit to access window-related functions. It includes a
function glfwSetKeyCallback, which is supposed to set a callback
function that is called whenever a key is pressed or released.
It does not support passing user-defined data. Is there any way to make
this work nonetheless? As I understand the manual and examples, the
implementation of CALLBACK seems specific to gtk (which does support
user-defined data), but many of the frameworks and libraries I've seen
do not support that, unfortunately.

This is the documentation for glfwSetKeyCallback:
http://www.glfw.org/docs/latest/group__input.html#ga7e496507126f35ea72f01b2e6ef6d155

Another thing that I found is that it seems impossible to load multiple
FFI-bindings in the same image. I'd like to use sqlite3, glfw and opengl
(all of which I've defined myself as separate FFI includes). Is there a
way to make this work?

Thanks for any help!

Greetings,
Peter