Problem solved, complete brain failure, nothing to do with OpenGL. Had failed to tell Allegro that I wanted an OpenGL context with a depth buffer.
Thanks for the help anyway.
Angus

Don't think so, firstly it's sides disappearing, not chunks of cube, secondly I've tried pushing the cube a long way back in the frustrum and the problem persists.
Thanks anyway :)

Recently finished making a cube rotate using functions I wrote myself to calculate MVP matrices and such.

The cube appears and rotates, but seems to be partially transparent despite me telling it...

Thanks for all the help everyone, changed the matrices to be column major which didn't help at first, then found the real bug which made me feel like a total idiot. My program is filled with code to...

Tried flipping round the order of the transformations just now which didn't help. I'll do a full proper check of the entire piece of code tomorrow/over the next week, mainly worried about these bits...

Thanks, don't know why I didn't think to check which way matrices should be. Will change that and see if it at all improves things.
Angus

Hi,
I'm very new to OpenGL and for various reasons I'm rolling my own functions to calculate the various parts of my MVP matrix (described here). Anyway the code based off of them doesn't work...