On Wed, Jul 2, 2014 at 8:06 AM, Elise Huard <hopengl@elisehuard.be> wrote:

Hi,
I've been trying to get a texture mapped onto a circle.
I've pounded my head against this problem for a good while,
been reading lots of posts about how to do it in C,

For folks who are experienced with low-level Haskell I actually recommend they use the OpenGLRaw library as it matches C examples more closely. Although, if you're a Haskell beginner that may just be an extra hassle.

reproduced those as much as possible,
but the best I get is a fairly distorted texture
(I'm working with a basic checkerboard as displayed in the Redbook4
examples of GLUT,
just to make sure I've got it right before moving on to actual images).
Code here:
loading texture
https://github.com/elisehuard/game-prototype/blob/master/src/Main.hs#L90
using the texture in a circle (mapping):
https://github.com/elisehuard/game-prototype/blob/master/src/Main.hs#L130

It's hard to say what's going on with all those unsafeCoerce in there.

the result is here
https://github.com/elisehuard/game-prototype/blob/master/images/texture.jpg

(as you can see, it is not a checkerboard)
My aim is to make a 2D game to start with, so the perspective is orthogonal,
I don't know if that helps.

Lots of things can be orthogonal, but I believe in this case that orthographic is the word you want :)