Question

I’ve encountered a problem whilst learning how to texture in OpenGL (from OpenGL 5th Edition Bible). The problem is that I can’t display my texture. I load it from a BMP file with a function I’ve written myself.

Since code is quite lengthy I uploaded all neccessery files. You can download it from here.

EDIT: I’ve tried copying code from the mentioned book (TGA loading described there) and it doesn’t work as well. It seems that loading stucks at loading image data from file (strange). I suppose it isn’t relevant as far as my problem is concern.

Answer 1

There are general debug steps for checking for problems. I will list them below in the hope you might find the bug (and for future readers):

• Does the file exist? Is the file being read properly according to the format? Did you get it to gel well with OpenGL? My suggestion: Do not mess with these things yourself. Use a library. There’s an amazingly light weight SOIL (Simple OpenGL Image library)
• Are you loading the textures before initialising OpenGL? This was always my problem because I used to “load” and do a glBindTexture(..) in the constructor (of some class). The objects were created before OpenGL was initialised.
• Have you enabled GL_TEXTURE_2D? Check the initialise code, use: glEnable(GL_TEXTURE_2D)
• Did you map the textures properly with the quad or the shape you want it on? Expanding on this here is (sort of) out of scope. There are great tutorials out there.
• (Would seem stupid, but happens sometimes) Are you blacking out the object by glColor3f(0,0,0) ?

_{There could be more checks, but these are the ones hitting my head now}