Opengl texture not showing

Question

I'm trying to display a simple texture (from an array) in opengl, but I just get a blank white screen.

My code to generate the texture:

GLbyte textureData[] = { 0, 0, 0, 255, 0, 0, 0, 255, 0, 0, 0, 255 };
GLsizei width = 2;
GLsizei height = 2;


glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
glPixelStorei(GL_PACK_ALIGNMENT, 1);
glGenTextures(1, &textureName);   
glBindTexture(GL_TEXTURE_2D, textureName); 

glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB8, width, height, 0, GL_UNSIGNED_BYTE, GL_RGB8, (GLvoid*)textureData);

And the display code:

glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

glEnable(GL_TEXTURE_2D);
glBindTexture(GL_TEXTURE_2D, textureName);
glBegin(GL_TRIANGLE_STRIP);
glTexCoord2f(0.0, 0.0);
glVertex2f(-1.0, -1.0);

glTexCoord2f(1.0, 0.0);
glVertex2f(1.0, -1.0);

glTexCoord2f(0.0, 1.0);
glVertex2f(-1.0, 1.0);

glTexCoord2f(1.0, 1.0);
glVertex2f(1.0, 1.0);
glEnd();

glutSwapBuffers();

I know the problem is with the textures as I can draw solid shapes to the screen.

Answer 1

Default minification filtering setting is to use mipmaps. Since you do not provide all mipmap levels down to 1×1 and didn't switch to a filter method that does not require mipmapping, texture sampling will be skipped.

You have to add setting the filter method to something non-mipmapped, like this:

glTexImage2D(…);
glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);

Or provide a full stack of image levels.

update due to comment

Also there's a problem with the glTexImage2D call: GL_RGB8 is not a valid token for the data format. Explicitly sized format tokens are permitted only for the internal format. However for starters you should probably use the unsized tokens (just GL_RGB without the 8 ) anyway (explicit size should be used only, when it really matters, eg for certain precision requirements or to avoid conversion costs for streaming texture updates).