(Shadow Maps) Rendering the depth buffer to a texture and Drawing it to check it

Question

I have been trying to get shadow maps to work, but I can;t even get past the depth buffer part of it. I've been looking on the internet for hours now, yadayadayada. Here is my code so far -

Making the FBO and the texture for depth:

GLuint framebuffer;
    GLuint depth;
    GLuint texture;

    glGenFramebuffers(1, &framebuffer);
    glBindFramebuffer(GL_FRAMEBUFFER, framebuffer);

    glGenTextures(1, &texture);
    glBindTexture(GL_TEXTURE_2D, texture);

    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA8, 1280, 800, 0, GL_RGBA, GL_FLOAT, NULL);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);

    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);

    glBindTexture(GL_TEXTURE_2D, 0);


    glGenTextures(1, &depth);
    glBindTexture(GL_TEXTURE_2D, depth);

    glTexImage2D(GL_TEXTURE_2D, 0, GL_DEPTH_COMPONENT, 1280, 800, 0, GL_DEPTH_COMPONENT, GL_FLOAT, NULL);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);

    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);

    glBindTexture(GL_TEXTURE_2D, 0);




    glFramebufferTexture2D(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_TEXTURE_2D, depth, 0);
    //glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, texture, 0);
    glDrawBuffer(GL_NONE);


    if (glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE)
        std::cout << "There was a problem with making the framebuffer\n";
    glBindFramebuffer(GL_FRAMEBUFFER, 0);

    return framebuffer;

Rendering the 'depth' to a quad for viewing:

 glBindFramebuffer(GL_FRAMEBUFFER, FBO);
   glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);

   for (int i = 0; i < objects.size(); i++)
   {
    objects[i].renderObjectForDepth();
   }
   glBindFrameBuffer(GL_TEXTURE_2D,0);
   glBindTexture2D(GL_TEXTURE_2D, texture)
   drawQuad();

And to me, everything looks fine, but It generates images like the picture attached. I've been ripping out my hair for days now, and any help would be appreciated.

EDIT: It was because I was rendering a blank texture, IE the texture color that never got written to. After drawing the depth texture and writing the color texture, it works fine. But how do I do it without a color texture?

Answer 1

Check that the following two states are set when rendering to your depth-only FBO:

glDrawBuffer(GL_NONE);
glReadBuffer(GL_NONE);