IDK OpenGL RTT 1

OGL_RTT1.cpp

// For Linux, NOT CROSS-PLATFORM
#include <GL/glew.h>
#include <GL/glut.h>
#include <SOIL/SOIL.h>
#include <cstdio>
#include <iostream>

using namespace std;

GLuint texImg;

int loadedImageWidth;
int loadedImageHeight;
unsigned char *loadedImageData;


bool CheckFramebufferStatus() 
{
    GLenum status = (GLenum) glCheckFramebufferStatus( GL_FRAMEBUFFER );
    switch( status ) 
    {
        case GL_FRAMEBUFFER_COMPLETE:
            return true;
        case GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT:
            fprintf( stderr, "Framebuffer incomplete, incomplete attachment\n" );
            return false;
        case GL_FRAMEBUFFER_INCOMPLETE_MISSING_ATTACHMENT:
            fprintf( stderr, "Framebuffer incomplete, missing attachment\n" );
            return false;
        case GL_FRAMEBUFFER_INCOMPLETE_DRAW_BUFFER:
            fprintf( stderr, "Framebuffer incomplete, missing draw buffer\n" );
            return false;
        case GL_FRAMEBUFFER_INCOMPLETE_READ_BUFFER:
            fprintf( stderr, "Framebuffer incomplete, missing read buffer\n" );
            return false;
        case GL_FRAMEBUFFER_UNSUPPORTED:
            fprintf( stderr, "Unsupported framebuffer format\n" );
            return false;
    }
    return false;
}

void loadTexture() {
    GLuint FramebufferName;
    glGenFramebuffers(1, &FramebufferName);
    glBindFramebuffer(GL_FRAMEBUFFER, FramebufferName);

    glActiveTexture(GL_TEXTURE0);
    glGenTextures(1, &texImg);

    glBindTexture(GL_TEXTURE_2D, texImg);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
    glTexImage2D(GL_TEXTURE_2D,
            0,
            GL_RGB,
            256,
            256,
            0,
            GL_RGB,
            GL_UNSIGNED_BYTE,
            NULL);

    GLuint depthrenderbuffer;
    glGenRenderbuffers(1, &depthrenderbuffer);
    glBindRenderbuffer(GL_RENDERBUFFER, depthrenderbuffer);
    glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH_COMPONENT, 256, 256);
    glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_ATTACHMENT, GL_RENDERBUFFER, depthrenderbuffer);
    glBindRenderbuffer(GL_RENDERBUFFER, 0);
    
    // Set "renderedTexture" as our colour attachment #0
    glFramebufferTexture2D(GL_FRAMEBUFFER, GL_COLOR_ATTACHMENT0, GL_TEXTURE_2D, texImg, 0);
     
    // Set the list of draw buffers.
    GLenum DrawBuffers[1] = {GL_COLOR_ATTACHMENT0};
    glDrawBuffers(1, DrawBuffers); // "1" is the size of DrawBuffers

    // Always check that our framebuffer is ok
    if (glCheckFramebufferStatus(GL_FRAMEBUFFER) != GL_FRAMEBUFFER_COMPLETE) {
        std::cout << "FrameBuffer done goofed." << std::endl;
	CheckFramebufferStatus();
        return;
    }

    // Render to our framebuffer
    glBindFramebuffer(GL_FRAMEBUFFER, FramebufferName);

    // Clear mask texture to all black
    glClearColor(1, 1, 1, 0);
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
    
    // Set up projection.
    glViewport(0, 0, 256, 256);
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    gluOrtho2D(0, 1, 0, 1);
    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity();

    // Render and stuff
    // Draw a polygon
    glBegin(GL_POLYGON);
        glColor3f(0, 0, 1);

        glVertex2d(0.5,   1);
        glVertex2d(  0, 0.5);

        glColor3f(1, 0, 1);
        glVertex2d(0.5,   0);
        glVertex2d(  1, 0.5);
    glEnd();
}

void display(void) {
    // Render to the screen
    glClearColor(0,0,0,0);
    glClear(GL_COLOR_BUFFER_BIT);

    glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE);

    // Draw a square
    glBegin(GL_QUADS);
        glColor3f(1,0,0);

        glVertex3f(-0.75, +0.75, 1);
        glVertex3f(+0.75, +0.75, 1);
        glVertex3f(+0.75, -0.75, 1);
        glVertex3f(-0.75, -0.75, 1);
    glEnd();
    
    glEnable(GL_TEXTURE_2D);
    glActiveTexture(GL_TEXTURE0);
    glBindTexture(GL_TEXTURE_2D, texImg);

    // Draw a square
    glBegin(GL_QUADS);
        glColor3f(0,1,0);

        glTexCoord2f(0, 0);
        glVertex2f(-0.5, +0.5);

        glTexCoord2f(1, 0);
        glVertex2f(+0.5, +0.5);

        glTexCoord2f(1, 1);
        glVertex2f(+0.5, -0.5);
        
        glTexCoord2f(0, 1);
        glVertex2f(-0.5, -0.5);
    glEnd();

    glDisable(GL_TEXTURE_2D);

    glutSwapBuffers();
}

void reshape(int w, int h) {
}

int main(int argc, char **argv) {
    glutInit(&argc, argv);

    glutInitDisplayMode(GLUT_DEPTH | GLUT_DOUBLE | GLUT_RGBA);  

    glutInitWindowPosition(200, 200);
    glutInitWindowSize(512, 512);
    glutCreateWindow("Hello OpenGL");

    glewInit(); // needed on linux and windows

    glutDisplayFunc(display);
    glutReshapeFunc(reshape);

    loadTexture();

    // Set up projection.
    glViewport(0, 0, 512, 512);
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    gluOrtho2D(-1, 1, -1, 1);
    glMatrixMode(GL_MODELVIEW);
    glLoadIdentity();

    glBindFramebuffer(GL_FRAMEBUFFER, 0);

    glutMainLoop();

    return 0;
}

Also, there are some redundant things going on here, I believe. Hmm. Indeed this could be tidied quite a bit.