title: Set background image of an openGL window
body: <p>I am trying to set a background image of my openGL window by creating a quad on an orthogonal projection matrix and adding texture to it. I am also making use of GLUT toolkit in my application.</p>
  
  <p>However I am having several problems. Below are screenshot illustrating the problem: image is grayscale and it repeats on x and y, even though texture size is set to be the same as the quad.</p>
  
  <p>That is what I am trying to achieve:
  <img src="https://i.stack.imgur.com/9c2L2.jpg" alt="Desired result"></p>
  
  <p>And that is what I am getting:
  <img src="https://i.stack.imgur.com/s4hzs.jpg" alt="Actual result"></p>
  
  <p>Code for rendering and loading texture looks like this:</p>
  
  <pre><code>void orthogonalStart (void) {
      glMatrixMode(GL_PROJECTION);
      glPushMatrix();
      glLoadIdentity();
      gluOrtho2D(0, w1, 0, h1);
      glScalef(1, -1, 1);
      glTranslatef(0, -h1, 0);
      glMatrixMode(GL_MODELVIEW);
  }
  
  void orthogonalEnd (void) {
      glMatrixMode(GL_PROJECTION);
      glPopMatrix();
      glMatrixMode(GL_MODELVIEW);
  }
  
  GLuint LoadTexture( const char * filename, int width, int height )
  {
      GLuint texture;
      unsigned char * data;
      FILE * file;
  
      //The following code will read in our RAW file
      file = fopen( filename, "rb" );
      if ( file == NULL ) return 0;
      data = (unsigned char *)malloc( width * height * 3 );
      fread( data, width * height * 3, 1, file );
      fclose( file );
  
      glGenTextures( 1, &amp;texture ); 
      glBindTexture( GL_TEXTURE_2D, texture ); 
      glTexEnvf( GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE ); 
  
  
      //even better quality, but this will do for now.
      glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER,GL_LINEAR );
      glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER,GL_LINEAR );
  
  
      //to the edge of our shape. 
      glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT );
      glTexParameterf( GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT );
  
      //Generate the texture
      glTexImage2D(GL_TEXTURE_2D, 0, GL_RGB, width, height, 0,GL_RGB, GL_UNSIGNED_BYTE, data);
      free( data ); //free the texture
      return texture; //return whether it was successful
  }
  
  void FreeTexture( GLuint texture )
  {
    glDeleteTextures( 1, &amp;texture );
  }
  
  void background (void) {
      glBindTexture( GL_TEXTURE_2D, texture ); 
  
      orthogonalStart();
  
      glBegin(GL_QUADS);
          glTexCoord2d(0.0,0.0); glVertex2f(0, 0);
          glTexCoord2d(1.0,0.0); glVertex2f(1024, 0);
          glTexCoord2d(1.0,1.0); glVertex2f(1024, 1024);
          glTexCoord2d(0.0,1.0); glVertex2f(0, 1024);
          glEnd();
  
      orthogonalEnd();
  }
  
  void display (void) {
      glClearColor (1.0,0.0,0.0,1.0);
      glClear (GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
      glLoadIdentity();
      glEnable( GL_TEXTURE_2D );
  
      background();
      gluLookAt (0.0, 0.0, 5.0, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0);
  
      glutSwapBuffers();
  }
  </code></pre>
  
  <p>To convert texture from png into Raw format I use photoshop, so I thought greyscale image might be due to conversion.</p>
  
  <p><strong>Note:</strong> I have just started learning open, so this might be not the best approach. Please let me know if there is a better way </p>
  
  <p><strong>Edit: Image has to stay on one place and not rescalse</strong></p>