title: Using OpenGL ES functions on a Mac
body: <p>I am trying to draw opengl into 2d space, and am doing the following, however it wont compile:</p>
  
  <pre><code>    int vPort[4];
      glGetIntegerv(GL_VIEWPORT, vPort);
  
      glMatrixMode(GL_PROJECTION);
      glPushMatrix();
      glLoadIdentity();
  
      glOrthof(0, vPort[2], 0, vPort[3], -1, 1);
      glMatrixMode(GL_MODELVIEW);
      glPushMatrix();
      glLoadIdentity();
  </code></pre>
  
  <p>I have included the OpenGL.framework framework, The compiler trace says the following.</p>
  
  <pre><code>In function '-[OpenGLView drawRect:]':
      warning: implicit declaration of function 'glOrthof'
  
  Ld build/Debug/OpenGLTest1.app/Contents/MacOS/OpenGLTest1 normal x86_64
  /Developer/usr/bin/gcc-4.2 -arch x86_64 -isysroot /Developer/SDKs/MacOSX10.6.sdk -        L/Users/user/Documents/cocoa/OpenGLTest1/build/Debug -F/Users/user/Documents/cocoa/OpenGLTest1/build/Debug -filelist /Users/user/Documents/cocoa/OpenGLTest1/build/OpenGLTest1.build/Debug/OpenGLTest1.build/Objects-normal/x86_64/OpenGLTest1.LinkFileList -mmacosx-version-min=10.6 -framework Cocoa -framework OpenGL -o /Users/user/Documents/cocoa/OpenGLTest1/build/Debug/OpenGLTest1.app/Contents/MacOS/OpenGLTest1
  
  Undefined symbols:
    "_glOrthof", referenced from:
        -[OpenGLView drawRect:] in OpenGLView.o
  ld: symbol(s) not found
  collect2: ld returned 1 exit status
  </code></pre>
  
  <p>I've run out of ideas on how to fix it. My target is currently a desktop app, but I am aiming to make an iphone app eventually.</p>