Using OpenGL ES functions on a Mac

Question

I am trying to draw opengl into 2d space, and am doing the following, however it wont compile:

    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();

I have included the OpenGL.framework framework, The compiler trace says the following.

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

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.

Answer 1

Have you included the appropriate headers?

On the Mac, these are

#import <OpenGL/OpenGL.h>

and possibly

#import <GLUT/GLUT.h>

On the iPhone they are

#import <OpenGLES/EAGL.h>
#import <OpenGLES/EAGLDrawable.h>
#import <OpenGLES/ES1/gl.h>
#import <OpenGLES/ES1/glext.h>

Also, if I'm not mistaken, glOrthof() is OpenGL-ES-specific. You may need to use glOrtho() on the Mac.