We start by calling glCreateProgram to create an empty program object. This function returns a handle to the program object, which we store in a variable named programHandle. If an error occurs with program creation, the function will return 0. We check for that, and if it occurs, we print an error message and exit.
Next, we attach each shader to the program object using glAttachShader. The first argument is the handle to the program object, and the second is the handle to the shader object to be attached.
Then, we link the program by calling glLinkProgram, providing the handle to the program object as the only argument. As with compilation, we check for the success or failure of the link, with the subsequent query.
We check ...
