var gl;

function start() {
    var canvas = document.getElementById("holochrist");

    initWebGL(canvas);      // Initialize the GL context

    // Only continue if WebGL is available and working

    if (gl) {
        gl.clearColor(0.0, 0.0, 0.0, 1.0);
        gl.enable(gl.DEPTH_TEST);
        gl.depthFunc(gl.LEQUAL);
        gl.clear(gl.COLOR_BUFFER_BIT|gl.DEPTH_BUFFER_BIT);

        /*******************************************************|
        |    1. Set clear color to black, fully opaque          |
        |    2. Enable depth testing                            |
        |    3. Near things obscure far things                  |
        |    4. Clear the color as well as the depth buffer.    |
        ********************************************************/
    }
}

function initWebGL(canvas) {
    gl = null;  //Initialize the global var gl to null.

    try {
        //Try to grab the standard context. If it fails, use experimental.
        gl = canvas.getContext("webgl") || canvas.getContext("experimantal-webgl");
        gl.viewport(0, 0, canvas.width, canvas.height();
    }
    catch(e) {}

    if (!gl) {  //If we can't get GL context, give up.
        alert("Unable to initalize WebGL.
                Your browser propably doesn't support it");
    }
}