/********************************************************
 * See tutorial at:
 * http://www.petercollingridge.appspot.com/3D-tutorial
*********************************************************/

var backgroundColour = color(255, 255, 255);
var nodeColour = color(40, 168, 107);
var edgeColour = color(34, 68, 204);
var nodeSize = 8;

var node0 = [-100, -100, -100];
var node1 = [-100, -100,  100];
var node2 = [-100,  100, -100];
var node3 = [-100,  100,  100];
var node4 = [ 100, -100, -100];
var node5 = [ 100, -100,  100];
var node6 = [ 100,  100, -100];
var node7 = [ 100,  100,  100];
var nodes = [node0, node1, node2, node3, node4, node5, node6, node7];

var edge0  = [0, 1];
var edge1  = [1, 3];
var edge2  = [3, 2];
var edge3  = [2, 0];
var edge4  = [4, 5];
var edge5  = [5, 7];
var edge6  = [7, 6];
var edge7  = [6, 4];
var edge8  = [0, 4];
var edge9  = [1, 5];
var edge10 = [2, 6];
var edge11 = [3, 7];
var edges = [edge0, edge1, edge2, edge3, edge4, edge5, edge6, edge7, edge8, edge9, edge10, edge11];

// Rotate shape around the z-axis
var rotateZ3D = function(theta) {
    var sin_t = sin(theta);
    var cos_t = cos(theta);

    for (var n=0; n<nodes.length; n++) {
        var node = nodes[n];
        var x = node[0];
        var y = node[1];
        node[0] = x * cos_t - y * sin_t;
        node[1] = y * cos_t + x * sin_t;
    }
};

var rotateY3D = function(theta) {
    var sin_t = sin(theta);
    var cos_t = cos(theta);

    for (var n=0; n<nodes.length; n++) {
        var node = nodes[n];
        var x = node[0];
        var z = node[2];
        node[0] = x * cos_t - z * sin_t;
        node[2] = z * cos_t + x * sin_t;
    }
};

var rotateX3D = function(theta) {
    var sin_t = sin(theta);
    var cos_t = cos(theta);

    for (var n=0; n<nodes.length; n++) {
        var node = nodes[n];
        var y = node[1];
        var z = node[2];
        node[1] = y * cos_t - z * sin_t;
        node[2] = z * cos_t + y * sin_t;
    }
};

//rotateZ3D(30);
rotateY3D(45);
//rotateX3D(30);

var draw= function() {
    background(backgroundColour);

    // Draw edges
    stroke(edgeColour);
    for (var e=0; e<edges.length; e++) {
        var n0 = edges[e][0];
        var n1 = edges[e][1];
        var node0 = nodes[n0];
        var node1 = nodes[n1];
        var x1 = -node0[0] - 0.5*node0[2] * sqrt(2)/2;
        var y1 =  node0[1] - 0.5*node0[2] * sqrt(2)/2;
        var x2 = -node1[0] - 0.5*node1[2] * sqrt(2)/2;
        var y2 =  node1[1] - 0.5*node1[2] * sqrt(2)/2;
        line(x1, y1, x2, y2);
    }

    // Draw nodes
    fill(nodeColour);
    noStroke();
    for (var n=0; n<nodes.length; n++) {
        var node = nodes[n];
        var x1 = -node[0] - 0.5*node[2] * sqrt(2)/2;
        var y1 =  node[1] - 0.5*node[2] * sqrt(2)/2;
        ellipse(x1, y1, nodeSize, nodeSize);
    }

};

var mouseDragged = function() {
    rotateY3D(-mouseX + pmouseX);
    rotateX3D(mouseY - pmouseY);
};

translate(200, 200);