C. Put it All Together And Turn Yourself About

So lets make us a good ole triangle!

  1. First we need some sort mass, a place to put all the stuff in.

    createEmptyMovieClip("mass", _root.depth++);

  2. Now we need the 3 points of a triangle.

    mass.pts = new Array();
    // only do this once, makes pts an array

    mass.pts[0] = new Object;
    //makes a point where we can add properties
    mass.pts[0].x = 0; mass.pts[0].y = 0; mass.pts[0].z = 0;

    mass.pts[1] = new Object;
    //makes another point
    mass.pts[1].x = 40; mass.pts[0].y =40; mass.pts[0].z = 0;

    mass.pts[2] = new Object;
    //makes another point
    mass.pts[2].x = 0; mass.pts[0].y =40; mass.pts[0].z = 0;

  3. Great, but they’re still just points in space. Lets make a shape out of them.
    First, we need to add something to our mass to hold the different shapes:

    mass.shapes = new Array ();
    // only write this once in the script

    Now we have some space for shapes, we need to make space in a shape for points:

    mass.shapes[0] = new Array();
    // gives room in the first shape for points

    And now lets finally make a shape out of points:

    mass.shapes[0][0] = 2;
    // first point in shape will be the point with ID = 0
    mass.shapes[0][1] = 0;
    // 2nd point in shape will be the point with ID = 1
    mass.shapes[0][2] = 1;
    // first point in shape will be the point with ID = 2

    The order didn’t really matter but illustrate how the external point list. For more advanced shapes, it could become a headache – different orders means the lines are connected in the different orders.

II. Extrude - Lets make it 3D

A. Point check

// A very useful function for optimization would be to check if a point exists, and if so, whats its ID
// if it doesn?t find one, the function will return ?1 (an impossible ID)

function checkPts(mc, x, y, z)
{
        f = -1;
        for (b = 0; b < mc.pts.length; b++)
        {
                if (mc.pts[b].x == x)
                if (mc.pts[b].y == y & mc.pts[b].z == z)
                f = b;
                if (f > -1) break;
        }
        return f;
}

B. Actual extrude:

function extrude (mc, from, amount) // which mass, shape, and desired depth
{
        // this will go through each point in our shape
        for (i = 0; i < mc.shapes[from].length; i++)
        {
                // let?s check if our point with a change depth (z) already exists
                k = checkPts(mc, mc.pts[mc.shapes[from][i]].x, mc.pts[mc.shapes[from][i]].y,
                 mc.pts[mc.shapes[from][i]].z + amount);
                
                if ( k == -1)
                {
                        // if it doesn?t, lets make a new one with the extruded z
                        k = mc.pts.length;
                        mc.pts[k] = new Object;
                        mc.pts[k].x = mc.pts[mc.shapes[from][i]].x;
                        mc.pts[k].y = mc.pts[mc.shapes[from][i]].y;
                        mc.pts[k].z = mc.pts[mc.shapes[from][i]].z + amount;
                        // the only change from the original coordinate is z, depth
                }
                
                // lets make a face out of this coordinate, the previous, and their extruded copy
                // that means it?ll be on of the sides of the new shape (not top or bottom)
                // need to make sure we start on the second coordinate though:
                if (i > 0)
                {
                        
                        // make a new face
                        mc.shapes[mc.shapes.length] = new Array();
                        mc.shapes[mc.shapes.length-1][0] = checkPts(mc, mc.pts[mc.shapes[from][i]].x,
                         mc.pts[mc.shapes[from][i]].y, mc.pts[mc.shapes[from][i]].z + amount);
                        mc.shapes[mc.shapes.length-1][1] = checkPts(mc, mc.pts[mc.shapes[from][i - 1]].x,
                         mc.pts[mc.shapes[from][i - 1]].y, mc.pts[mc.shapes[from][i - 1]].z + amount);
                        mc.shapes[mc.shapes.length-1][2] = mc.shapes[from][i - 1];
                        mc.shapes[mc.shapes.length-1][3] = mc.shapes[from][i];
                }
        }
        // we still need to make the last face, connecting from the first coordinate, last, and their extruded copies
        
        mc.shapes[mc.shapes.length] = new Array();
        mc.shapes[mc.shapes.length-1][0] = checkPts(mc, mc.pts[mc.shapes[from].length-1].x,
         mc.pts[mc.shapes[from].length-1].y, mc.pts[mc.shapes[from].length-1].z + amount );
        mc.shapes[mc.shapes.length-1][1] = mc.shapes[from][mc.shapes[from].length - 1];
        mc.shapes[mc.shapes.length-1][2] = mc.shapes[from][0];
        mc.shapes[mc.shapes.length-1][3] = checkPts(mc, mc.pts[ mc.shapes[from][0] ].x,
         mc.pts[ mc.shapes[from][0]].y, mc.pts[ mc.shapes[from][0]].z + amount);
        
        // and lets make the top of the shape
        mc.shapes[mc.shapes.length] = new Array();
        for (i = 0; i < mc.shapes[from].length; i++)
        mc.shapes[mc.shapes.length - 1][i] = checkPts(mc, mc.pts[mc.shapes[from][i]].x,
         mc.pts[mc.shapes[from][i]].y, mc.pts[mc.shapes[from][i]].z + amount);
}

C. Great.. how do extrude the thing again?

extrude(mass, 0, 20);
// takes the first shape in our mass and extrudes it 20 pixels