source: Dev/branches/rest-dojo-ui/client/dojox/gfx3d/vector.js @ 256

define(["dojo/_base/lang", "dojo/_base/array", "./_base"],function(lang, arrayUtil, gfx3d) {

gfx3d.vector =  {
        
        sum: function(){
                // summary: sum of the vectors
                var v = {x: 0, y: 0, z:0};
                arrayUtil.forEach(arguments, function(item){ v.x += item.x; v.y += item.y; v.z += item.z; });
                return v;
        },

        center: function(){
                // summary: center of the vectors
                var l = arguments.length;
                if(l == 0){
                        return {x: 0, y: 0, z: 0};
                }
                var v = gfx3d.vector.sum(arguments);
                return {x: v.x/l, y: v.y/l, z: v.z/l};
        },

        substract: function(/* Pointer */a, /* Pointer */b){
                return  {x: a.x - b.x, y: a.y - b.y, z: a.z - b.z};
        },

        _crossProduct: function(x, y, z, u, v, w){
                // summary: applies a cross product of two vectorss, (x, y, z) and (u, v, w)
                // x: Number: an x coordinate of a point
                // y: Number: a y coordinate of a point
                // z: Number: a z coordinate of a point
                // u: Number: an x coordinate of a point
                // v: Number: a y coordinate of a point
                // w: Number: a z coordinate of a point
                return {x: y * w - z * v, y: z * u - x * w, z: x * v - y * u}; // Object
        },

        crossProduct: function(/* Number||Point */ a, /* Number||Point */ b, /* Number, optional */ c, /* Number, optional */ d, /* Number, optional */ e, /* Number, optional */ f){
                // summary: applies a matrix to a point
                // matrix: dojox.gfx3d.matrix.Matrix3D: a 3D matrix object to be applied
                // a: Number: an x coordinate of a point
                // b: Number: a y coordinate of a point
                // c: Number: a z coordinate of a point
                // d: Number: an x coordinate of a point
                // e: Number: a y coordinate of a point
                // f: Number: a z coordinate of a point
                if(arguments.length == 6 && arrayUtil.every(arguments, function(item){ return typeof item == "number"; })){
                        return gfx3d.vector._crossProduct(a, b, c, d, e, f); // Object
                }
                // branch
                // a: Object: a point
                // b: Object: a point
                // c: null
                // d: null
                // e: null
                // f: null
                return gfx3d.vector._crossProduct(a.x, a.y, a.z, b.x, b.y, b.z); // Object
        },

        _dotProduct: function(x, y, z, u, v, w){
                // summary: applies a cross product of two vectorss, (x, y, z) and (u, v, w)
                // x: Number: an x coordinate of a point
                // y: Number: a y coordinate of a point
                // z: Number: a z coordinate of a point
                // u: Number: an x coordinate of a point
                // v: Number: a y coordinate of a point
                // w: Number: a z coordinate of a point
                return x * u + y * v + z * w; // Number
        },
        dotProduct: function(/* Number||Point */ a, /* Number||Point */ b, /* Number, optional */ c, /* Number, optional */ d, /* Number, optional */ e, /* Number, optional */ f){
                // summary: applies a matrix to a point
                // matrix: dojox.gfx3d.matrix.Matrix3D: a 3D matrix object to be applied
                // a: Number: an x coordinate of a point
                // b: Number: a y coordinate of a point
                // c: Number: a z coordinate of a point
                // d: Number: an x coordinate of a point
                // e: Number: a y coordinate of a point
                // f: Number: a z coordinate of a point
                if(arguments.length == 6 && arrayUtil.every(arguments, function(item){ return typeof item == "number"; })){
                        return gfx3d.vector._dotProduct(a, b, c, d, e, f); // Object
                }
                // branch
                // a: Object: a point
                // b: Object: a point
                // c: null
                // d: null
                // e: null
                // f: null
                return gfx3d.vector._dotProduct(a.x, a.y, a.z, b.x, b.y, b.z); // Object
        },

        normalize: function(/* Point||Array*/ a, /* Point */ b, /* Point */ c){
                // summary: find the normal of the implicit surface
                // a: Object: a point
                // b: Object: a point
                // c: Object: a point
                var l, m, n;
                if(a instanceof Array){
                        l = a[0]; m = a[1]; n = a[2];
                }else{
                        l = a; m = b; n = c;
                }

                var u = gfx3d.vector.substract(m, l);
                var v = gfx3d.vector.substract(n, l);
                return gfx3d.vector.crossProduct(u, v);
        }
};
        return gfx3d.vector;
});