source: Dev/trunk/src/client/dojox/gfx3d/lighting.js

define([
        "dojo/_base/lang",
        "dojo/_base/Color",     // dojo.Color
        "dojo/_base/declare",   // declare
        "dojox/gfx/_base",
        "./_base"
],function(lang,Color,declare,gfx,gfx3d) {

        var lite = gfx3d.lighting = {
                // color utilities
                black: function(){
                        return {r: 0, g: 0, b: 0, a: 1};
                },
                white: function(){
                        return {r: 1, g: 1, b: 1, a: 1};
                },
                toStdColor: function(c){
                        c = gfx.normalizeColor(c);
                        return {r: c.r / 255, g: c.g / 255, b: c.b / 255, a: c.a};
                },
                fromStdColor: function(c){
                        return new Color([Math.round(255 * c.r), Math.round(255 * c.g), Math.round(255 * c.b), c.a]);
                },
                scaleColor: function(s, c){
                        return {r: s * c.r, g: s * c.g, b: s * c.b, a: s * c.a};
                },
                addColor: function(a, b){
                        return {r: a.r + b.r, g: a.g + b.g, b: a.b + b.b, a: a.a + b.a};
                },
                multiplyColor: function(a, b){
                        return {r: a.r * b.r, g: a.g * b.g, b: a.b * b.b, a: a.a * b.a};
                },
                saturateColor: function(c){
                        return {
                                r: c.r < 0 ? 0 : c.r > 1 ? 1 : c.r,
                                g: c.g < 0 ? 0 : c.g > 1 ? 1 : c.g,
                                b: c.b < 0 ? 0 : c.b > 1 ? 1 : c.b,
                                a: c.a < 0 ? 0 : c.a > 1 ? 1 : c.a
                        };
                },
                mixColor: function(c1, c2, s){
                        return lite.addColor(lite.scaleColor(s, c1), lite.scaleColor(1 - s, c2));
                },
                diff2Color: function(c1, c2){
                        var r = c1.r - c2.r;
                        var g = c1.g - c2.g;
                        var b = c1.b - c2.b;
                        var a = c1.a - c2.a;
                        return r * r + g * g + b * b + a * a;
                },
                length2Color: function(c){
                        return c.r * c.r + c.g * c.g + c.b * c.b + c.a * c.a;
                },
                
                // vector utilities
                //TODO: move vector utilities from this file to vector.js
                dot: function(a, b){
                        return a.x * b.x + a.y * b.y + a.z * b.z;
                },
                scale: function(s, v){
                        return {x: s * v.x, y: s * v.y, z: s * v.z};
                },
                add: function(a, b){
                        return {x: a.x + b.x, y: a.y + b.y, z: a.z + b.z};
                },
                saturate: function(v){
                        return Math.min(Math.max(v, 0), 1);
                },
                length: function(v){
                        return Math.sqrt(gfx3d.lighting.dot(v, v));
                },
                normalize: function(v){
                        return lite.scale(1 / lite.length(v), v);
                },
                faceforward: function(n, i){
                        var p = gfx3d.lighting;
                        var s = p.dot(i, n) < 0 ? 1 : -1;
                        return p.scale(s, n);
                },
                reflect: function(i, n){
                        var p = gfx3d.lighting;
                        return p.add(i, p.scale(-2 * p.dot(i, n), n));
                },
                
                // lighting utilities
                diffuse: function(normal, lights){
                        var c = lite.black();
                        for(var i = 0; i < lights.length; ++i){
                                var l = lights[i],
                                        d = lite.dot(lite.normalize(l.direction), normal);
                                c = lite.addColor(c, lite.scaleColor(d, l.color));
                        }
                        return lite.saturateColor(c);
                },
                specular: function(normal, v, roughness, lights){
                        var c = lite.black();
                        for(var i = 0; i < lights.length; ++i){
                                var l = lights[i],
                                        h = lite.normalize(lite.add(lite.normalize(l.direction), v)),
                                        s = Math.pow(Math.max(0, lite.dot(normal, h)), 1 / roughness);
                                c = lite.addColor(c, lite.scaleColor(s, l.color));
                        }
                        return lite.saturateColor(c);
                },
                phong: function(normal, v, size, lights){
                        normal = lite.normalize(normal);
                        var c = lite.black();
                        for(var i = 0; i < lights.length; ++i){
                                var l = lights[i],
                                        r = lite.reflect(lite.scale(-1, lite.normalize(v)), normal),
                                        s = Math.pow(Math.max(0, lite.dot(r, lite.normalize(l.direction))), size);
                                c = lite.addColor(c, lite.scaleColor(s, l.color));
                        }
                        return lite.saturateColor(c);
                }
        };

        // this lighting model is derived from RenderMan Interface Specification Version 3.2

        declare("dojox.gfx3d.lighting.Model", null, {
                constructor: function(incident, lights, ambient, specular){
                        this.incident = lite.normalize(incident);
                        this.lights = [];
                        for(var i = 0; i < lights.length; ++i){
                                var l = lights[i];
                                this.lights.push({direction: lite.normalize(l.direction), color: lite.toStdColor(l.color)});
                        }
                        this.ambient = lite.toStdColor(ambient.color ? ambient.color : "white");
                        this.ambient = lite.scaleColor(ambient.intensity, this.ambient);
                        this.ambient = lite.scaleColor(this.ambient.a, this.ambient);
                        this.ambient.a = 1;
                        this.specular = lite.toStdColor(specular ? specular : "white");
                        this.specular = lite.scaleColor(this.specular.a, this.specular);
                        this.specular.a = 1;
                        this.npr_cool = {r: 0,   g: 0,   b: 0.4, a: 1};
                        this.npr_warm = {r: 0.4, g: 0.4, b: 0.2, a: 1};
                        this.npr_alpha = 0.2;
                        this.npr_beta  = 0.6;
                        this.npr_scale = 0.6;
                },
                constant: function(normal, finish, pigment){
                        pigment   = lite.toStdColor(pigment);
                        var alpha = pigment.a, color = lite.scaleColor(alpha, pigment);
                        color.a   = alpha;
                        return lite.fromStdColor(lite.saturateColor(color));
                },
                matte: function(normal, finish, pigment){
                        if(typeof finish == "string"){ finish = lite.finish[finish]; }
                        pigment = lite.toStdColor(pigment);
                        normal  = lite.faceforward(lite.normalize(normal), this.incident);
                        var ambient = lite.scaleColor(finish.Ka, this.ambient),
                                shadow  = lite.saturate(-4 * lite.dot(normal, this.incident)),
                                diffuse = lite.scaleColor(shadow * finish.Kd, lite.diffuse(normal, this.lights)),
                                color   = lite.scaleColor(pigment.a, lite.multiplyColor(pigment, lite.addColor(ambient, diffuse)));
                        color.a = pigment.a;
                        return lite.fromStdColor(lite.saturateColor(color));
                },
                metal: function(normal, finish, pigment){
                        if(typeof finish == "string"){ finish = lite.finish[finish]; }
                        pigment = lite.toStdColor(pigment);
                        normal  = lite.faceforward(lite.normalize(normal), this.incident);
                        var v = lite.scale(-1, this.incident), specular, color,
                                ambient = lite.scaleColor(finish.Ka, this.ambient),
                                shadow  = lite.saturate(-4 * lite.dot(normal, this.incident));
                        if("phong" in finish){
                                specular = lite.scaleColor(shadow * finish.Ks * finish.phong, lite.phong(normal, v, finish.phong_size, this.lights));
                        }else{
                                specular = lite.scaleColor(shadow * finish.Ks, lite.specular(normal, v, finish.roughness, this.lights));
                        }
                        color = lite.scaleColor(pigment.a, lite.addColor(lite.multiplyColor(pigment, ambient), lite.multiplyColor(this.specular, specular)));
                        color.a = pigment.a;
                        return lite.fromStdColor(lite.saturateColor(color));
                },
                plastic: function(normal, finish, pigment){
                        if(typeof finish == "string"){ finish = lite.finish[finish]; }
                        pigment = lite.toStdColor(pigment);
                        normal  = lite.faceforward(lite.normalize(normal), this.incident);
                        var v = lite.scale(-1, this.incident), specular, color,
                                ambient = lite.scaleColor(finish.Ka, this.ambient),
                                shadow  = lite.saturate(-4 * lite.dot(normal, this.incident)),
                                diffuse = lite.scaleColor(shadow * finish.Kd, lite.diffuse(normal, this.lights));
                        if("phong" in finish){
                                specular = lite.scaleColor(shadow * finish.Ks * finish.phong, lite.phong(normal, v, finish.phong_size, this.lights));
                        }else{
                                specular = lite.scaleColor(shadow * finish.Ks, lite.specular(normal, v, finish.roughness, this.lights));
                        }
                        color = lite.scaleColor(pigment.a, lite.addColor(lite.multiplyColor(pigment, lite.addColor(ambient, diffuse)), lite.multiplyColor(this.specular, specular)));
                        color.a = pigment.a;
                        return lite.fromStdColor(lite.saturateColor(color));
                },
                npr: function(normal, finish, pigment){
                        if(typeof finish == "string"){ finish = lite.finish[finish]; }
                        pigment = lite.toStdColor(pigment);
                        normal  = lite.faceforward(lite.normalize(normal), this.incident);
                        var ambient  = lite.scaleColor(finish.Ka, this.ambient),
                                shadow   = lite.saturate(-4 * lite.dot(normal, this.incident)),
                                diffuse  = lite.scaleColor(shadow * finish.Kd, lite.diffuse(normal, this.lights)),
                                color = lite.scaleColor(pigment.a, lite.multiplyColor(pigment, lite.addColor(ambient, diffuse))),
                                cool = lite.addColor(this.npr_cool, lite.scaleColor(this.npr_alpha, color)),
                                warm = lite.addColor(this.npr_warm, lite.scaleColor(this.npr_beta,  color)),
                                d = (1 + lite.dot(this.incident, normal)) / 2,
                                color = lite.scaleColor(this.npr_scale, lite.addColor(color, lite.mixColor(cool, warm, d)));
                        color.a = pigment.a;
                        return lite.fromStdColor(lite.saturateColor(color));
                }
        });


        // POV-Ray basic finishes
        
        gfx3d.lighting.finish = {
        
                // Default
                
                defaults: {Ka: 0.1, Kd: 0.6, Ks: 0.0, roughness: 0.05},
                
                dull:     {Ka: 0.1, Kd: 0.6, Ks: 0.5, roughness: 0.15},
                shiny:    {Ka: 0.1, Kd: 0.6, Ks: 1.0, roughness: 0.001},
                glossy:   {Ka: 0.1, Kd: 0.6, Ks: 1.0, roughness: 0.0001},
                
                phong_dull:   {Ka: 0.1, Kd: 0.6, Ks: 0.5, phong: 0.5, phong_size: 1},
                phong_shiny:  {Ka: 0.1, Kd: 0.6, Ks: 1.0, phong: 1.0, phong_size: 200},
                phong_glossy: {Ka: 0.1, Kd: 0.6, Ks: 1.0, phong: 1.0, phong_size: 300},
        
                luminous: {Ka: 1.0, Kd: 0.0, Ks: 0.0, roughness: 0.05},
        
                // Metals
        
                // very soft and dull
                metalA: {Ka: 0.35, Kd: 0.3, Ks: 0.8, roughness: 1/20},
                // fairly soft and dull
                metalB: {Ka: 0.30, Kd: 0.4, Ks: 0.7, roughness: 1/60},
                // medium reflectivity, holds color well
                metalC: {Ka: 0.25, Kd: 0.5, Ks: 0.8, roughness: 1/80},
                // highly hard and polished, high reflectivity
                metalD: {Ka: 0.15, Kd: 0.6, Ks: 0.8, roughness: 1/100},
                // very highly polished and reflective
                metalE: {Ka: 0.10, Kd: 0.7, Ks: 0.8, roughness: 1/120}
        };

        return lite;
});