Quintus.SVG = function(Q) {
    var SVG_NS ="http://www.w3.org/2000/svg"; 
    Q.setupSVG = function(id,options) {
      options = options || {};
      id = id || "quintus";
      Q.svg = $(_.isString(id) ? "#" + id : id)[0];
      if(!Q.svg) {
        Q.svg = document.createElementNS(SVG_NS,'svg');
        Q.svg.setAttribute('width',320);
        Q.svg.setAttribute('height',420);
        document.body.appendChild(Q.svg);
      }
  
      if(options.maximize) {
        var w = window.width()-1;
        var h = window.height()-10;
        Q.svg.setAttribute('width',w);
        Q.svg.setAttribute('height',h);
      }
   
      Q.width = Q.svg.getAttribute('width');
      Q.height = Q.svg.getAttribute('height');
      Q.wrapper = $(Q.svg)
                   .wrap("<div id='" + id + "_container'/>")
                   .parent()
                   .css({ width: Q.width,
                          height: Q.height,
                          margin: '0 auto' });
   
      setTimeout(function() { window.scrollTo(0,1); }, 0);
      window.bind('orientationchange',function() {
        setTimeout(function() { window.scrollTo(0,1); }, 0);
      });
      return Q;
    };
  
    Q.SVGSprite = Q.Sprite.extend({
      init: function(props) {
        this._super(_(props).defaults({
          shape: 'block',
          color: 'black',
          angle: 0,
          active: true,
          cx: 0,
          cy: 0
        }));
        this.createShape();
        this.svg.sprite = this;
        this.rp = {};
        this.setTransform();
      },
  
      set: function(attr) {
        _.each(attr,function(value,key) {
          this.svg.setAttribute(key,value);
        },this);
      },
      
      createShape: function() {
        var p = this.p;
        switch(p.shape) {
          case 'block':
            this.svg = document.createElementNS(SVG_NS,'rect');
            _.extend(p,{ cx: p.w/2, cy: p.h/2 });
            this.set({ width: p.w, height: p.h });
            break;
          case 'circle':
            this.svg = document.createElementNS(SVG_NS,'circle');
            this.set({ r: p.r, cx: 0, cy: 0 });
            break;
          case 'polygon':
            this.svg = document.createElementNS(SVG_NS,'polygon');
            var pts = _.map(p.points, 
                            function(pt) { 
                              return pt[0] + "," + pt[1];
                            }).join(" ");
            this.set({ points: pts });
            break;
            
        }
        this.set({ fill: p.color });
        if(p.outline) {
          this.set({
            stroke: p.outline,
            "stroke-width": p.outlineWidth || 1
          });
        }
      },
  
      setTransform: function() {
        var p = this.p;
        var rp = this.rp;
        if(rp.x !== p.x || 
           rp.y !== p.y || 
           rp.angle !== p.angle ) {
          var transform = "translate(" + (p.x - p.cx) + "," +
                                       + (p.y - p.cy) + ") " +
                          "rotate(" + p.angle + 
                                  "," + p.cx +
                                  "," + p.cy +
                                  ")";
          this.svg.setAttribute('transform',transform);
          rp.angle = p.angle;
          rp.x = p.x;
          rp.y = p.y;
        } 
      },
  
      draw: function(ctx) {
        this.trigger('draw');
      },
  
      step: function(dt) {
        this.trigger('step',dt);
        this.setTransform();
      },
  
      destroy: function() {
        if(this.destroyed) return false;
        this._super();
        this.parent.svg.removeChild(this.svg);
      }
    });
  
    Q.SVGStage = Q.Stage.extend({
      init: function(scene) {
        this.svg = document.createElementNS(SVG_NS,'svg');
        this.svg.setAttribute('width',Q.width);
        this.svg.setAttribute('height',Q.height);
        Q.svg.appendChild(this.svg);
        
        this.viewBox = { x: 0, y: 0, w: Q.width, h: Q.height };
        this._super(scene);
      },
  
      insert: function(itm) {
        if(itm.svg) { this.svg.appendChild(itm.svg); }
        return this._super(itm);
      },
  
      destroy: function() {
        Q.svg.removeChild(this.svg);
        this._super();
      },
  
      viewport: function(w,h) {
        this.viewBox.w = w;
        this.viewBox.h = h;
        if(this.viewBox.cx || this.viewBox.cy) {
          this.centerOn(this.viewBox.cx,
                        this.viewBox.cy);
        } else {
          this.setViewBox();
        }
      },
  
      centerOn: function(x,y) {
        this.viewBox.cx = x;
        this.viewBox.cy = y;
        this.viewBox.x = x - this.viewBox.w/2;
        this.viewBox.y = y - this.viewBox.h/2;
        this.setViewBox();
      },
  
      setViewBox: function() {
        this.svg.setAttribute('viewBox',
                              this.viewBox.x + " " + this.viewBox.y + " " +
                              this.viewBox.w + " " + this.viewBox.h);
      },
  
      browserToWorld: function(x,y) {
        var m = this.svg.getScreenCTM();
        var p = this.svg.createSVGPoint();
        p.x = x; p.y = y;
        return p.matrixTransform(m.inverse());
      }
    });
  
    Q.svgOnly = function() {
      Q.Stage = Q.SVGStage;
      Q.setup = Q.setupSVG;
      Q.Sprite = Q.SVGSprite;
      return Q;
    };
  
  };