Path rendering routines

Author: bitnenfer

v3/src/gameobjects/graphics/Graphics.js

@@ -3,6 +3,70 @@ var GameObject = require('../GameObject');
 var Components = require('../../components');
 var Render = require('./GraphicsRender');
 
+/* This is specific to Graphics internal */
+var GraphicsPointPool = [];
+var GraphicsPathPool = [];
+var MakeGraphicsPoint = function (x, y) 
+{
+    var point;
+    if (GraphicsPointPool.length > 0) 
+    {
+        point = GraphicsPointPool.pop();
+        point.x = x;
+        point.y = y;
+    }
+    else
+    {
+        point = new GraphicsPoint(x, y);
+    }
+    return point;
+};
+var MakeGraphicsPath = function (x, y, color) {
+    var path;
+    if (GraphicsPathPool.length > 0) 
+    {
+        path = GraphicsPathPool.pop();
+        path.points.length = 0;
+        path.points.push({x: x, y: y});
+    }
+    else
+    {
+        path = new GraphicsPath(x, y);
+    }
+    path.color = color;
+    return path;
+};
+var RecycleGraphicsPoint = function (point) {
+    var index = GraphicsPointPool.indexOf(point);
+    if (index < 0)
+    {
+        GraphicsPointPool.push(point);
+    }
+};
+var RecycleGraphicsPath = function (path) {
+    var index = GraphicsPathPool.indexOf(path);
+    if (index < 0)
+    {
+        GraphicsPathPool.push(path);
+    }
+};
+var GraphicsPoint = function (x, y) 
+{
+    this.x = x;
+    this.y = y;
+};
+var GraphicsPath = function (x, y, color) 
+{
+    this.color = color;
+    this.points = [];
+    this.points.push(MakeGraphicsPoint(x, y));
+};
+var lerp = function (norm, min, max) 
+{
+    return (max - min) * norm + min;
+};
+var cos = Math.cos;
+var sin = Math.sin;
 var Graphics = new Class({
 
     Mixins: [
@@ -19,9 +83,92 @@ var Graphics = new Class({
     {
         GameObject.call(this, state);
 
+        this._lastPath = null;
+        this._pathArray = [];
+        this._lastColor = 0xFFFFFFFF;
+
         this.setPosition(x, y);
-    }
+    },
+
+    arc: function (x, y, radius, startAngle, endAngle, anticlockwise) {
+        var iteration = 0;
+        var iterStep = 0.01;
+        var tx = 0;
+        var ty = 0;
+        var ta = 0;
+        var moveTo = this.moveTo;
+        var lineTo = this.lineTo;
+        while (iteration < 1) {
+            ta = lerp(iteration, startAngle, endAngle);
+            tx = x + cos(ta) * radius;
+            ty = y + sin(ta) * radius;
+            if (iteration === 0) {
+                moveTo(tx, ty);
+            } else {
+                lineTo(tx, ty);
+            }
+            iteration += iterStep;
+        }
+    },
+
+    beginFill: function (color) {
+        this.clear();
+        this._lastColor = color;
+    },
+
+    endFill: function () {
+        var lastPath = this._lastPath;
+        if (lastPath !== null && lastPath.point.length > 0) 
+        {
+            var firstPoint = lastPath.points[0];
+            var lastPoint = lastPath.points[lastPath.points.length - 1];
+            lastPath.points.push(firstPoint);
+            this.moveTo(lastPoint.x, lastPoint.y);
+        }
+    },
+
+    clear: function () {
+        var path; 
+        var points;
+        var pathArray = this._pathArray;
+        var pointIndex = 0;
+        for (var pathIndex = 0, pathLength = pathArray.length; pathIndex < pathLength; ++pathIndex) 
+        {
+            path = pathArray[pathIndex];
+            points = path.points;
+            RecycleGraphicsPoint(path);
+            for (pointIndex = 0, pointsLength = points.length; pointIndex < pointsLength; ++pointIndex)
+            {
+                RecycleGraphicsPoint(points[pointIndex]);
+            }
+            points.length = 0;
+        }
+        pathArray.length = 0;
+        this._lastColor = 0xFFFFFFFF;
+        this._lastPath = null;
+    },
 
+    drawCircle: function (x, y, diameter) {},
+
+    drawPolygon: function (path) {},
+
+    drawRect: function (x, y, width, height) {},
+
+    lineTo: function (x, y) {
+        if (this._lastPath !== null) 
+        {
+            this._lastPath.points.push(MakeGraphicsPath(x, y, this._lastColor));
+        }
+        else
+        {
+            this.moveTo(x, y);
+        }
+    },
+
+    moveTo: function (x, y) {
+        this._lastPath = MakeGraphicsPath(x, y, this._lastColor);
+        this._pathArray.push(this._lastPath);
+    }
 });
 
 module.exports = Graphics;