Source: gfx/core/graphics/Graphics.js

var Node = require('../Node'),
  Texture = require('../textures/Texture'),
  CanvasBuffer = require('../renderers/canvas/utils/CanvasBuffer'),
  CanvasGraphics = require('../renderers/canvas/utils/CanvasGraphics'),
  GraphicsData = require('./GraphicsData'),
  math = require('../math'),
  CONST = require('../../const'),
  tempPoint = new math.Point();

/**
 * The Graphics class contains methods used to draw primitive shapes such as lines, circles and
 * rectangles to the display, and to color and fill them.
 *
 * @class
 * @extends Node
 */
class Graphics extends Node {
  /**
   * @constructor
   */
  constructor() {
    super();

    /**
     * The alpha value used when filling the Graphics object.
     *
     * @member {number}
     * @default 1
     */
    this.fillAlpha = 1;

    /**
     * The width (thickness) of any lines drawn.
     *
     * @member {number}
     * @default 0
     */
    this.lineWidth = 0;

    /**
     * The color of any lines drawn.
     *
     * @member {string}
     * @default 0
     */
    this.lineColor = 0;

    /**
     * Graphics data
     *
     * @member {GraphicsData[]}
     * @private
     */
    this.graphicsData = [];

    /**
     * The tint applied to the graphic shape. This is a hex value. Apply a value of 0xFFFFFF to reset the tint.
     *
     * @member {number}
     * @default 0xFFFFFF
     */
    this.tint = 0xFFFFFF;

    /**
     * The previous tint applied to the graphic shape. Used to compare to the current tint and check if theres change.
     *
     * @member {number}
     * @private
     * @default 0xFFFFFF
     */
    this._prevTint = 0xFFFFFF;

    /**
     * The blend mode to be applied to the graphic shape. Apply a value of `BLEND_MODES.NORMAL` to reset the blend mode.
     *
     * @member {number}
     * @default BLEND_MODES.NORMAL;
     * @see BLEND_MODES
     */
    this.blendMode = CONST.BLEND_MODES.NORMAL;

    /**
     * Current path
     *
     * @member {GraphicsData}
     * @private
     */
    this.currentPath = null;

    /**
     * Array containing some WebGL-related properties used by the WebGL renderer.
     *
     * @member {object<number, object>}
     * @private
     */
    // TODO - _webgl should use a prototype object, not a random undocumented object...
    this._webGL = {};

    /**
     * Whether this shape is being used as a mask.
     *
     * @member {boolean}
     */
    this.isMask = false;

    /**
     * The bounds' padding used for bounds calculation.
     *
     * @member {number}
     */
    this.boundsPadding = 0;

    /**
     * A cache of the local bounds to prevent recalculation.
     *
     * @member {Rectangle}
     * @private
     */
    this._localBounds = new math.Rectangle(0,0,1,1);

    /**
     * Used to detect if the graphics object has changed. If this is set to true then the graphics
     * object will be recalculated.
     *
     * @member {boolean}
     * @private
     */
    this.dirty = true;

    /**
     * Used to detect if the WebGL graphics object has changed. If this is set to true then the
     * graphics object will be recalculated.
     *
     * @member {boolean}
     * @private
     */
    this.glDirty = false;

    this.boundsDirty = true;

    /**
     * Used to detect if the cached sprite object needs to be updated.
     *
     * @member {boolean}
     * @private
     */
    this.cachedSpriteDirty = false;
  }

  /**
   * Creates a new Graphics object with the same values as this one.
   * Note that the only the properties of the object are cloned, not its transform (position,scale,etc)
   *
   * @return {Graphics} A new graphics instance
   */
  clone() {
    var clone = new Graphics();

    clone.renderable = this.renderable;
    clone.fillAlpha = this.fillAlpha;
    clone.lineWidth = this.lineWidth;
    clone.lineColor = this.lineColor;
    clone.tint = this.tint;
    clone.blendMode = this.blendMode;
    clone.isMask = this.isMask;
    clone.boundsPadding = this.boundsPadding;
    clone.dirty = true;
    clone.glDirty = true;
    clone.cachedSpriteDirty = this.cachedSpriteDirty;

    // copy graphics data
    for (var i = 0; i < this.graphicsData.length; ++i) {
      clone.graphicsData.push(this.graphicsData[i].clone());
    }

    clone.currentPath = clone.graphicsData[clone.graphicsData.length - 1];

    clone.updateLocalBounds();

    return clone;
  }

  /**
   * Specifies the line style used for subsequent calls to Graphics methods such as the lineTo() method or the drawCircle() method.
   *
   * @param {number} lineWidth  width of the line to draw, will update the objects stored style
   * @param {number} color      color of the line to draw, will update the objects stored style
   * @param {number} alpha      alpha of the line to draw, will update the objects stored style
   * @return {Graphics}         Self for chaining
   */
  lineStyle(lineWidth, color, alpha) {
    this.lineWidth = lineWidth || 0;
    this.lineColor = color || 0;
    this.lineAlpha = (alpha === undefined) ? 1 : alpha;

    if (this.currentPath) {
      if (this.currentPath.shape.points.length) {
        // halfway through a line? start a new one!
        var shape = new math.Polygon(this.currentPath.shape.points.slice(-2));
        shape.closed = false;
        this.drawShape(shape);
      }
      else {
        // otherwise its empty so lets just set the line properties
        this.currentPath.lineWidth = this.lineWidth;
        this.currentPath.lineColor = this.lineColor;
        this.currentPath.lineAlpha = this.lineAlpha;
      }
    }

    return this;
  }

  /**
   * Moves the current drawing position to x, y.
   *
   * @param {number} x    the X coordinate to move to
   * @param {number} y    the Y coordinate to move to
   * @return {Graphics}   Self for chaining
    */
  moveTo(x, y) {
    var shape = new math.Polygon([x,y]);
    shape.closed = false;
    this.drawShape(shape);

    return this;
  }

  /**
   * Draws a line using the current line style from the current drawing position to (x, y);
   * The current drawing position is then set to (x, y).
   *
   * @param {number} x  the X coordinate to draw to
   * @param {number} y  the Y coordinate to draw to
   * @return {Graphics} Self for chaining
   */
  lineTo(x, y) {
    this.currentPath.shape.points.push(x, y);
    this.dirty = true;

    return this;
  }

  /**
   * Calculate the points for a quadratic bezier curve and then draws it.
   * Based on: https://stackoverflow.com/questions/785097/how-do-i-implement-a-bezier-curve-in-c
   *
   * @param {number} cpX  Control point x
   * @param {number} cpY  Control point y
   * @param {number} toX  Destination point x
   * @param {number} toY  Destination point y
   * @return {Graphics}   Self for chaining
   */
  quadraticCurveTo(cpX, cpY, toX, toY) {
    if (this.currentPath) {
      if (this.currentPath.shape.points.length === 0) {
        this.currentPath.shape.points = [0, 0];
      }
    }
    else {
      this.moveTo(0,0);
    }

    var xa,
      ya,
      n = 20,
      points = this.currentPath.shape.points;

    if (points.length === 0) {
      this.moveTo(0, 0);
    }

    var fromX = points[points.length - 2];
    var fromY = points[points.length - 1];

    var j = 0;
    for (var i = 1; i <= n; ++i) {
      j = i / n;

      xa = fromX + ((cpX - fromX) * j);
      ya = fromY + ((cpY - fromY) * j);

      points.push(xa + (((cpX + ((toX - cpX) * j)) - xa) * j),
        ya + (((cpY + ((toY - cpY) * j)) - ya) * j));
    }

    this.dirty = this.boundsDirty = true;

    return this;
  }

  /**
   * Calculate the points for a bezier curve and then draws it.
   *
   * @param {number} cpX    Control point x
   * @param {number} cpY    Control point y
   * @param {number} cpX2   Second Control point x
   * @param {number} cpY2   Second Control point y
   * @param {number} toX    Destination point x
   * @param {number} toY    Destination point y
   * @return {Graphics}     Self for chaining
   */
  bezierCurveTo(cpX, cpY, cpX2, cpY2, toX, toY) {
    if (this.currentPath) {
      if (this.currentPath.shape.points.length === 0) {
        this.currentPath.shape.points = [0, 0];
      }
    }
    else {
      this.moveTo(0,0);
    }

    var n = 20,
      dt,
      dt2,
      dt3,
      t2,
      t3,
      points = this.currentPath.shape.points;

    var fromX = points[points.length - 2];
    var fromY = points[points.length - 1];

    var j = 0;

    for (var i = 1; i <= n; ++i) {
      j = i / n;

      dt = (1 - j);
      dt2 = dt * dt;
      dt3 = dt2 * dt;

      t2 = j * j;
      t3 = t2 * j;

      points.push(dt3 * fromX + 3 * dt2 * j * cpX + 3 * dt * t2 * cpX2 + t3 * toX,
        dt3 * fromY + 3 * dt2 * j * cpY + 3 * dt * t2 * cpY2 + t3 * toY);
    }

    this.dirty = this.boundsDirty = true;

    return this;
  }

  /**
   * The arcTo() method creates an arc/curve between two tangents on the canvas.
   *
   * "borrowed" from https://code.google.com/p/fxcanvas/ - thanks google!
   *
   * @param {number} x1     The x-coordinate of the beginning of the arc
   * @param {number} y1     The y-coordinate of the beginning of the arc
   * @param {number} x2     The x-coordinate of the end of the arc
   * @param {number} y2     The y-coordinate of the end of the arc
   * @param {number} radius The radius of the arc
   * @return {Graphics}     Self for chaining
   */
  arcTo(x1, y1, x2, y2, radius) {
    if (this.currentPath) {
      if (this.currentPath.shape.points.length === 0) {
        this.currentPath.shape.points.push(x1, y1);
      }
    }
    else {
      this.moveTo(x1, y1);
    }

    var points = this.currentPath.shape.points,
      fromX = points[points.length - 2],
      fromY = points[points.length - 1],
      a1 = fromY - y1,
      b1 = fromX - x1,
      a2 = y2 - y1,
      b2 = x2 - x1,
      mm = Math.abs(a1 * b2 - b1 * a2);

    if (mm < 1.0e-8 || radius === 0) {
      if (points[points.length - 2] !== x1 || points[points.length - 1] !== y1) {
        points.push(x1, y1);
      }
    }
    else {
      var dd = a1 * a1 + b1 * b1,
        cc = a2 * a2 + b2 * b2,
        tt = a1 * a2 + b1 * b2,
        k1 = radius * Math.sqrt(dd) / mm,
        k2 = radius * Math.sqrt(cc) / mm,
        j1 = k1 * tt / dd,
        j2 = k2 * tt / cc,
        cx = k1 * b2 + k2 * b1,
        cy = k1 * a2 + k2 * a1,
        px = b1 * (k2 + j1),
        py = a1 * (k2 + j1),
        qx = b2 * (k1 + j2),
        qy = a2 * (k1 + j2),
        startAngle = Math.atan2(py - cy, px - cx),
        endAngle = Math.atan2(qy - cy, qx - cx);

      this.arc(cx + x1, cy + y1, radius, startAngle, endAngle, b1 * a2 > b2 * a1);
    }

    this.dirty = this.boundsDirty = true;

    return this;
  }

  /**
   * The arc method creates an arc/curve (used to create circles, or parts of circles).
   *
   * @param {number} cx             The x-coordinate of the center of the circle
   * @param {number} cy             The y-coordinate of the center of the circle
   * @param {number} radius         The radius of the circle
   * @param {number} startAngle     The starting angle, in radians (0 is at the 3 o'clock position of the arc's circle)
   * @param {number} endAngle       The ending angle, in radians
   * @param {boolean} anticlockwise Optional. Specifies whether the drawing should be counterclockwise or clockwise. False is default, and indicates clockwise, while true indicates counter-clockwise.
   * @return {Graphics}             Self for chaining
   */
  arc(cx, cy, radius, startAngle, endAngle, anticlockwise) {
    anticlockwise = anticlockwise || false;

    if (startAngle === endAngle) {
      return this;
    }

    if (!anticlockwise && endAngle <= startAngle) {
      endAngle += Math.PI * 2;
    }
    else if (anticlockwise && startAngle <= endAngle) {
      startAngle += Math.PI * 2;
    }

    var sweep = anticlockwise ? (startAngle - endAngle) * -1 : (endAngle - startAngle);
    var segs = Math.ceil(Math.abs(sweep) / (Math.PI * 2)) * 40;

    if (sweep === 0) {
      return this;
    }

    var startX = cx + Math.cos(startAngle) * radius;
    var startY = cy + Math.sin(startAngle) * radius;

    if (this.currentPath) {
      this.currentPath.shape.points.push(startX, startY);
    }
    else {
      this.moveTo(startX, startY);
    }

    var points = this.currentPath.shape.points;

    var theta = sweep / (segs * 2);
    var theta2 = theta * 2;

    var cTheta = Math.cos(theta);
    var sTheta = Math.sin(theta);

    var segMinus = segs - 1;

    var remainder = (segMinus % 1) / segMinus;

    for (var i = 0; i <= segMinus; i++) {
      var real = i + remainder * i;


      var angle = ((theta) + startAngle + (theta2 * real));

      var c = Math.cos(angle);
      var s = -Math.sin(angle);

      points.push(((cTheta * c) + (sTheta * s)) * radius + cx,
                      ((cTheta * -s) + (sTheta * c)) * radius + cy);
    }

    this.dirty = this.boundsDirty = true;

    return this;
  }

  /**
   * Specifies a simple one-color fill that subsequent calls to other Graphics methods
   * (such as lineTo() or drawCircle()) use when drawing.
   *
   * @param {number} color  the color of the fill
   * @param {number} alpha  the alpha of the fill
   * @return {Graphics}     Self for chaining
   */
  beginFill(color, alpha) {
    this.filling = true;
    this.fillColor = color || 0;
    this.fillAlpha = (alpha === undefined) ? 1 : alpha;

    if (this.currentPath) {
      if (this.currentPath.shape.points.length <= 2) {
        this.currentPath.fill = this.filling;
        this.currentPath.fillColor = this.fillColor;
        this.currentPath.fillAlpha = this.fillAlpha;
      }
    }
    return this;
  }

  /**
   * Applies a fill to the lines and shapes that were added since the last call to the beginFill() method.
   *
   * @return {Graphics} Self for chaining
   */
  endFill() {
    this.filling = false;
    this.fillColor = null;
    this.fillAlpha = 1;

    return this;
  }

  /**
   * Draw a rectangle
   * @param {number} x      The X coord of the top-left of the rectangle
   * @param {number} y      The Y coord of the top-left of the rectangle
   * @param {number} width  The width of the rectangle
   * @param {number} height The height of the rectangle
   * @return {Graphics}     Self for chaining
   */
  drawRect(x, y, width, height) {
    this.drawShape(new math.Rectangle(x,y, width, height));

    return this;
  }

  /**
   *
   * @param {number} x      The X coord of the top-left of the rectangle
   * @param {number} y      The Y coord of the top-left of the rectangle
   * @param {number} width  The width of the rectangle
   * @param {number} height The height of the rectangle
   * @param {number} radius Radius of the rectangle corners
   * @return {Graphics}     Self for chaining
   */
  drawRoundedRect(x, y, width, height, radius) {
    this.drawShape(new math.RoundedRectangle(x, y, width, height, radius));

    return this;
  }

  /**
   * Draws a circle.
   *
   * @param {number} x      The X coordinate of the center of the circle
   * @param {number} y      The Y coordinate of the center of the circle
   * @param {number} radius The radius of the circle
   * @return {Graphics}     Self for chaining
   */
  drawCircle(x, y, radius) {
    this.drawShape(new math.Circle(x,y, radius));

    return this;
  }

  /**
   * Draws an ellipse.
   *
   * @param {number} x      The X coordinate of the center of the ellipse
   * @param {number} y      The Y coordinate of the center of the ellipse
   * @param {number} width  The half width of the ellipse
   * @param {number} height The half height of the ellipse
   * @return {Graphics}     Self for chaining
   */
  drawEllipse(x, y, width, height) {
    this.drawShape(new math.Ellipse(x, y, width, height));

    return this;
  }

  /**
   * Draws a polygon using the given path.
   *
   * @param {number[]|Point[]} path The path data used to construct the polygon.
   * @return {Graphics}             Self for chaining
   */
  drawPolygon(path) {
    // prevents an argument assignment deopt
    // see section 3.1: https://github.com/petkaantonov/bluebird/wiki/Optimization-killers#3-managing-arguments
    var points = path;

    var closed = true;

    if (points instanceof math.Polygon) {
      closed = points.closed;
      points = points.points;
    }

    if (!Array.isArray(points)) {
      // prevents an argument leak deopt
      // see section 3.2: https://github.com/petkaantonov/bluebird/wiki/Optimization-killers#3-managing-arguments
      points = new Array(arguments.length);

      for (var i = 0; i < points.length; ++i) {
        points[i] = arguments[i];
      }
    }

    var shape = new math.Polygon(points);
    shape.closed = closed;

    this.drawShape(shape);

    return this;
  }

  /**
   * Clears the graphics that were drawn to this Graphics object, and resets fill and line style settings.
   *
   * @return {Graphics} Self for chaining
   */
  clear() {
    this.lineWidth = 0;
    this.filling = false;

    this.dirty = true;
    this.clearDirty = true;
    this.graphicsData = [];

    return this;
  }

  /**
   * Useful function that returns a texture of the graphics object that can then be used to create sprites
   * This can be quite useful if your geometry is complicated and needs to be reused multiple times.
   *
   * @param {number} resolution The resolution of the texture being generated
   * @param {number} scaleMode  Should be one of the scaleMode consts
   * @return {Texture}          a texture of the graphics object
   */
  generateTexture(resolution, scaleMode) {
    resolution = resolution || 1;

    var bounds = this.getLocalBounds();

    var canvasBuffer = new CanvasBuffer(bounds.width * resolution, bounds.height * resolution);

    var texture = Texture.fromCanvas(canvasBuffer.canvas, scaleMode);
    texture.baseTexture.resolution = resolution;

    canvasBuffer.context.scale(resolution, resolution);

    canvasBuffer.context.translate(-bounds.x,-bounds.y);

    CanvasGraphics.renderGraphics(this, canvasBuffer.context);

    return texture;
  }

  /**
   * Renders the object using the WebGL renderer
   *
   * @param {WebGLRenderer} renderer Renderer to draw to
   * @private
   */
  _renderWebGL(renderer) {
    if (this.glDirty) {
      this.dirty = true;
      this.glDirty = false;
    }

    renderer.setObjectRenderer(renderer.plugins.graphics);
    renderer.plugins.graphics.render(this);
  }

  /**
   * Renders the object using the Canvas renderer
   *
   * @param {CanvasRenderer} renderer Renderer to draw to
   * @private
   */
  _renderCanvas(renderer) {
    if (this.isMask === true) {
      return;
    }

    // if the tint has changed, set the graphics object to dirty.
    if (this._prevTint !== this.tint) {
      this.dirty = true;
    }

    var context = renderer.context;
    var transform = this.worldTransform;

    var compositeOperation = renderer.blendModes[this.blendMode];
    if (compositeOperation !== context.globalCompositeOperation) {
      context.globalCompositeOperation = compositeOperation;
    }

    var resolution = renderer.resolution;
    context.setTransform(
      transform.a * resolution,
      transform.b * resolution,
      transform.c * resolution,
      transform.d * resolution,
      transform.tx * resolution,
      transform.ty * resolution
    );

    CanvasGraphics.renderGraphics(this, context);
  }

  /**
   * Retrieves the bounds of the graphic shape as a rectangle object
   *
   * @param {Matrix} [matrix]   The world transform matrix to use, defaults to this
   *  object's worldTransform.
   * @return {Rectangle}        the rectangular bounding area
   */
  getBounds(matrix) {
    if (!this._currentBounds) {

      // return an empty object if the item is a mask!
      if (!this.renderable) {
        return math.Rectangle.EMPTY;
      }

      if (this.boundsDirty) {
        this.updateLocalBounds();

        this.glDirty = true;
        this.cachedSpriteDirty = true;
        this.boundsDirty = false;
      }

      var bounds = this._localBounds;

      var w0 = bounds.x;
      var w1 = bounds.width + bounds.x;

      var h0 = bounds.y;
      var h1 = bounds.height + bounds.y;

      var worldTransform = matrix || this.worldTransform;

      var a = worldTransform.a;
      var b = worldTransform.b;
      var c = worldTransform.c;
      var d = worldTransform.d;
      var tx = worldTransform.tx;
      var ty = worldTransform.ty;

      var x1 = a * w1 + c * h1 + tx;
      var y1 = d * h1 + b * w1 + ty;

      var x2 = a * w0 + c * h1 + tx;
      var y2 = d * h1 + b * w0 + ty;

      var x3 = a * w0 + c * h0 + tx;
      var y3 = d * h0 + b * w0 + ty;

      var x4 = a * w1 + c * h0 + tx;
      var y4 = d * h0 + b * w1 + ty;

      var maxX = x1;
      var maxY = y1;

      var minX = x1;
      var minY = y1;

      minX = x2 < minX ? x2 : minX;
      minX = x3 < minX ? x3 : minX;
      minX = x4 < minX ? x4 : minX;

      minY = y2 < minY ? y2 : minY;
      minY = y3 < minY ? y3 : minY;
      minY = y4 < minY ? y4 : minY;

      maxX = x2 > maxX ? x2 : maxX;
      maxX = x3 > maxX ? x3 : maxX;
      maxX = x4 > maxX ? x4 : maxX;

      maxY = y2 > maxY ? y2 : maxY;
      maxY = y3 > maxY ? y3 : maxY;
      maxY = y4 > maxY ? y4 : maxY;

      this._bounds.x = minX;
      this._bounds.width = maxX - minX;

      this._bounds.y = minY;
      this._bounds.height = maxY - minY;

      this._currentBounds = this._bounds;
    }

    return this._currentBounds;
  }

  /**
  * Tests if a point is inside this graphics object
  *
  * @param {Point} point  the point to test
  * @return {boolean}     the result of the test
  */
  containsPoint(point) {
    this.worldTransform.applyInverse(point, tempPoint);

    var graphicsData = this.graphicsData;

    for (var i = 0; i < graphicsData.length; i++) {
      var data = graphicsData[i];

      if (!data.fill) {
        continue;
      }

      // only deal with fills..
      if (data.shape) {
        if (data.shape.contains(tempPoint.x, tempPoint.y)) {
          return true;
        }
      }
    }

    return false;
  }

  /**
   * Update the bounds of the object
   */
  updateLocalBounds() {
    var minX = Infinity;
    var maxX = -Infinity;

    var minY = Infinity;
    var maxY = -Infinity;

    if (this.graphicsData.length) {
      var shape, points, x, y, w, h;

      for (var i = 0; i < this.graphicsData.length; i++) {
        var data = this.graphicsData[i];
        var type = data.type;
        var lineWidth = data.lineWidth;
        shape = data.shape;

        if (type === CONST.SHAPES.RECT || type === CONST.SHAPES.RREC) {
          x = shape.x - lineWidth / 2;
          y = shape.y - lineWidth / 2;
          w = shape.width + lineWidth;
          h = shape.height + lineWidth;

          minX = x < minX ? x : minX;
          maxX = x + w > maxX ? x + w : maxX;

          minY = y < minY ? y : minY;
          maxY = y + h > maxY ? y + h : maxY;
        }
        else if (type === CONST.SHAPES.CIRC) {
          x = shape.x;
          y = shape.y;
          w = shape.radius + lineWidth / 2;
          h = shape.radius + lineWidth / 2;

          minX = x - w < minX ? x - w : minX;
          maxX = x + w > maxX ? x + w : maxX;

          minY = y - h < minY ? y - h : minY;
          maxY = y + h > maxY ? y + h : maxY;
        }
        else if (type === CONST.SHAPES.ELIP) {
          x = shape.x;
          y = shape.y;
          w = shape.width + lineWidth / 2;
          h = shape.height + lineWidth / 2;

          minX = x - w < minX ? x - w : minX;
          maxX = x + w > maxX ? x + w : maxX;

          minY = y - h < minY ? y - h : minY;
          maxY = y + h > maxY ? y + h : maxY;
        }
        else {
          // POLY
          points = shape.points;

          for (var j = 0; j < points.length; j += 2) {
            x = points[j];
            y = points[j + 1];

            minX = x - lineWidth < minX ? x - lineWidth : minX;
            maxX = x + lineWidth > maxX ? x + lineWidth : maxX;

            minY = y - lineWidth < minY ? y - lineWidth : minY;
            maxY = y + lineWidth > maxY ? y + lineWidth : maxY;
          }
        }
      }
    }
    else {
      minX = 0;
      maxX = 0;
      minY = 0;
      maxY = 0;
    }

    var padding = this.boundsPadding;

    this._localBounds.x = minX - padding;
    this._localBounds.width = (maxX - minX) + padding * 2;

    this._localBounds.y = minY - padding;
    this._localBounds.height = (maxY - minY) + padding * 2;
  }

  /**
   * Draws the given shape to this Graphics object. Can be any of Circle, Rectangle, Ellipse, Line or Polygon.
   *
   * @param {Circle|Rectangle|Ellipse|Line|Polygon} shape The shape object to draw.
   * @return {GraphicsData} The generated GraphicsData object.
   */
  drawShape(shape) {
    if (this.currentPath) {
      // check current path!
      if (this.currentPath.shape.points.length <= 2) {
        this.graphicsData.pop();
      }
    }

    this.currentPath = null;

    var data = new GraphicsData(this.lineWidth, this.lineColor, this.lineAlpha, this.fillColor, this.fillAlpha, this.filling, shape);

    this.graphicsData.push(data);

    if (data.type === CONST.SHAPES.POLY) {
      data.shape.closed = data.shape.closed || this.filling;
      this.currentPath = data;
    }

    this.dirty = this.boundsDirty = true;

    return data;
  }

  /**
   * Destroys the Graphics object.
   */
  destroy() {
    Node.prototype.destroy.apply(this, arguments);

    // destroy each of the GraphicsData objects
    for (var i = 0; i < this.graphicsData.length; ++i) {
      this.graphicsData[i].destroy();
    }

    // for each webgl data entry, destroy the WebGLGraphicsData
    for (var id in this._webgl) {
      for (var j = 0; j < this._webgl[id].data.length; ++j) {
        this._webgl[id].data[j].destroy();
      }
    }

    this.graphicsData = null;

    this.currentPath = null;
    this._webgl = null;
    this._localBounds = null;
  }
}

module.exports = Graphics;