Source: Scene/PointPrimitive.js

/*global define*/
define([
        '../Core/BoundingRectangle',
        '../Core/Cartesian2',
        '../Core/Cartesian3',
        '../Core/Cartesian4',
        '../Core/Color',
        '../Core/defaultValue',
        '../Core/defined',
        '../Core/defineProperties',
        '../Core/DeveloperError',
        '../Core/DistanceDisplayCondition',
        '../Core/Matrix4',
        '../Core/NearFarScalar',
        './SceneMode',
        './SceneTransforms'
    ], function(
        BoundingRectangle,
        Cartesian2,
        Cartesian3,
        Cartesian4,
        Color,
        defaultValue,
        defined,
        defineProperties,
        DeveloperError,
        DistanceDisplayCondition,
        Matrix4,
        NearFarScalar,
        SceneMode,
        SceneTransforms) {
    'use strict';

    /**
     * A graphical point positioned in the 3D scene, that is created
     * and rendered using a {@link PointPrimitiveCollection}.  A point is created and its initial
     * properties are set by calling {@link PointPrimitiveCollection#add}.
     *
     * @alias PointPrimitive
     *
     * @performance Reading a property, e.g., {@link PointPrimitive#show}, is constant time.
     * Assigning to a property is constant time but results in
     * CPU to GPU traffic when {@link PointPrimitiveCollection#update} is called.  The per-pointPrimitive traffic is
     * the same regardless of how many properties were updated.  If most pointPrimitives in a collection need to be
     * updated, it may be more efficient to clear the collection with {@link PointPrimitiveCollection#removeAll}
     * and add new pointPrimitives instead of modifying each one.
     *
     * @exception {DeveloperError} scaleByDistance.far must be greater than scaleByDistance.near
     * @exception {DeveloperError} translucencyByDistance.far must be greater than translucencyByDistance.near
     * @exception {DeveloperError} distanceDisplayCondition.far must be greater than distanceDisplayCondition.near
     *
     * @see PointPrimitiveCollection
     * @see PointPrimitiveCollection#add
     *
     * @internalConstructor
     *
     * @demo {@link http://cesiumjs.org/Cesium/Apps/Sandcastle/index.html?src=Points.html|Cesium Sandcastle Points Demo}
     */
    function PointPrimitive(options, pointPrimitiveCollection) {
        options = defaultValue(options, defaultValue.EMPTY_OBJECT);

        //>>includeStart('debug', pragmas.debug);
        if (defined(options.scaleByDistance) && options.scaleByDistance.far <= options.scaleByDistance.near) {
            throw new DeveloperError('scaleByDistance.far must be greater than scaleByDistance.near.');
        }
        if (defined(options.translucencyByDistance) && options.translucencyByDistance.far <= options.translucencyByDistance.near) {
            throw new DeveloperError('translucencyByDistance.far must be greater than translucencyByDistance.near.');
        }
        if (defined(options.distanceDisplayCondition) && options.distanceDisplayCondition.far <= options.distanceDisplayCondition.near) {
            throw new DeveloperError('distanceDisplayCondition.far must be greater than distanceDisplayCondition.near');
        }
        //>>includeEnd('debug');

        this._show = defaultValue(options.show, true);
        this._position = Cartesian3.clone(defaultValue(options.position, Cartesian3.ZERO));
        this._actualPosition = Cartesian3.clone(this._position); // For columbus view and 2D
        this._color = Color.clone(defaultValue(options.color, Color.WHITE));
        this._outlineColor = Color.clone(defaultValue(options.outlineColor, Color.TRANSPARENT));
        this._outlineWidth = defaultValue(options.outlineWidth, 0.0);
        this._pixelSize = defaultValue(options.pixelSize, 10.0);
        this._scaleByDistance = options.scaleByDistance;
        this._translucencyByDistance = options.translucencyByDistance;
        this._distanceDisplayCondition = options.distanceDisplayCondition;
        this._id = options.id;
        this._collection = defaultValue(options.collection, pointPrimitiveCollection);

        this._clusterShow = true;

        this._pickId = undefined;
        this._pointPrimitiveCollection = pointPrimitiveCollection;
        this._dirty = false;
        this._index = -1; //Used only by PointPrimitiveCollection
    }

    var SHOW_INDEX = PointPrimitive.SHOW_INDEX = 0;
    var POSITION_INDEX = PointPrimitive.POSITION_INDEX = 1;
    var COLOR_INDEX = PointPrimitive.COLOR_INDEX = 2;
    var OUTLINE_COLOR_INDEX = PointPrimitive.OUTLINE_COLOR_INDEX = 3;
    var OUTLINE_WIDTH_INDEX = PointPrimitive.OUTLINE_WIDTH_INDEX = 4;
    var PIXEL_SIZE_INDEX = PointPrimitive.PIXEL_SIZE_INDEX = 5;
    var SCALE_BY_DISTANCE_INDEX = PointPrimitive.SCALE_BY_DISTANCE_INDEX = 6;
    var TRANSLUCENCY_BY_DISTANCE_INDEX = PointPrimitive.TRANSLUCENCY_BY_DISTANCE_INDEX = 7;
    var DISTANCE_DISPLAY_CONDITION_INDEX = PointPrimitive.DISTANCE_DISPLAY_CONDITION = 8;
    PointPrimitive.NUMBER_OF_PROPERTIES = 9;

    function makeDirty(pointPrimitive, propertyChanged) {
        var pointPrimitiveCollection = pointPrimitive._pointPrimitiveCollection;
        if (defined(pointPrimitiveCollection)) {
            pointPrimitiveCollection._updatePointPrimitive(pointPrimitive, propertyChanged);
            pointPrimitive._dirty = true;
        }
    }

    defineProperties(PointPrimitive.prototype, {
        /**
         * Determines if this point will be shown.  Use this to hide or show a point, instead
         * of removing it and re-adding it to the collection.
         * @memberof PointPrimitive.prototype
         * @type {Boolean}
         */
        show : {
            get : function() {
                return this._show;
            },
            set : function(value) {
                //>>includeStart('debug', pragmas.debug);
                if (!defined(value)) {
                    throw new DeveloperError('value is required.');
                }
                //>>includeEnd('debug');

                if (this._show !== value) {
                    this._show = value;
                    makeDirty(this, SHOW_INDEX);
                }
            }
        },

        /**
        * Gets or sets the Cartesian position of this point.
        * @memberof PointPrimitive.prototype
        * @type {Cartesian3}
        */
        position : {
            get : function() {
                return this._position;
            },
            set : function(value) {
                //>>includeStart('debug', pragmas.debug)
                if (!defined(value)) {
                    throw new DeveloperError('value is required.');
                }
                //>>includeEnd('debug');

                var position = this._position;
                if (!Cartesian3.equals(position, value)) {
                    Cartesian3.clone(value, position);
                    Cartesian3.clone(value, this._actualPosition);

                    makeDirty(this, POSITION_INDEX);
                }
            }
        },

        /**
         * Gets or sets near and far scaling properties of a point based on the point's distance from the camera.
         * A point's scale will interpolate between the {@link NearFarScalar#nearValue} and
         * {@link NearFarScalar#farValue} while the camera distance falls within the upper and lower bounds
         * of the specified {@link NearFarScalar#near} and {@link NearFarScalar#far}.
         * Outside of these ranges the point's scale remains clamped to the nearest bound.  This scale
         * multiplies the pixelSize and outlineWidth to affect the total size of the point.  If undefined,
         * scaleByDistance will be disabled.
         * @memberof PointPrimitive.prototype
         * @type {NearFarScalar}
         *
         * @example
         * // Example 1.
         * // Set a pointPrimitive's scaleByDistance to scale to 15 when the
         * // camera is 1500 meters from the pointPrimitive and disappear as
         * // the camera distance approaches 8.0e6 meters.
         * p.scaleByDistance = new Cesium.NearFarScalar(1.5e2, 15, 8.0e6, 0.0);
         *
         * @example
         * // Example 2.
         * // disable scaling by distance
         * p.scaleByDistance = undefined;
         */
        scaleByDistance : {
            get : function() {
                return this._scaleByDistance;
            },
            set : function(value) {
                //>>includeStart('debug', pragmas.debug);
                if (defined(value) && value.far <= value.near) {
                    throw new DeveloperError('far distance must be greater than near distance.');
                }
                //>>includeEnd('debug');

                var scaleByDistance = this._scaleByDistance;
                if (!NearFarScalar.equals(scaleByDistance, value)) {
                    this._scaleByDistance = NearFarScalar.clone(value, scaleByDistance);
                    makeDirty(this, SCALE_BY_DISTANCE_INDEX);
                }
            }
        },

        /**
         * Gets or sets near and far translucency properties of a point based on the point's distance from the camera.
         * A point's translucency will interpolate between the {@link NearFarScalar#nearValue} and
         * {@link NearFarScalar#farValue} while the camera distance falls within the upper and lower bounds
         * of the specified {@link NearFarScalar#near} and {@link NearFarScalar#far}.
         * Outside of these ranges the point's translucency remains clamped to the nearest bound.  If undefined,
         * translucencyByDistance will be disabled.
         * @memberof PointPrimitive.prototype
         * @type {NearFarScalar}
         *
         * @example
         * // Example 1.
         * // Set a point's translucency to 1.0 when the
         * // camera is 1500 meters from the point and disappear as
         * // the camera distance approaches 8.0e6 meters.
         * p.translucencyByDistance = new Cesium.NearFarScalar(1.5e2, 1.0, 8.0e6, 0.0);
         *
         * @example
         * // Example 2.
         * // disable translucency by distance
         * p.translucencyByDistance = undefined;
         */
        translucencyByDistance : {
            get : function() {
                return this._translucencyByDistance;
            },
            set : function(value) {
                //>>includeStart('debug', pragmas.debug);
                if (defined(value) && value.far <= value.near) {
                    throw new DeveloperError('far distance must be greater than near distance.');
                }
                //>>includeEnd('debug');

                var translucencyByDistance = this._translucencyByDistance;
                if (!NearFarScalar.equals(translucencyByDistance, value)) {
                    this._translucencyByDistance = NearFarScalar.clone(value, translucencyByDistance);
                    makeDirty(this, TRANSLUCENCY_BY_DISTANCE_INDEX);
                }
            }
        },

        /**
         * Gets or sets the inner size of the point in pixels.
         * @memberof PointPrimitive.prototype
         * @type {Number}
         */
        pixelSize : {
            get : function() {
                return this._pixelSize;
            },
            set : function(value) {
                //>>includeStart('debug', pragmas.debug);
                if (!defined(value)) {
                    throw new DeveloperError('value is required.');
                }
                //>>includeEnd('debug');

                if (this._pixelSize !== value) {
                    this._pixelSize = value;
                    makeDirty(this, PIXEL_SIZE_INDEX);
                }
            }
        },

        /**
         * Gets or sets the inner color of the point.
         * The red, green, blue, and alpha values are indicated by <code>value</code>'s <code>red</code>, <code>green</code>,
         * <code>blue</code>, and <code>alpha</code> properties as shown in Example 1.  These components range from <code>0.0</code>
         * (no intensity) to <code>1.0</code> (full intensity).
         * @memberof PointPrimitive.prototype
         * @type {Color}
         *
         * @example
         * // Example 1. Assign yellow.
         * p.color = Cesium.Color.YELLOW;
         *
         * @example
         * // Example 2. Make a pointPrimitive 50% translucent.
         * p.color = new Cesium.Color(1.0, 1.0, 1.0, 0.5);
         */
        color : {
            get : function() {
                return this._color;
            },
            set : function(value) {
                //>>includeStart('debug', pragmas.debug);
                if (!defined(value)) {
                    throw new DeveloperError('value is required.');
                }
                //>>includeEnd('debug');

                var color = this._color;
                if (!Color.equals(color, value)) {
                    Color.clone(value, color);
                    makeDirty(this, COLOR_INDEX);
                }
            }
        },

        /**
         * Gets or sets the outline color of the point.
         * @memberof PointPrimitive.prototype
         * @type {Color}
         */
        outlineColor : {
            get : function() {
                return this._outlineColor;
            },
            set : function(value) {
                //>>includeStart('debug', pragmas.debug);
                if (!defined(value)) {
                    throw new DeveloperError('value is required.');
                }
                //>>includeEnd('debug');

                var outlineColor = this._outlineColor;
                if (!Color.equals(outlineColor, value)) {
                    Color.clone(value, outlineColor);
                    makeDirty(this, OUTLINE_COLOR_INDEX);
                }
            }
        },

        /**
         * Gets or sets the outline width in pixels.  This width adds to pixelSize,
         * increasing the total size of the point.
         * @memberof PointPrimitive.prototype
         * @type {Number}
         */
        outlineWidth : {
            get : function() {
                return this._outlineWidth;
            },
            set : function(value) {
                //>>includeStart('debug', pragmas.debug);
                if (!defined(value)) {
                    throw new DeveloperError('value is required.');
                }
                //>>includeEnd('debug');

                if (this._outlineWidth !== value) {
                    this._outlineWidth = value;
                    makeDirty(this, OUTLINE_WIDTH_INDEX);
                }
            }
        },

        /**
         * Gets or sets the condition specifying at what distance from the camera that this point will be displayed.
         * @memberof PointPrimitive.prototype
         * @type {DistanceDisplayCondition}
         * @default undefined
         */
        distanceDisplayCondition : {
            get : function() {
                return this._distanceDisplayCondition;
            },
            set : function(value) {
                //>>includeStart('debug', pragmas.debug);
                if (defined(value) && value.far <= value.near) {
                    throw new DeveloperError('far must be greater than near');
                }
                //>>includeEnd('debug');
                if (!DistanceDisplayCondition.equals(this._distanceDisplayCondition, value)) {
                    this._distanceDisplayCondition = DistanceDisplayCondition.clone(value, this._distanceDisplayCondition);
                    makeDirty(this, DISTANCE_DISPLAY_CONDITION_INDEX);
                }
            }
        },

        /**
         * Gets or sets the user-defined object returned when the point is picked.
         * @memberof PointPrimitive.prototype
         * @type {Object}
         */
        id : {
            get : function() {
                return this._id;
            },
            set : function(value) {
                this._id = value;
                if (defined(this._pickId)) {
                    this._pickId.object.id = value;
                }
            }
        },

        /**
         * Determines whether or not this point will be shown or hidden because it was clustered.
         * @memberof PointPrimitive.prototype
         * @type {Boolean}
         * @private
         */
        clusterShow : {
            get : function() {
                return this._clusterShow;
            },
            set : function(value) {
                if (this._clusterShow !== value) {
                    this._clusterShow = value;
                    makeDirty(this, SHOW_INDEX);
                }
            }
        }
    });

    PointPrimitive.prototype.getPickId = function(context) {
        if (!defined(this._pickId)) {
            this._pickId = context.createPickId({
                primitive : this,
                collection : this._collection,
                id : this._id
            });
        }

        return this._pickId;
    };

    PointPrimitive.prototype._getActualPosition = function() {
        return this._actualPosition;
    };

    PointPrimitive.prototype._setActualPosition = function(value) {
        Cartesian3.clone(value, this._actualPosition);
        makeDirty(this, POSITION_INDEX);
    };

    var tempCartesian3 = new Cartesian4();
    PointPrimitive._computeActualPosition = function(position, frameState, modelMatrix) {
        if (frameState.mode === SceneMode.SCENE3D) {
            return position;
        }

        Matrix4.multiplyByPoint(modelMatrix, position, tempCartesian3);
        return SceneTransforms.computeActualWgs84Position(frameState, tempCartesian3);
    };

    var scratchCartesian4 = new Cartesian4();

    // This function is basically a stripped-down JavaScript version of PointPrimitiveCollectionVS.glsl
    PointPrimitive._computeScreenSpacePosition = function(modelMatrix, position, scene, result) {
        // Model to world coordinates
        var positionWorld = Matrix4.multiplyByVector(modelMatrix, Cartesian4.fromElements(position.x, position.y, position.z, 1, scratchCartesian4), scratchCartesian4);
        var positionWC = SceneTransforms.wgs84ToWindowCoordinates(scene, positionWorld, result);
        return positionWC;
    };

    /**
     * Computes the screen-space position of the point's origin.
     * The screen space origin is the top, left corner of the canvas; <code>x</code> increases from
     * left to right, and <code>y</code> increases from top to bottom.
     *
     * @param {Scene} scene The scene.
     * @param {Cartesian2} [result] The object onto which to store the result.
     * @returns {Cartesian2} The screen-space position of the point.
     *
     * @exception {DeveloperError} PointPrimitive must be in a collection.
     *
     * @example
     * console.log(p.computeScreenSpacePosition(scene).toString());
     */
    PointPrimitive.prototype.computeScreenSpacePosition = function(scene, result) {
        var pointPrimitiveCollection = this._pointPrimitiveCollection;
        if (!defined(result)) {
            result = new Cartesian2();
        }

        //>>includeStart('debug', pragmas.debug);
        if (!defined(pointPrimitiveCollection)) {
            throw new DeveloperError('PointPrimitive must be in a collection.');
        }
        if (!defined(scene)) {
            throw new DeveloperError('scene is required.');
        }
        //>>includeEnd('debug');

        var modelMatrix = pointPrimitiveCollection.modelMatrix;
        var windowCoordinates = PointPrimitive._computeScreenSpacePosition(modelMatrix, this._actualPosition, scene, result);
        if (!defined(windowCoordinates)) {
            return undefined;
        }

        windowCoordinates.y = scene.canvas.clientHeight - windowCoordinates.y;
        return windowCoordinates;
    };

    /**
     * Gets a point's screen space bounding box centered around screenSpacePosition.
     * @param {PointPrimitive} point The point to get the screen space bounding box for.
     * @param {Cartesian2} screenSpacePosition The screen space center of the label.
     * @param {BoundingRectangle} [result] The object onto which to store the result.
     * @returns {BoundingRectangle} The screen space bounding box.
     *
     * @private
     */
    PointPrimitive.getScreenSpaceBoundingBox = function(point, screenSpacePosition, result) {
        var size = point.pixelSize;
        var halfSize = size * 0.5;

        var x = screenSpacePosition.x - halfSize;
        var y = screenSpacePosition.y - halfSize;
        var width = size;
        var height = size;

        if (!defined(result)) {
            result = new BoundingRectangle();
        }

        result.x = x;
        result.y = y;
        result.width = width;
        result.height = height;

        return result;
    };

    /**
     * Determines if this point equals another point.  Points are equal if all their properties
     * are equal.  Points in different collections can be equal.
     *
     * @param {PointPrimitive} other The point to compare for equality.
     * @returns {Boolean} <code>true</code> if the points are equal; otherwise, <code>false</code>.
     */
    PointPrimitive.prototype.equals = function(other) {
        return this === other ||
               defined(other) &&
               this._id === other._id &&
               Cartesian3.equals(this._position, other._position) &&
               Color.equals(this._color, other._color) &&
               this._pixelSize === other._pixelSize &&
               this._outlineWidth === other._outlineWidth &&
               this._show === other._show &&
               Color.equals(this._outlineColor, other._outlineColor) &&
               NearFarScalar.equals(this._scaleByDistance, other._scaleByDistance) &&
               NearFarScalar.equals(this._translucencyByDistance, other._translucencyByDistance) &&
               DistanceDisplayCondition.equals(this._distanceDisplayCondition, other._distanceDisplayCondition);
    };

    PointPrimitive.prototype._destroy = function() {
        this._pickId = this._pickId && this._pickId.destroy();
        this._pointPrimitiveCollection = undefined;
    };

    return PointPrimitive;
});