CorridorOutlineGeometry.js

/*global define*/
define([
        './arrayRemoveDuplicates',
        './BoundingSphere',
        './Cartesian3',
        './ComponentDatatype',
        './CornerType',
        './CorridorGeometryLibrary',
        './defaultValue',
        './defined',
        './DeveloperError',
        './Ellipsoid',
        './Geometry',
        './GeometryAttribute',
        './GeometryAttributes',
        './IndexDatatype',
        './Math',
        './PolygonPipeline',
        './PrimitiveType'
    ], function(
        arrayRemoveDuplicates,
        BoundingSphere,
        Cartesian3,
        ComponentDatatype,
        CornerType,
        CorridorGeometryLibrary,
        defaultValue,
        defined,
        DeveloperError,
        Ellipsoid,
        Geometry,
        GeometryAttribute,
        GeometryAttributes,
        IndexDatatype,
        CesiumMath,
        PolygonPipeline,
        PrimitiveType) {
    'use strict';

    var cartesian1 = new Cartesian3();
    var cartesian2 = new Cartesian3();
    var cartesian3 = new Cartesian3();

    function combine(computedPositions, cornerType) {
        var wallIndices = [];
        var positions = computedPositions.positions;
        var corners = computedPositions.corners;
        var endPositions = computedPositions.endPositions;
        var attributes = new GeometryAttributes();
        var corner;
        var leftCount = 0;
        var rightCount = 0;
        var i;
        var indicesLength = 0;
        var length;
        for (i = 0; i < positions.length; i += 2) {
            length = positions[i].length - 3;
            leftCount += length; //subtracting 3 to account for duplicate points at corners
            indicesLength += length / 3 * 4;
            rightCount += positions[i + 1].length - 3;
        }
        leftCount += 3; //add back count for end positions
        rightCount += 3;
        for (i = 0; i < corners.length; i++) {
            corner = corners[i];
            var leftSide = corners[i].leftPositions;
            if (defined(leftSide)) {
                length = leftSide.length;
                leftCount += length;
                indicesLength += length / 3 * 2;
            } else {
                length = corners[i].rightPositions.length;
                rightCount += length;
                indicesLength += length / 3 * 2;
            }
        }

        var addEndPositions = defined(endPositions);
        var endPositionLength;
        if (addEndPositions) {
            endPositionLength = endPositions[0].length - 3;
            leftCount += endPositionLength;
            rightCount += endPositionLength;
            endPositionLength /= 3;
            indicesLength += endPositionLength * 4;
        }
        var size = leftCount + rightCount;
        var finalPositions = new Float64Array(size);
        var front = 0;
        var back = size - 1;
        var UL, LL, UR, LR;
        var rightPos, leftPos;
        var halfLength = endPositionLength / 2;

        var indices = IndexDatatype.createTypedArray(size / 3, indicesLength + 4);
        var index = 0;

        indices[index++] = front / 3;
        indices[index++] = (back - 2) / 3;
        if (addEndPositions) { // add rounded end
            wallIndices.push(front / 3);
            leftPos = cartesian1;
            rightPos = cartesian2;
            var firstEndPositions = endPositions[0];
            for (i = 0; i < halfLength; i++) {
                leftPos = Cartesian3.fromArray(firstEndPositions, (halfLength - 1 - i) * 3, leftPos);
                rightPos = Cartesian3.fromArray(firstEndPositions, (halfLength + i) * 3, rightPos);
                CorridorGeometryLibrary.addAttribute(finalPositions, rightPos, front);
                CorridorGeometryLibrary.addAttribute(finalPositions, leftPos, undefined, back);

                LL = front / 3;
                LR = LL + 1;
                UL = (back - 2) / 3;
                UR = UL - 1;
                indices[index++] = UL;
                indices[index++] = UR;
                indices[index++] = LL;
                indices[index++] = LR;

                front += 3;
                back -= 3;
            }
        }

        var posIndex = 0;
        var rightEdge = positions[posIndex++]; //add first two edges
        var leftEdge = positions[posIndex++];
        finalPositions.set(rightEdge, front);
        finalPositions.set(leftEdge, back - leftEdge.length + 1);

        length = leftEdge.length - 3;
        wallIndices.push(front / 3, (back - 2) / 3);
        for (i = 0; i < length; i += 3) {
            LL = front / 3;
            LR = LL + 1;
            UL = (back - 2) / 3;
            UR = UL - 1;
            indices[index++] = UL;
            indices[index++] = UR;
            indices[index++] = LL;
            indices[index++] = LR;

            front += 3;
            back -= 3;
        }

        for (i = 0; i < corners.length; i++) {
            var j;
            corner = corners[i];
            var l = corner.leftPositions;
            var r = corner.rightPositions;
            var start;
            var outsidePoint = cartesian3;
            if (defined(l)) {
                back -= 3;
                start = UR;
                wallIndices.push(LR);
                for (j = 0; j < l.length / 3; j++) {
                    outsidePoint = Cartesian3.fromArray(l, j * 3, outsidePoint);
                    indices[index++] = start - j - 1;
                    indices[index++] = start - j;
                    CorridorGeometryLibrary.addAttribute(finalPositions, outsidePoint, undefined, back);
                    back -= 3;
                }
                wallIndices.push(start - Math.floor(l.length / 6));
                if (cornerType === CornerType.BEVELED) {
                    wallIndices.push((back - 2) / 3 + 1);
                }
                front += 3;
            } else {
                front += 3;
                start = LR;
                wallIndices.push(UR);
                for (j = 0; j < r.length / 3; j++) {
                    outsidePoint = Cartesian3.fromArray(r, j * 3, outsidePoint);
                    indices[index++] = start + j;
                    indices[index++] = start + j + 1;
                    CorridorGeometryLibrary.addAttribute(finalPositions, outsidePoint, front);
                    front += 3;
                }
                wallIndices.push(start + Math.floor(r.length / 6));
                if (cornerType === CornerType.BEVELED) {
                    wallIndices.push(front / 3 - 1);
                }
                back -= 3;
            }
            rightEdge = positions[posIndex++];
            leftEdge = positions[posIndex++];
            rightEdge.splice(0, 3); //remove duplicate points added by corner
            leftEdge.splice(leftEdge.length - 3, 3);
            finalPositions.set(rightEdge, front);
            finalPositions.set(leftEdge, back - leftEdge.length + 1);
            length = leftEdge.length - 3;

            for (j = 0; j < leftEdge.length; j += 3) {
                LR = front / 3;
                LL = LR - 1;
                UR = (back - 2) / 3;
                UL = UR + 1;
                indices[index++] = UL;
                indices[index++] = UR;
                indices[index++] = LL;
                indices[index++] = LR;
                front += 3;
                back -= 3;
            }
            front -= 3;
            back += 3;
            wallIndices.push(front / 3, (back - 2) / 3);
        }

        if (addEndPositions) { // add rounded end
            front += 3;
            back -= 3;
            leftPos = cartesian1;
            rightPos = cartesian2;
            var lastEndPositions = endPositions[1];
            for (i = 0; i < halfLength; i++) {
                leftPos = Cartesian3.fromArray(lastEndPositions, (endPositionLength - i - 1) * 3, leftPos);
                rightPos = Cartesian3.fromArray(lastEndPositions, i * 3, rightPos);
                CorridorGeometryLibrary.addAttribute(finalPositions, leftPos, undefined, back);
                CorridorGeometryLibrary.addAttribute(finalPositions, rightPos, front);

                LR = front / 3;
                LL = LR - 1;
                UR = (back - 2) / 3;
                UL = UR + 1;
                indices[index++] = UL;
                indices[index++] = UR;
                indices[index++] = LL;
                indices[index++] = LR;

                front += 3;
                back -= 3;
            }

            wallIndices.push(front / 3);
        } else {
            wallIndices.push(front / 3, (back - 2) / 3);
        }
        indices[index++] = front / 3;
        indices[index++] = (back - 2) / 3;

        attributes.position = new GeometryAttribute({
            componentDatatype : ComponentDatatype.DOUBLE,
            componentsPerAttribute : 3,
            values : finalPositions
        });

        return {
            attributes : attributes,
            indices : indices,
            wallIndices : wallIndices
        };
    }

    function computePositionsExtruded(params) {
        var ellipsoid = params.ellipsoid;
        var computedPositions = CorridorGeometryLibrary.computePositions(params);
        var attr = combine(computedPositions, params.cornerType);
        var wallIndices = attr.wallIndices;
        var height = params.height;
        var extrudedHeight = params.extrudedHeight;
        var attributes = attr.attributes;
        var indices = attr.indices;
        var positions = attributes.position.values;
        var length = positions.length;
        var extrudedPositions = new Float64Array(length);
        extrudedPositions.set(positions);
        var newPositions = new Float64Array(length * 2);

        positions = PolygonPipeline.scaleToGeodeticHeight(positions, height, ellipsoid);
        extrudedPositions = PolygonPipeline.scaleToGeodeticHeight(extrudedPositions, extrudedHeight, ellipsoid);
        newPositions.set(positions);
        newPositions.set(extrudedPositions, length);
        attributes.position.values = newPositions;

        length /= 3;
        var i;
        var iLength = indices.length;
        var newIndices = IndexDatatype.createTypedArray(newPositions.length / 3, (iLength + wallIndices.length) * 2);
        newIndices.set(indices);
        var index = iLength;
        for (i = 0; i < iLength; i += 2) { // bottom indices
            var v0 = indices[i];
            var v1 = indices[i + 1];
            newIndices[index++] = v0 + length;
            newIndices[index++] = v1 + length;
        }

        var UL, LL;
        for (i = 0; i < wallIndices.length; i++) { //wall indices
            UL = wallIndices[i];
            LL = UL + length;
            newIndices[index++] = UL;
            newIndices[index++] = LL;
        }

        return {
            attributes : attributes,
            indices : newIndices
        };
    }

    /**
     * A description of a corridor outline.
     *
     * @alias CorridorOutlineGeometry
     * @constructor
     *
     * @param {Object} options Object with the following properties:
     * @param {Cartesian3[]} options.positions An array of positions that define the center of the corridor outline.
     * @param {Number} options.width The distance between the edges of the corridor outline.
     * @param {Ellipsoid} [options.ellipsoid=Ellipsoid.WGS84] The ellipsoid to be used as a reference.
     * @param {Number} [options.granularity=CesiumMath.RADIANS_PER_DEGREE] The distance, in radians, between each latitude and longitude. Determines the number of positions in the buffer.
     * @param {Number} [options.height=0] The distance in meters between the positions and the ellipsoid surface.
     * @param {Number} [options.extrudedHeight] The distance in meters between the extruded face and the ellipsoid surface.
     * @param {CornerType} [options.cornerType=CornerType.ROUNDED] Determines the style of the corners.
     *
     * @see CorridorOutlineGeometry.createGeometry
     *
     * @example
     * var corridor = new Cesium.CorridorOutlineGeometry({
     *   positions : Cesium.Cartesian3.fromDegreesArray([-72.0, 40.0, -70.0, 35.0]),
     *   width : 100000
     * });
     */
    function CorridorOutlineGeometry(options) {
        options = defaultValue(options, defaultValue.EMPTY_OBJECT);
        var positions = options.positions;
        var width = options.width;

        //>>includeStart('debug', pragmas.debug);
        if (!defined(positions)) {
            throw new DeveloperError('options.positions is required.');
        }
        if (!defined(width)) {
            throw new DeveloperError('options.width is required.');
        }
        //>>includeEnd('debug');

        this._positions = positions;
        this._ellipsoid = Ellipsoid.clone(defaultValue(options.ellipsoid, Ellipsoid.WGS84));
        this._width = width;
        this._height = defaultValue(options.height, 0);
        this._extrudedHeight = defaultValue(options.extrudedHeight, this._height);
        this._cornerType = defaultValue(options.cornerType, CornerType.ROUNDED);
        this._granularity = defaultValue(options.granularity, CesiumMath.RADIANS_PER_DEGREE);
        this._workerName = 'createCorridorOutlineGeometry';

        /**
         * The number of elements used to pack the object into an array.
         * @type {Number}
         */
        this.packedLength = 1 + positions.length * Cartesian3.packedLength + Ellipsoid.packedLength + 5;
    }

    /**
     * Stores the provided instance into the provided array.
     *
     * @param {CorridorOutlineGeometry} value The value to pack.
     * @param {Number[]} array The array to pack into.
     * @param {Number} [startingIndex=0] The index into the array at which to start packing the elements.
     *
     * @returns {Number[]} The array that was packed into
     */
    CorridorOutlineGeometry.pack = function(value, array, startingIndex) {
        //>>includeStart('debug', pragmas.debug);
        if (!defined(value)) {
            throw new DeveloperError('value is required');
        }
        if (!defined(array)) {
            throw new DeveloperError('array is required');
        }
        //>>includeEnd('debug');

        startingIndex = defaultValue(startingIndex, 0);

        var positions = value._positions;
        var length = positions.length;
        array[startingIndex++] = length;

        for (var i = 0; i < length; ++i, startingIndex += Cartesian3.packedLength) {
            Cartesian3.pack(positions[i], array, startingIndex);
        }

        Ellipsoid.pack(value._ellipsoid, array, startingIndex);
        startingIndex += Ellipsoid.packedLength;

        array[startingIndex++] = value._width;
        array[startingIndex++] = value._height;
        array[startingIndex++] = value._extrudedHeight;
        array[startingIndex++] = value._cornerType;
        array[startingIndex]   = value._granularity;

        return array;
    };

    var scratchEllipsoid = Ellipsoid.clone(Ellipsoid.UNIT_SPHERE);
    var scratchOptions = {
        positions : undefined,
        ellipsoid : scratchEllipsoid,
        width : undefined,
        height : undefined,
        extrudedHeight : undefined,
        cornerType : undefined,
        granularity : undefined
    };

    /**
     * Retrieves an instance from a packed array.
     *
     * @param {Number[]} array The packed array.
     * @param {Number} [startingIndex=0] The starting index of the element to be unpacked.
     * @param {CorridorOutlineGeometry} [result] The object into which to store the result.
     * @returns {CorridorOutlineGeometry} The modified result parameter or a new CorridorOutlineGeometry instance if one was not provided.
     */
    CorridorOutlineGeometry.unpack = function(array, startingIndex, result) {
        //>>includeStart('debug', pragmas.debug);
        if (!defined(array)) {
            throw new DeveloperError('array is required');
        }
        //>>includeEnd('debug');

        startingIndex = defaultValue(startingIndex, 0);

        var length = array[startingIndex++];
        var positions = new Array(length);

        for (var i = 0; i < length; ++i, startingIndex += Cartesian3.packedLength) {
            positions[i] = Cartesian3.unpack(array, startingIndex);
        }

        var ellipsoid = Ellipsoid.unpack(array, startingIndex, scratchEllipsoid);
        startingIndex += Ellipsoid.packedLength;

        var width = array[startingIndex++];
        var height = array[startingIndex++];
        var extrudedHeight = array[startingIndex++];
        var cornerType = array[startingIndex++];
        var granularity = array[startingIndex];

        if (!defined(result)) {
            scratchOptions.positions = positions;
            scratchOptions.width = width;
            scratchOptions.height = height;
            scratchOptions.extrudedHeight = extrudedHeight;
            scratchOptions.cornerType = cornerType;
            scratchOptions.granularity = granularity;
            return new CorridorOutlineGeometry(scratchOptions);
        }

        result._positions = positions;
        result._ellipsoid = Ellipsoid.clone(ellipsoid, result._ellipsoid);
        result._width = width;
        result._height = height;
        result._extrudedHeight = extrudedHeight;
        result._cornerType = cornerType;
        result._granularity = granularity;

        return result;
    };

    /**
     * Computes the geometric representation of a corridor, including its vertices, indices, and a bounding sphere.
     *
     * @param {CorridorOutlineGeometry} corridorOutlineGeometry A description of the corridor.
     * @returns {Geometry|undefined} The computed vertices and indices.
     */
    CorridorOutlineGeometry.createGeometry = function(corridorOutlineGeometry) {
        var positions = corridorOutlineGeometry._positions;
        var height = corridorOutlineGeometry._height;
        var width = corridorOutlineGeometry._width;
        var extrudedHeight = corridorOutlineGeometry._extrudedHeight;
        var extrude = (height !== extrudedHeight);

        var cleanPositions = arrayRemoveDuplicates(positions, Cartesian3.equalsEpsilon);

        if ((cleanPositions.length < 2) || (width <= 0)) {
            return;
        }

        var ellipsoid = corridorOutlineGeometry._ellipsoid;
        var params = {
            ellipsoid : ellipsoid,
            positions : cleanPositions,
            width : width,
            cornerType : corridorOutlineGeometry._cornerType,
            granularity : corridorOutlineGeometry._granularity,
            saveAttributes : false
        };
        var attr;
        if (extrude) {
            var h = Math.max(height, extrudedHeight);
            extrudedHeight = Math.min(height, extrudedHeight);
            height = h;
            params.height = height;
            params.extrudedHeight = extrudedHeight;
            attr = computePositionsExtruded(params);
        } else {
            var computedPositions = CorridorGeometryLibrary.computePositions(params);
            attr = combine(computedPositions, params.cornerType);
            attr.attributes.position.values = PolygonPipeline.scaleToGeodeticHeight(attr.attributes.position.values, height, ellipsoid);
        }
        var attributes = attr.attributes;
        var boundingSphere = BoundingSphere.fromVertices(attributes.position.values, undefined, 3);

        return new Geometry({
            attributes : attributes,
            indices : attr.indices,
            primitiveType : PrimitiveType.LINES,
            boundingSphere : boundingSphere
        });
    };

    return CorridorOutlineGeometry;
});