cesiumDemo/Source/WorkersES6/createVerticesFromGoogleEarthEnterpriseBuffer.js

import AxisAlignedBoundingBox from '../Core/AxisAlignedBoundingBox.js';
import BoundingSphere from '../Core/BoundingSphere.js';
import Cartesian2 from '../Core/Cartesian2.js';
import Cartesian3 from '../Core/Cartesian3.js';
import Cartographic from '../Core/Cartographic.js';
import defaultValue from '../Core/defaultValue.js';
import defined from '../Core/defined.js';
import Ellipsoid from '../Core/Ellipsoid.js';
import EllipsoidalOccluder from '../Core/EllipsoidalOccluder.js';
import CesiumMath from '../Core/Math.js';
import Matrix4 from '../Core/Matrix4.js';
import OrientedBoundingBox from '../Core/OrientedBoundingBox.js';
import Rectangle from '../Core/Rectangle.js';
import RuntimeError from '../Core/RuntimeError.js';
import TerrainEncoding from '../Core/TerrainEncoding.js';
import Transforms from '../Core/Transforms.js';
import WebMercatorProjection from '../Core/WebMercatorProjection.js';
import createTaskProcessorWorker from './createTaskProcessorWorker.js';

    var sizeOfUint16 = Uint16Array.BYTES_PER_ELEMENT;
    var sizeOfInt32 = Int32Array.BYTES_PER_ELEMENT;
    var sizeOfUint32 = Uint32Array.BYTES_PER_ELEMENT;
    var sizeOfFloat = Float32Array.BYTES_PER_ELEMENT;
    var sizeOfDouble = Float64Array.BYTES_PER_ELEMENT;

    function indexOfEpsilon(arr, elem, elemType) {
        elemType = defaultValue(elemType, CesiumMath);
        var count = arr.length;
        for (var i = 0; i < count; ++i) {
            if (elemType.equalsEpsilon(arr[i], elem, CesiumMath.EPSILON12)) {
                return i;
            }
        }

        return -1;
    }

    function createVerticesFromGoogleEarthEnterpriseBuffer(parameters, transferableObjects) {
        parameters.ellipsoid = Ellipsoid.clone(parameters.ellipsoid);
        parameters.rectangle = Rectangle.clone(parameters.rectangle);

        var statistics = processBuffer(parameters.buffer, parameters.relativeToCenter, parameters.ellipsoid,
            parameters.rectangle, parameters.nativeRectangle, parameters.exaggeration, parameters.skirtHeight,
            parameters.includeWebMercatorT, parameters.negativeAltitudeExponentBias, parameters.negativeElevationThreshold);
        var vertices = statistics.vertices;
        transferableObjects.push(vertices.buffer);
        var indices = statistics.indices;
        transferableObjects.push(indices.buffer);

        return {
            vertices : vertices.buffer,
            indices : indices.buffer,
            numberOfAttributes : statistics.encoding.getStride(),
            minimumHeight : statistics.minimumHeight,
            maximumHeight : statistics.maximumHeight,
            boundingSphere3D : statistics.boundingSphere3D,
            orientedBoundingBox : statistics.orientedBoundingBox,
            occludeePointInScaledSpace : statistics.occludeePointInScaledSpace,
            encoding : statistics.encoding,
            vertexCountWithoutSkirts : statistics.vertexCountWithoutSkirts,
            skirtIndex : statistics.skirtIndex,
            westIndicesSouthToNorth : statistics.westIndicesSouthToNorth,
            southIndicesEastToWest : statistics.southIndicesEastToWest,
            eastIndicesNorthToSouth : statistics.eastIndicesNorthToSouth,
            northIndicesWestToEast : statistics.northIndicesWestToEast
        };
    }

    var scratchCartographic = new Cartographic();
    var scratchCartesian = new Cartesian3();
    var minimumScratch = new Cartesian3();
    var maximumScratch = new Cartesian3();
    var matrix4Scratch = new Matrix4();

    function processBuffer(buffer, relativeToCenter, ellipsoid, rectangle, nativeRectangle, exaggeration, skirtHeight, includeWebMercatorT, negativeAltitudeExponentBias, negativeElevationThreshold) {
        var geographicWest;
        var geographicSouth;
        var geographicEast;
        var geographicNorth;
        var rectangleWidth, rectangleHeight;

        if (!defined(rectangle)) {
            geographicWest = CesiumMath.toRadians(nativeRectangle.west);
            geographicSouth = CesiumMath.toRadians(nativeRectangle.south);
            geographicEast = CesiumMath.toRadians(nativeRectangle.east);
            geographicNorth = CesiumMath.toRadians(nativeRectangle.north);
            rectangleWidth = CesiumMath.toRadians(rectangle.width);
            rectangleHeight = CesiumMath.toRadians(rectangle.height);
        } else {
            geographicWest = rectangle.west;
            geographicSouth = rectangle.south;
            geographicEast = rectangle.east;
            geographicNorth = rectangle.north;
            rectangleWidth = rectangle.width;
            rectangleHeight = rectangle.height;
        }

        // Keep track of quad borders so we can remove duplicates around the borders
        var quadBorderLatitudes = [geographicSouth, geographicNorth];
        var quadBorderLongitudes = [geographicWest, geographicEast];

        var fromENU = Transforms.eastNorthUpToFixedFrame(relativeToCenter, ellipsoid);
        var toENU = Matrix4.inverseTransformation(fromENU, matrix4Scratch);

        var southMercatorY;
        var oneOverMercatorHeight;
        if (includeWebMercatorT) {
            southMercatorY = WebMercatorProjection.geodeticLatitudeToMercatorAngle(geographicSouth);
            oneOverMercatorHeight = 1.0 / (WebMercatorProjection.geodeticLatitudeToMercatorAngle(geographicNorth) - southMercatorY);
        }

        var dv = new DataView(buffer);

        var minHeight = Number.POSITIVE_INFINITY;
        var maxHeight = Number.NEGATIVE_INFINITY;

        var minimum = minimumScratch;
        minimum.x = Number.POSITIVE_INFINITY;
        minimum.y = Number.POSITIVE_INFINITY;
        minimum.z = Number.POSITIVE_INFINITY;

        var maximum = maximumScratch;
        maximum.x = Number.NEGATIVE_INFINITY;
        maximum.y = Number.NEGATIVE_INFINITY;
        maximum.z = Number.NEGATIVE_INFINITY;

        // Compute sizes
        var offset = 0;
        var size = 0;
        var indicesSize = 0;
        var quadSize;
        var quad;
        for (quad = 0; quad < 4; ++quad) {
            var o = offset;
            quadSize = dv.getUint32(o, true);
            o += sizeOfUint32;

            var x = CesiumMath.toRadians(dv.getFloat64(o, true) * 180.0);
            o += sizeOfDouble;
            if (indexOfEpsilon(quadBorderLongitudes, x) === -1) {
                quadBorderLongitudes.push(x);
            }

            var y = CesiumMath.toRadians(dv.getFloat64(o, true) * 180.0);
            o += sizeOfDouble;
            if (indexOfEpsilon(quadBorderLatitudes, y) === -1) {
                quadBorderLatitudes.push(y);
            }

            o += 2 * sizeOfDouble; // stepX + stepY

            var c = dv.getInt32(o, true); // Read point count
            o += sizeOfInt32;
            size += c;

            c = dv.getInt32(o, true); // Read index count
            indicesSize += c * 3;

            offset += quadSize + sizeOfUint32; // Jump to next quad
        }

        // Quad Border points to remove duplicates
        var quadBorderPoints = [];
        var quadBorderIndices = [];

        // Create arrays
        var positions = new Array(size);
        var uvs = new Array(size);
        var heights = new Array(size);
        var webMercatorTs = includeWebMercatorT ? new Array(size) : [];
        var indices = new Array(indicesSize);

        // Points are laid out in rows starting at SW, so storing border points as we
        //  come across them all points will be adjacent.
        var westBorder = [];
        var southBorder = [];
        var eastBorder = [];
        var northBorder = [];

        // Each tile is split into 4 parts
        var pointOffset = 0;
        var indicesOffset = 0;
        offset = 0;
        for (quad = 0; quad < 4; ++quad) {
            quadSize = dv.getUint32(offset, true);
            offset += sizeOfUint32;
            var startQuad = offset;

            var originX = CesiumMath.toRadians(dv.getFloat64(offset, true) * 180.0);
            offset += sizeOfDouble;

            var originY = CesiumMath.toRadians(dv.getFloat64(offset, true) * 180.0);
            offset += sizeOfDouble;

            var stepX = CesiumMath.toRadians(dv.getFloat64(offset, true) * 180.0);
            var halfStepX = stepX * 0.5;
            offset += sizeOfDouble;

            var stepY = CesiumMath.toRadians(dv.getFloat64(offset, true) * 180.0);
            var halfStepY = stepY * 0.5;
            offset += sizeOfDouble;

            var numPoints = dv.getInt32(offset, true);
            offset += sizeOfInt32;

            var numFaces = dv.getInt32(offset, true);
            offset += sizeOfInt32;

            //var level = dv.getInt32(offset, true);
            offset += sizeOfInt32;

            // Keep track of quad indices to overall tile indices
            var indicesMapping = new Array(numPoints);
            for (var i = 0; i < numPoints; ++i) {
                var longitude = originX + dv.getUint8(offset++) * stepX;
                scratchCartographic.longitude = longitude;
                var latitude = originY + dv.getUint8(offset++) * stepY;
                scratchCartographic.latitude = latitude;

                var height = dv.getFloat32(offset, true);
                offset += sizeOfFloat;

                // In order to support old clients, negative altitude values are stored as
                // height/-2^32. Old clients see the value as really close to 0 but new clients multiply
                // by -2^32 to get the real negative altitude value.
                if (height !== 0 && height < negativeElevationThreshold) {
                    height *= -Math.pow(2, negativeAltitudeExponentBias);
                }

                // Height is stored in units of (1/EarthRadius) or (1/6371010.0)
                height *= 6371010.0 * exaggeration;

                scratchCartographic.height = height;

                // Is it along a quad border - if so check if already exists and use that index
                if (indexOfEpsilon(quadBorderLongitudes, longitude) !== -1 ||
                    indexOfEpsilon(quadBorderLatitudes, latitude) !== -1) {
                    var index = indexOfEpsilon(quadBorderPoints, scratchCartographic, Cartographic);
                    if (index === -1) {
                        quadBorderPoints.push(Cartographic.clone(scratchCartographic));
                        quadBorderIndices.push(pointOffset);
                    } else {
                        indicesMapping[i] = quadBorderIndices[index];
                        continue;
                    }
                }
                indicesMapping[i] = pointOffset;

                if (Math.abs(longitude - geographicWest) < halfStepX) {
                    westBorder.push({
                        index : pointOffset,
                        cartographic : Cartographic.clone(scratchCartographic)
                    });
                } else if (Math.abs(longitude - geographicEast) < halfStepX) {
                    eastBorder.push({
                        index : pointOffset,
                        cartographic : Cartographic.clone(scratchCartographic)
                    });
                } else if (Math.abs(latitude - geographicSouth) < halfStepY) {
                    southBorder.push({
                        index : pointOffset,
                        cartographic : Cartographic.clone(scratchCartographic)
                    });
                } else if (Math.abs(latitude - geographicNorth) < halfStepY) {
                    northBorder.push({
                        index : pointOffset,
                        cartographic : Cartographic.clone(scratchCartographic)
                    });
                }

                minHeight = Math.min(height, minHeight);
                maxHeight = Math.max(height, maxHeight);
                heights[pointOffset] = height;

                var pos = ellipsoid.cartographicToCartesian(scratchCartographic);
                positions[pointOffset] = pos;

                if (includeWebMercatorT) {
                    webMercatorTs[pointOffset] = (WebMercatorProjection.geodeticLatitudeToMercatorAngle(latitude) - southMercatorY) * oneOverMercatorHeight;
                }

                Matrix4.multiplyByPoint(toENU, pos, scratchCartesian);

                Cartesian3.minimumByComponent(scratchCartesian, minimum, minimum);
                Cartesian3.maximumByComponent(scratchCartesian, maximum, maximum);

                var u = (longitude - geographicWest) / (geographicEast - geographicWest);
                u = CesiumMath.clamp(u, 0.0, 1.0);
                var v = (latitude - geographicSouth) / (geographicNorth - geographicSouth);
                v = CesiumMath.clamp(v, 0.0, 1.0);

                uvs[pointOffset] = new Cartesian2(u, v);
                ++pointOffset;
            }

            var facesElementCount = numFaces * 3;
            for (var j = 0; j < facesElementCount; ++j, ++indicesOffset) {
                indices[indicesOffset] = indicesMapping[dv.getUint16(offset, true)];
                offset += sizeOfUint16;
            }

            if (quadSize !== (offset - startQuad)) {
                throw new RuntimeError('Invalid terrain tile.');
            }
        }

        positions.length = pointOffset;
        uvs.length = pointOffset;
        heights.length = pointOffset;
        if (includeWebMercatorT) {
            webMercatorTs.length = pointOffset;
        }

        var vertexCountWithoutSkirts = pointOffset;
        var skirtIndex = indicesOffset;

        // Add skirt points
        var skirtOptions = {
            hMin : minHeight,
            lastBorderPoint : undefined,
            skirtHeight : skirtHeight,
            toENU : toENU,
            ellipsoid : ellipsoid,
            minimum : minimum,
            maximum : maximum
        };

        // Sort counter clockwise from NW corner
        // Corner points are in the east/west arrays
        westBorder.sort(function(a, b) {
            return b.cartographic.latitude - a.cartographic.latitude;
        });
        southBorder.sort(function(a, b) {
            return a.cartographic.longitude - b.cartographic.longitude;
        });
        eastBorder.sort(function(a, b) {
            return a.cartographic.latitude - b.cartographic.latitude;
        });
        northBorder.sort(function(a, b) {
            return b.cartographic.longitude - a.cartographic.longitude;
        });

        var percentage = 0.00001;
        addSkirt(positions, heights, uvs, webMercatorTs, indices, skirtOptions,
            westBorder, -percentage * rectangleWidth, true, -percentage * rectangleHeight);
        addSkirt(positions, heights, uvs, webMercatorTs, indices, skirtOptions,
            southBorder, -percentage * rectangleHeight, false);
        addSkirt(positions, heights, uvs, webMercatorTs, indices, skirtOptions,
            eastBorder, percentage * rectangleWidth, true, percentage * rectangleHeight);
        addSkirt(positions, heights, uvs, webMercatorTs, indices, skirtOptions,
            northBorder, percentage * rectangleHeight, false);

        // Since the corner between the north and west sides is in the west array, generate the last
        //  two triangles between the last north vertex and the first west vertex
        if (westBorder.length > 0 && northBorder.length > 0) {
            var firstBorderIndex = westBorder[0].index;
            var firstSkirtIndex = vertexCountWithoutSkirts;
            var lastBorderIndex = northBorder[northBorder.length - 1].index;
            var lastSkirtIndex = positions.length - 1;

            indices.push(lastBorderIndex, lastSkirtIndex, firstSkirtIndex, firstSkirtIndex, firstBorderIndex, lastBorderIndex);
        }

        size = positions.length; // Get new size with skirt vertices

        var boundingSphere3D = BoundingSphere.fromPoints(positions);
        var orientedBoundingBox;
        if (defined(rectangle) && rectangle.width < CesiumMath.PI_OVER_TWO + CesiumMath.EPSILON5) {
            // Here, rectangle.width < pi/2, and rectangle.height < pi
            // (though it would still work with rectangle.width up to pi)
            orientedBoundingBox = OrientedBoundingBox.fromRectangle(rectangle, minHeight, maxHeight, ellipsoid);
        }

        var occluder = new EllipsoidalOccluder(ellipsoid);
        var occludeePointInScaledSpace = occluder.computeHorizonCullingPoint(relativeToCenter, positions);

        var aaBox = new AxisAlignedBoundingBox(minimum, maximum, relativeToCenter);
        var encoding = new TerrainEncoding(aaBox, skirtOptions.hMin, maxHeight, fromENU, false, includeWebMercatorT);
        var vertices = new Float32Array(size * encoding.getStride());

        var bufferIndex = 0;
        for (var k = 0; k < size; ++k) {
            bufferIndex = encoding.encode(vertices, bufferIndex, positions[k], uvs[k], heights[k], undefined, webMercatorTs[k]);
        }

        var westIndicesSouthToNorth = westBorder.map(function(vertex) { return vertex.index; }).reverse();
        var southIndicesEastToWest = southBorder.map(function(vertex) { return vertex.index; }).reverse();
        var eastIndicesNorthToSouth = eastBorder.map(function(vertex) { return vertex.index; }).reverse();
        var northIndicesWestToEast = northBorder.map(function(vertex) { return vertex.index; }).reverse();

        southIndicesEastToWest.unshift(eastIndicesNorthToSouth[eastIndicesNorthToSouth.length - 1]);
        southIndicesEastToWest.push(westIndicesSouthToNorth[0]);

        northIndicesWestToEast.unshift(westIndicesSouthToNorth[westIndicesSouthToNorth.length - 1]);
        northIndicesWestToEast.push(eastIndicesNorthToSouth[0]);

        return {
            vertices : vertices,
            indices : new Uint16Array(indices),
            maximumHeight : maxHeight,
            minimumHeight : minHeight,
            encoding : encoding,
            boundingSphere3D : boundingSphere3D,
            orientedBoundingBox : orientedBoundingBox,
            occludeePointInScaledSpace : occludeePointInScaledSpace,
            vertexCountWithoutSkirts : vertexCountWithoutSkirts,
            skirtIndex : skirtIndex,
            westIndicesSouthToNorth : westIndicesSouthToNorth,
            southIndicesEastToWest : southIndicesEastToWest,
            eastIndicesNorthToSouth : eastIndicesNorthToSouth,
            northIndicesWestToEast : northIndicesWestToEast
        };
    }

    function addSkirt(positions, heights, uvs, webMercatorTs, indices, skirtOptions,
                      borderPoints, fudgeFactor, eastOrWest, cornerFudge) {
        var count = borderPoints.length;
        for (var j = 0; j < count; ++j) {
            var borderPoint = borderPoints[j];
            var borderCartographic = borderPoint.cartographic;
            var borderIndex = borderPoint.index;
            var currentIndex = positions.length;

            var longitude = borderCartographic.longitude;
            var latitude = borderCartographic.latitude;
            latitude = CesiumMath.clamp(latitude, -CesiumMath.PI_OVER_TWO, CesiumMath.PI_OVER_TWO); // Don't go over the poles
            var height = borderCartographic.height - skirtOptions.skirtHeight;
            skirtOptions.hMin = Math.min(skirtOptions.hMin, height);

            Cartographic.fromRadians(longitude, latitude, height, scratchCartographic);

            // Adjust sides to angle out
            if (eastOrWest) {
                scratchCartographic.longitude += fudgeFactor;
            }

            // Adjust top or bottom to angle out
            // Since corners are in the east/west arrays angle the first and last points as well
            if (!eastOrWest) {
                scratchCartographic.latitude += fudgeFactor;
            } else if (j === (count - 1)) {
                scratchCartographic.latitude += cornerFudge;
            } else if (j === 0) {
                scratchCartographic.latitude -= cornerFudge;
            }

            var pos = skirtOptions.ellipsoid.cartographicToCartesian(scratchCartographic);
            positions.push(pos);
            heights.push(height);
            uvs.push(Cartesian2.clone(uvs[borderIndex])); // Copy UVs from border point
            if (webMercatorTs.length > 0) {
                webMercatorTs.push(webMercatorTs[borderIndex]);
            }

            Matrix4.multiplyByPoint(skirtOptions.toENU, pos, scratchCartesian);

            var minimum = skirtOptions.minimum;
            var maximum = skirtOptions.maximum;
            Cartesian3.minimumByComponent(scratchCartesian, minimum, minimum);
            Cartesian3.maximumByComponent(scratchCartesian, maximum, maximum);

            var lastBorderPoint = skirtOptions.lastBorderPoint;
            if (defined(lastBorderPoint)) {
                var lastBorderIndex = lastBorderPoint.index;
                indices.push(lastBorderIndex, currentIndex - 1, currentIndex, currentIndex, borderIndex, lastBorderIndex);
            }

            skirtOptions.lastBorderPoint = borderPoint;
        }
    }
export default createTaskProcessorWorker(createVerticesFromGoogleEarthEnterpriseBuffer);