/*
* Copyright 2003-2006, 2009, 2017, United States Government, as represented by the Administrator of the
* National Aeronautics and Space Administration. All rights reserved.
*
* The NASAWorldWind/WebWorldWind platform is licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
/**
* @exports GeographicMesh
*/
define([
'../shapes/AbstractMesh',
'../error/ArgumentError',
'../shaders/BasicTextureProgram',
'../geom/BoundingBox',
'../util/Color',
'../util/ImageSource',
'../geom/Location',
'../util/Logger',
'../geom/Matrix',
'../pick/PickedObject',
'../geom/Position',
'../shapes/ShapeAttributes',
'../shapes/SurfacePolygon',
'../geom/Vec2',
'../geom/Vec3',
],
function (AbstractMesh,
ArgumentError,
BasicTextureProgram,
BoundingBox,
Color,
ImageSource,
Location,
Logger,
Matrix,
PickedObject,
Position,
ShapeAttributes,
SurfacePolygon,
Vec2,
Vec3) {
"use strict";
/**
* Constructs a geographic mesh.
* @alias GeographicMesh
* @constructor
* @augments AbstractMesh
* @classdesc Represents a 3D geographic mesh.
* <p>
* Altitudes within the mesh's positions are interpreted according to the mesh's altitude mode, which
* can be one of the following:
* <ul>
* <li>[WorldWind.ABSOLUTE]{@link WorldWind#ABSOLUTE}</li>
* <li>[WorldWind.RELATIVE_TO_GROUND]{@link WorldWind#RELATIVE_TO_GROUND}</li>
* <li>[WorldWind.CLAMP_TO_GROUND]{@link WorldWind#CLAMP_TO_GROUND}</li>
* </ul>
* If the latter, the mesh positions' altitudes are ignored. (If the mesh should be draped onto the
* terrain, you might want to use {@link SurfacePolygon} instead.)
* <p>
* Meshes have separate attributes for normal display and highlighted display. They use the interior and
* outline attributes of {@link ShapeAttributes}. If those attributes identify an image, that image is
* applied to the mesh. Texture coordinates for the image may be specified, but if not specified the full
* image is stretched over the full mesh. If texture coordinates are specified, there must be one texture
* coordinate for each vertex in the mesh.
*
* @param {Position[][]} positions A two-dimensional array containing the mesh vertices.
* Each entry of the array specifies the vertices of one row of the mesh. The arrays for all rows must
* have the same length. There must be at least two rows, and each row must have at least two vertices.
* There must be no more than 65536 positions.
* @param {ShapeAttributes} attributes The attributes to associate with this mesh. May be null, in which case
* default attributes are associated.
*
* @throws {ArgumentError} If the specified positions array is null or undefined, the number of rows or the
* number of vertices per row is less than 2, the array lengths are inconsistent, or too many positions are
* specified (limit is 65536).
*/
var GeographicMesh = function (positions, attributes) {
if (!positions) {
throw new ArgumentError(
Logger.logMessage(Logger.LEVEL_SEVERE, "GeographicMesh", "constructor", "missingPositions"));
}
if (positions.length < 2 || positions[0].length < 2) {
throw new ArgumentError(
Logger.logMessage(Logger.LEVEL_SEVERE, "GeographicMesh", "constructor",
"Number of positions is insufficient."));
}
// Check for size limit, which is the max number of available indices for a 16-bit unsigned int.
if (positions.length * positions[0].length > 65536) {
throw new ArgumentError(
Logger.logMessage(Logger.LEVEL_SEVERE, "GeographicMesh", "constructor",
"Too many positions. Must be fewer than 65536. Try using multiple meshes."));
}
var length = positions[0].length;
for (var i = 1; i < positions.length; i++) {
if (positions[i].length !== length) {
throw new ArgumentError(
Logger.logMessage(Logger.LEVEL_SEVERE, "GeographicMesh", "constructor",
"Array lengths are inconsistent."));
}
}
var numRows = positions.length,
numCols = positions[0].length;
AbstractMesh.call(this, attributes);
/**
* Indicates whether this mesh is pickable when the pick point intersects transparent pixels of the
* image applied to this mesh. If no image is applied to this mesh, this property is ignored. If this
* property is true and an image with fully transparent pixels is applied to the mesh, the mesh is
* pickable at those transparent pixels, otherwise this mesh is not pickable at those transparent pixels.
* @type {Boolean}
* @default true
*/
this.pickTransparentImagePixels = true;
// Private. Documentation is with the defined property below and the constructor description above.
this._positions = positions;
// Private. Documentation is with the defined property below.
this._altitudeScale = 1;
// Internal. Intentionally not documented.
this.numRows = numRows;
this.numColumns = numCols;
// Internal. Intentionally not documented.
this._textureCoordinates = null;
// Internal. Intentionally not documented.
this.referencePosition = this.determineReferencePosition(this._positions);
};
GeographicMesh.prototype = Object.create(AbstractMesh.prototype);
Object.defineProperties(GeographicMesh.prototype, {
/**
* This mesh's positions. Each array in the positions array specifies the geographic positions of one
* row of the mesh.
*
* @type {Position[][]}
* @memberof GeographicMesh.prototype
*/
positions: {
get: function () {
return this._positions;
},
set: function (positions) {
if (!positions) {
throw new ArgumentError(
Logger.logMessage(Logger.LEVEL_SEVERE, "GeographicMesh", "positions", "missingPositions"));
}
if (positions.length < 2 || positions[0].length < 2) {
throw new ArgumentError(
Logger.logMessage(Logger.LEVEL_SEVERE, "GeographicMesh", "positions",
"Number of positions is insufficient."));
}
var length = positions[0].length;
for (var i = 1; i < positions.length; i++) {
if (positions[i].length !== length) {
throw new ArgumentError(
Logger.logMessage(Logger.LEVEL_SEVERE, "GeographicMesh", "positions",
"Array lengths are inconsistent."));
}
}
this.numRows = positions.length;
this.numColumns = positions[0].length;
this._positions = positions;
this.referencePosition = this.determineReferencePosition(this._positions);
this.reset();
this.meshIndices = null;
this.meshOutlineIndices = null;
}
},
/**
* This mesh's texture coordinates if this mesh is textured. A texture coordinate must be
* provided for each mesh position. The texture coordinates are specified as a two-dimensional array,
* each entry of which specifies the texture coordinates for one row of the mesh. Each texture coordinate
* is a {@link Vec2} containing the s and t coordinates. If no texture coordinates are specified and
* the attributes associated with this mesh indicate an image source, then texture coordinates are
* automatically generated for the mesh.
* @type {Vec2[][]}
* @default null
* @memberof GeographicMesh.prototype
*/
textureCoordinates: {
get: function () {
return this._textureCoordinates;
},
set: function (coords) {
if (coords && coords.length != this.numRows) {
throw new ArgumentError(
Logger.logMessage(Logger.LEVEL_SEVERE, "GeographicMesh", "textureCoordinates",
"Number of texture coordinate rows is inconsistent with the currently specified positions."));
}
for (var i = 0; i < this.numRows; i++) {
if (coords[i].length !== this.numColumns) {
throw new ArgumentError(
Logger.logMessage(Logger.LEVEL_SEVERE, "GeographicMesh", "textureCoordinates",
"Texture coordinate row lengths are inconsistent with the currently specified positions."));
}
}
this._textureCoordinates = coords;
this.reset();
this.texCoords = null;
}
},
});
GeographicMesh.makeGridIndices = function (nRows, nCols) {
// Compute indices for individual triangles.
var gridIndices = [],
i = 0;
for (var r = 0; r < nRows - 1; r++) {
for (var c = 0; c < nCols - 1; c++) {
var k = r * nCols + c;
gridIndices[i++] = k;
gridIndices[i++] = k + 1;
gridIndices[i++] = k + nCols;
gridIndices[i++] = k + 1;
gridIndices[i++] = k + 1 + nCols;
gridIndices[i++] = k + nCols;
}
}
return gridIndices;
};
// Intentionally not documented.
GeographicMesh.prototype.determineReferencePosition = function (positions) {
// Assign the first position as the reference position.
return positions[0][0];
};
// Overridden from AbstractShape base class.
GeographicMesh.prototype.createSurfaceShape = function () {
var boundaries = [];
for (var c = 0; c < this.numColumns; c++) {
boundaries.push(this._positions[0][c]);
}
for (var r = 1; r < this.numRows; r++) {
boundaries.push(this._positions[r][this.numColumns - 1]);
}
for (c = this.numColumns - 2; c >= 0; c--) {
boundaries.push(this._positions[this.numRows - 1][c]);
}
for (r = this.numRows - 2; r > 0; r--) {
boundaries.push(this._positions[r][0]);
}
return new SurfacePolygon(boundaries, null);
};
GeographicMesh.prototype.computeMeshPoints = function (dc, currentData) {
// Unwrap the mesh row arrays into one long array.
var eyeDistSquared = Number.MAX_VALUE,
eyePoint = dc.eyePoint,
meshPoints = new Float32Array((this.numRows * this.numColumns) * 3),
pt = new Vec3(0, 0, 0),
k = 0,
pos, dSquared;
for (var r = 0; r < this._positions.length; r++) {
for (var c = 0, len = this._positions[r].length; c < len; c++) {
pos = this._positions[r][c];
dc.surfacePointForMode(pos.latitude, pos.longitude, pos.altitude * this._altitudeScale,
this.altitudeMode, pt);
dSquared = pt.distanceToSquared(eyePoint);
if (dSquared < eyeDistSquared) {
eyeDistSquared = dSquared;
}
pt.subtract(this.currentData.referencePoint);
meshPoints[k++] = pt[0];
meshPoints[k++] = pt[1];
meshPoints[k++] = pt[2];
}
}
currentData.eyeDistance = Math.sqrt(eyeDistSquared);
return meshPoints;
};
GeographicMesh.prototype.computeTexCoords = function () {
if (this._textureCoordinates) {
return this.computeExplicitTexCoords();
} else {
return this.computeImplicitTexCoords();
}
};
// Intentionally not documented.
GeographicMesh.prototype.computeExplicitTexCoords = function () {
// Capture the texture coordinates to a single array parallel to the mesh points array.
var texCoords = new Float32Array(2 * this.numRows * this.numColumns),
k = 0;
for (var r = 0; r < this._textureCoordinates.length; r++) {
for (var c = 0, len = this._textureCoordinates[r].length; c < len; c++) {
var texCoord = this._textureCoordinates[r][c];
texCoords[k++] = texCoord[0];
texCoords[k++] = texCoord[1];
}
}
return texCoords;
};
// Intentionally not documented.
GeographicMesh.prototype.computeImplicitTexCoords = function () {
// Create texture coordinates that map the full image source into the full mesh.
var texCoords = new Float32Array(2 * this.numRows * this.numColumns),
rowDelta = 1.0 / (this.numRows - 1),
columnDelta = 1.0 / (this.numColumns - 1),
k = 0;
for (var r = 0; r < this._positions.length; r++) {
var t = (r === this.numRows - 1) ? 1.0 : r * rowDelta;
for (var c = 0, len = this._positions[r].length; c < len; c++) {
texCoords[k++] = (c === this.numColumns - 1) ? 1.0 : c * columnDelta;
texCoords[k++] = t;
}
}
return texCoords;
};
GeographicMesh.prototype.computeMeshIndices = function () {
// Compute indices for individual triangles.
var meshIndices = new Uint16Array((this.numRows - 1) * (this.numColumns - 1) * 6),
i = 0;
for (var r = 0; r < this.numRows - 1; r++) {
for (var c = 0; c < this.numColumns - 1; c++) {
var k = r * this.numColumns + c;
meshIndices[i++] = k;
meshIndices[i++] = k + 1;
meshIndices[i++] = k + this.numColumns;
meshIndices[i++] = k + 1;
meshIndices[i++] = k + 1 + this.numColumns;
meshIndices[i++] = k + this.numColumns;
}
}
return meshIndices;
};
GeographicMesh.prototype.computeOutlineIndices = function () {
// Walk the mesh boundary and capture those positions for the outline.
var outlineIndices = new Uint16Array(2 * this.numRows + 2 * this.numColumns),
k = 0;
for (var c = 0; c < this.numColumns; c++) {
outlineIndices[k++] = c;
}
for (var r = 1; r < this.numRows; r++) {
outlineIndices[k++] = (r + 1) * this.numColumns - 1;
}
for (c = this.numRows * this.numColumns - 2; c >= (this.numRows - 1) * this.numColumns; c--) {
outlineIndices[k++] = c;
}
for (r = this.numRows - 2; r >= 0; r--) {
outlineIndices[k++] = r * this.numColumns;
}
return outlineIndices;
};
return GeographicMesh;
});