cesium
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Cesium is a JavaScript library for creating 3D globes and 2D maps in a web browser without a plugin.
413 lines (361 loc) • 15.6 kB
JavaScript
/*global define*/
define([
'./BoundingSphere',
'./Cartesian2',
'./Cartesian3',
'./ComponentDatatype',
'./CylinderGeometryLibrary',
'./defaultValue',
'./defined',
'./DeveloperError',
'./Geometry',
'./GeometryAttribute',
'./GeometryAttributes',
'./IndexDatatype',
'./Math',
'./PrimitiveType',
'./VertexFormat'
], function(
BoundingSphere,
Cartesian2,
Cartesian3,
ComponentDatatype,
CylinderGeometryLibrary,
defaultValue,
defined,
DeveloperError,
Geometry,
GeometryAttribute,
GeometryAttributes,
IndexDatatype,
CesiumMath,
PrimitiveType,
VertexFormat) {
'use strict';
var radiusScratch = new Cartesian2();
var normalScratch = new Cartesian3();
var binormalScratch = new Cartesian3();
var tangentScratch = new Cartesian3();
var positionScratch = new Cartesian3();
/**
* A description of a cylinder.
*
* @alias CylinderGeometry
* @constructor
*
* @param {Object} options Object with the following properties:
* @param {Number} options.length The length of the cylinder.
* @param {Number} options.topRadius The radius of the top of the cylinder.
* @param {Number} options.bottomRadius The radius of the bottom of the cylinder.
* @param {Number} [options.slices=128] The number of edges around perimeter of the cylinder.
* @param {VertexFormat} [options.vertexFormat=VertexFormat.DEFAULT] The vertex attributes to be computed.
*
* @exception {DeveloperError} options.length must be greater than 0.
* @exception {DeveloperError} options.topRadius must be greater than 0.
* @exception {DeveloperError} options.bottomRadius must be greater than 0.
* @exception {DeveloperError} bottomRadius and topRadius cannot both equal 0.
* @exception {DeveloperError} options.slices must be greater that 3.
*
* @see CylinderGeometry.createGeometry
*
* @example
* // create cylinder geometry
* var cylinder = new Cesium.CylinderGeometry({
* length: 200000,
* topRadius: 80000,
* bottomRadius: 200000,
* });
* var geometry = Cesium.CylinderGeometry.createGeometry(cylinder);
*/
function CylinderGeometry(options) {
options = defaultValue(options, defaultValue.EMPTY_OBJECT);
var length = options.length;
var topRadius = options.topRadius;
var bottomRadius = options.bottomRadius;
var vertexFormat = defaultValue(options.vertexFormat, VertexFormat.DEFAULT);
var slices = defaultValue(options.slices, 128);
//>>includeStart('debug', pragmas.debug);
if (!defined(length)) {
throw new DeveloperError('options.length must be defined.');
}
if (!defined(topRadius)) {
throw new DeveloperError('options.topRadius must be defined.');
}
if (!defined(bottomRadius)) {
throw new DeveloperError('options.bottomRadius must must be defined.');
}
if (slices < 3) {
throw new DeveloperError('options.slices must be greater that 3.');
}
//>>includeEnd('debug');
this._length = length;
this._topRadius = topRadius;
this._bottomRadius = bottomRadius;
this._vertexFormat = VertexFormat.clone(vertexFormat);
this._slices = slices;
this._workerName = 'createCylinderGeometry';
}
/**
* The number of elements used to pack the object into an array.
* @type {Number}
*/
CylinderGeometry.packedLength = VertexFormat.packedLength + 4;
/**
* Stores the provided instance into the provided array.
*
* @param {CylinderGeometry} 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.
*/
CylinderGeometry.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);
VertexFormat.pack(value._vertexFormat, array, startingIndex);
startingIndex += VertexFormat.packedLength;
array[startingIndex++] = value._length;
array[startingIndex++] = value._topRadius;
array[startingIndex++] = value._bottomRadius;
array[startingIndex] = value._slices;
};
var scratchVertexFormat = new VertexFormat();
var scratchOptions = {
vertexFormat : scratchVertexFormat,
length : undefined,
topRadius : undefined,
bottomRadius : undefined,
slices : 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 {CylinderGeometry} [result] The object into which to store the result.
* @returns {CylinderGeometry} The modified result parameter or a new CylinderGeometry instance if one was not provided.
*/
CylinderGeometry.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 vertexFormat = VertexFormat.unpack(array, startingIndex, scratchVertexFormat);
startingIndex += VertexFormat.packedLength;
var length = array[startingIndex++];
var topRadius = array[startingIndex++];
var bottomRadius = array[startingIndex++];
var slices = array[startingIndex];
if (!defined(result)) {
scratchOptions.length = length;
scratchOptions.topRadius = topRadius;
scratchOptions.bottomRadius = bottomRadius;
scratchOptions.slices = slices;
return new CylinderGeometry(scratchOptions);
}
result._vertexFormat = VertexFormat.clone(vertexFormat, result._vertexFormat);
result._length = length;
result._topRadius = topRadius;
result._bottomRadius = bottomRadius;
result._slices = slices;
return result;
};
/**
* Computes the geometric representation of a cylinder, including its vertices, indices, and a bounding sphere.
*
* @param {CylinderGeometry} cylinderGeometry A description of the cylinder.
* @returns {Geometry|undefined} The computed vertices and indices.
*/
CylinderGeometry.createGeometry = function(cylinderGeometry) {
var length = cylinderGeometry._length;
var topRadius = cylinderGeometry._topRadius;
var bottomRadius = cylinderGeometry._bottomRadius;
var vertexFormat = cylinderGeometry._vertexFormat;
var slices = cylinderGeometry._slices;
if ((length <= 0) || (topRadius < 0) || (bottomRadius < 0) || ((topRadius === 0) && (bottomRadius === 0))) {
return;
}
var twoSlices = slices + slices;
var threeSlices = slices + twoSlices;
var numVertices = twoSlices + twoSlices;
var positions = CylinderGeometryLibrary.computePositions(length, topRadius, bottomRadius, slices, true);
var st = (vertexFormat.st) ? new Float32Array(numVertices * 2) : undefined;
var normals = (vertexFormat.normal) ? new Float32Array(numVertices * 3) : undefined;
var tangents = (vertexFormat.tangent) ? new Float32Array(numVertices * 3) : undefined;
var binormals = (vertexFormat.binormal) ? new Float32Array(numVertices * 3) : undefined;
var i;
var computeNormal = (vertexFormat.normal || vertexFormat.tangent || vertexFormat.binormal);
if (computeNormal) {
var computeTangent = (vertexFormat.tangent || vertexFormat.binormal);
var normalIndex = 0;
var tangentIndex = 0;
var binormalIndex = 0;
var normal = normalScratch;
normal.z = 0;
var tangent = tangentScratch;
var binormal = binormalScratch;
for (i = 0; i < slices; i++) {
var angle = i / slices * CesiumMath.TWO_PI;
var x = Math.cos(angle);
var y = Math.sin(angle);
if (computeNormal) {
normal.x = x;
normal.y = y;
if (computeTangent) {
tangent = Cartesian3.normalize(Cartesian3.cross(Cartesian3.UNIT_Z, normal, tangent), tangent);
}
if (vertexFormat.normal) {
normals[normalIndex++] = x;
normals[normalIndex++] = y;
normals[normalIndex++] = 0;
normals[normalIndex++] = x;
normals[normalIndex++] = y;
normals[normalIndex++] = 0;
}
if (vertexFormat.tangent) {
tangents[tangentIndex++] = tangent.x;
tangents[tangentIndex++] = tangent.y;
tangents[tangentIndex++] = tangent.z;
tangents[tangentIndex++] = tangent.x;
tangents[tangentIndex++] = tangent.y;
tangents[tangentIndex++] = tangent.z;
}
if (vertexFormat.binormal) {
binormal = Cartesian3.normalize(Cartesian3.cross(normal, tangent, binormal), binormal);
binormals[binormalIndex++] = binormal.x;
binormals[binormalIndex++] = binormal.y;
binormals[binormalIndex++] = binormal.z;
binormals[binormalIndex++] = binormal.x;
binormals[binormalIndex++] = binormal.y;
binormals[binormalIndex++] = binormal.z;
}
}
}
for (i = 0; i < slices; i++) {
if (vertexFormat.normal) {
normals[normalIndex++] = 0;
normals[normalIndex++] = 0;
normals[normalIndex++] = -1;
}
if (vertexFormat.tangent) {
tangents[tangentIndex++] = 1;
tangents[tangentIndex++] = 0;
tangents[tangentIndex++] = 0;
}
if (vertexFormat.binormal) {
binormals[binormalIndex++] = 0;
binormals[binormalIndex++] = -1;
binormals[binormalIndex++] = 0;
}
}
for (i = 0; i < slices; i++) {
if (vertexFormat.normal) {
normals[normalIndex++] = 0;
normals[normalIndex++] = 0;
normals[normalIndex++] = 1;
}
if (vertexFormat.tangent) {
tangents[tangentIndex++] = 1;
tangents[tangentIndex++] = 0;
tangents[tangentIndex++] = 0;
}
if (vertexFormat.binormal) {
binormals[binormalIndex++] = 0;
binormals[binormalIndex++] = 1;
binormals[binormalIndex++] = 0;
}
}
}
var numIndices = 12 * slices - 12;
var indices = IndexDatatype.createTypedArray(numVertices, numIndices);
var index = 0;
var j = 0;
for (i = 0; i < slices - 1; i++) {
indices[index++] = j;
indices[index++] = j + 2;
indices[index++] = j + 3;
indices[index++] = j;
indices[index++] = j + 3;
indices[index++] = j + 1;
j += 2;
}
indices[index++] = twoSlices - 2;
indices[index++] = 0;
indices[index++] = 1;
indices[index++] = twoSlices - 2;
indices[index++] = 1;
indices[index++] = twoSlices - 1;
for (i = 1; i < slices - 1; i++) {
indices[index++] = twoSlices + i + 1;
indices[index++] = twoSlices + i;
indices[index++] = twoSlices;
}
for (i = 1; i < slices - 1; i++) {
indices[index++] = threeSlices;
indices[index++] = threeSlices + i;
indices[index++] = threeSlices + i + 1;
}
var textureCoordIndex = 0;
if (vertexFormat.st) {
var rad = Math.max(topRadius, bottomRadius);
for (i = 0; i < numVertices; i++) {
var position = Cartesian3.fromArray(positions, i * 3, positionScratch);
st[textureCoordIndex++] = (position.x + rad) / (2.0 * rad);
st[textureCoordIndex++] = (position.y + rad) / (2.0 * rad);
}
}
var attributes = new GeometryAttributes();
if (vertexFormat.position) {
attributes.position = new GeometryAttribute({
componentDatatype: ComponentDatatype.DOUBLE,
componentsPerAttribute: 3,
values: positions
});
}
if (vertexFormat.normal) {
attributes.normal = new GeometryAttribute({
componentDatatype : ComponentDatatype.FLOAT,
componentsPerAttribute : 3,
values : normals
});
}
if (vertexFormat.tangent) {
attributes.tangent = new GeometryAttribute({
componentDatatype : ComponentDatatype.FLOAT,
componentsPerAttribute : 3,
values : tangents
});
}
if (vertexFormat.binormal) {
attributes.binormal = new GeometryAttribute({
componentDatatype : ComponentDatatype.FLOAT,
componentsPerAttribute : 3,
values : binormals
});
}
if (vertexFormat.st) {
attributes.st = new GeometryAttribute({
componentDatatype : ComponentDatatype.FLOAT,
componentsPerAttribute : 2,
values : st
});
}
radiusScratch.x = length * 0.5;
radiusScratch.y = Math.max(bottomRadius, topRadius);
var boundingSphere = new BoundingSphere(Cartesian3.ZERO, Cartesian2.magnitude(radiusScratch));
return new Geometry({
attributes : attributes,
indices : indices,
primitiveType : PrimitiveType.TRIANGLES,
boundingSphere : boundingSphere
});
};
return CylinderGeometry;
});