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refactor code, added comments and license headers

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strikerM 2017-01-12 10:38:47 +02:00
parent 5b77742dc9
commit f79abe5f16
3 changed files with 143 additions and 68 deletions
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13
examples/StarField.js
View File

@ -2,9 +2,6 @@
* Copyright (C) 2014 United States Government as represented by the Administrator of the
* National Aeronautics and Space Administration. All Rights Reserved.
*/
/**
* @version $Id: BasicExample.js 3320 2015-07-15 20:53:05Z dcollins $
*/
requirejs([
'../src/WorldWind',
@ -25,16 +22,14 @@ requirejs([
var starFieldLayer = new WorldWind.StarFieldLayer();
var atmosphereLayer = new WorldWind.AtmosphereLayer();
wwd.addLayer(BMNGLayer);
wwd.addLayer(atmosphereLayer);
wwd.addLayer(starFieldLayer);
atmosphereLayer.lightLocation = sunCalculator(new Date());
var layerManger = new LayerManager(wwd);
wwd.redraw();
wwd._redrawCallbacks.push(runSunSimulation1);
wwd._redrawCallbacks.push(runSunSimulation);
var sunSimulationCheckBox = document.getElementById('sun-simulation');
var doRunSimulation = false;
@ -48,17 +43,17 @@ requirejs([
if (!doRunSimulation) {
var date = new Date();
atmosphereLayer.lightLocation = sunCalculator(date);
starFieldLayer.date = date;
starFieldLayer.time = date;
}
wwd.redraw();
}
function runSunSimulation1(wwd, stage) {
function runSunSimulation(wwd, stage) {
if (stage === WorldWind.AFTER_REDRAW && doRunSimulation) {
timeStamp += (factor * 60 * 1000);
var date = new Date(timeStamp);
atmosphereLayer.lightLocation = sunCalculator(date);
starFieldLayer.date = date;
starFieldLayer.time = date;
wwd.redraw();
}
}

136
src/layer/StarFieldLayer.js
View File

@ -1,7 +1,10 @@
/**
* Created by Florin on 12/22/2016.
/*
* Copyright (C) 2014 United States Government as represented by the Administrator of the
* National Aeronautics and Space Administration. All Rights Reserved.
*/
/**
* @exports StarFieldLayer
*/
define([
'./Layer',
'../geom/Matrix',
@ -12,47 +15,100 @@ define([
StarFieldProgram) {
'use strict';
var StarFieldLayer = function () {
/**
* Constructs a layer showing bright stars visible from the Earth with the naked eye.
* @alias StarFieldLayer
* @constructor
* @classdesc Provides a layer showing bright stars visible from the Earth with the naked eye.
* @param {URL} starDataSource optional url for the stars data.
* @augments Layer
*/
var StarFieldLayer = function (starDataSource) {
Layer.call(this, 'StarField');
// The StarField Layer is not pickable.
this.pickEnabled = false;
this._date = new Date();
this._positions = [];
//Documented in defineProperties below.
this._starDataSource = starDataSource ||
WorldWind.configuration.baseUrl + 'examples/data/stars.json';
//Internal use only.
//The MVP matrix of this layer.
this._matrix = Matrix.fromIdentity();
//Internal use only.
//gpu cache key for this layer vbo.
this._positionsVboCacheKey = null;
//Internal use only.
this._numStars = 0;
//Internal use only.
this._starData = null;
//Internal use only.
//A flag to indicate the star data is currently being retrieved.
this._loadStarted = false;
};
StarFieldLayer.prototype = Object.create(Layer.prototype);
Object.defineProperties(StarFieldLayer.prototype, {
date: {
/**
* Url for the stars data.
* @memberof StarFieldLayer.prototype
* @type {URL}
*/
starDataSource: {
get: function () {
return this._date;
return this._starDataSource;
},
set: function (value) {
this._date = value;
this._starDataSource = value;
this.invalidateStarData();
}
}
});
// Documented in superclass.
StarFieldLayer.prototype.doRender = function (dc) {
if (dc.globe.is2D()) {
return;
}
if (!this._starData) {
this.fetchStarData();
return;
}
if (!this._positions.length) {
this.createGeometry(dc);
this.beginRendering(dc);
try {
this.doDraw(dc);
}
finally {
this.endRendering(dc);
}
};
// Internal. Intentionally not documented.
StarFieldLayer.prototype.beginRendering = function (dc) {
dc.findAndBindProgram(StarFieldProgram);
};
// Internal. Intentionally not documented.
StarFieldLayer.prototype.doDraw = function (dc) {
var gl = dc.currentGlContext;
this.loadUniforms(dc);
this.loadAttributes(dc);
gl.depthMask(false);
gl.drawArrays(gl.POINTS, 0, this._numStars);
};
// Internal. Intentionally not documented.
StarFieldLayer.prototype.loadUniforms = function (dc) {
var gl = dc.currentGlContext;
var program = dc.currentProgram;
var gpuResourceCache = dc.gpuResourceCache;
//multiplyByScale is necessary until the new camera implementation with the infinite projection matrix
var eyePoint = dc.navigatorState.eyePoint;
@ -62,21 +118,29 @@ define([
this._matrix.multiplyByScale(altitude, altitude, altitude);
program.loadModelviewProjection(gl, this._matrix);
var JD = this.julianDate(this._date);
var JD = this.julianDate(this.time);
//this subtraction does not work properly on the GPU, it must be done on the CPU
//possibly due to precision loss
//number of days (positive or negative) since Greenwich noon, Terrestrial Time, on 1 January 2000 (J2000.0)
program.loadJD(gl, JD - 2451545.0);
program.loadNumDays(gl, JD - 2451545.0);
};
// Internal. Intentionally not documented.
StarFieldLayer.prototype.loadAttributes = function (dc) {
var gl = dc.currentGlContext;
var gpuResourceCache = dc.gpuResourceCache;
if (!this._positionsVboCacheKey) {
this._positionsVboCacheKey = dc.gpuResourceCache.generateCacheKey();
this._positionsVboCacheKey = gpuResourceCache.generateCacheKey();
}
var vboId = gpuResourceCache.resourceForKey(this._positionsVboCacheKey);
if (!vboId) {
vboId = gl.createBuffer();
gpuResourceCache.putResource(this._positionsVboCacheKey, vboId, this._positions.length * 4);
var positions = this.createGeometry();
gpuResourceCache.putResource(this._positionsVboCacheKey, vboId, positions.length * 4);
gl.bindBuffer(gl.ARRAY_BUFFER, vboId);
gl.bufferData(gl.ARRAY_BUFFER, new Float32Array(this._positions), gl.STATIC_DRAW);
gl.bufferData(gl.ARRAY_BUFFER, new Float32Array(positions), gl.STATIC_DRAW);
this._numStars = Math.floor(positions.length / 4);
}
else {
gl.bindBuffer(gl.ARRAY_BUFFER, vboId);
@ -85,14 +149,16 @@ define([
gl.enableVertexAttribArray(0);
gl.vertexAttribPointer(0, 4, gl.FLOAT, false, 0, 0);
gl.depthMask(false);
gl.drawArrays(gl.POINTS, 0, Math.floor(this._positions.length / 4));
gl.depthMask(true);
};
// Internal. Intentionally not documented.
StarFieldLayer.prototype.endRendering = function (dc) {
var gl = dc.currentGlContext;
gl.depthMask(true);
gl.disableVertexAttribArray(0);
};
// Internal. Intentionally not documented.
StarFieldLayer.prototype.fetchStarData = function () {
if (this._loadStarted) {
return;
@ -124,26 +190,30 @@ define([
self._loadStarted = false;
};
xhr.open('GET', './data/stars.json', true);
xhr.open('GET', this._starDataSource, true);
xhr.send();
};
// Internal. Intentionally not documented.
StarFieldLayer.prototype.createGeometry = function () {
var data = this._starData.data;
var positions = [];
for (var i = 0, len = data.length; i < len; i++) {
var starInfo = data[i];
var dec = starInfo[2]; //for latitude
var ra = starInfo[1]; //for longitude
var mag = starInfo[3];
var pSize = mag < 4 ? 2 : 1;
this._positions.push(dec, ra, pSize, mag);
var declination = starInfo[2]; //for latitude
var rightAscension = starInfo[1]; //for longitude
var magnitude = starInfo[3];
var pointSize = magnitude < 4 ? 2 : 1;
positions.push(declination, rightAscension, pointSize, magnitude);
}
return positions;
};
// Internal. Intentionally not documented.
StarFieldLayer.prototype.julianDate = function julianDate(date) {
//http://quasar.as.utexas.edu/BillInfo/JulianDatesG.html
//date = date || new Date();
date = date || new Date();
var year = date.getUTCFullYear();
var month = date.getUTCMonth() + 1;
var day = date.getUTCDate();
@ -166,6 +236,12 @@ define([
};
// Internal. Intentionally not documented.
StarFieldLayer.prototype.invalidateStarData = function (){
this._starData = null;
this._positionsVboCacheKey = null;
};
return StarFieldLayer;
});

62
src/shaders/StarFieldProgram.js
View File

@ -3,17 +3,14 @@
* National Aeronautics and Space Administration. All Rights Reserved.
*/
/**
* @exports BasicProgram
* @version $Id: BasicProgram.js 3327 2015-07-21 19:03:39Z dcollins $
* @exports StarFieldProgram
*/
define([
'../error/ArgumentError',
'../util/Color',
'../shaders/GpuProgram',
'../util/Logger'
],
function (ArgumentError,
Color,
GpuProgram,
Logger) {
"use strict";
@ -22,48 +19,39 @@ define([
* Constructs a new program.
* Initializes, compiles and links this GLSL program with the source code for its vertex and fragment shaders.
* <p>
* This method creates WebGL shaders for the program's shader sources and attaches them to a new GLSL program. This
* method then compiles the shaders and then links the program if compilation is successful. Use the bind method to make the
* program current during rendering.
* This method creates WebGL shaders for the program's shader sources and attaches them to a new GLSL program.
* This method then compiles the shaders and then links the program if compilation is successful.
* Use the bind method to make the program current during rendering.
*
* @alias BasicProgram
* @alias StarFieldProgram
* @constructor
* @augments GpuProgram
* @classdesc BasicProgram is a GLSL program that draws geometry in a solid color.
* @classdesc StarFieldProgram is a GLSL program that draws points representing stars.
* @param {WebGLRenderingContext} gl The current WebGL context.
* @throws {ArgumentError} If the shaders cannot be compiled, or linking of
* the compiled shaders into a program fails.
* @throws {ArgumentError} If the shaders cannot be compiled, or linking of the compiled shaders into a program
* fails.
*/
var StarFieldProgram = function (gl) {
var vertexShaderSource =
'attribute vec4 vertexPoint;\n' +
'uniform mat4 mvpMatrix;\n' +
'uniform float JD;\n' +
'uniform float numDays;\n' +
'varying float mag;\n' +
'const float altitude = 1.0;\n' + //67310000.0
'float normalizeAngle(float angle) {\n' +
' float angleDivisions = angle / 360.0;\n' +
' return 360.0 * (angleDivisions - floor(angleDivisions));\n' +
'}\n' +
'float normalizedDegreesLongitude(float angle) {\n' +
' float na = angle + 179.0;\n' +
' return mod((mod(na, 360.0) + 360.0), 360.0) - 179.0;\n' +
'}\n' +
'vec3 computePosition(float dec, float ra) {\n' +
//' float n = JD - 2451545.0;\n' +
' float GMST = normalizeAngle(280.46061837 + 360.98564736629 * JD);\n' +
' float GMST = normalizeAngle(280.46061837 + 360.98564736629 * numDays);\n' +
' float lon = 180.0 - normalizeAngle(GMST - ra);\n' +
//' lon = normalizedDegreesLongitude(lon);\n' +
' float latRad = radians(dec);\n' +
' float lonRad = radians(lon);\n' +
' float radCosLat = altitude * cos(latRad);\n' +
' return vec3(radCosLat * sin(lonRad), altitude * sin(latRad), radCosLat * cos(lonRad));\n' +
' float radCosLat = cos(latRad);\n' +
' return vec3(radCosLat * sin(lonRad), sin(latRad), radCosLat * cos(lonRad));\n' +
'}\n' +
'void main() {\n' +
@ -83,11 +71,10 @@ define([
'void main() {\n' +
' gl_FragColor = mix(white, grey, mag);\n' + //doesn't appear to be correct
//' gl_FragColor = white;\n' +
'}';
// Call to the superclass, which performs shader program compiling and linking.
GpuProgram.call(this, gl, vertexShaderSource, fragmentShaderSource, ['vertexPoint']);
GpuProgram.call(this, gl, vertexShaderSource, fragmentShaderSource, ["vertexPoint"]);
/**
* The WebGL location for this program's 'vertexPoint' attribute.
@ -103,7 +90,12 @@ define([
*/
this.mvpMatrixLocation = this.uniformLocation(gl, "mvpMatrix");
this.JDLocation = this.uniformLocation(gl, "JD");
/**
* The WebGL location for this program's 'numDays' uniform.
* @type {WebGLUniformLocation}
* @readonly
*/
this.numDaysLocation = this.uniformLocation(gl, "numDays");
};
/**
@ -132,8 +124,20 @@ define([
this.loadUniformMatrix(gl, matrix, this.mvpMatrixLocation);
};
StarFieldProgram.prototype.loadJD = function(gl, JD){
gl.uniform1f(this.JDLocation, JD);
/**
* Loads the specified number as the value of this program's 'numDays' uniform variable.
*
* @param {WebGLRenderingContext} gl The current WebGL context.
* @param {Number} numDays The number of days (positive or negative) since Greenwich noon, Terrestrial Time,
* on 1 January 2000 (J2000.0)
* @throws {ArgumentError} If the specified number is null or undefined.
*/
StarFieldProgram.prototype.loadNumDays = function (gl, numDays) {
if (!numDays) {
throw new ArgumentError(
Logger.logMessage(Logger.LEVEL_SEVERE, "StarFieldProgram", "loadNumDays", "missingNumDays"));
}
gl.uniform1f(this.numDaysLocation, numDays);
};
return StarFieldProgram;