【ANT】构建文件build.xml

运行ant：

ant 使用当前目录下的build.xml运行ant，指定缺省的target;

ant –buildfile mybuild.xml 使用当前目录下的mybuild.xml运行ant，并执行缺省的target；

ant –buildfile mybuild.xml mytarget使用当前目录下mybuild.xml运行ant，并执行名为mytarget的target;

编写build.xml

project

例如：
```
<project name="Cesium" default="combine">
```
属性：

name : 项目名称

default:指定运行的target名称，没有指定时使用缺省的target；

basedir：基准路径，其他的相对路径都是基于这个基准路径的；

description:项目描述信息。
target
```
<target name="combine" depends="build,combineJavaScript" description="Combines all source files into a single stand-alone script." />
```
注意：一个target可以依赖于其他target。例如combine依赖于build target和combineJaveScript target，ant会按照depends中target出现的顺序依次执行，并且每个target只会被执行依次，即使有多个target依赖于他。

target有以下属性：

name：target名称，这个属性是必须的；

depends：依赖目标，非必须

if：当属性设置时才执行该target，非必须；

unless：当属性没有设置时才执行该target，非必须；

description：target的描述信息，非必须；

task

Task分为内置task和自定义task，每个task都是一段可执行的代码。

内置task：

<copy file="${requirejsPath}/require.min.js" tofile="${cesiumViewerOutputDirectory}/require.js" />

自定义task

调用任务：

<glslToJavascript minify="${build.minification}" minifystatefile="${buildDirectory}/minifyShaders.state">

    <glslfiles dir="${shadersDirectory}" includes="**/*.glsl" />

    <existingjsfiles dir="${shadersDirectory}" includes="**/*.js" excludes="*.profile.js" />

</glslToJavascript>

定义任务：

<scriptdef name="glslToJavascript" language="javascript" src="${tasksDirectory}/glslToJavaScript.js" manager="bsf" classpathref="javascriptClassPath" loaderref="javascript.loader">

            <attribute name="minify" />

            <attribute name="minifystatefile" />

            <element name="glslfiles" type="fileset" />

            <element name="existingjsfiles" type="fileset" />

</scriptdef>

这是glslToJavaScript.js源代码：

/*global importClass,project,attributes,elements,java,Packages*/

importClass(Packages.org.mozilla.javascript.tools.shell.Main); /*global Main*/

Main.exec(['-e', '{}']);

var load = Main.global.load;

load(project.getProperty('tasksDirectory') + '/shared.js'); /*global forEachFile,readFileContents,writeFileContents,File,FileReader,FileWriter,FileUtils*/

importClass(java.io.StringReader); /*global StringReader*/

importClass(java.util.HashSet); /*global HashSet*/

importClass(Packages.org.apache.tools.ant.filters.StripJavaComments); /*global StripJavaComments*/

var minify = /^true$/.test(attributes.get('minify'));

var minifyStateFilePath = attributes.get('minifystatefile');

writeFileContents(minifyStateFilePath, minify);

var minifyStateFileLastModified = new File(minifyStateFilePath).lastModified();

// collect all currently existing JS files into a set, later we will remove the ones

// we still are using from the set, then delete any files remaining in the set.

var leftOverJsFiles = new HashSet();

forEachFile('existingjsfiles', function(relativePath, file) {

    "use strict";

    leftOverJsFiles.add(file.getAbsolutePath());

});

var builtinFunctions = [];

var builtinConstants = [];

var builtinStructs = [];

forEachFile('glslfiles', function(relativePath, file) {

    "use strict";

    var glslFile = file;

    var jsFile = new File(file.getParent(), file.getName().replace('.glsl', '.js'));

    // identify built in functions, structs, and constants

    if(glslFile.getPath().indexOf('Builtin' + File.separator + 'Functions') !== -1) {

        builtinFunctions.push(file.getName().replace('.glsl', ''));

    }

    else if(glslFile.getPath().indexOf('Builtin' + File.separator + 'Constants') !== -1) {

        builtinConstants.push(file.getName().replace('.glsl', ''));

    }

    else if(glslFile.getPath().indexOf('Builtin' + File.separator + 'Structs') !== -1) {

        builtinStructs.push(file.getName().replace('.glsl', ''));

    }

    leftOverJsFiles.remove(jsFile.getAbsolutePath());

    if (jsFile.exists() && jsFile.lastModified() > glslFile.lastModified() && jsFile.lastModified() > minifyStateFileLastModified) {

        return;

    }

    var contents = readFileContents(glslFile);

    contents = contents.replace(/\r\n/gm, '\n');

    var copyrightComments = '';

    var extractedCopyrightComments = contents.match(/\/\*\*(?:[^*\/]|\*(?!\/)|\n)*?@license(?:.|\n)*?\*\//gm);

    if (extractedCopyrightComments) {

        copyrightComments = extractedCopyrightComments.join('\n') + '\n';

    }

    if (minify) {

        contents = String(FileUtils.readFully(new StripJavaComments(new StringReader(contents))));

        contents = contents.replace(/\s+$/gm, '').replace(/^\s+/gm, '').replace(/\n+/gm, '\n');

        contents += '\n';

    }

    contents = contents.split('"').join('\\"').replace(/\n/gm, '\\n\\\n');

    contents = copyrightComments + '\

    //This file is automatically rebuilt by the Cesium build process.\n\

    /*global define*/\n\

    define(function() {\n\

    "use strict";\n\

    return "' + contents + '";\n\

});';

    writeFileContents(jsFile.getAbsolutePath(), contents, true);

});

// delete any left over JS files from old shaders

for ( var it = leftOverJsFiles.iterator(); it.hasNext();) {

    new File(it.next())['delete']();

}

var generateBuiltinContents = function(contents, builtins, path){

    "use strict";

    var amdPath = contents.amdPath;

    var amdClassName = contents.amdClassName;

    var builtinLookup = contents.builtinLookup;

    for (var i = 0; i < builtins.length; i++) {

        var builtin = builtins[i];

        amdPath = amdPath + ',\n        \'./' + path + '/' + builtin + '\'';

        amdClassName = amdClassName + ',\n        ' + 'czm_' + builtin;

        builtinLookup = builtinLookup + ',\n        ' + 'czm_' + builtin + ' : ' + 'czm_' + builtin;

    }

    contents.amdPath = amdPath;

    contents.amdClassName = amdClassName;

    contents.builtinLookup = builtinLookup;

};

//generate the JS file for Built-in GLSL Functions, Structs, and Constants

var contents = {amdPath:'', amdClassName:'', builtinLookup:''};

generateBuiltinContents(contents, builtinConstants, 'Constants');

generateBuiltinContents(contents, builtinStructs, 'Structs');

generateBuiltinContents(contents, builtinFunctions, 'Functions');

contents.amdPath = contents.amdPath.replace(',\n', '');

contents.amdClassName = contents.amdClassName.replace(',\n', '');

contents.builtinLookup = contents.builtinLookup.replace(',\n', '');

var fileContents = '\

//This file is automatically rebuilt by the Cesium build process.\n\

/*global define*/\n\

define([\n' +

contents.amdPath +

'\n    ], function(\n' +

contents.amdClassName +

') {\n\

    "use strict";\n\

    return {\n' + contents.builtinLookup + '};\n\

});';

var builtinFile = new File(project.getProperty('shadersDirectory') + '/Builtin', 'CzmBuiltins.js');

writeFileContents(builtinFile.getAbsolutePath(), fileContents, true);

Scriptdef使用脚本语言定义一个ant task，ant scripting languanges支持BSF引擎和JSR_223引擎来定义脚本。

属性：

name : 任务名称，必需；

language ：脚本语言，必须被BSF或者JSR引擎支持，必须；

manager ： BSF或者JSR引擎；

src ：执行任务的脚本路径

uri ： xml 命名空间；

classpath ： script引入的class的classpath路径

classpathref ：使用refid引入classpath；

loaderfef ：加载script的loader，从指定的classpath来构造