[x3d-public] X3D Java SAI. Declarative style

[Don Brutzman]

I read a very interesting book on the flight to Korea.  This cleared up several mysteries for me... highly recommended.

*Functional Programming in Java: Harnessing the Power of Java 8 Lambda Expressions, Venkat Subramaniam, Pragmatic Bookshelf, Dallas Texas, 2014.
   https://pragprog.com/book/vsjava8/functional-programming-in-java

John, here is a new style of coding that mostly eliminates the need for declaring each and every object.

Benefits include more concise, no side effects, no need to keep track of names for object instances, automatically parallelizable by compiler.  Syntax looks a lot like node.js style.

I picked a scene that shows ProtoDeclare, Script, fields, IS/connect and CDATA source code to get a good workout.  The only object member is "scene", everything else is local.

New code block in HelloWorldProgram.java:
=============================================

	/** Test declarative style, prototype fields and scripting */
	private void addMaterialModulatorModulator ()
	{
		ProtoDeclareObject materialModulatorPrototype = new ProtoDeclareObject ("MaterialModulator");
		materialModulatorPrototype
			.setAppinfo("mimic a Material node and modulate fields as an animation effect")
			.setDocumentation("http://x3dgraphics.com/examples/X3dForWebAuthors/Chapter14-Prototypes/MaterialModulatorIndex.html")
			.setProtoInterface(
				new ProtoInterfaceObject()
					.addField(new fieldObject ()
						.setName("enabled")
						.setType(fieldObject.TYPE_SFBOOL)
						.setAccessType( fieldObject.ACCESSTYPE_INPUTOUTPUT)
						.setValue(SFBoolObject.TRUE))
					.addField(new fieldObject (
						"diffuseColor", fieldObject.TYPE_SFCOLOR,fieldObject.ACCESSTYPE_INPUTOUTPUT,
							(SFColorObject.toString(SFColorObject.DEFAULT_VALUE))))
					.addField(new fieldObject (
						"emissiveColor",fieldObject.TYPE_SFCOLOR,fieldObject.ACCESSTYPE_INPUTOUTPUT,
							Integer.toString(0x000080)))
//							SFColorObject.toString(0x000080))) // TODO fix
							// TODO major side effect follows that affects all MaterialObject specularColor values, why?
							// design change needed to make things work?  how to prevent user from provoking it?
//							(new SFColorObject(0.05f, 0.05f, 0.85f)).toString()))
					.addField(new fieldObject (
						"specularColor",fieldObject.TYPE_SFCOLOR,fieldObject.ACCESSTYPE_INPUTOUTPUT,
							(SFColorObject.toString(SFColorObject.BLACK))))
					.addField(new fieldObject (
						"transparency", fieldObject.TYPE_SFFLOAT,fieldObject.ACCESSTYPE_INPUTOUTPUT,
							"0.0"))
					.addField(new fieldObject (
						"shininess",    fieldObject.TYPE_SFFLOAT,fieldObject.ACCESSTYPE_INPUTOUTPUT,
							Float.toString(0.0f)))
					.addField(new fieldObject (
						"ambientIntensity",fieldObject.TYPE_SFFLOAT,fieldObject.ACCESSTYPE_INPUTOUTPUT,
							SFFloatObject.toString(0.0f)))
//						.setChildren((MaterialObject newMaterial = new MaterialObject ("MaterialNode"))))
						// TODO fix syntax or add utility methods
		);
		ProtoBodyObject materialModulatorProtoBody = new ProtoBodyObject();
		materialModulatorPrototype.setProtoBody(materialModulatorProtoBody);
		materialModulatorProtoBody.addChildren(
			new MaterialObject("MaterialNode")
				.setIS(new ISObject()
					.addConnect(new connectObject().setNodeField("diffuseColor"    ).setProtoField("diffuseColor"))
					.addConnect(new connectObject().setNodeField("emissiveColor"   ).setProtoField("emissiveColor"))
					.addConnect(new connectObject().setNodeField("specularColor"   ).setProtoField("specularColor"))
					.addConnect(new connectObject().setNodeField("transparency"    ).setProtoField("transparency"))
					.addConnect(new connectObject().setNodeField("shininess"       ).setProtoField("shininess"))
					.addConnect(new connectObject().setNodeField("ambientIntensity").setProtoField("ambientIntensity"))
			));
		materialModulatorProtoBody.addChildren(
			new CommentsBlock ("Only first node (the node type) is renderable, others are along for the ride"));
		materialModulatorProtoBody.addChildren(
			new ScriptObject ("MaterialModulatorScript")
				.addField(new fieldObject().setName("enabled").setType(fieldObject.TYPE_SFBOOL)
					.setAccessType(fieldObject.ACCESSTYPE_INPUTOUTPUT))
				.addField(new fieldObject().setName("diffuseColor").setType(fieldObject.TYPE_SFCOLOR)
					.setAccessType(fieldObject.ACCESSTYPE_INPUTOUTPUT))
				.addField(new fieldObject().setName("newColor").setType(fieldObject.TYPE_SFCOLOR)
					.setAccessType(fieldObject.ACCESSTYPE_OUTPUTONLY))
				.addField(new fieldObject().setName("clockTrigger").setType(fieldObject.TYPE_SFTIME)
					.setAccessType(fieldObject.ACCESSTYPE_INPUTONLY))
				.setIS(new ISObject()
					.addConnect(new connectObject().setNodeField("enabled"     ).setProtoField("enabled"))
					.addConnect(new connectObject().setNodeField("diffuseColor").setProtoField("diffuseColor")))
				.setSourceCode(new String("ecmascript:\n" +
"function initialize ()\n" +
"{\n" +
"    newColor = diffuseColor; // start with correct color\n" +
"}\n" +
"function set_enabled (newValue)\n" +
"{\n" +
"	enabled = newValue;\n" +
"}\n" +
"function clockTrigger (timeValue)\n" +
"{\n" +
"    if (!enabled) return;\n" +
"    red   = newColor.r;\n" +
"    green = newColor.g;\n" +
"    blue  = newColor.b;\n" +
"    \n" +
"    // note different modulation rates for each color component, % is modulus operator\n" +
"    newColor = new SFColor ((red + 0.02) % 1, (green + 0.03) % 1, (blue + 0.04) % 1);\n" +
"	if (enabled)\n" +
"	{\n" +
"		Browser.print ('diffuseColor=(' + red +',' + green + ',' + blue + ') newColor=' + newColor.toString() + '\\n');\n" +
"	}\n" +
"}")));
		scene.addChildren(materialModulatorPrototype);
	}

=============================================

Pretty darn cool.  Some more work to follow on my part to tighten up need to repeat addChildren calls for every individual child and source text, but this is a big step.

When ready I recommend you shift to declarative style to avoid need to generate individual objects with unique suffixes.

all the best, Don
-- 
Don Brutzman  Naval Postgraduate School, Code USW/Br       brutzman at nps.edu
Watkins 270,  MOVES Institute, Monterey CA 93943-5000 USA   +1.831.656.2149
X3D graphics, virtual worlds, navy robotics http://faculty.nps.edu/brutzman