But isn't Java slow ?

What platforms does GL4Java run on ?

How does GL4Java compare to Java3D ?

Does GL4Java support extensions ? How do I load them ?

Does GL4Java support tesselation ? How do I use it ?

	gl4java.GLUTFunc

Jean-Yves BRUD asked:

> What is the meaning of parameter signature ?
> If my callback method name is myVertexCallBack (for a GLU_TESS_VERTEX
> callback),
> what is the value of the signature parameter ?

public void  gluTessCallback(     long tobj, int which,
			          Object methodClassInstance, 
			          String methodName, 
				  String signature,
				  int voidArrayLen1,
				  int voidArrayLen2,
				  int voidArrayLen3,
				  int voidArrayLen4,
				  int voidArrayLen5
				  );


Example (tessdemo.java line 337):
	glu.gluTessCallback ( tobj, GLU_TESS_VERTEX, gl,
			      "glVertex2fv", "([F)V",
			      2, 0, 0, 0, 0);

The signature "([F)V" is the original java style signature of the
argument-list, your callback method takes (here: glVertex2fv) !

	void glVertex2fv( const GLfloat v[2] ) 

	(...) := within the brackets are function arguments signature part
	[F    := float array
	V     := void - 
                 the signature part after the brackets 
		 means the return value

Read SUN's Java Documentation for Java-Callback methods:
         http://java.sun.com/docs/books/tutorial/native1.1/implementing/method.html

Here you can find the mapping of function arguments to its corresponding
string signature representation !

Jean-Yves BRUD asked:

>
> What is the meaning of the 5 parameters: voidArrayLen1, voidArrayLen2,
> voidArrayLen3,
> voidArrayLen4, voidArrayLen5, and what value do I need to put ?
>

public void  gluTessCallback(     long tobj, int which,
			          Object methodClassInstance, 
			          String methodName, 
				  String signature,
				  int voidArrayLen1,
				  int voidArrayLen2,
				  int voidArrayLen3,
				  int voidArrayLen4,
				  int voidArrayLen5
				  );

The maximum number of arrays within the argumentlist of 
a GLU Callback function for Tesselation is 5 !

So, the arguments voidArrayLen[1-5] refines the expected
size of the arrays, 
which are passed into and from the java callback funtion.

	OpenGL-Machine <-> GL4Java-Callback-Handler <-> Java-Callback-Method

E.g. (tessdemo.java):
         glu.gluTessCallback ( tobj, GLU_TESS_COMBINE, this,
                                "combine_callback", "([D[D[F[F)V",
                                2, 0, 0, 2, 0);

        public void combine_callback( double coords[/*3*/],
                               double vertex_data[/*4xn(=0)*/],
                               float weight[/*4*/], float[/*m(=2)*/] data )
        {
           data[0] = (float) coords[0];
           data[1] = (float) coords[1];
        }

You can see, we do use the arrays "data" and "coords" with a size of 2 !
You are not allowed to use nonsense sizes, because this can hurt your
application with a segementation fault !
(Well the GL4Java Callback functions checks
 the array sizes to OpenGL's maximum, .. but be kind of ..)

The OpenGL machine calls GL4Java's callback function,
which dispatches the call (incl. data) to your java callback function !

How Do I Use Offscreen Rendering with GL4Java ?

How Do I Use Fullscreen with GL4Java ?

How Do I Use Bump Mapping with GL4Java ?

How to use the Installer ?

GL4Java Installation Check-List (for Java2) !

	JAVA_HOME

WIN32 JDK:	C:\jdk1.3.1\jre
WIN32 JRE:	C:\Program Files\JavaSoft\JRE\1.3.1
UNIX  JDK:	/usr/lib/jdk1.3.1/jre

	DIRECTORY SEPERATOR /

JAVA_HOME/lib/ext/gl4java.jar
JAVA_HOME/lib/ext/gl4java-glutfonts.jar
JAVA_HOME/lib/ext/gl4java-glffonts.jar
JAVA_HOME/lib/ext/png.jar

	WINDOWS:
	========
	JAVA_HOME/bin/GL4JavaGljMSJDirect.dll
	JAVA_HOME/bin/GL4JavaJauGljJNI.dll
	JAVA_HOME/bin/GL4JavaJauGljJNI12.dll
	JAVA_HOME/bin/GL4JavaJauGljJNI13.dll
	JAVA_HOME/bin/GL4JavaJauGljJNI14.dll

	UNIX X86:
	========
	JAVA_HOME/lib/i386/GL4JavaGljMSJDirect.so
	JAVA_HOME/lib/i386/GL4JavaJauGljJNI.so
	JAVA_HOME/lib/i386/GL4JavaJauGljJNI12.so
	JAVA_HOME/lib/i386/GL4JavaJauGljJNI13.so
	JAVA_HOME/lib/i386/GL4JavaJauGljJNI14.so

	UNIX PPC:
	========
	JAVA_HOME/lib/ppc/GL4JavaGljMSJDirect.so
	JAVA_HOME/lib/ppc/GL4JavaJauGljJNI.so
	JAVA_HOME/lib/ppc/GL4JavaJauGljJNI12.so
	JAVA_HOME/lib/ppc/GL4JavaJauGljJNI13.so
	JAVA_HOME/lib/ppc/GL4JavaJauGljJNI14.so

	JAVA_HOME/bin

libjava.so (unix)

java.dll (win32)

	WINDOWS VARIANTS:
	=================
	C:/WIN98/SYSTEM 
	C:/WIN95/SYSTEM 
	C:/WINNT/SYSTEM32 

	UNIX FLAVORS
	============
	/usr/lib

	JAVA_HOME/lib/security/java.policy

grant codeBase "file:${java.home}/lib/ext/*" {
	permission java.security.AllPermission;
};

Please Help - It won't run !

JAVA_HOME/lib/ext/gl4java.jar

What should I read before you reply with RTFM ? Whom should I ask ?
(RTFM = Unix abbreviation for `Read The Fucking Manual')

How-To Complain About Non Working GL4Java ?