path: root/gl4java/GLContext.java.skel

/**
 * @(#) GLContext.java
 */


package gl4java;

import gl4java.jau.awt.WinHandleAccess;

import java.awt.*;
import java.applet.Applet;
import java.awt.event.*;
import java.lang.reflect.*;
import java.security.*;

/**
 * The base manager class for the OpenGL language mapping for Java !
 *
 * <p>
 * If you are interessting in further Documentation and/or
 * the history of GL4Java follow the following link.
 * 
 * <pre>
        <a href="../GL4Java.html">The GL4Java Documentation</a>
 * </pre>
 * <p>
 *
 * All native libraries and GLFunc* and GLUFunc* implementations
 * can/should be loaded right here !
 *
 * <pre>
 	<a href="GLContext.html#doLoadNativeLibraries(java.lang.String, java.lang.String, java.lang.String)">doLoadNativeLibraries</a>
 	<a href="GLContext.html#createGLFunc(java.lang.String)">createGLFunc</a>
 	<a href="GLContext.html#createGLUFunc(java.lang.String)">createGLUFunc</a>
        <p>
        To check the library versions, you can start the 
 	<a href="GLContext.html#main(java.lang.String[])">main</a>
        function with <code>java gl4java.GLContext</code>
 * </pre>
 *
 * <p>
 *
 * This class creates a GLContext in the constructor which fits to the native Window 
 * of the given Component !
 *
 * <pre>
   	<a href="GLContext.html#GLContext(java.awt.Component, gl4java.GLFunc, gl4java.GLUFunc>
 * </pre>
 *
 * <p>
 *
 * If you want to port any OpenGL program to GL4Java,
 * you can use 'glc2glj'. This easy kornshell-sed script converts
 * many types and Math function calls ;-). E.g.: All C double constant literals
 * will be changed to floats (0.0 -> 0.0f) and all sin, cos, .. functions
 * will get the '(float)Math.' prefix !
 *
 * <pre>
	<a href="../../../demos/glc2glj">glc2glj - A simple c to java converter for C- and GL-types</a>
 * </pre>
 * <p>
 *
 * The native libraries are plattform depended. 
 *
 * <pre>
	  The default native library's are:
	  <p>
		GL4JavaJauGljJNI    (jdk ==1.1), 
		GL4JavaJauGljJNI12  (jdk ==1.2),
		GL4JavaJauGljJNI13  (jdk ==1.3)
		GL4JavaJauGljJNI14  (jdk >=1.4)
	  <p>
	  To check wich version and vendors are currently used,
	  just call while a GLContext is created :
	  <p>
	  <a href="GLContext.html#gljShowVersions()">gljShowVersions</a>
	  <p>
	  Or just run at the command line:
	  <p>
	  	java gl4java.GLContext -info
	  <p>
 * </pre>
 *
 * Make sure that this library is installed in your library path.
 * The library path is for Unices one path of the environment 
 * variable �LD_LIBRARY_PATH� and for Windows 32 
 * �c:/winnt/system32� (WinNT) or 'c:/windows/system' (Windows 95) .
 * Or it should be installed in the 'jre/bin' or 
 * 'Netscape/communicator/Program/java/bin'  path !
 *
 * <p>
 *
 * To have a convinient usage, e.g. automatic resizing, GLContext
 * and painting/gl-rendering, some classes in the package gl4java.awt
 * may help you.
 * 
 * <pre>
          E.g.: <a href="awt/GLCanvas.html">gl4java.awt.GLCanvas</a> 
	  <p>
	  <a href="awt/GLCanvas.html#init()">init</a> to create the java-stuff and GL-inits 
	  <a href="awt/GLCanvas.html#display()">display</a> to render one frame, called by paint
	  <a href="awt/GLCanvas.html#reshape(int, int)">reshape</a> to reshape (window resize)
          <p>
          Or look for animation at 
	  <a href="awt/GLAnimCanvas.html">gl4java.awt.GLAnimCanvas</a> !
 * </pre>
 *
 * <p>
 *
 * IF you remove/release a The component which is binded to this GLContext,
 * you have to release the GLContext also - while calling:
 *
 * <pre>
 	<a href="GLContext.html#gljDestroy()">gljDestroy</a>
 * </pre>
 *
 * before releasing/dispose it�s Window !
 * 
 * <p>
 *
 * We also define our own OpenGL extension. This extension functions
 * start with the prefix glj like you can see here:
 *
 * <pre>
        THIS FUNCTIONS ARE FOR USERS PURPOSES:
	======================================

 	<a href="GLContext.html#doLoadNativeLibraries(java.lang.String, java.lang.String, java.lang.String)">doLoadNativeLibraries</a>
 	<a href="GLContext.html#createGLFunc(java.lang.String)">createGLFunc</a>
 	<a href="GLContext.html#createGLUFunc(java.lang.String)">createGLUFunc</a>
 	<a href="GLContext.html#gljIsInit()">gljIsInit</a>
 	<a href="GLContext.html#gljMakeCurrent()">gljMakeCurrent</a>
 	<a href="GLContext.html#gljSwap()">gljSwap</a>
 	<a href="GLContext.html#gljFree()">gljFree</a>
 	<a href="GLContext.html#gljDestroy()">gljDestroy</a>
 	<a href="GLContext.html#gljGetNativeLibVersion()">gljGetNativeLibVersion</a>
 	<a href="GLContext.html#gljGetClassVersion()">gljGetClassVersion</a>
	<a href="GLContext.html#gljShowVersions()">gljShowVersions</a>
 	<a href="GLContext.html#gljCheckGL()">gljCheckGL</a>
 	<a href="GLContext.html#gljCheckGLTypes()">gljCheckGLTypes</a>
 	<a href="GLContext.html#gljResize(int, int)">gljResize</a>

 * </pre>
 * <p>
 *
 * You can see our example demo sources:
 * <pre>
	<a href="../../../demos/olympicCvs.java">olympicCvs.java as java source</a>
	<a href="../../../demos/glLogoCvs.java">glLogoCvs.java as java source</a>
	<a href="../../../demos/glDemosCvs.java">glDemosCvs.java as java source</a>
 * </pre>
 * <p>
 *
 * If you are interessting in further Documentation, downloading the latest
 * version,  and/or the history of GL4Java click on the following link.
 * 
 * <pre>
	<a href="http://www.jausoft.com/gl4java.html">The GL4Java Homepage</a>
 * </pre>
 * <p>
 *
 * @version 	2.00, 21. April 1999
 * @author      Sven Goethel
 * 
 */
public class GLContext extends Object 
	implements Runnable
{
    protected boolean isInitialized = false;

   /**
    * Flag is the native library is loaded.
    * The native library is loaded at startup.
    * If we failed loading the lib., 
    * gljMakeCurrent and gljIsInit will return false.
    *
    * @see gl4java.GLContext#gljIsInit
    */
    protected static boolean libsLoaded 	        = false;

    /**
     * The default extra native library for Windows 95/NT && MS-JVM
     *
     */
    public final static String defGljMSWinLib   = "GL4JavaGljMSJDirect" ;

    /**
     * The default GLContext/GLFunc/GLUFunc native library for all 
     *
     */
    public final static String defGljLib   = "GL4JavaJauGljJNI" ;

    /**
     * The default GLFunc implementation 
     *
     */
    public static final String defGLFuncClass 	   = "GLFuncJauJNI" ;
    public static final String defGLFunc14Class	   = "GLFunc14JauJNI" ;

    /**
     * The default GLUFunc implementation 
     *
     */
    public static final String defGLUFuncClass = "GLUFuncJauJNI" ;
    public static final String defGLUFunc14Class = "GLUFunc14JauJNI" ;

    /**
     * The default native GL library ... for X11
     */
    public final static String defNativeGLLibX11 = "libGL.so";

    /**
     * The default native GL library ... for MacOS9
     */
    public final static String defNativeGLLibMacOS9 = "\\pOpenGLLibrary";

    /**
     * The default native GL library ... for MacOSX
     */
    public final static String defNativeGLLibMacOSX = "libGL.so";

    /**
     * The default native GL library ... for Win32
     */
    public final static String defNativeGLLibWin32 = "OPENGL32.DLL";


    /**
     * The default native GLU library ... for X11
     */
    public final static String defNativeGLULibX11 = "libGLU.so";

    /**
     * The default native GLU library ... for MacOS9
     */
    public final static String defNativeGLULibMacOS9 = "\\pOpenGLULibrary";

    /**
     * The default native GLU library ... for MacOSX
     */
    public final static String defNativeGLULibMacOSX = "libGLU.so";

    /**
     * The default native GLU library ... for Win32
     */
    public final static String defNativeGLULibWin32 = "GLU32.DLL";

   /**
    * the version of this java-class
    *
    * <Major>.<Minor>.<BugFix>.<Release>
    *
    * Each <Value> is dezimal !
    */
   public final static String version             = __SED_CLASS_VERSION__ ;

   /**
    * Flag's to enable/disable verbose Information.
    * Usually for debugging.
    */
    public static boolean gljClassDebug 	= false;
    public static boolean gljThreadDebug 	= false;
    public static boolean gljNativeDebug 	= false;
    
   /**
    * We will store the GL Context right here.
    *
    * @see gl4java.GLContext#createGLContext
    * @see gl4java.GLContext#gljInit
    */
    protected long glContext=0;	
    protected static int glContextNumber=0;	

   /**
    * The context with witch display lists and textures will be shared.
    *
    * @see gl4java.GLContext#createGLContext
    * @see gl4java.GLContext#gljInit
    */
    protected GLContext sharedGLContext;	
    protected long sharedGLContextNative= 0; // No sharing by default.	

   /**
    * Xwindow data AND Windows data for the widget
    *
    * @see gl4java.GLContext#createGLContext
    * @see gl4java.GLContext#gljInit
    */
    protected long pixmapHandle=0;     // unique handle for the Pixmap
    protected long windowHandle=0;     // unique handle for this widget's window
    protected long displayHandle=0;    // unqiue handle to the display
    private int createwinw;
    private int createwinh;

   /**
    * MS-JDirect-Window data for the MS-JVM interface
    *
    * @see gl4java.GLContext#createGLContext
    * @see gl4java.GLContext#gljInit
    */
    private int createwinx;
    private int createwiny;
    private boolean threadRunning = false;
    private boolean destroyWindow = false;
    protected Container containerWindow = null;

   /**
    * The custom set offscreen Size
    *
    * If this is set to != null, 
    * the offscreen pixmap is used in this size,
    * not in the components-size (-> faster if smaller)
    *
    * Must be set via createOffScreenCtx
    *
    * @see gl4java.swing.GLJPanel#paint
    * @see gl4java.GLContext#createOffScreenCtx
    */
    protected Dimension offScrnSize = null;

   /**
    * Windows data AND flag is Window-Handel is read (for X11 also) ! 
    *
    * @see gl4java.GLContext#createGLContext
    * @see gl4java.GLContext#gljInit
    */
    long pData = 0;  // stores the pointer structure that holds windows info

    /**
     * Flag to check, if the OpenGL-Context is active !
     *
     * @see	gl4java.GLContext#isEnabled
     * @see	gl4java.GLContext#setEnabled
     */
    protected boolean glEnabled = true;

   /**
    * Do we use offscreen rendering 
    *  X11: pixmap eq window-ressources, 
    *       window eq. GLXPixmap a GLXDrawable
    *       glContext eq. GLXContext
    *
    * This is set via the constructor !
    * 
    * @see gl4java.GLContext#GLContext
    */
    protected boolean offScreenRenderer = false;    

   /**
    * We normally do not have to create an own Window !
    * This is the default visual property ... !
    * But some machines, like SGI's Irix, 
    * must use an own created overlapped window !
    * For these machines, a compiler flag is set, 
    * so that this value is alsways set to true !
    *
    * This is set via the constructor !
    * 
    * @see gl4java.GLContext#isOwnWindowCreated
    * @see gl4java.GLContext#GLContext
    */
    protected boolean createOwnWindow = false;

   /**
    * The GLCapabilities ..
    *
    * This is set via the constructor !
    * 
    * @see gl4java.GLContext#GLContext
    */
    protected GLCapabilities glCaps = null;

   /**
    * The resize flag, which indicates a resize for the next paint function !
    * This flag will bes set in 'componentResized'
    * and will be cleared after resize (glViewport) in sDisplay !!
    *
    * @see gl4java.awt.GLCanvas#sDisplay
    */
    protected boolean mustResize = false;

    protected Dimension size = null;

    /**
     * the light- or heavy component
     * where GL commands should be drawn
     */
    protected Component _comp = null;

    /**
     * the heavy component
     * where GL commands should be drawn
     *
     * if the _comp component is a swing (light)
     * component, this component contains its heavy parent !
     */
    protected Component _compHeavy = null;

   /**
    * Variable to tell is where windows or not (X11) 
    * Usally X11 ;-))
    *
    * Ok - lets give one to the Max :-) 
    */
    public final static int
       OsWindoof	= -1,
       OsUnknown	=  0,
       OsX11	   	=  1,
       OsMac9		=  2, // for Gerard Ziemski's port
       OsMacX		=  3; // for Gerard Ziemski's port
 
    private static int osType=OsUnknown;
  
    private static boolean isNetscapeJvm = false;
    private static boolean isMicrosoftJvm = false;
    private static boolean isIBMJvm = false;
    private static boolean useMSJDirect = false;
    private static String jvmVendor = null;
    private static String jvmVersion = null;
    private static int    jvmVersionMajor = 1; // min. defaults
    private static int    jvmVersionMinor = 1; // min. defaults
    private static String osName = null;

    private static String jniEXTsuff = "";

   /**
    * Get the native GL Context !
    *
    * @see gl4java.GLContext#glContext
    */
    public final long getNativeGLContext() { return glContext; }

    public final static int getNativeGLContextNumber() 
    { return glContextNumber; }

   /**
    * Get the native Window Handle !
    *
    * @see gl4java.GLContext#windowHandle
    *
    * @deprecated The native window handle is no more accessible
    *             through this method since JDK >= 1.3 !
    */
    public final long getNativeWindoHandle() { return windowHandle; }

   /**
    * Get the optional shared GL Context !
    *
    * @see gl4java.GLContext#sharedGLContext
    */
    public final GLContext getSharedGLContext() { return sharedGLContext; }

   /**
    * Get the native OS-Type !
    *
    * @see gl4java.GLContext#OsWindoof
    * @see gl4java.GLContext#OsUnknown
    * @see gl4java.GLContext#OsX11
    * @see gl4java.GLContext#OsMac9
    * @see gl4java.GLContext#OsMacX
    */
    public static int getNativeOSType() { return osType; }

    public static String getNativeOSName() { return osName; }

   /**
    * Query the visual property ... !
    *
    * After a GLContext is created, this property can be queried !
    *
    * @see gl4java.GLContext#glCaps
    * @see gl4java.GLContext#GLContext
    */
    public final GLCapabilities getGLCapabilities() { return glCaps; }

   /**
    * Query the visual property ... !
    *
    * After a GLContext is created, this property can be queried !
    *
    * @see gl4java.GLContext#glCaps
    * @see gl4java.GLContext#GLContext
    */
    public final boolean isDoubleBuffer() { return glCaps.getDoubleBuffered(); }

   /**
    * Query the visual property ... !
    *
    * After a GLContext is created, this property can be queried !
    *
    * @see gl4java.GLContext#glCaps
    * @see gl4java.GLContext#GLContext
    */
    public final int getStencilBitNumber() { return glCaps.getStencilBits(); }

   /**
    * Query the visual property ... !
    *
    * After a GLContext is created, this property can be queried !
    *
    * @see gl4java.GLContext#glCaps
    * @see gl4java.GLContext#GLContext
    */
    public final int getAccumSize() 
    { return glCaps.getAccumRedBits()+
             glCaps.getAccumGreenBits()+
             glCaps.getAccumBlueBits()+
             glCaps.getAccumAlphaBits();
    }

   /**
    * Query the visual property ... !
    *
    * After a GLContext is created, this property can be queried !
    *
    * @see gl4java.GLContext#glCaps
    * @see gl4java.GLContext#GLContext
    */
    public final boolean isStereoView() { return glCaps.getStereo(); }

   /**
    * Query the visual property ... !
    *
    * After a GLContext is created, this property can be queried !
    *
    * @see gl4java.GLContext#glCaps
    * @see gl4java.GLContext#GLContext
    */
    public final boolean isRGBA() { return glCaps.getTrueColor(); }

   /**
    * Query the visual property ... !
    *
    * After a GLContext is created, this property can be queried !
    *
    * @see gl4java.GLContext#createOwnWindow
    * @see gl4java.GLContext#GLContext
    */
    public final boolean isOwnWindowCreated() { return createOwnWindow; }

    /**
     * Support of loading the native library seperatly.
     *
     * Link with the default native OpenGL library.  
     * If we cannot link, an exception is thrown.  
     *
     * The name of the library is named e.g.: "GL4JavaJauGljJNI" at the 
     * Java level, or "libGL4JavaJauGljJNI.so" at the solaris level,
     * or "GL4JavaJauGljJNI.dll" at the win32 level :-).
     *
     * <p> 
     *
     * The user must call loadNativeLibrary !
     * E.g. he can add the default loader like this:
     * <pre>
	    static {
		if(GLContext.loadNativeLibraries(null, null, null)==false)
		  System.out.println("could not load def. native libs.");
	    }
     * </pre> 
     *
     * @param gljLibName The name of the GLContex/GLFunc/GLUFunc 
     *                   native library.
     *                   If gljLibName==null, the default library will be used !
     *
     * @param glLibName  deprecated
     *
     * @param gluLibName deprecated
     *
     * @return 		boolean, true if succesfull !
     *
     * @see	gl4java.GLContext#defGljLib   
     *
     * @deprecated The arguments glLibName and gluLibName are obsolete,
     *             because all glj/gl/glu stuff resides within 
     *		   the gljLib !
     *		   Now you can use doLoadNativeLibraries !
     */
    public final static boolean loadNativeLibraries ( String gljLibName,
    						String glLibName,
						String gluLibName
					      )
    {
    	return doLoadNativeLibraries(gljLibName, null, null);
    }

    /**
     * Support of loading the native library seperatly.
     *
     * Link with the given OpenGL library.  
     * If we cannot link, an exception is thrown.  
     *
     * You can also specify the OpenGL and GLU library by 
     * the environment variables:
     * <pre>
     		GLTOOL_USE_GLLIB	- OpenGL library name
     		GLTOOL_USE_GLULIB	- GLU    library name
     * </pre>
     * these environment variables does _always_ overrides
     * any given ones at this point !!
     *
     * The name of the library is named e.g.: "GL4JavaJauGljJNI" at the 
     * Java level, or "libGL4JavaJauGljJNI.so" at the solaris level,
     * or "GL4JavaJauGljJNI.dll" at the win32 level :-).
     *
     * <p> 
     *
     * The user must call doLoadNativeLibrary !
     * E.g. he can add the default loader like this:
     * <pre>
	    static {
		if(GLContext.doLoadNativeLibraries(null, null, null)==false)
		  System.out.println("could not load def. native libs.");
	    }
     * </pre> 
     *
     * @param gljLibName The name of the GLContex/GLFunc/GLUFunc 
     *                   native library.
     *                   If gljLibName==null, the default library will be used !
     *
     * @param nativeGLLibName  The name of the native GL library.
     *                   If nativeGLLibName==null, the default library will be used !
     *
     * @param nativeGLULibName The name of the native GLU library.
     *                   If nativeGLULibName==null, the default library will be used !
     *
     * @return 		boolean, true if succesfull !
     *
     * @see	gl4java.GLContext#defGljLib   
     * @see	gl4java.GLContext#defNativeGLLibX11
     * @see	gl4java.GLContext#defNativeGLLibMacOS9
     * @see	gl4java.GLContext#defNativeGLLibMacOSX
     * @see	gl4java.GLContext#defNativeGLLibWin32
     * @see	gl4java.GLContext#defNativeGLULibX11
     * @see	gl4java.GLContext#defNativeGLULibMacOS9
     * @see	gl4java.GLContext#defNativeGLULibMacOSX
     * @see	gl4java.GLContext#defNativeGLULibWin32
     */
    public final static boolean doLoadNativeLibraries ( String gljLibName,
						String nativeGLLibName,
						String nativeGLULibName
					      )
    {
        if(libsLoaded) return true;

        if(gljClassDebug)
	    System.out.println("GLContext.doLoadNativeLibraries will do it !");

        jvmVendor = java.lang.System.getProperty("java.vendor");
        jvmVersion = java.lang.System.getProperty("java.version");

        if(gljClassDebug)
	{
		System.out.println("jvm vendor: "+jvmVendor);
		System.out.println("jvm version: "+jvmVersion);
        }

	int i0 = 0;
	int i1 = jvmVersion.indexOf(".", i0);
        String strhlp = null;
	if(i1>0)
	{
	    strhlp = jvmVersion.substring(i0,i1);
	    try {
	      jvmVersionMajor = Integer.valueOf(strhlp).intValue();
	    } catch (Exception e) 
	    {System.out.println("Not a number: "+strhlp+" ("+jvmVersion+")");}
	}
	i0 = i1+1;
	i1 = jvmVersion.indexOf(".", i0);
	if( i1 < 0 )
		i1 = jvmVersion.length(); // no 2nd dot, no bug version number

	if( 0<i0 && i0<i1 )
	{
	    strhlp = jvmVersion.substring(i0,i1);
	    try {
	      jvmVersionMinor = Integer.valueOf(strhlp).intValue();
	    } catch (Exception e) 
	    {System.out.println("Not a number: "+strhlp+" ("+jvmVersion+")");}
	}

        if(gljClassDebug)
	{
		System.out.println("jvm version (parsed): "+
				   "major: "+jvmVersionMajor+
		                   ", minor: "+jvmVersionMinor);
        }

        isNetscapeJvm = jvmVendor!=null && jvmVendor.indexOf("Netscape")>=0 ;
        isMicrosoftJvm = jvmVendor!=null && jvmVendor.indexOf("Microsoft")>=0 ;
        isIBMJvm = jvmVendor!=null && jvmVendor.indexOf("IBM")>=0 ;

 	// Determine the OS
 	osName = System.getProperty( "os.name" );
 	if( osName.startsWith( "Wind" ) )
	   osType = OsWindoof;
 	else if( osName.startsWith( "Mac OS X" ) )
	   osType = OsMacX;
 	else if( osName.startsWith( "Mac OS" ) )
	   osType = OsMac9;
	else /* oops - lets guess unix/x11 :-) */
	   osType = OsX11;

	String libNames[] = null;

	if( jvmVersionMajor>=2 ||
	       ( jvmVersionMajor==1 && jvmVersionMinor>=4 )
	  )
	{
		jniEXTsuff = "14";
	}

	else 

	if( jvmVersionMajor==1 && jvmVersionMinor>=3 
	    && !isIBMJvm && !isMicrosoftJvm 
	  )
	{
		jniEXTsuff = "13";
	}

	else 

	if( jvmVersionMajor==1 && jvmVersionMinor>=2 )
	{
		jniEXTsuff = "12";
	}

	else 

	{
		jniEXTsuff = "";
	}


	if(gljLibName==null)
	    gljLibName = defGljLib+jniEXTsuff;

	if(nativeGLLibName==null)
	{
	    if ( osType==OsWindoof )
		    nativeGLLibName = defNativeGLLibWin32;
	    else if ( osType==OsMac9 )
		    nativeGLLibName = defNativeGLLibMacOS9;
	    else if ( osType==OsMacX )
		    nativeGLLibName = defNativeGLLibMacOSX;
	    else
		    nativeGLLibName = defNativeGLLibX11;
        }

	if(nativeGLULibName==null)
	{
	    if ( osType==OsWindoof )
		    nativeGLULibName = defNativeGLULibWin32;
	    else if ( osType==OsMac9 )
		    nativeGLULibName = defNativeGLULibMacOS9;
	    else if ( osType==OsMacX )
		    nativeGLULibName = defNativeGLULibMacOSX;
	    else
		    nativeGLULibName = defNativeGLULibX11;
        }

	if ( (osType==OsWindoof) && (isMicrosoftJvm) )
	{
	   // JDirect loads the GL libraries automatically,
	   // so we don't have to.
	   libNames = new String[2];
	   libNames[0]= gljLibName;
	   libNames[1]= defGljMSWinLib;
	   useMSJDirect = true;
	} else {
	   /* For MAC, Win32+SunJVM, Unices ... 
	    */
	   libNames = new String[1];
	   libNames[0]= gljLibName;
	   useMSJDirect = false;
	}

	final String f_libNames[] = libNames;

	if(isNetscapeJvm)
	{
	  System.out.println("Netscape JVM try to get Privileges");
	  try {
	        Class privmgr = 
			Class.forName("netscape.security.PrivilegeManager");
		Class[] parameterTypes = new Class[1];
		parameterTypes[0] = Class.forName("java.lang.String");
		Method m = privmgr.getMethod("enablePrivilege",parameterTypes);
		Object args[] = new Object[1];
		args[0] = (Object)(new String("UniversalLinkAccess"));
		m.invoke(privmgr,args);
		/*
		netscape.security.PrivilegeManager.enablePrivilege
			("UniversalLinkAccess");
		*/
		System.out.println("Netscape-Privilege: enabled UniversalLinkAccess priv.");
	  } catch (Exception ex) 
	  { 
		System.out.println("Not enabled Netscape-Privilege: UniversalLinkAccess priv.");
	  }
	}

	boolean ok;

	if( jvmVersionMajor>=2 ||
	    (jvmVersionMajor==1 && jvmVersionMinor>=2)
	  )
	{
	   Boolean ook = (Boolean)
	     AccessController.doPrivileged(new PrivilegedAction() {
	      public Object run() 
	      {
		/* load libs */
		int libNumber = 0;
		String _libName = null ;
		boolean libLoaded[] = new boolean[f_libNames.length];

		for(libNumber=0; libNumber<f_libNames.length; libNumber++)
		    libLoaded[libNumber]=false;

		for(libNumber=0; libNumber<f_libNames.length; libNumber++)
		{
			do {
			      try {
				System.loadLibrary( f_libNames[libNumber] );  
				libLoaded[libNumber]=true;
				if(gljClassDebug)
				{
				    System.out.println("loaded native library: "+
							f_libNames[libNumber]);
				}
			      } catch ( UnsatisfiedLinkError e) {
				System.out.println
				( "Sorry, can't find the library: "+
				  f_libNames[libNumber]+"\n"+e );
				
				f_libNames[libNumber]=null; // stop trying ... :-(
			      }
			} while( libLoaded[libNumber]==false && 
				 f_libNames[libNumber]!=null );
		}
		for(libNumber=0; libNumber<f_libNames.length; libNumber++)
			if(libLoaded[libNumber]==false) 
				return new Boolean(false);
		return new Boolean(true);
	      }
	     });
	   ok = ook.booleanValue();  
	} else
	{
		/* load libs */
		int libNumber = 0;
		String _libName = null ;
		boolean libLoaded[] = new boolean[f_libNames.length];

		for(libNumber=0; libNumber<f_libNames.length; libNumber++)
		    libLoaded[libNumber]=false;

		for(libNumber=0; libNumber<f_libNames.length; libNumber++)
		{
			do {
			      try {
				System.loadLibrary( f_libNames[libNumber] );  
				libLoaded[libNumber]=true;
				if(gljClassDebug)
				{
				    System.out.println("loaded native library: "+
							f_libNames[libNumber]);
				}
			      } catch ( UnsatisfiedLinkError e) {
				System.out.println
				( "Sorry, can't find the library: "+
				  f_libNames[libNumber]+"\n"+e );
				
				f_libNames[libNumber]=null; // stop trying ... :-(
			      }
			} while( libLoaded[libNumber]==false && 
				 f_libNames[libNumber]!=null );
		}
		ok = true;
		for(libNumber=0; libNumber<f_libNames.length; libNumber++)
			if(libLoaded[libNumber]==false) { ok = false; break; }
	}

	if(ok)
	{
		/**
		 * load the GL/GLU libs natively first, so
		 * the OS can use the dynamic loader to
		 * solve the symbol names ..
		 */
		if(gljClassDebug)
			System.out.println("fetching GL/GLU functions ...");
		if(gljFetchGLFunctions 
			(nativeGLLibName, nativeGLULibName, true)
		  )
		{
			System.out.println("fetched GL/GLU functions succesfully !");
			libsLoaded=true;
		} else {
			System.out.println("GL4Java-ERROR: can't fetch GL/GLU functions !");
		}

	}

	if(!libsLoaded)
		System.exit(1);

	return libsLoaded;
    }
 
    /**
     * Test to load the native library, GLFunc and GLUFunc implementation !
     * If succesfull, a Frame will created and the GL-Infos (vendor, ...)
     * are shown in it !
     *
     * @param args, a list of args, 
     *
     *	  -GLLib    <OpenGL libname> 
     *	  -GLULib   <GLU libname> 
     *    -gljlib   <glj-libname> gl4java-glj-lib native library
     *    -glclass  <gl-class> gl4java-gl-class java GLFunc implementation
     *    -gluclass <glu-class> gl4java-glu-class java GLUFunc implementation
     *    -info     creates a GLContext and prints all avaiable information of GL/GLU and GL4Java
     *    -infotxt  like -info, but exits straight after -info !
     *
     *    without any arguments, a help screen is shown 
     */
    public static void main( String args[] ) 
    {
    	String nativeGLLib = null;
    	String nativeGLULib = null;
     	String gljLibName = null;
     	String glName = null;
     	String gluName = null;
	boolean info=false;
	boolean exitImmediatly=false;
	boolean noFactory=false;
	int i = 0;
	boolean ok=true;

	if(args.length==0)
	{
		System.out.println("usage: java gl4java.GLContext <options>, where options can be: ");
		System.out.println("	-GLLib <OpenGL Libname> \t choose a custom OpenGL native library (default: libGL, or OPENGL32, ..)");
		System.out.println("	-GLULib <GLU Libname> \t choose a custom GLU native library (default: libGLU, or GLU32, ..)");
		System.out.println("	-gljlib <glj-libname> \t choose a custom gl4java-glj-lib native library (default: GL4JavaJauGljJNI)");
		System.out.println("	-glclass <gl-class> \t choose a custom gl4java-gl-class java GLFunc implementation (default: GLFuncJauJNI)");
		System.out.println("	-gluclass <glu-class> \t choose a custom gl4java-glu-class java GLUFunc implementation (default: GLUFuncJauJNI)");
		System.out.println("	-info \t creates a GLContext and prints all avaiable information of GL/GLU and GL4Java");
		System.out.println("	-infotxt \t like -info, but exits straight after -info !");
		System.out.println("	-noFactory \t creates a GLContext without the new GLDrawableFactory API");
	        System.exit(0);
	}

	while(args.length>i)
	{
		if(args[i].equals("-GLLib")) {
			if(args.length>++i) nativeGLLib=args[i];
		} else if(args[i].equals("-GLULib")) {
			if(args.length>++i) nativeGLULib=args[i];
		} else if(args[i].equals("-gljlib")) {
			if(args.length>++i) gljLibName=args[i];
		} else if(args[i].equals("-glclass")) {
			if(args.length>++i) glName=args[i];
		} else if(args[i].equals("-gluclass")) {
			if(args.length>++i) gluName=args[i];
		} else if(args[i].equals("-info")) {
			info=true;
		} else if(args[i].equals("-infotxt")) {
			info=true;
			exitImmediatly=true;
		} else if(args[i].equals("-noFactory")) {
			noFactory=true;
		} else {
		  System.out.println("illegal arg "+i+": "+args[i]);
		  ok=false;
		}
		i++;
	}

	GLContext.gljNativeDebug = true;
	GLContext.gljClassDebug = true;

	GLFunc  gl = null;
	GLUFunc glu = null;

	if(GLContext.doLoadNativeLibraries(gljLibName, 
					 nativeGLLib, nativeGLULib
					)
	  )
		System.out.println("native Libraries loaded succesfull");
	else {
		System.out.println("native library NOT loaded complete");
		ok=false;
	}

	if( (gl=GLContext.createGLFunc(glName)) !=null)
		System.out.println("GLFunc implementation "+gl.getClass().getName()+" created succesfull");
	else {
		System.out.println("GLFunc implementation "+glName+" not created");
		ok=false;
	}
	if( (glu=GLContext.createGLUFunc(gluName)) !=null)
		System.out.println("GLUFunc implementation "+glu.getClass().getName()+" created succesfull");
	else {
	        System.out.println("GLUFunc implementation "+gluName+" not created");
		ok=false;
	}

	if( info && ok==true) {
		Frame f = new Frame("GL4Java Info");
		f.setSize(10, 10);

		Canvas cvs = null;
		GLCapabilities glCaps = new GLCapabilities();
		gl4java.drawable.GLDrawableFactory df = 
			gl4java.drawable.GLDrawableFactory.getFactory();

		if(noFactory || 
		   !(df instanceof gl4java.drawable.SunJDK13GLDrawableFactory)
		  )
		{
			cvs = new Canvas();
		} else {
		        gl4java.drawable.SunJDK13GLDrawableFactory sdf =
			  (gl4java.drawable.SunJDK13GLDrawableFactory)df;
			cvs = new Canvas(sdf.getGraphicsConfiguration(glCaps));
		}
		cvs.setVisible(true);
		cvs.setSize(50,50);
		f.add("Center", cvs);
		f.setSize(60,60);

		// f.pack();
		f.setVisible(true);

		GLContext glj = new GLContext( cvs, gl, glu, glCaps, null);

		Frame fInfo = glj.gljShowVersions();

                fInfo.addWindowListener
		                   ( new WindowAdapter()
                                      {
                                        public void windowClosed(WindowEvent e)
                                        {
                                           // button exit
                                           System.exit(0);
                                        }
                                      }
                                    );              

	        glj.gljDestroy();

		if(exitImmediatly)
		   System.exit(0);
	}
    }
		
    public static String getJVMVersion() { return jvmVersion; }
    public static int getJVMVersionMajor() { return jvmVersionMajor; }
    public static int getJVMVersionMinor() { return jvmVersionMinor; }

    public static String getJVMVendor() { return jvmVendor; }
    public static boolean isNetscapeJVM() { return isNetscapeJvm; }
    public static boolean isMicrosoftJVM() { return isMicrosoftJvm; }
 
    /**
     * Used to hold the user given GLFunc implementation
     */
    private GLFunc gl 	= null;

    /**
     * Used to hold the user given GLUFunc implementation
     */
    private GLUFunc glu = null;

   /**
    *
    * Constructor
    *
    * This privat constructor is for all possible
    * compinations and is called from the customized
    * constructors.
    *
    *  First the GLContext is fetched from the Component itself !
    * To do so, the Component is set visible if it is not !
    *
    * If a GLContext is fetched, it is current !
    *
    * @param comp	  the users component for the gl-context
    * @param glf	  the users selected GLFunc implementation
    * @param glf	  the users selected GLUFunc implementation
    * @param _createOwnWindow the flag for the visual property
    * @param _offScreenRenderer the flag for the visual property
    * @param _offScrnSize the fixed offscreen pixmap size
    * @param _glCaps      the GLCapabilities
    * @param _sharedGLContext the shared GLContext
    *
    */
    protected GLContext( Component comp, GLFunc glf, GLUFunc gluf, 
		         boolean _createOwnWindow, 
			 boolean _offScreenRenderer,
    			 Dimension _offScrnSize,
			 GLCapabilities _glCaps,
		         GLContext _sharedGLContext
                       )
    {
		super( );

		_comp = comp ;  // the light- or heavy component
		gl    = glf ;
		glu   = gluf ;
	        createOwnWindow = _createOwnWindow;
	        offScreenRenderer = _offScreenRenderer;
		offScrnSize= _offScrnSize;

		glCaps = _glCaps;

		this.sharedGLContext  = _sharedGLContext;
		if(sharedGLContext != null) 
			sharedGLContextNative =
				(int)sharedGLContext.getNativeGLContext();

		// fetch the heavy peer component in temporary var. comp
		while(comp!=null &&
		      (comp.getPeer() instanceof java.awt.peer.LightweightPeer)
		     )
			comp=comp.getParent();

		_compHeavy = comp ;  // the heavy component

    		Graphics  _gr = null;

		if(_compHeavy!=null)
		{
			if( ! _comp.isVisible() )
				setVisible(true); // use our own ...


			_gr = _compHeavy.getGraphics();
			if(_gr==null)
			  System.out.println("got empty Graphics");
		} else
		  System.out.println("got empty Component");

		if(_comp!=null && _gr!=null)
		{
			int i = 0;
			do {
				createGLContext(_gr); // uses _comp
				if(gljIsInit()==false)
				{
				    try
				    {
				      Thread.sleep( 100 );
				    }
				    catch( Exception e )
				    { }
				}
				i++;
			} while(gljIsInit()==false && i<5) ;
		}

	        if(gljClassDebug)
		{
			if(gljIsInit())
			  System.out.println("GLContext GLContext() succeded");
			else
			  System.out.println("GLContext GLContext() failed");
		}
    }

   /**
    *
    * Constructor
    *
    * This privat constructor is for all possible
    * compinations and is called from the customized
    * constructors.
    *
    *  First the GLContext is fetched from the Component itself !
    * To do so, the Component is set visible if it is not !
    *
    * If a GLContext is fetched, it is current !
    *
    * @param comp	  the users component for the gl-context
    * @param glf	  the users selected GLFunc implementation
    * @param glf	  the users selected GLUFunc implementation
    * @param _createOwnWindow the flag for the visual property
    * @param _offScreenRenderer the flag for the visual property
    * @param _doubleBuffer the flag for the visual property
    * @param _stereoView  the flag for the visual property
    * @param _rgba	  the flag for the visual property
    * @param _stencilBits the flag for the visual property
    * @param _accumSize   the flag for the visual property
    * @param _sharedGLContext the shared GLContext
    * @param _offScrnSize the fixed offscreen pixmap size
    *
    */
    protected GLContext( Component comp, GLFunc glf, GLUFunc gluf, 
		         boolean _createOwnWindow, boolean _offScreenRenderer,
                         boolean _doubleBuffer, boolean _stereoView,
		         boolean _rgba,
		         int _stencilBits,
		         int _accumSize,
		         GLContext _sharedGLContext,
    			 Dimension _offScrnSize
                       )
    {
		this( comp, glf, gluf, _createOwnWindow, 
		      _offScreenRenderer, _offScrnSize,
		      new GLCapabilities(_doubleBuffer, _stereoView,
					 _rgba, _stencilBits, 
					 _accumSize, _accumSize, 
					 _accumSize, _accumSize),
		      _sharedGLContext);
    }

   /**
    *
    * Constructor
    *
    * First the GLContext is fetched from the Component itself !
    * To do so, the Component is set visible if it is not !
    *
    * If a GLContext is fetched, it is current !
    *
    * @param comp	  the users component for the gl-context
    * @param glf	  the users selected GLFunc implementation
    * @param glf	  the users selected GLUFunc implementation
    * @param _glCaps      the GLCapabilities
    * @param _sharedGLContext the shared GLContext
    *
    */
    public GLContext( Component comp, GLFunc glf, GLUFunc gluf, 
		      GLCapabilities _glCaps,
		      GLContext _sharedGLContext
                    )
    {
		this( comp, glf, gluf, false, 
		      false, null, _glCaps, 
		      _sharedGLContext);
    }

   /**
    *
    * Constructor
    *
    * First the GLContext is fetched from the Component itself !
    * To do so, the Component is set visible if it is not !
    *
    * If a GLContext is fetched, it is current !
    *
    * @param comp	  the users component for the gl-context
    * @param glf	  the users selected GLFunc implementation
    * @param glf	  the users selected GLUFunc implementation
    * @param _createOwnWindow the flag for the visual property
    * @param _doubleBuffer the flag for the visual property
    * @param _stereoView  the flag for the visual property
    * @param _rgba	  the flag for the visual property
    * @param _stencilBits the flag for the visual property
    * @param _accumSize   the flag for the visual property
    * @param _sharedGLContext the shared GLContext
    *
    */
    public GLContext( Component comp, GLFunc glf, GLUFunc gluf, 
		      boolean _createOwnWindow,
                      boolean _doubleBuffer, boolean _stereoView,
		      boolean _rgba,
		      int _stencilBits,
		      int _accumSize,
		      GLContext _sharedGLContext
                    )
    {
    	this(comp, glf, gluf, 
	      _createOwnWindow, false /* offscreen renderer */,
	      _doubleBuffer,
	      _stereoView,
	      _rgba,
	      _stencilBits,
	      _accumSize,
	      _sharedGLContext,
	      null /* offscreen size */
	    );
    }

   /**
    *
    * Constructor
    *
    * First the GLContext is fetched from the Component itself !
    * To do so, the Component is set visible if it is not !
    *
    * If a GLContext is fetched, it is current !
    *
    * @param comp	  the users component for the gl-context
    * @param glf	  the users selected GLFunc implementation
    * @param glf	  the users selected GLUFunc implementation
    * @param _createOwnWindow the flag for the visual property
    * @param _doubleBuffer the flag for the visual property
    * @param _stereoView  the flag for the visual property
    * @param _rgba	  the flag for the visual property
    * @param _stencilBits the flag for the visual property
    * @param _accumSize   the flag for the visual property
    *
    */
    public GLContext( Component comp, GLFunc glf, GLUFunc gluf, 
		      boolean _createOwnWindow,
                      boolean _doubleBuffer, boolean _stereoView,
		      boolean _rgba,
		      int _stencilBits,
		      int _accumSize
                    )
    {
    	this(comp, glf, gluf, 
	      _createOwnWindow, false /* offscreen renderer */,
	      _doubleBuffer,
	      _stereoView,
	      _rgba,
	      _stencilBits,
	      _accumSize,
	      null /* sharedGLContext */,
	      null /* offscreen size */
	    );
    }

   /**
    *
    * Constructor
    *
    * First the GLContext is fetched from the Component itself !
    * To do so, the Component is set visible if it is not !
    *
    * If a GLContext is fetched, it is current !
    *
    * @param comp	  the users component for the gl-context
    * @param glf	  the users selected GLFunc implementation
    * @param glf	  the users selected GLUFunc implementation
    * @param _createOwnWindow the flag for the visual property
    * @param _doubleBuffer the flag for the visual property
    * @param _stereoView  the flag for the visual property
    * @param _rgba	  the flag for the visual property
    * @param _stencilBits the flag for the visual property
    *
    */
    public GLContext( Component comp, GLFunc glf, GLUFunc gluf, 
		      boolean _createOwnWindow,
                      boolean _doubleBuffer, boolean _stereoView,
		      boolean _rgba,
		      int _stencilBits
                    )
    {
    	this(comp, glf, gluf, 
	      _createOwnWindow, false /* offscreen renderer */,
	      _doubleBuffer,
	      _stereoView,
	      _rgba,
	      _stencilBits,
	      0 /* accumSize */,
	      null /* sharedGLContext */,
	      null /* offscreen size */
	    );
    }

   /**
    *
    * Constructor
    *
    * First the GLContext is fetched from the Component itself !
    * To do so, the Component is set visible if it is not !
    *
    * If a GLContext is fetched, it is current !
    *
    * @param comp	  the users component for the gl-context
    * @param glf	  the users selected GLFunc implementation
    * @param glf	  the users selected GLUFunc implementation
    * @param _doubleBuffer the flag for the visual property
    * @param _stereoView  the flag for the visual property
    * @param _rgba	  the flag for the visual property
    * @param _stencilBits the flag for the visual property
    *
    */
    public GLContext( Component comp, GLFunc glf, GLUFunc gluf, 
                      boolean _doubleBuffer, boolean _stereoView,
		      boolean _rgba,
		      int _stencilBits,
		      int _accumSize
                    )
    {
    	this(comp, glf, gluf, 
	      false /* ownWindow */, false /* offscreen renderer */,
	      _doubleBuffer,
	      _stereoView,
	      _rgba,
	      _stencilBits,
	      _accumSize,
	      null /* sharedGLContext */,
	      null /* offscreen size */
	    );
    }

   /**
    *
    * Constructor
    *
    * First the GLContext is fetched from the Component itself !
    * To do so, the Component is set visible if it is not !
    *
    * If a GLContext is fetched, it is current !
    *
    * @param comp	  the users component for the gl-context
    * @param glf	  the users selected GLFunc implementation
    * @param glf	  the users selected GLUFunc implementation
    * @param _doubleBuffer the flag for the visual property
    * @param _stereoView  the flag for the visual property
    * @param _rgba	  the flag for the visual property
    * @param _stencilBits the flag for the visual property
    *
    */
    public GLContext( Component comp, GLFunc glf, GLUFunc gluf, 
                      boolean _doubleBuffer, boolean _stereoView,
		      boolean _rgba,
		      int _stencilBits
                    )
    {
    	this(comp, glf, gluf, 
	      false /* ownWindow */, false /* offscreen renderer */,
	      _doubleBuffer,
	      _stereoView,
	      _rgba,
	      _stencilBits,
	      0 /* accumSize */,
	      null /* sharedGLContext */,
	      null /* offscreen size */
	    );
    }

   /**
    *
    * Constructor
    *
    * First the GLContext is fetched from the Component itself !
    * To do so, the Component is set visible if it is not !
    *
    * If a GLContext is fetched, it is current !
    *
    * @param comp	  the users component for the gl-context
    * @param glf	  the users selected GLFunc implementation
    * @param glf	  the users selected GLUFunc implementation
    * @param _doubleBuffer the flag for the visual property
    * @param _stereoView  the flag for the visual property
    * @param _rgba	  the flag for the visual property
    * @param _stencilBits the flag for the visual property
    *
    */
    public GLContext( Component comp, GLFunc glf, GLUFunc gluf, 
                      boolean _doubleBuffer, boolean _stereoView,
		      boolean _rgba
                    )
    {
    	this(comp, glf, gluf, 
	      false /* ownWindow */, false /* offscreen renderer */,
	      _doubleBuffer,
	      _stereoView,
	      _rgba,
	      0, /* _stencilBits */
	      0 /* accumSize */,
	      null /* sharedGLContext */,
	      null /* offscreen size */
	    );
    }

   /**
    *
    * Constructor
    *
    * First the GLContext is fetched from the Component itself !
    * To do so, the Component is set visible if it is not !
    *
    * If a GLContext is fetched, it is current !
    *
    * ! WARNING ! This flag is just for testing purpose !!!
    *
    * @param comp	  the users component for the gl-context
    * @param glf	  the users selected GLFunc implementation
    * @param glf	  the users selected GLUFunc implementation
    * @param _doubleBuffer the flag for the visual property
    * @param _stereoView  the flag for the visual property
    *
    */
    public GLContext( Component comp, GLFunc glf, GLUFunc gluf, 
                      boolean _doubleBuffer, boolean _stereoView
                    )
    {
    	this(comp, glf, gluf, 
	      false /* ownWindow */, false /* offscreen renderer */,
	      _doubleBuffer,
	      _stereoView,
	      true /* _rgba */,
	      0, /* _stencilBits */
	      0 /* accumSize */,
	      null /* sharedGLContext */,
	      null /* offscreen size */
	    );
    }

   /**
    *
    * Constructor
    *
    * First the GLContext is fetched from the Component itself !
    * To do so, the Component is set visible if it is not !
    *
    * We use a visual with doubleBuffer and NO stereoView !
    * Do not force a new native window !
    *
    * If a GLContext is fetched, it is current !
    *
    * @param comp	the users component for the gl-context
    * @param glf	the users selected GLFunc implementation
    * @param glf	the users selected GLUFunc implementation
    */
    public GLContext( Component comp, GLFunc glf, GLUFunc gluf )
    {
    	this(comp, glf, gluf, 
	      false /* ownWindow */, false /* offscreen renderer */,
	      true /* _doubleBuffer */,
	      false /* _stereoView */,
	      true /* _rgba */,
	      0, /* _stencilBits */
	      0 /* accumSize */,
	      null /* sharedGLContext */,
	      null /* offscreen size */
	    );
    }

   /**
    *
    * Constructor Function for offscreen rendering !
    *
    * First the GLContext is fetched from the Component itself !
    * To do so, the Component is set visible if it is not !
    *
    * If a GLContext is fetched, it is current !
    *
    * @param comp	  the users component for the gl-context
    * @param glf	  the users selected GLFunc implementation
    * @param glf	  the users selected GLUFunc implementation
    * @param _stereoView  the flag for the visual property
    * @param _rgba	  the flag for the visual property
    * @param _stencilBits the flag for the visual property
    * @param _sharedGLContext the shared GLContext
    *
    * @return             the created offscreen context
    */
    public final static GLContext createOffScreenCtx
    		       ( Component comp, GLFunc glf, GLUFunc gluf, 
                         boolean _stereoView,
		         boolean _rgba,
		         int _stencilBits,
		         int _accumSize,
		         GLContext _sharedGLContext
                       )
    {
    	return new GLContext(comp, glf, gluf, 
		      false /* _createOwnWindow */, 
		      true /* offscreen renderer */,
		      false /* _doubleBuffer */,
		      _stereoView,
		      _rgba,
		      _stencilBits,
		      _accumSize,
		      _sharedGLContext,
		      null
		    );
    }

   /**
    *
    * Constructor Function for offscreen rendering !
    *
    * First the GLContext is fetched from the Component itself !
    * To do so, the Component is set visible if it is not !
    *
    * If a GLContext is fetched, it is current !
    *
    * @param comp	  the users component for the gl-context
    * @param glf	  the users selected GLFunc implementation
    * @param glf	  the users selected GLUFunc implementation
    * @param _stereoView  the flag for the visual property
    * @param _rgba	  the flag for the visual property
    * @param _stencilBits the flag for the visual property
    * @param _sharedGLContext the shared GLContext
    * @param _offScrnSize the fixed offscreen pixmap size
    *
    * @return             the created offscreen context
    */
    public final static GLContext createOffScreenCtx
    		       ( Component comp, GLFunc glf, GLUFunc gluf, 
                         boolean _stereoView,
		         boolean _rgba,
		         int _stencilBits,
		         int _accumSize,
		         GLContext _sharedGLContext,
    			 Dimension _offScrnSize
                       )
    {
    	return new GLContext(comp, glf, gluf, 
		      false /* _createOwnWindow */, 
		      true /* offscreen renderer */,
		      false /* _doubleBuffer */,
		      _stereoView,
		      _rgba,
		      _stencilBits,
		      _accumSize,
		      _sharedGLContext,
		      _offScrnSize
		    );
    }

    /**
     * @see	gl4java.GLContext#gljDestroy   
     */
    protected void finalize()
    	throws Throwable
    {
	gljDestroy();
	super.finalize();
    }

    /**
     * Used to set the user given GLFunc implementation
     */
    public final void setGLFunc(GLFunc _gl) { gl = _gl; }

    /**
     * Used to set the user given GLUFunc implementation
     */
    public final void setGLUFunc(GLUFunc _glu) { glu = _glu; }

    /**
     * Used to return the user given GLFunc implementation
     */
    public final GLFunc getGLFunc() { return gl; }

    /**
     * Used to return the user given GLUFunc implementation
     */
    public final GLUFunc getGLUFunc() { return glu; }

    /**
     * Support of loading a vendors GLFunc implementation
     *
     * Try to load the Class, if succesfull we do return the instance of it.
     * Else null is returned !
     *
     * The Class-Name is: "GL4Java." + vendorClass + ".class" !
     *
     * @param vendorClass  The name of the GLFunc implementation.
     *                     If vendorSuffix==null, the default implementation 
     *			   "GLFuncJauJNI" (-> GL4Java.GLFuncJauJNI.class ) 
     *			   will be used !
     *
     * @return 		GLFunc, the implementation's instance if exists 
     *			and valid, or null
     *
     * @see	gl4java.GLContext#defGLFuncClass   
     */
    public final static GLFunc createGLFunc(String vendorClass)
    {
        String access_name = "gl4java.";
	GLFunc gl = null;
	Object clazz = null;

	if(vendorClass==null) 
	{
          if (jvmVersionMajor>=2 ||
              (jvmVersionMajor==1 && jvmVersionMinor>=4)) {
            vendorClass = defGLFunc14Class;
          } else {
            vendorClass = defGLFuncClass;
          }
	}

	String clazzName   = access_name + vendorClass ;

	try {
		clazz = Class.forName(clazzName).newInstance();
	} catch (Exception ex) {
		// thats ok :-)
		System.out.println("could not create instance of: "+ clazzName);
	}
	if(clazz !=null && (clazz instanceof GLFunc))
		gl = (GLFunc) clazz;
	else
		System.out.println("Not a GLFunc implementation: "+ clazzName);

	return gl;
    }

    /**
     * Support of loading a vendors GLUFunc implementation
     *
     * Try to load the Class, if succesfull we do return the instance of it.
     * Else null is returned !
     *
     * The Class-Name is: "GL4Java." + vendorClass + ".class" !
     *
     * @param vendorClass  The name of the GLUFunc implementation.
     *                     If vendorSuffix==null, the default implementation 
     *			   "GLUFuncJauJNI" (-> GL4Java.GLUFuncJauJNI.class ) 
     *			   will be used !
     *
     * @return 		GLUFunc, the implementation's instance if exists 
     *			and valid, or null
     *
     * @see	gl4java.GLContext#defGLUFuncClass   
     */
    public final static GLUFunc createGLUFunc(String vendorClass)
    {
        String access_name = "gl4java.";
	GLUFunc glu = null;
	Object clazz = null;

	if(vendorClass==null) 
	{
          if (jvmVersionMajor>=2 ||
              (jvmVersionMajor==1 && jvmVersionMinor>=4)) {
	    vendorClass = defGLUFunc14Class ;
          } else {
	    vendorClass = defGLUFuncClass ;
          }
	}


	String clazzName   = access_name + vendorClass ;

	try {
		clazz = Class.forName(clazzName).newInstance();
	} catch (Exception ex) {
		// thats ok :-)
		System.out.println("could not create instance of: "+ clazzName);
	}
	if(clazz!=null && (clazz instanceof GLUFunc))
		glu = (GLUFunc) clazz;
	else
		System.out.println("Not a GLUFunc implementation: "+ clazzName);
		

	return glu;
    }

   /**
    *
    * Own setVisible
    * This one set's us visible - and wait's for that result !
    *
    * @param visible	boolean: visible==true, hide==false
    * @return 		void
    */ 
    public void setVisible( boolean visible )
    {
    	    int i= 0;

	    _comp.setVisible( visible );

	    while( _comp.isVisible() != visible  && i<5) 
	    {
		_comp.setVisible( visible );

	        try
	        {
		    Thread.sleep( 100 );
	        }
	        catch( Exception e )
	        {
		    System.out.println( "GLContext:setVisible: Error - " + e );
	        }
		i++;
	    }
	    if(i>=5)
	      System.out.println( "GLContext:setVisible: Error, could not set to "+visible); 
    }

   /**
    *
    * createGLContext gets the window handle and calls gljInit,
    * so the gl-context will be initialised here.
    *
    * this method will be invoked by the constructor
    *
    * this method is left public - this time,
    * to allow the user to to it again later - if it was not succesfull !
    *
    * @param g		the graphics reference, 
    *			where we will get the native window handle from.
    *
    * @return 		void
    *
    * @see gl4java.GLContext#GLContext
    */ 
    public final void createGLContext(Graphics g)
    {
        String access_name = "gl4java.jau.awt.";
        WinHandleAccess win_access = null;

	try {
	    if(gljClassDebug)
	      System.out.println("GLContext createGLContext");
 
          if(pData == 0)
	  {
	    if ( useMSJDirect )
	    {
	          if(gljClassDebug)
			  System.out.println("using MSJDirect ...");

		  win_access = (WinHandleAccess)
		    Class.forName(
	               access_name+"windows.MSWin32HandleAccess"
		    ).newInstance();
                  /* _comp should be a subclass of Canvas, and its parent
                     class should be of type Panel, Frame or Window.  If not,
                     this all falls apart. */

		  /* This part is now rewritten, 
	             to respect direkt Windows (Frames and Dialogs)
		     and Applets .. */

                  Component ob = _comp;

		  while ( (ob instanceof Window)==false &&
		  	  (ob instanceof Applet)==false
			)
		  {
                      ob = ob.getParent();
                  }

		  containerWindow = (Container)ob;

		  /* refetch the Graphics component */
		  g = ob.getGraphics();
		  if(g==null)
		    System.out.println("GL4Java-MSJVM: got empty Graphics");

		  pData = win_access.getWinHandle(ob,g);

		  if (pData != 0)
		  {
			Point p1;
			try
			{
				p1 = _comp.getLocationOnScreen();
			}
			catch (Exception e)
			{
				p1 = _comp.getLocation();
				Point p2 = containerWindow.getLocation();
				p1.x += p2.x;
				p1.y += p2.y;
				Insets is = containerWindow.getInsets();
				p1.x += is.left;
				p1.y += is.top;
			}
			Rectangle r = _comp.getBounds();
			createwinx = p1.x;
			createwiny = p1.y;
			createwinw = r.width;
			createwinh = r.height;
			windowHandle = 0;
			threadRunning = true;
			destroyWindow = false;
			Thread th = new Thread(this);
			th.start();
			while ( (windowHandle == 0) && (threadRunning) )
			{
				try
				{
					Thread.currentThread().sleep(100);
				}
				catch( Exception e )
				{ }
			}
		  }
 	    } else if(osType==OsWindoof && !useJAWT())
	    {
		  win_access = (WinHandleAccess) 
		    Class.forName(
		        access_name+"windows.Win32HandleAccess"
		    ).newInstance();
		  pData = win_access.getWinHandle(_compHeavy, g);
		  windowHandle = pData;
	    }
            else if((osType==OsMac9 || osType==OsMacX) && !useJAWT())
            {
		  win_access = (WinHandleAccess)
		    Class.forName(
			access_name+"macintosh.MacHandleAccess"
		    ).newInstance();
		  pData = win_access.getWinHandle(_compHeavy, g);
		  windowHandle = pData;
            }     
	    else if(!useJAWT())
	    {
		  win_access = (WinHandleAccess) 
		    Class.forName(
		         access_name+"motif.X11HandleAccess"
		    ).newInstance();
		  pData = win_access.getWinHandle(_compHeavy, g);
		  windowHandle = pData;
	    }
	  }

	  if(offScrnSize!=null)
	  {
		  createwinw = offScrnSize.width;
		  createwinh = offScrnSize.height;
	  } else {
		  Rectangle r = _comp.getBounds();
		  createwinw = r.width;
		  createwinh = r.height;
	  }

	  /* try to establish a context to OpenGL */
	  try 
	  {
		    gljInit();
	  }
	  catch( GL4JavaInitException e ) 
	  {
		    System.out.println( "can't create a GL context\n");
	  }
    
	} catch (Exception e) {
	      System.out.println( "An exception is thrown, while creating a GL context\n");
	      System.out.println(e);
	      e.printStackTrace();
	}
    }

    /* glj* stuff */
    			
   /**
    *
    * Initializes the gl-context. 
    * gljInit is called by createGLContext (which is calles by the first paint)!
    *
    * Also gljInit will call the init method after GL initialisation,
    * so the user can override �init� to initialize his own stuff !
    *
    * @return 		void
    * @exception 	GL4Java.GL4JavaInitException 
    *			this class throws an exception 
    *			if the native call to create a OpenGL context failed.
    * @see gl4java.GLContext#createGLContext
    * @see gl4java.awt.GLCanvas#paint
    * @see gl4java.awt.GLCanvas#init
    */ 
    protected final synchronized void gljInit() 
      throws GL4JavaInitException 
    {
	if( libsLoaded==false ) return ;

	if(glCaps==null)
	{
	    System.out.println("Internal error: glCaps not initialized !!");
            throw new GL4JavaInitException ();
	}

	if(pData==0 && !offScreenRenderer && !useJAWT())
	{
	    System.out.println("could not open a GL widget -- Win CONTEXT");
            throw new GL4JavaInitException ();
	}

	if(gljClassDebug)
	  System.out.println("GLContext gljInit");

        boolean ok;

	ok = openOpenGLNative(_comp);

        if( ! ok )
        {
	    if ( useMSJDirect )
	    {
		destroyWindow = true;
		while (threadRunning)
		{
			try
			{
				Thread.currentThread().sleep(100);
			}
			catch( Exception e )
			{ }
		}
		pData = 0;
		windowHandle = 0;
	    }
	    System.out.println("could not open a GL widget -- GL CONTEXT");
            throw new GL4JavaInitException ();
          } else {
	    isInitialized = true;
	    glEnabled=true;
	    glContextNumber++;
	}
    }

    /**
     * For MSJVM Only !
     *
     * This functions fetches the window-handle within a special thread !
     */
    public void run()
    {
	if ( !useMSJDirect )
	{
		System.err.println("GL4Java-MSJVM-Run: INTERNAL ERROR"); 
		System.exit(0);
	}

	/*
	System.out.println("OGL create win: x="+createwinx+", y="+createwiny+
				", w="+createwinw+", h="+createwinh);
	System.out.println("OGL create parent: "+pData);
	*/

	pData = gl4java.system.GljMSJDirect.createOGLWindowNative( 
					      pData,
	                                      createwinx,createwiny,
					      createwinw,createwinh);
	if (pData != 0)
	{
		windowHandle = pData;
		while (!destroyWindow)
		{
			gl4java.system.GljMSJDirect.OGLWindowMsgPump();
			try
			{
				Thread.currentThread().sleep(10);
			}
			catch( Exception e )
			{ }
		}
		destroyWindow = false;
		gl4java.system.GljMSJDirect.destroyOGLWindowNative(
								windowHandle);
		windowHandle = 0;
		pData = 0;
		gl4java.system.GljMSJDirect.OGLWindowMsgPump();
	}
	threadRunning = false;
    }

   /**
    *
    * Checks if the gl-context is Initializes
    * If returns true,
    * gljInit is allready called and a valid gl-context is achieved.
    *
    * No glMakeCurrent is done - 
    * like gljMakeCurrent (important for more gl-context) !
    * 
    * <p>
    *
    * The user can use this method to check if he can start rendering
    * and to be sure his initialisation (init) is done !
    *
    * <p>
    *
    * If you use gl4java.awt.GLCanvas, you should use the cvsIsInit
    * method !
    * <p>
    *
    * @return 		boolean
    * @see gl4java.GLContext#gljInit
    * @see gl4java.awt.GLCanvas#cvsIsInit
    */ 
    public final boolean gljIsInit() 
    {
	return isInitialized;
    }

    /**
     * Resizes the gl-viewport
     *
     * Should be called, if the component is resized.
     * The user should take advantage of this functionality.
     *
     * Be sure to resize not within the event-method of the
     * ComponentHandler, you better resize while normal painting.
     * This can be done while using a boolean flag ;-)
     * 
     * Look at GLComponent !
     */
    public final void gljResize(int width, int height)
    {
    	if ( ! isInitialized || !glEnabled ) return;

	if(offScreenRenderer)
	{
		//JAU: TODO
		return;
	}

	if ( useMSJDirect )
        {
		try
		{
			Point p = _comp.getLocationOnScreen();
			gl4java.system.GljMSJDirect.moveOGLWindowNative(
					     windowHandle,p.x,p.y,width,height);
		}
		catch (Exception e)
		{ }
	}
        else
                gljResizeNative( createOwnWindow,
		                 displayHandle, windowHandle,
		                 width,height);
    }

    private final native void gljResizeNative( boolean isOwnWindow,
				               long disp, long thisWin,
				               int width, int height );

    /**
     * native C function of GLJ Library,
     * which query if it uses the JDK 1.3 JAWT interface
     * to fetch the native window handle
     */
    protected final native boolean useJAWT();

    /**
     * native C function of GLJ Library,
     * which query if the JAWT Surface has changed !
     *
     * Use this after gljMakeCurrent -> jawt_lock !
     *  
     * If true, we need a new GLContext !
     */
    protected final native boolean hasJAWTSurfaceChanged(long thisWin);

    /**
     * native C function to open the OpenGLwidget
     */
    protected final native boolean openOpenGLNative(Component canvas);

    /**
     * native C function to check the gl types.
     * At this time, all GL* types will be checked if they fit's
     * in the used java JNI types.
     *
     * this checks is allready performed, while the GL context is
     * fetched with gljInit !
     *
     * BUT we used this function, to perform a check without an
     * X11-connection to our AIX host ;-))
     * So a call to this function is not needed !
     */
    public final static boolean gljCheckGLTypes()
    {
        return gljCheckGLTypesNative();
    }

    private final static native boolean gljCheckGLTypesNative();

    public final boolean gljCheckGL()
    {
    	if ( ! isInitialized || !glEnabled ) return false;

	int ec = gl.glGetError();

	if(ec!=GLFunc.GL_NO_ERROR)
	{
		String errStr = glu.gluErrorString(ec);

		try
		{
		   throw new Exception();
		}
		catch (Exception e)
		{
		   System.out.println("GL ERROR : "+errStr);
		   System.out.println("GL ERROR : "+ec+" == 0x"+Integer.toHexString(ec));
		   e.printStackTrace();
		   System.out.println();
		   System.out.flush();
		}

		return false;
	}
	return true;
    }

   private Thread ctxThread = null;
   private Thread nextThread = null;

   /**
    *
    * gljIsCurrent checks 
    * if the current Thread holds the GL context of this 
    * GLContext instance !
    *
    * @return 		boolean
    *
    * @see gl4java.GLContext#gljIsRequested
    * @see gl4java.GLContext#gljMakeCurrent
    * @see gl4java.GLContext#getNativeGLContext
    * @see gl4java.GLContext#gljGetCurrentContext
    */ 
   public synchronized final boolean gljIsCurrent()
   {
    	if ( ! isInitialized || !glEnabled )
	    return false;

	Thread thisThread = Thread.currentThread();

        if (ctxThread==thisThread && glContext==gljGetCurrentContext())
	     return true;

        return false;
   }

   /**
    *
    * gljIsRequested checks 
    * if the this GLContext instance's native context
    * is requested by another thread !
    *
    * @return 		boolean
    *
    * @see gl4java.GLContext#gljIsCurrent
    * @see gl4java.GLContext#gljMakeCurrent
    * @see gl4java.GLContext#getNativeGLContext
    * @see gl4java.GLContext#gljGetCurrentContext
    */ 
   public synchronized final boolean gljIsRequested()
   {
    	if ( ! isInitialized || !glEnabled )
	    return false;

	Thread thisThread = Thread.currentThread();

        if (nextThread!=null && nextThread!=thisThread)
	     return true;

        return false;
   }

   /**
    *
    * gljMakeCurrent checks whether GL4Java is initializes 
    * AND makes the GL-Context current for this thread.
    *
    * <p>
    *
    * This functions now optimizes the context-switch !
    *
    * The context is changed, only if :
    * <pre>
    	- another thread has requested this context -> release it
	  this gives the other thread a chance to get it ..

	- this thread does not own the current context
    * </pre>
    *
    * <p>
    *
    * You MUST encapsulate your OpenGL call's within:
    * <pre>
    	- gljMakeCurrent()
		YOUR OpenGL commands here !
    	- gljFree()
    * </pre>
    *
    * @return 		boolean
    *
    * @see gl4java.GLContext#gljSwap
    * @see gl4java.awt.GLCanvas#display
    * @see gl4java.awt.GLCanvas#sDisplay
    */ 
    public synchronized final boolean gljMakeCurrent()
    {
    	if ( ! isInitialized || !glEnabled )
	    return false;

	Thread thisThread = Thread.currentThread();
	boolean dbgPrinted = false;

	/**
	 * force a thread switch to improve responsiveness !
	 *
	 * if an earmarked thread exist (nextThread)
	 * we have to wait ..
	 */
	while (nextThread!=null && nextThread!=thisThread)
	{
	     if(gljThreadDebug && !dbgPrinted)
	     {
		     System.out.println("wait-switch: "+thisThread);
	     	     System.out.println("\tctxstate thisThread="+thisThread+", ctxThread="+ctxThread+", nextThread="+nextThread+", thisContext="+glContext+", currentContext="+gljGetCurrentContext());
	     }

	     if(ctxThread==thisThread)
	     {
	         /** 
	          * Force freeing this threads context .. to avoid a deadlock ..
	          * This makes sense, because it is possible,
	          * that the same thread enters this point twice,
	          * before calling gljFree !
	          */
	         if(gljThreadDebug && !dbgPrinted)
	         {
	             System.out.println("wait-current: "+thisThread+" for earmarked: "+nextThread);
	             System.out.println("\tfreeing context force .. ctxThread="+ctxThread);
	         }

	         gljFree(true); // force freeing the context
	     }

	     dbgPrinted=true;

	     try {
		  // wait till earmarked nextThread has its chance ..
	          wait();
	     } catch (InterruptedException e) { }
	}
        dbgPrinted=false;

	/**
	 *  put all req. threads to the wait-state,
	 *  if another thread owns the GLXContext !
	 */
	while (ctxThread!=null && ctxThread!=thisThread)
	{
	     /**
	      * remember this thread as earmarked,
	      * to be sure being the next one ...
	      */
	     nextThread = thisThread;

	     if(gljThreadDebug && !dbgPrinted)
	     {
		     System.out.println("wait-earmarked: "+thisThread);
	     	     System.out.println("\tctxstate thisThread="+thisThread+", ctxThread="+ctxThread+", nextThread="+nextThread+", thisContext="+glContext+", currentContext="+gljGetCurrentContext());
		     dbgPrinted=true;
	     }
             if( _comp instanceof GLRunnable )
	     {
	     	if ( ((GLRunnable)_comp).ownsThread(ctxThread) )
		{
			synchronized (_comp) {
				((GLRunnable)_comp).freeGLContext();
				((GLRunnable)_comp).notifyAll();
			}
			notifyAll();
		        if(gljThreadDebug)
				System.out.println("\tfreeGLContext -> "+ctxThread);
		}
	     }

	     try {
		  // wait for gljFree to release the GLXContext
	          wait();
	     } catch (InterruptedException e) { }
	}

	boolean result = false;

	/* is this thread allready owning the context ? */
        if ( gljIsCurrent() )
	{
		result = lockJAWT(_comp, windowHandle, gljThreadDebug);
		if(gljThreadDebug)
		     System.out.println("MakeCurrent: "+thisThread+" no CTX change, allready own, lockJAWT: "+result);
		return result;
	} else if( ctxThread!=null && ctxThread!=thisThread ) {
	     System.out.println("MakeCurrent: ctxThread ain't zero, funny failure");
	     System.out.println("\tctxstate thisThread="+thisThread+", ctxThread="+ctxThread+", nextThread="+nextThread+", thisContext="+glContext+", currentContext="+gljGetCurrentContext());
	     return result;
	}

	ctxThread = thisThread ; // blocking asap ..

        if(gljThreadDebug)
	{
		if(nextThread==thisThread)
		{
		     System.out.println("MakeCurrent: "+thisThread+" <EarMarked Run>");
	        } else {
		     System.out.println("MakeCurrent: "+thisThread+" <New>");
		}
	        System.out.println("\tctxstate thisThread="+thisThread+", ctxThread="+ctxThread+", nextThread="+nextThread+", thisContext="+glContext+", currentContext="+gljGetCurrentContext());
	}

	/**
	 * if next thread gotten the context, it is no more earmarked ..
	 */
        if(nextThread==thisThread)
	     nextThread = null;

        result =  gljMakeCurrentNative( _comp, displayHandle, 
	                                windowHandle, glContext);

	/**
	 * If glXMakeCurrent failed, nobody holds this GLXContext ..
	 */
	if(!result)
	{
	        if(gljThreadDebug)
		{
			     System.out.println("Native MakeCurrent failed");
			     System.out.println("\tctxstate thisThread="+thisThread+", ctxThread="+ctxThread+", nextThread="+nextThread+", thisContext="+glContext+", currentContext="+gljGetCurrentContext());
			     Exception e = new Exception();
			     e.printStackTrace();
		}

		if(hasJAWTSurfaceChanged(windowHandle))
		{
			/**
			 * This can only happen while using JAWT ..
			 */
			System.out.println("GL4Java: JAWT Surface-Change !!!");
			System.out.println("\t destroying GLContext ...!!!");
			gljDestroy();

			System.out.println("GL4Java: JAWT Surface-Change !!!");
			System.out.println("\t creating GLContext ...!!!");

			/* try to establish a context to OpenGL */
			try 
			{
			    System.out.println("GL4Java: JAWT Surface-Change !!!");
			    gljInit();
			    System.out.println("GL4Java: JAWT Surface-Change finished !!!");
			}
			catch( GL4JavaInitException e ) 
			{
			    System.out.println( "\tcan't create a GL context\n");
			    System.out.println("GL4Java: JAWT Surface Change FAILED!!!");
			}
			System.out.println("\t GLContext Recreated ...!!!");
		}
	}

	notifyAll(); // notify gljFree after action is done ..

        // Workaround for problem on Windows where extensions do not
        // become visible until the first time an OpenGL context is
        // made current (at least with NVidia's drivers).
        if (firstContextMakeCurrent) {
          firstContextMakeCurrent = false;
          gljFetchGLFunctions0(null, null, false, true);
        }

	return result;
    }


   /**
    *
    * gljMakeCurrent checks whether GL4Java is initializes 
    * AND makes the GL-Context current for this thread.
    *
    * It's more save to use �gljMakeCurrent�, instead of
    * �gljMakeCurrentNative�, because we do check if GL is initalised !
    *
    * @param	freeContextFirst is obsolete !
    *
    * @return 		boolean
    *
    * @deprecated The argument freeContextFirst is obsolete !
    */ 
    public final boolean gljMakeCurrent(boolean freeContextFirst)
    {
        return gljMakeCurrent();
    }

    /**
     * if using JAWT, this function handles the JAWT lock also
     */
    private final static native boolean gljMakeCurrentNative(
    						Component canvas,
    						long disp, 
    					        long thisWin,
					        long glContext);

    private final static native boolean lockJAWT(
    						Component canvas,
    					        long thisWin, boolean verbose);

   /**
    *
    * gljGetCurrentContext fetches the current native
    * GL-Context, which is attached to this _native_ thread !
    *
    * @return 		int
    */ 
    public final static native long gljGetCurrentContext();

    /**
     *
     * gljDestroy destroy�s the GL Context
     *
     * This function should be called when removing 
     * a GLContext !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
     *
     * Call gljFree befor this method, to be sure ..
     *
     * @return 		void
     *
     * @see gl4java.GLContext#gljMakeCurrent
     * @see gl4java.GLContext#gljFree
     * @see gl4java.GLContext#gljSwap
     */ 
     public synchronized final boolean gljDestroy()
     {
    	if ( ! isInitialized ) return false;

        boolean result = true;

        if (!gljDestroyNative(_comp)) 
		result = false;

        windowHandle = 0;
        glContext = 0;
	pixmapHandle = 0;


	if ( useMSJDirect )
	{
		destroyWindow = false;
		gl4java.system.GljMSJDirect.destroyOGLWindowNative( pData );
		windowHandle = 0;
		gl4java.system.GljMSJDirect.OGLWindowMsgPump();
	}

        pData = 0;
        isInitialized = false;
	glContextNumber--;

	if(gljClassDebug)
	  System.out.println("GLContext destroyed (remaining ctx="+
	  	glContextNumber+")");
        return result;
    }

     private final native boolean gljDestroyNative(Component canvas);

    /**
     *
     * gljFree free�s the GL Context
     *
     * This MUST be called at last in your display function !
     *
     * <p>
     *
     * This functions now optimizes the context-switch !
     *
     * The context is changed, only if :
     * <pre>
    	- another thread has requested this context -> release it
     * </pre>
     *
     * <p>
     *
     * @return 		boolean
     *
     * @see gl4java.GLContext#gljFree
     * @see gl4java.GLContext#gljIsCurrent
     * @see gl4java.GLContext#gljIsRequested
     * @see gl4java.GLContext#gljMakeCurrent
     * @see gl4java.GLContext#gljSwap
     * @see gl4java.awt.GLCanvas#display
     * @see gl4java.awt.GLCanvas#sDisplay
     */ 
    public final boolean gljFree()
    {
	return gljFree(false);
    }

    /**
     *
     * gljFree free�s the GL Context
     *
     * This MUST be called at last in your display function !
     *
     * <p>
     *
     * This functions now optimizes the context-switch !
     *
     * The context is changed, only if one of the following is true:
     * <pre>
    	- another thread has requested this context
	- the force flag is true
	- this thread is the AWT thread
	- the component of this context does _not_ implement GLRunnable
	- the calling thread is not the thread, this GLRunnable component holds !
     * </pre>
     * 
     * <p>
     *
     * @return 		boolean
     *
     * @see gl4java.GLContext#gljIsCurrent
     * @see gl4java.GLContext#gljIsRequested
     * @see gl4java.GLContext#gljMakeCurrent
     * @see gl4java.GLContext#gljSwap
     * @see gl4java.GLRunnable#run
     */ 
    public synchronized final boolean gljFree(boolean force)
    {
    	if ( ! isInitialized ) return false;

	boolean result = true;
	Thread thisThread = Thread.currentThread();

	if ( ctxThread!=thisThread )
	{
	     if(gljThreadDebug)
	     {
	         System.out.println("gljFree: denied, not holding context ! ");
	         System.out.println("\tctxstate thisThread="+thisThread+", ctxThread="+ctxThread+", nextThread="+nextThread+", thisContext="+glContext+", currentContext="+gljGetCurrentContext());
	         Exception e = new Exception();
	         e.printStackTrace();
	     }
	     return true;
	}

        if( (_comp instanceof GLRunnable) == false ||
	    ((GLRunnable)_comp).ownsThread(thisThread) == false
	  )
		force=true;

	/**
	 * only free the context, if another thread does 
	 * request this context ...
	 * or the force-flag is true
	 */
        if ( force==true || ( nextThread!=null && nextThread!=thisThread ) )
	{
        	result = gljFreeNative ( _comp, displayHandle,
		                         windowHandle,
		                         glContext);

		ctxThread = null ;

	        if(gljThreadDebug)
		{
		     System.out.println("gljFree: gljFreeNative result: "+result);
	     	     System.out.println("\tctxstate thisThread="+thisThread+", ctxThread="+ctxThread+", nextThread="+nextThread+", thisContext="+glContext+", currentContext="+gljGetCurrentContext());
	        }
	} else {
    		result = unlockJAWT(windowHandle, false);
		if(gljThreadDebug)
		{
	     	     System.out.println("gljFree: no CTX change, no requests, unlockJAWT: "+result);
	     	     System.out.println("\tctxstate thisThread="+thisThread+", ctxThread="+ctxThread+", nextThread="+nextThread+", thisContext="+glContext+", currentContext="+gljGetCurrentContext());
	        }
	}
	notifyAll();

	return result;
    }

    /**
     * if using JAWT, this function handles the JAWT unlock also
     */
    private final static native boolean gljFreeNative( Component canvas,
     							long disp, 
    					                long thisWin,
					                long glContext );

    private final static native boolean unlockJAWT(long thisWin, boolean verbose);

    /**
     * swap method are for double buffering
     */
    public final boolean gljSwap()
    {
    	if ( ! isInitialized || !glEnabled ) return false;

        return gljSwapNative( displayHandle,
			      windowHandle,
			      glContext,
			      glCaps.getDoubleBuffered());
    }

    private final static native boolean gljSwapNative( long disp, 
    					              long thisWin,
					              long glContext,
						      boolean doubleBuffer );

    /**
     * This function enables, disables the GL-Context !
     * If false is given, the openGL renderer/context is 
     * disabled and disconected (gljFree is called, if initialized) !
     *
     * If disabled, all GL Functions are disabled but the 
     * Destroy & Free are not !
     *
     * @return 	boolean
     *
     * @see     gl4java.GLContext#gljMakeCurrent
     * @see     gl4java.GLContext#gljDestroy
     * @see     gl4java.GLContext#gljFree
     */ 
    public void setEnabled(boolean b)
    {
        glEnabled = b;
    	if ( b==false && isInitialized ) 
		gljFree();
    }

    /**
     * This function queries, if the GL-Context is enabled !
     *
     * @return 	boolean
     *
     * @see	gl4java.GLContext#setEnabled
     * @see     gl4java.GLContext#gljMakeCurrent
     */ 
    public boolean isEnabled()
    {
        return glEnabled;
    }

    /**
     * This functions fetches/dispatches the GL/GLU functions,
     * which must be allready loaded via the doLoadNativeLibraries
     * function !
     *
     * @see	gl4java.GLContext#doLoadNativeLibraries
     */
    public final static native boolean gljFetchOSGLFunctions 
			( String gllibname, String glulibname, boolean force );
    public final static boolean gljFetchGLFunctions(String gllibname,
                                                    String glulibname,
                                                    boolean force) {
      return gljFetchGLFunctions0(gllibname, glulibname, force, false);
    }

    // This routine is used internally only. On Windows it appears
    // that extensions only become visible once an OpenGL context is
    // made current for the first time (at least with NVidia's
    // drivers). To avoid making drastic changes to the code
    // structure, we reload all of the OpenGL functions the first time
    // a context is made current. (This could be made more efficient
    // by only loading extensions' routines at this time.)
    private volatile static boolean firstContextMakeCurrent = true;
    private final static native boolean gljFetchGLFunctions0(String gllibname,
                                                             String glulibname,
                                                             boolean force,
                                                             boolean reload);

    /**
     * This functions checks the existence of 
     * the GL functions !
     */
    public final static boolean gljTestGLProc ( String name, boolean verbose ) {
      // Special case any routines which are exposed in a different fashion
      if (name.equals("glAllocateMemoryNV")) {
        int os = getNativeOSType();
        if (os == OsWindoof) {
          name = "wglAllocateMemoryNV";
        } else if (os == OsX11) {
          name = "glXAllocateMemoryNV";
        } // else will fail anyway; fall through
      }
      return gljTestGLProc0(name, verbose);
    }

    private static final native boolean gljTestGLProc0(String name, boolean verbose);

    /**
     * This functions reads the pixel from the GL frame
     * and puts it into the pixelDest array,
     * while converting them correctly to the AWT pixel format,
     * using GL_BGRA and BufferedImage.TYPE_INT_ARGB !
     */
    public final static native void gljReadPixelGL2AWT (
    			int pack_rowlen,
    			int pack_x, int pack_y,
			int x, int y, int width, int height,
			int format, int type, int bufferName,
			int[] pixelDest);

    /**
     * This functions reads the pixel from the GL frame
     * and puts it into the pixelDest array,
     * while converting them correctly to the AWT pixel format,
     * using GL_RGB and BufferedImage.TYPE_USHORT_565_RGB !
     */
    public final static native void gljReadPixelGL2AWT (
    			int pack_rowlen,
    			int pack_x, int pack_y,
			int x, int y, int width, int height,
			int format, int type, int bufferName,
			short[] pixelDest);

    /**
     * This functions reads the pixel from the GL frame
     * and puts it into the pixelDest array,
     * while using hardware correct AWT and GL pixel format,
     * using GL_BGR and BufferedImage.TYPE_3BYTE_BGR !
     */
    public final static native void gljReadPixelGL2AWT (
    			int pack_rowlen,
    			int pack_x, int pack_y,
			int x, int y, int width, int height,
			int format, int type, int bufferName,
			byte[] pixelGLDest);

    /**
     * native C function to achieve the native lib vendor !
     *
     * now it is possible to check the native-lib at runtime !
     */
    public final static String gljGetNativeLibVendor()
    {
        return gljGetNativeLibVendorNative();
    }

    private final static native String gljGetNativeLibVendorNative();

    /**
     * native C function to achieve the native lib version !
     *
     * now it is possible to check the native-lib at runtime !
     */
    public final static String gljGetNativeLibVersion()
    {
        return gljGetNativeLibVersionNative();
    }

    private final static native String gljGetNativeLibVersionNative();

    /**
     * function to achieve the java-class version !
     *
     * now it is possible to check the java-class at runtime !
     */
    public final static String gljGetClassVersion()
    { return version; }

    /**
     * function to achieve the java-class vendor !
     *
     * now it is possible to check the java-class at runtime !
     */
    public final static String gljGetClassVendor()
    { return "Jausoft - Sven Goethel Software Development"; }

    /**
     * function to achieve complete version info
     *
     * Be sure that the native library must be loaded !
     */
    public final String gljGetVersions()
    {
	return gljGetVersions(false);
    }

    public final String gljGetVersions(boolean verbose)
    {
      if(libsLoaded==false || gl==null || glu==null || !gljIsInit())
      	return null;

      String jvmstr = "Java Virtual Machine: Version "+ getJVMVersion() +
                     " ("+getJVMVersionMajor()+"."+getJVMVersionMinor()+")"+
		     ", Vendor: "+ getJVMVendor() + "\n" ;

      gl4java.utils.glf.GLF glf = new gl4java.utils.glf.GLF();

      String info1= "GL4Java - LGPL-Version"                       + "\n" +
      	            "-------------------------------------------------\n" +
      	            "-------------------------------------------------\n" +
		    "Java-Class         : GL4Java.GLContext           \n" +
		    "          : Version: "+gljGetClassVersion()   + "\n" +
		    "            Vendor : "+gljGetClassVendor()    + "\n" +
		    "Native-Library     : GL4Java.GLContext           \n" +
		    "            Version: "+gljGetNativeLibVersion()+"\n" +
		    "            Vendor : "+gljGetNativeLibVendor() +"\n" +
      	            "-------------------------------------------------\n" +
		    "Java-Class         : GL4Java.GLFunc impl.        \n" +
		    "          : Version: "+gl.getClassVersion()   + "\n" +
		    "            Vendor : "+gl.getClassVendor()    + "\n" +
		    "Native-Library     : GL4Java.GLFunc impl.        \n" +
		    "            Version: "+gl.getNativeVersion()  + "\n" +
		    "            Vendor : "+gl.getNativeVendor()   + "\n" +
      	            "-------------------------------------------------\n" +
		    "Java-Class         : GL4Java.GLUFunc impl.       \n" +
		    "          : Version: "+glu.getClassVersion()  + "\n" +
		    "            Vendor : "+glu.getClassVendor()   + "\n" +
		    "Native-Library     : GL4Java.GLUFunc impl.       \n" +
		    "            Version: "+glu.getNativeVersion() + "\n" +
		    "            Vendor : "+glu.getNativeVendor()  + "\n" +
      	            "-------------------------------------------------\n" +
		    "Java-Class         : GL4Java.utils.glf.GLFFuncJNI  \n" +
		    "          : Version: "+glf.getClassVersion()  + "\n" +
		    "            Vendor : "+glf.getClassVendor()   + "\n" +
		    "Native-Library     : GL4Javautils.glf..GLFFuncJNI  \n" +
		    "            Version: "+glf.getNativeVersion() + "\n" +
		    "            Vendor : "+glf.getNativeVendor()  + "\n" +
      	            "-------------------------------------------------\n" +
		    "\n"+
		    jvmstr +
		    "\n" ;

        String glVen = gl.glGetString(GLFunc.GL_VENDOR);
	String glRen = gl.glGetString(GLFunc.GL_RENDERER);
	String glVer = gl.glGetString(GLFunc.GL_VERSION);
	String glExt = gl.glGetString(GLFunc.GL_EXTENSIONS);
	String gluVer = glu.gluGetString(GLUFunc.GLU_VERSION);
	String gluExt = glu.gluGetString(GLUFunc.GLU_EXTENSIONS);

     String info2=      "OpenGL - Versions                              \n" +
      	                "-----------------------------------------------\n" +
	                "GL  VENDOR: "+glVen+"\n"+
			"GL  RENDERER: "+glRen+"\n"+
			"GL  VERSION: "+glVer+"\n"+
			"GL  EXTENSIONS: "+glExt+"\n"+
			"GLU VERSION: "+gluVer+"\n"+
			"GLU EXTENSIONS: "+gluExt+"\n"+"\n" ;
	
     String info3=      "OpenGL - Function Test ("+ 
     			GLFunc.GL_PROC_NAMES.length +" Functions)       \n" +
      	                "-----------------------------------------------\n";

     if(verbose)
     {
	 System.out.println(info1);
	 System.out.println(info2);
	 System.out.println(info3);
     }
	 
     String h;	
     String tmp;
     int okNum=0;

     for(int i=0; i<GLFunc.GL_PROC_NAMES.length; i++)
     {
        h=GLFunc.GL_PROC_NAMES[i];
	if(h==null) break;

     	if(gljTestGLProc (h, verbose))
	{
		tmp= "#"+i+" OK   : "+h+"\n";
		okNum++;
	} else 
		tmp= "#"+i+" NOPE : "+h+"\n";
	    
	info3 += tmp;
     }
     info3 += "-----------------------------------------------\n";
     info3 += "Got "+okNum+" / "+GLFunc.GL_PROC_NAMES.length+" Functions \n";
     info3 += "===============================================\n";

     return info1+"\n"+info2+"\n"+info3;
    }

    /**
     * function to show complete version info into an extra Frame
     *
     * Be sure that the native library must be loaded !
     */
    public final Frame gljShowVersions()
    {
	Frame f = new Frame("GL4Java Version");
	TextArea info= new TextArea(25, 80);
	info.setEditable(false);
	f.add(info);
	f.setSize(600, 400);

	f.pack();
	f.setVisible(true);

	String str = "null string";
	if( gljMakeCurrent(true) == false ) 
	{
		str="problem in use() method\n";
	} else {
		str=gljGetVersions(gljNativeDebug);
		if(str==null)
			str="could not get versions";
		System.out.println(str);
		gljFree();
	}
	info.append(str);

	f.addWindowListener
			   ( new WindowAdapter()
			      {
				public void windowClosing(WindowEvent e)
				{
				   // button window menu ... :-)
				   e.getWindow().dispose();
				}
			      }
			    );              

	return f;
    }

}