Implemented reference counted loading of gl library in java

src/java/org/lwjgl/opengl/Display.java

@@ -508,19 +508,29 @@ public final class Display {
 			throw new IllegalStateException("Only one LWJGL context may be instantiated at any one time.");
 		if (fullscreen)
 			switchDisplayMode(current_mode);
-		createContext(pixel_format);
-		context = new Display();
 		try {
-			createWindow();
+			GLContext.loadOpenGLLibrary();
+			try {
+				createContext(pixel_format);
+				try {
+					context = new Display();
+					createWindow();
+					makeCurrent();
+					initContext();
+				} catch (LWJGLException e) {
+					destroyContext();
+					context = null;
+					throw e;
+				}
+			} catch (LWJGLException e) {
+				GLContext.unloadOpenGLLibrary();
+				throw e;
+			}
 		} catch (LWJGLException e) {
-			destroyContext();
-			context = null;
 			if (fullscreen)
 				resetDisplayMode();
 			throw e;
 		}
-		makeCurrent();
-		initContext();
 	}
 
 	/**
@@ -595,6 +605,7 @@ public final class Display {
 		
 		destroyWindow();
 		destroyContext();
+		GLContext.unloadOpenGLLibrary();
 		context = null;
 		try {
 			GLContext.useContext(null);

src/java/org/lwjgl/opengl/GLContext.java

@@ -183,6 +183,8 @@ public final class GLContext {
 
 	/** Map of classes that have native stubs loaded */
 	private static Map exts;
+	private static int gl_ref_count = 0;
+	private static boolean did_auto_load = false;
 
 	static {
 		Sys.initialize();
@@ -228,6 +230,8 @@ public final class GLContext {
 	public static synchronized void useContext(Object context) throws LWJGLException {
 		if (context == null) {
 			unloadStubs();
+			if (did_auto_load)
+				unloadOpenGLLibrary();
 			return;
 		}
 		// Is this the same as last time?
@@ -238,11 +242,19 @@ public final class GLContext {
 		}
 		
 		// Ok, now it's the current context.
-		loadOpenGLLibrary();
-		GL11.initNativeStubs();
-		loadStubs();
-		currentContext = new WeakReference(context);
-		VBOTracker.setCurrent(currentContext);
+		if (gl_ref_count == 0) {
+			loadOpenGLLibrary();
+			did_auto_load = true;
+		}
+		try {
+			GL11.initNativeStubs();
+			loadStubs();
+			currentContext = new WeakReference(context);
+			VBOTracker.setCurrent(currentContext);
+		} catch (LWJGLException e) {
+			if (did_auto_load)
+				unloadOpenGLLibrary();
+		}
 	}
 
 	private static void getExtensionClassesAndNames(Map exts, Set exts_names) {
@@ -338,9 +350,28 @@ public final class GLContext {
 	}
 
 	/**
-	 * Native method to load the OpenGL library
+	 * If the OpenGL reference count is 0, the library is loaded. The
+	 * reference count is then incremented.
 	 */
-	private static native void loadOpenGLLibrary();
+	public static void loadOpenGLLibrary() throws LWJGLException {
+		if (gl_ref_count == 0)
+			nLoadOpenGLLibrary();
+		gl_ref_count++;
+	}
+
+	private static native void nLoadOpenGLLibrary() throws LWJGLException;
+
+	/**
+	 * The OpenGL library reference count is decremented, and if it 
+	 * reaches 0, the library is unloaded.
+	 */
+	public static void unloadOpenGLLibrary() {
+		gl_ref_count--;
+		if (gl_ref_count == 0)
+			nUnloadOpenGLLibrary();
+	}
+
+	private static native void nUnloadOpenGLLibrary();
 
 	/**
 	 * Native method to clear native stub bindings

src/java/org/lwjgl/test/opengl/PbufferTest.java

@@ -97,6 +97,7 @@ public class PbufferTest {
   private void initialize() {
     try {
       //find displaymode
+      pbuffer = new Pbuffer(512, 512, new PixelFormat(), null);
       mode = findDisplayMode(800, 600, 16);
       Display.setDisplayMode(mode);
       // start of in windowed mode
@@ -175,7 +176,12 @@ public class PbufferTest {
     if (pbuffer.isBufferLost()) {
         System.out.println("Buffer contents lost - will recreate the buffer");
         pbuffer.destroy();
-        initPbuffer();
+	try {
+	        pbuffer = new Pbuffer(512, 512, new PixelFormat(), null);
+        	initPbuffer();
+	} catch (LWJGLException e) {
+		e.printStackTrace();
+	}
     }
 	try {
 	    pbuffer.makeCurrent();
@@ -235,7 +241,6 @@ public class PbufferTest {
 
   private void initPbuffer() {
       try {
-          pbuffer = new Pbuffer(512, 512, new PixelFormat(), null);
           pbuffer.makeCurrent();
           initGLState(256, 256, 0.5f);
           GL11.glBindTexture(GL11.GL_TEXTURE_2D, tex_handle);