Java 类org.lwjgl.LWJGLUtil 实例源码

public void destroy() {
    synchronized ( GlobalLock.lock ) {
        if ( context == null )
            return;

        try {
            releaseContext();

            context.forceDestroy();
            context = null;

            if ( peer_info != null ) {
                peer_info.destroy();
                peer_info = null;
            }
        } catch (LWJGLException e) {
            LWJGLUtil.log("Exception occurred while destroying Drawable: " + e);
        }
    }
}

public static int getNativeCursorCapabilities() {
    if (LWJGLUtil.getPlatform() != LWJGLUtil.PLATFORM_MACOSX || LWJGLUtil.isMacOSXEqualsOrBetterThan(10, 4)) {
        int cursor_colors = Toolkit.getDefaultToolkit().getMaximumCursorColors();
        boolean supported = cursor_colors >= Short.MAX_VALUE && getMaxCursorSize() > 0;
        int caps = supported ? org.lwjgl.input.Cursor.CURSOR_8_BIT_ALPHA | org.lwjgl.input.Cursor.CURSOR_ONE_BIT_TRANSPARENCY: 0 | org.lwjgl.input.Cursor.CURSOR_ANIMATION;
        return caps;
    } else {
        /* Return no capability in Mac OS X 10.3 and earlier , as there are two unsolved bugs (both reported to apple along with
           minimal test case):
           1. When a custom cursor (or some standard) java.awt.Cursor is assigned to a
           Componennt, it is reset to the default pointer cursor when the window is de-
           activated and the re-activated. The Cursor can not be reset to the custom cursor,
           with another setCursor.
           2. When the cursor is moving in the top pixel row (y = 0 in AWT coordinates) in fullscreen
           mode, no mouse moved events are reported, even though mouse pressed/released and dragged
           events are reported
         */
        return 0;
    }
}

/**
 * Use reflection to access the JDK 1.5 pointer location, if possible and
 * only if the given component is on the same screen as the cursor. Return
 * null otherwise.
 */
private static Point getPointerLocation(final Component component) {
    try {
        final GraphicsConfiguration config = component.getGraphicsConfiguration();
        if (config != null) {
            PointerInfo pointer_info = AccessController.doPrivileged(new PrivilegedExceptionAction<PointerInfo>() {
                public PointerInfo run() throws Exception {
                    return MouseInfo.getPointerInfo();
                }
            });
            GraphicsDevice device = pointer_info.getDevice();
            if (device == config.getDevice()) {
                return pointer_info.getLocation();
            }
            return null;
        }
    } catch (Exception e) {
        LWJGLUtil.log("Failed to query pointer location: " + e.getCause());
    }
    return null;
}

public final synchronized ByteBuffer lockAndGetHandle() throws LWJGLException {
    Thread this_thread = Thread.currentThread();
    while (locking_thread != null && locking_thread != this_thread) {
        try {
            wait();
        } catch (InterruptedException e) {
            LWJGLUtil.log("Interrupted while waiting for PeerInfo lock: " + e);
        }
    }
    if (lock_count == 0) {
        locking_thread = this_thread;
        doLockAndInitHandle();
    }
    lock_count++;
    return getHandle();
}

private static boolean isXrandrSupported() {
    if (Display.getPrivilegedBoolean("LWJGL_DISABLE_XRANDR"))
        return false;
    lockAWT();
    try {
        incDisplay();
        try {
            return nIsXrandrSupported(getDisplay());
        } finally {
            decDisplay();
        }
    } catch (LWJGLException e) {
        LWJGLUtil.log("Got exception while querying Xrandr support: " + e);
        return false;
    } finally {
        unlockAWT();
    }
}

private static boolean isXF86VidModeSupported() {
    lockAWT();
    try {
        incDisplay();
        try {
            return nIsXF86VidModeSupported(getDisplay());
        } finally {
            decDisplay();
        }
    } catch (LWJGLException e) {
        LWJGLUtil.log("Got exception while querying XF86VM support: " + e);
        return false;
    } finally {
        unlockAWT();
    }
}

private static boolean isNetWMFullscreenSupported() throws LWJGLException {
    if (Display.getPrivilegedBoolean("LWJGL_DISABLE_NETWM"))
        return false;
    lockAWT();
    try {
        incDisplay();
        try {
            return nIsNetWMFullscreenSupported(getDisplay(), getDefaultScreen());
        } finally {
            decDisplay();
        }
    } catch (LWJGLException e) {
        LWJGLUtil.log("Got exception while querying NetWM support: " + e);
        return false;
    } finally {
        unlockAWT();
    }
}

public void destroyWindow() {
    lockAWT();
    try {
        if (parent != null) {
            parent.removeFocusListener(focus_listener);
        }
        try {
            setNativeCursor(null);
        } catch (LWJGLException e) {
            LWJGLUtil.log("Failed to reset cursor: " + e.getMessage());
        }
        nDestroyCursor(getDisplay(), blank_cursor);
        blank_cursor = None;
        ungrabKeyboard();
        nDestroyWindow(getDisplay(), getWindow());
        decDisplay();

        if ( current_window_mode != WINDOWED )
            Compiz.setLegacyFullscreenSupport(false);
    } finally {
        unlockAWT();
    }
}

public void resetDisplayMode() {
    lockAWT();
    try {
        if( current_displaymode_extension == XRANDR && savedXrandrConfig.length > 0 )
        {
            AccessController.doPrivileged(new PrivilegedAction<Object>() {
                public Object run() {
                    XRandR.setConfiguration( savedXrandrConfig );
                    return null;
                }
            });
        }
        else
        {
            switchDisplayMode(saved_mode);
        }
        if (isXF86VidModeSupported())
            doSetGamma(saved_gamma);

        Compiz.setLegacyFullscreenSupport(false);
    } catch (LWJGLException e) {
        LWJGLUtil.log("Caught exception while resetting mode: " + e);
    } finally {
        unlockAWT();
    }
}

public int getMinCursorSize() {
    lockAWT();
    try {
        incDisplay();
        try {
            return nGetMinCursorSize(getDisplay(), getWindow());
        } finally {
            decDisplay();
        }
    } catch (LWJGLException e) {
        LWJGLUtil.log("Exception occurred in getMinCursorSize: " + e);
        return 0;
    } finally {
        unlockAWT();
    }
}

public int getMaxCursorSize() {
    lockAWT();
    try {
        incDisplay();
        try {
            return nGetMaxCursorSize(getDisplay(), getWindow());
        } finally {
            decDisplay();
        }
    } catch (LWJGLException e) {
        LWJGLUtil.log("Exception occurred in getMaxCursorSize: " + e);
        return 0;
    } finally {
        unlockAWT();
    }
}

public int getPbufferCapabilities() {
    lockAWT();
    try {
        incDisplay();
        try {
            return nGetPbufferCapabilities(getDisplay(), getDefaultScreen());
        } finally {
            decDisplay();
        }
    } catch (LWJGLException e) {
        LWJGLUtil.log("Exception occurred in getPbufferCapabilities: " + e);
        return 0;
    } finally {
        unlockAWT();
    }
}

/**
 * Helper method to ContextCapabilities. It will try to initialize the native stubs,
 * and remove the given extension name from the extension set if the initialization fails.
 */
static void initNativeStubs(final Class<?> extension_class, Set supported_extensions, String ext_name) {
    resetNativeStubs(extension_class);
    if ( supported_extensions.contains(ext_name) ) {
        try {
            AccessController.doPrivileged(new PrivilegedExceptionAction<Object>() {
                public Object run() throws Exception {
                    Method init_stubs_method = extension_class.getDeclaredMethod("initNativeStubs");
                    init_stubs_method.invoke(null);
                    return null;
                }
            });
        } catch (Exception e) {
            LWJGLUtil.log("Failed to initialize extension " + extension_class + " - exception: " + e);
            supported_extensions.remove(ext_name);
        }
    }
}

/**
 * Returns the entire list of possible fullscreen display modes as an array, in no
 * particular order. Although best attempts to filter out invalid modes are done, any
 * given mode is not guaranteed to be available nor is it guaranteed to be within the
 * current monitor specs (this is especially a problem with the frequency parameter).
 * Furthermore, it is not guaranteed that create() will detect an illegal display mode.
 * <p/>
 * The only certain way to check
 * is to call create() and make sure it works.
 * Only non-palette-indexed modes are returned (ie. bpp will be 16, 24, or 32).
 * Only DisplayModes from this call can be used when the Display is in fullscreen
 * mode.
 *
 * @return an array of all display modes the system reckons it can handle.
 */
public static DisplayMode[] getAvailableDisplayModes() throws LWJGLException {
    synchronized ( GlobalLock.lock ) {
        DisplayMode[] unfilteredModes = display_impl.getAvailableDisplayModes();

        if ( unfilteredModes == null ) {
            return new DisplayMode[0];
        }

        // We'll use a HashSet to filter out the duplicated modes
        HashSet<DisplayMode> modes = new HashSet<DisplayMode>(unfilteredModes.length);

        modes.addAll(Arrays.asList(unfilteredModes));
        DisplayMode[] filteredModes = new DisplayMode[modes.size()];
        modes.toArray(filteredModes);

        LWJGLUtil.log("Removed " + (unfilteredModes.length - filteredModes.length) + " duplicate displaymodes");

        return filteredModes;
    }
}

/**
 * Find a proper GraphicsConfiguration from the given GraphicsDevice and PixelFormat.
 *
 * @return The GraphicsConfiguration corresponding to a visual that matches the pixel format.
 */
public GraphicsConfiguration findConfiguration(GraphicsDevice device, PixelFormat pixel_format) throws LWJGLException {
    try {
        int screen = getScreenFromDevice(device);
        int visual_id_matching_format = findVisualIDFromFormat(screen, pixel_format);
        GraphicsConfiguration[] configurations = device.getConfigurations();
        for ( GraphicsConfiguration configuration : configurations ) {
            int visual_id = getVisualIDFromConfiguration(configuration);
            if ( visual_id == visual_id_matching_format )
                return configuration;
        }
    } catch (LWJGLException e) {
        LWJGLUtil.log("Got exception while trying to determine configuration: " + e);
    }
    return null; // In case we failed to locate the visual, or if we're not on a SUN JDK
}

public void update() {
    nUpdate();

    if ( !isFocused && parent != null && parent.isFocusOwner() ) {
        KeyboardFocusManager.getCurrentKeyboardFocusManager().clearGlobalFocusOwner();
        setFocus(getHwnd());
    }

    if (redoMakeContextCurrent) {
        redoMakeContextCurrent = false;
        /**
         * WORKAROUND:
         * Making the context current (redundantly) when the window
         * is maximized helps some gfx cards recover from fullscreen
         */
        try {
            Context context = ((DrawableLWJGL)Display.getDrawable()).getContext();
            if (context != null && context.isCurrent())
                context.makeCurrent();
        } catch (LWJGLException e) {
            LWJGLUtil.log("Exception occurred while trying to make context current: " + e);
        }
    }
}

/**
 * Initializes ALC11, including any extensions
 * @return true if initialization was successfull
 */
static boolean initialize() {
    try {
        IntBuffer ib = BufferUtils.createIntBuffer(2);
        ALC10.alcGetInteger(AL.getDevice(), ALC10.ALC_MAJOR_VERSION, ib);
        ib.position(1);
        ALC10.alcGetInteger(AL.getDevice(), ALC10.ALC_MINOR_VERSION, ib);

        int major = ib.get(0);
        int minor = ib.get(1);

        // checking for version 1.x+
        if(major >= 1) {

            // checking for version 1.1+
            if(major > 1 || minor >= 1) {
                ALC11.initNativeStubs();
                                       AL11.initNativeStubs();
            }
        }
    } catch (LWJGLException le) {
        LWJGLUtil.log("failed to initialize ALC11: " + le);
        return false;
    }
    return true;
}

/**
 * Calculates the number of bytes in the specified cl_mem image region.
 * This implementation assumes 1 byte per element, because we cannot the
 * image type.
 *
 * @param region      the image region
 * @param row_pitch   the row pitch
 * @param slice_pitch the slice pitch
 *
 * @return the region size in bytes
 */
static int calculateImageSize(final PointerBuffer region, long row_pitch, long slice_pitch) {
    if ( !LWJGLUtil.CHECKS )
        return 0;

    final long w = region.get(0);
    final long h = region.get(1);
    final long d = region.get(2);

    if ( LWJGLUtil.DEBUG && (w < 1 || h < 1 || d < 1) )
        throw new IllegalArgumentException("Invalid cl_mem image region dimensions: " + w + " x " + h + " x " + d);

    if ( row_pitch == 0 )
        row_pitch = w;
    else if ( LWJGLUtil.DEBUG && row_pitch < w )
        throw new IllegalArgumentException("Invalid row pitch specified: " + row_pitch);

    if ( slice_pitch == 0 )
        slice_pitch = row_pitch * h;
    else if ( LWJGLUtil.DEBUG && slice_pitch < (row_pitch * h) )
        throw new IllegalArgumentException("Invalid slice pitch specified: " + slice_pitch);

    return (int)(slice_pitch * d);

}

/**
 * Calculates the number of bytes in the specified 2D image.
 *
 * @param format    the cl_image_format struct
 * @param w         the image width
 * @param h         the image height
 * @param row_pitch the image row pitch
 *
 * @return the 2D image size in bytes
 */
static int calculateImage2DSize(final ByteBuffer format, final long w, final long h, long row_pitch) {
    if ( !LWJGLUtil.CHECKS )
        return 0;

    if ( LWJGLUtil.DEBUG && (w < 1 || h < 1) )
        throw new IllegalArgumentException("Invalid 2D image dimensions: " + w + " x " + h);

    final int elementSize = getElementSize(format);

    if ( row_pitch == 0 )
        row_pitch = w * elementSize;
    else if ( LWJGLUtil.DEBUG && ((row_pitch < w * elementSize) || (row_pitch % elementSize != 0)) )
        throw new IllegalArgumentException("Invalid image_row_pitch specified: " + row_pitch);

    return (int)(row_pitch * h);
}

/**
 * Calculates the number of bytes in the specified 3D image.
 *
 * @param format      the cl_image_format struct
 * @param w           the image width
 * @param h           the image height
 * @param d           the image depth
 * @param row_pitch   the image row pitch
 * @param slice_pitch the image slice pitch
 *
 * @return the 3D image size in bytes
 */
static int calculateImage3DSize(final ByteBuffer format, final long w, final long h, final long d, long row_pitch, long slice_pitch) {
    if ( !LWJGLUtil.CHECKS )
        return 0;

    if ( LWJGLUtil.DEBUG && (w < 1 || h < 1 || d < 2) )
        throw new IllegalArgumentException("Invalid 3D image dimensions: " + w + " x " + h + " x " + d);

    final int elementSize = getElementSize(format);

    if ( row_pitch == 0 )
        row_pitch = w * elementSize;
    else if ( LWJGLUtil.DEBUG && ((row_pitch < w * elementSize) || (row_pitch % elementSize != 0)) )
        throw new IllegalArgumentException("Invalid image_row_pitch specified: " + row_pitch);

    if ( slice_pitch == 0 )
        slice_pitch = row_pitch * h;
    else if ( LWJGLUtil.DEBUG && ((row_pitch < row_pitch * h) || (slice_pitch % row_pitch != 0)) )
        throw new IllegalArgumentException("Invalid image_slice_pitch specified: " + row_pitch);

    return (int)(slice_pitch * d);
}

/**
 * Returns the number of channels in the specified cl_channel_order.
 *
 * @param channelOrder the cl_channel_order
 *
 * @return the number of channels
 */
private static int getChannelCount(final int channelOrder) {
    switch ( channelOrder ) {
        case CL_R:
        case CL_A:
        case CL_INTENSITY:
        case CL_LUMINANCE:
        case CL_Rx:
            return 1;
        case CL_RG:
        case CL_RA:
        case CL_RGx:
            return 2;
        case CL_RGB:
        case CL_RGBx:
            return 3;
        case CL_RGBA:
        case CL_BGRA:
        case CL_ARGB:
            return 4;
        default:
            throw new IllegalArgumentException("Invalid cl_channel_order specified: " + LWJGLUtil.toHexString(channelOrder));
    }
}

/**
 * Returns the number of bytes in the specified cl_channel_type.
 *
 * @param channelType the cl_channel_type
 *
 * @return the number of bytes
 */
private static int getChannelSize(final int channelType) {
    switch ( channelType ) {
        case CL_SNORM_INT8:
        case CL_UNORM_INT8:
        case CL_SIGNED_INT8:
        case CL_UNSIGNED_INT8:
            return 1;
        case CL_SNORM_INT16:
        case CL_UNORM_INT16:
        case CL_UNORM_SHORT_565:
        case CL_UNORM_SHORT_555:
        case CL_SIGNED_INT16:
        case CL_UNSIGNED_INT16:
        case CL_HALF_FLOAT:
            return 2;
        case CL_UNORM_INT_101010:
        case CL_SIGNED_INT32:
        case CL_UNSIGNED_INT32:
        case CL_FLOAT:
            return 4;
        default:
            throw new IllegalArgumentException("Invalid cl_channel_type specified: " + LWJGLUtil.toHexString(channelType));
    }
}

/**
  * Tests debug mode
  */
 private void testDebug() {
   System.out.println("==== Test Debug ====");
   if (LWJGLUtil.DEBUG) {
     LWJGLUtil.log("Debug is enabled, you should now see output from LWJGL during the following tests.");
   } else {
     System.out.println("Debug is not enabled. Please set the org.lwjgl.Sys.debug property to true to enable debugging");
     System.out.println("Example:\n  java -Dorg.lwjgl.util.Debug=true ...");
     System.out.println("You will not see any debug output in the following tests.");
   }    

   // get some display modes, to force some debug info
try {
    Display.getAvailableDisplayModes();
} catch (LWJGLException e) {
    throw new RuntimeException(e);
}

   System.out.println("---- Test Debug ----\n");
 }

private void saveWindowParams() {
    int width = Display.getWidth();
    int height = Display.getHeight();
    int x = Display.getX();
    int y = Display.getY();

    //FIXME by some reason actual window position shifted by 6 pixels on Windows (by 12 at y when maximized)
    if (LWJGLUtil.getPlatform() == LWJGLUtil.PLATFORM_WINDOWS) {
        x += 6;
        y += 6;
    }

    Preferences prefs = Gdx.app.getPreferences("window_params.xml");
    prefs.putInteger("x", x);
    prefs.putInteger("y", y);
    prefs.putInteger("width", width);
    prefs.putInteger("height", height);
    prefs.flush();
}

public void destroyWindow() {
    lockAWT();
    try {
        if (parent != null) {
            parent.removeFocusListener(focus_listener);
        }
        try {
            setNativeCursor(null);
        } catch (LWJGLException e) {
            LWJGLUtil.log("Failed to reset cursor: " + e.getMessage());
        }
        nDestroyCursor(getDisplay(), blank_cursor);
        blank_cursor = None;
        ungrabKeyboard();
        nDestroyWindow(getDisplay(), getWindow());
        decDisplay();

        if ( current_window_mode != WINDOWED )
            Compiz.setLegacyFullscreenSupport(false);
    } finally {
        unlockAWT();
    }
}

public static int getNativeCursorCapabilities() {
    if (LWJGLUtil.getPlatform() != LWJGLUtil.PLATFORM_MACOSX || LWJGLUtil.isMacOSXEqualsOrBetterThan(10, 4)) {
        int cursor_colors = Toolkit.getDefaultToolkit().getMaximumCursorColors();
        boolean supported = cursor_colors >= Short.MAX_VALUE && getMaxCursorSize() > 0;
        int caps = supported ? org.lwjgl.input.Cursor.CURSOR_8_BIT_ALPHA | org.lwjgl.input.Cursor.CURSOR_ONE_BIT_TRANSPARENCY: 0 | org.lwjgl.input.Cursor.CURSOR_ANIMATION;
        return caps;
    } else {
        /* Return no capability in Mac OS X 10.3 and earlier , as there are two unsolved bugs (both reported to apple along with
           minimal test case):
           1. When a custom cursor (or some standard) java.awt.Cursor is assigned to a
           Componennt, it is reset to the default pointer cursor when the window is de-
           activated and the re-activated. The Cursor can not be reset to the custom cursor,
           with another setCursor.
           2. When the cursor is moving in the top pixel row (y = 0 in AWT coordinates) in fullscreen
           mode, no mouse moved events are reported, even though mouse pressed/released and dragged
           events are reported
         */
        return 0;
    }
}

/**
 * Use reflection to access the JDK 1.5 pointer location, if possible and
 * only if the given component is on the same screen as the cursor. Return
 * null otherwise.
 */
private static Point getPointerLocation(final Component component) {
    try {
        final GraphicsConfiguration config = component.getGraphicsConfiguration();
        if (config != null) {
            PointerInfo pointer_info = AccessController.doPrivileged(new PrivilegedExceptionAction<PointerInfo>() {
                public PointerInfo run() throws Exception {
                    return MouseInfo.getPointerInfo();
                }
            });
            GraphicsDevice device = pointer_info.getDevice();
            if (device == config.getDevice()) {
                return pointer_info.getLocation();
            }
            return null;
        }
    } catch (Exception e) {
        LWJGLUtil.log("Failed to query pointer location: " + e.getCause());
    }
    return null;
}

private static boolean isXF86VidModeSupported() {
    lockAWT();
    try {
        incDisplay();
        try {
            return nIsXF86VidModeSupported(getDisplay());
        } finally {
            decDisplay();
        }
    } catch (LWJGLException e) {
        LWJGLUtil.log("Got exception while querying XF86VM support: " + e);
        return false;
    } finally {
        unlockAWT();
    }
}

/**
 * Returns the entire list of possible fullscreen display modes as an array, in no
 * particular order. Although best attempts to filter out invalid modes are done, any
 * given mode is not guaranteed to be available nor is it guaranteed to be within the
 * current monitor specs (this is especially a problem with the frequency parameter).
 * Furthermore, it is not guaranteed that create() will detect an illegal display mode.
 * <p/>
 * The only certain way to check
 * is to call create() and make sure it works.
 * Only non-palette-indexed modes are returned (ie. bpp will be 16, 24, or 32).
 * Only DisplayModes from this call can be used when the Display is in fullscreen
 * mode.
 *
 * @return an array of all display modes the system reckons it can handle.
 */
public static DisplayMode[] getAvailableDisplayModes() throws LWJGLException {
    synchronized ( GlobalLock.lock ) {
        DisplayMode[] unfilteredModes = display_impl.getAvailableDisplayModes();

        if ( unfilteredModes == null ) {
            return new DisplayMode[0];
        }

        // We'll use a HashSet to filter out the duplicated modes
        HashSet<DisplayMode> modes = new HashSet<DisplayMode>(unfilteredModes.length);

        modes.addAll(Arrays.asList(unfilteredModes));
        DisplayMode[] filteredModes = new DisplayMode[modes.size()];
        modes.toArray(filteredModes);

        LWJGLUtil.log("Removed " + (unfilteredModes.length - filteredModes.length) + " duplicate displaymodes");

        return filteredModes;
    }
}

public static int getNativeCursorCapabilities() {
    if (LWJGLUtil.getPlatform() != LWJGLUtil.PLATFORM_MACOSX || LWJGLUtil.isMacOSXEqualsOrBetterThan(10, 4)) {
        int cursor_colors = Toolkit.getDefaultToolkit().getMaximumCursorColors();
        boolean supported = cursor_colors >= Short.MAX_VALUE && getMaxCursorSize() > 0;
        int caps = supported ? org.lwjgl.input.Cursor.CURSOR_8_BIT_ALPHA | org.lwjgl.input.Cursor.CURSOR_ONE_BIT_TRANSPARENCY: 0 | org.lwjgl.input.Cursor.CURSOR_ANIMATION;
        return caps;
    } else {
        /* Return no capability in Mac OS X 10.3 and earlier , as there are two unsolved bugs (both reported to apple along with
           minimal test case):
           1. When a custom cursor (or some standard) java.awt.Cursor is assigned to a
           Componennt, it is reset to the default pointer cursor when the window is de-
           activated and the re-activated. The Cursor can not be reset to the custom cursor,
           with another setCursor.
           2. When the cursor is moving in the top pixel row (y = 0 in AWT coordinates) in fullscreen
           mode, no mouse moved events are reported, even though mouse pressed/released and dragged
           events are reported
         */
        return 0;
    }
}

public static void setup(MappedObject mo, ByteBuffer buffer, int align, int sizeof) {
    if ( LWJGLUtil.CHECKS && mo.baseAddress != 0L )
        throw new IllegalStateException("this method should not be called by user-code");

    if ( LWJGLUtil.CHECKS && !buffer.isDirect() )
        throw new IllegalArgumentException("bytebuffer must be direct");
    mo.preventGC = buffer;

    if ( LWJGLUtil.CHECKS && align <= 0 )
        throw new IllegalArgumentException("invalid alignment");

    if ( LWJGLUtil.CHECKS && (sizeof <= 0 || sizeof % align != 0) )
        throw new IllegalStateException("sizeof not a multiple of alignment");

    long addr = MemoryUtil.getAddress(buffer);
    if ( LWJGLUtil.CHECKS && addr % align != 0 )
        throw new IllegalStateException("buffer address not aligned on " + align + " bytes");

    mo.baseAddress = mo.viewAddress = addr;
}

public final synchronized ByteBuffer lockAndGetHandle() throws LWJGLException {
    Thread this_thread = Thread.currentThread();
    while (locking_thread != null && locking_thread != this_thread) {
        try {
            wait();
        } catch (InterruptedException e) {
            LWJGLUtil.log("Interrupted while waiting for PeerInfo lock: " + e);
        }
    }
    if (lock_count == 0) {
        locking_thread = this_thread;
        doLockAndInitHandle();
    }
    lock_count++;
    return getHandle();
}

public void update() {
    nUpdate();

    if ( !isFocused && parent != null && parent_focused.compareAndSet(true, false) ) {
        setFocus(getHwnd());
    }

    if (redoMakeContextCurrent) {
        redoMakeContextCurrent = false;
        /**
         * WORKAROUND:
         * Making the context current (redundantly) when the window
         * is maximized helps some gfx cards recover from fullscreen
         */
        try {
            Context context = ((DrawableLWJGL)Display.getDrawable()).getContext();
            if (context != null && context.isCurrent())
                context.makeCurrent();
        } catch (LWJGLException e) {
            LWJGLUtil.log("Exception occurred while trying to make context current: " + e);
        }
    }
}

public void destroyWindow() {
    lockAWT();
    try {
        if (parent != null) {
            parent.removeFocusListener(focus_listener);
        }
        try {
            setNativeCursor(null);
        } catch (LWJGLException e) {
            LWJGLUtil.log("Failed to reset cursor: " + e.getMessage());
        }
        nDestroyCursor(getDisplay(), blank_cursor);
        blank_cursor = None;
        ungrabKeyboard();
        nDestroyWindow(getDisplay(), getWindow());
        decDisplay();

        if ( current_window_mode != WINDOWED )
            Compiz.setLegacyFullscreenSupport(false);
    } finally {
        unlockAWT();
    }
}

/**
 * Calculates the number of bytes in the specified cl_mem image region.
 * This implementation assumes 1 byte per element, because we cannot the
 * image type.
 *
 * @param region      the image region
 * @param row_pitch   the row pitch
 * @param slice_pitch the slice pitch
 *
 * @return the region size in bytes
 */
static int calculateImageSize(final PointerBuffer region, long row_pitch, long slice_pitch) {
    if ( !LWJGLUtil.CHECKS )
        return 0;

    final long w = region.get(0);
    final long h = region.get(1);
    final long d = region.get(2);

    if ( LWJGLUtil.DEBUG && (w < 1 || h < 1 || d < 1) )
        throw new IllegalArgumentException("Invalid cl_mem image region dimensions: " + w + " x " + h + " x " + d);

    if ( row_pitch == 0 )
        row_pitch = w;
    else if ( LWJGLUtil.DEBUG && row_pitch < w )
        throw new IllegalArgumentException("Invalid row pitch specified: " + row_pitch);

    if ( slice_pitch == 0 )
        slice_pitch = row_pitch * h;
    else if ( LWJGLUtil.DEBUG && slice_pitch < (row_pitch * h) )
        throw new IllegalArgumentException("Invalid slice pitch specified: " + slice_pitch);

    return (int)(slice_pitch * d);

}

/**
 * Find a proper GraphicsConfiguration from the given GraphicsDevice and PixelFormat.
 *
 * @return The GraphicsConfiguration corresponding to a visual that matches the pixel format.
 */
public GraphicsConfiguration findConfiguration(GraphicsDevice device, PixelFormat pixel_format) throws LWJGLException {
    try {
        int screen = getScreenFromDevice(device);
        int visual_id_matching_format = findVisualIDFromFormat(screen, pixel_format);
        GraphicsConfiguration[] configurations = device.getConfigurations();
        for ( GraphicsConfiguration configuration : configurations ) {
            int visual_id = getVisualIDFromConfiguration(configuration);
            if ( visual_id == visual_id_matching_format )
                return configuration;
        }
    } catch (LWJGLException e) {
        LWJGLUtil.log("Got exception while trying to determine configuration: " + e);
    }
    return null; // In case we failed to locate the visual, or if we're not on a SUN JDK
}

/**
 * Helper method to ContextCapabilities. It will try to initialize the native stubs,
 * and remove the given extension name from the extension set if the initialization fails.
 */
static void initNativeStubs(final Class<?> extension_class, Set supported_extensions, String ext_name) {
    resetNativeStubs(extension_class);
    if ( supported_extensions.contains(ext_name) ) {
        try {
            AccessController.doPrivileged(new PrivilegedExceptionAction<Object>() {
                public Object run() throws Exception {
                    Method init_stubs_method = extension_class.getDeclaredMethod("initNativeStubs");
                    init_stubs_method.invoke(null);
                    return null;
                }
            });
        } catch (Exception e) {
            LWJGLUtil.log("Failed to initialize extension " + extension_class + " - exception: " + e);
            supported_extensions.remove(ext_name);
        }
    }
}

/**
 * Calculates the number of bytes in the specified 2D image.
 *
 * @param format    the cl_image_format struct
 * @param w         the image width
 * @param h         the image height
 * @param row_pitch the image row pitch
 *
 * @return the 2D image size in bytes
 */
static int calculateImage2DSize(final ByteBuffer format, final long w, final long h, long row_pitch) {
    if ( !LWJGLUtil.CHECKS )
        return 0;

    if ( LWJGLUtil.DEBUG && (w < 1 || h < 1) )
        throw new IllegalArgumentException("Invalid 2D image dimensions: " + w + " x " + h);

    final int elementSize = getElementSize(format);

    if ( row_pitch == 0 )
        row_pitch = w * elementSize;
    else if ( LWJGLUtil.DEBUG && ((row_pitch < w * elementSize) || (row_pitch % elementSize != 0)) )
        throw new IllegalArgumentException("Invalid image_row_pitch specified: " + row_pitch);

    return (int)(row_pitch * h);
}

public int getMaxCursorSize() {
    lockAWT();
    try {
        incDisplay();
        try {
            return nGetMaxCursorSize(getDisplay(), getWindow());
        } finally {
            decDisplay();
        }
    } catch (LWJGLException e) {
        LWJGLUtil.log("Exception occurred in getMaxCursorSize: " + e);
        return 0;
    } finally {
        unlockAWT();
    }
}

public int getMinCursorSize() {
    lockAWT();
    try {
        incDisplay();
        try {
            return nGetMinCursorSize(getDisplay(), getWindow());
        } finally {
            decDisplay();
        }
    } catch (LWJGLException e) {
        LWJGLUtil.log("Exception occurred in getMinCursorSize: " + e);
        return 0;
    } finally {
        unlockAWT();
    }
}