/*

 * Copyright (c) 2007, 2014, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

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 */

package sun.java2d.d3d;

import java.awt.Color;

import java.awt.Component;

import java.awt.Container;

import java.awt.Font;

import java.awt.Graphics2D;

import java.awt.Rectangle;

import java.awt.Window;

import java.security.AccessController;

import java.security.PrivilegedAction;

import java.util.ArrayList;

import java.util.HashMap;

import sun.awt.AWTAccessor;

import sun.awt.util.ThreadGroupUtils;

import sun.awt.Win32GraphicsConfig;

import sun.awt.windows.WComponentPeer;

import sun.java2d.InvalidPipeException;

import sun.java2d.ScreenUpdateManager;

import sun.java2d.SunGraphics2D;

import sun.java2d.SurfaceData;

import sun.java2d.windows.GDIWindowSurfaceData;

import sun.java2d.d3d.D3DSurfaceData.D3DWindowSurfaceData;

import sun.java2d.windows.WindowsFlags;

/**

 * This class handles rendering to the screen with the D3D pipeline.

 *

 * Since it is not possible to render directly to the front buffer

 * with D3D9, we create a swap chain surface (with COPY effect) in place of the

 * GDIWindowSurfaceData. A background thread handles the swap chain flips.

 *

 * There are some restrictions to which windows we would use this for.

 * @see #createScreenSurface()

 */

public class D3DScreenUpdateManager extends ScreenUpdateManager

    implements Runnable

{

    /**

     * A window must be at least MIN_WIN_SIZE in one or both dimensions

     * to be considered for the update manager.

     */

    private static final int MIN_WIN_SIZE = 150;

    private volatile boolean done;

    private volatile Thread screenUpdater;

    private boolean needsUpdateNow;

    /**

     * Object used by the screen updater thread for waiting

     */

    private Object runLock = new Object();

    /**

     * List of D3DWindowSurfaceData surfaces. Surfaces are added to the

     * list when a graphics object is created, and removed when the surface

     * is invalidated.

     */

    private ArrayList<D3DWindowSurfaceData> d3dwSurfaces;

    /**

     * Cache of GDIWindowSurfaceData surfaces corresponding to the

     * D3DWindowSurfaceData surfaces. Surfaces are added to the list when

     * a d3dw surface is lost and could not be restored (due to lack of vram,

     * for example), and removed then the d3dw surface is invalidated.

     */

    private HashMap<D3DWindowSurfaceData, GDIWindowSurfaceData> gdiSurfaces;

    public D3DScreenUpdateManager() {

        done = false;

        AccessController.doPrivileged(

                (PrivilegedAction<Void>) () -> {

                    ThreadGroup rootTG = ThreadGroupUtils.getRootThreadGroup();

                    Thread shutdown = new Thread(rootTG, () -> {

                        done = true;

                        wakeUpUpdateThread();

                    });

                    shutdown.setContextClassLoader(null);

                    try {

                        Runtime.getRuntime().addShutdownHook(shutdown);

                    } catch (Exception e) {

                        done = true;

                    }

                    return null;

                }

        );

    }

    /**

     * If possible, creates a D3DWindowSurfaceData (which is actually

     * a back-buffer surface). If the creation fails, returns GDI

     * onscreen surface instead.

     *

     * Note that the created D3D surface does not initialize the native

     * resources (and is marked lost) to avoid wasting video memory. It is

     * restored when a graphics object is requested from the peer.

     *

     * Note that this method is called from a synchronized block in

     * WComponentPeer, so we don't need to synchronize

     *

     * Note that we only create a substibute d3dw surface if certain conditions

     * are met

     * <ul>

     *  <li>the fake d3d rendering on screen is not disabled via flag

     *  <li>d3d on the device is enabled

     *  <li>surface is larger than MIN_WIN_SIZE (don't bother for smaller ones)

     *  <li>it doesn't have a backBuffer for a BufferStrategy already

     *  <li>the peer is either Canvas, Panel, Window, Frame,

     *  Dialog or EmbeddedFrame

     * </ul>

     *

     * @param gc GraphicsConfiguration on associated with the surface

     * @param peer peer for which the surface is to be created

     * @param bbNum number of back-buffers requested. if this number is >0,

     * method returns GDI surface (we don't want to have two swap chains)

     * @param isResize whether this surface is being created in response to

     * a component resize event. This determines whether a repaint event will

     * be issued after a surface is created: it will be if <code>isResize</code>

     * is <code>true</code>.

     * @return surface data to be use for onscreen rendering

     */

    @Override

    public SurfaceData createScreenSurface(Win32GraphicsConfig gc,

                                           WComponentPeer peer,

                                           int bbNum, boolean isResize)

    {

        if (done || !(gc instanceof D3DGraphicsConfig)) {

            return super.createScreenSurface(gc, peer, bbNum, isResize);

        }

        SurfaceData sd = null;

        if (canUseD3DOnScreen(peer, gc, bbNum)) {

            try {

                // note that the created surface will be in the "lost"

                // state, it will be restored prior to rendering to it

                // for the first time. This is done so that vram is not

                // wasted for surfaces never rendered to

                sd = D3DSurfaceData.createData(peer);

            }  catch (InvalidPipeException ipe) {

                sd = null;

            }

        }

        if (sd == null) {

            sd = GDIWindowSurfaceData.createData(peer);

            // note that we do not add this surface to the list of cached gdi

            // surfaces as there's no d3dw surface to associate it with;

            // this peer will have a gdi surface until next time a surface

            // will need to be replaced

        }

        if (isResize) {

            // since we'd potentially replaced the back-buffer surface

            // (either with another bb, or a gdi one), the

            // component will need to be completely repainted;

            // this only need to be done when the surface is created in

            // response to a resize event since when a component is created it

            // will be repainted anyway

            repaintPeerTarget(peer);

        }

        return sd;

    }

    /**

     * Determines if we can use a d3d surface for onscreen rendering for this

     * peer.

     * We only create onscreen d3d surfaces if the following conditions are met:

     *  - d3d is enabled on this device and onscreen emulation is enabled

     *  - window is big enough to bother (either dimension > MIN_WIN_SIZE)

     *  - this heavyweight doesn't have a BufferStrategy

     *  - if we are in full-screen mode then it must be the peer of the

     *    full-screen window (since there could be only one SwapChain in fs)

     *    and it must not have any heavyweight children

     *    (as Present() doesn't respect component clipping in fullscreen mode)

     *  - it's one of the classes likely to have custom rendering worth

     *    accelerating

     *

     * @returns true if we can use a d3d surface for this peer's onscreen

     *          rendering

     */

    public static boolean canUseD3DOnScreen(final WComponentPeer peer,

                                            final Win32GraphicsConfig gc,

                                            final int bbNum)

    {

        if (!(gc instanceof D3DGraphicsConfig)) {

            return false;

        }

        D3DGraphicsConfig d3dgc = (D3DGraphicsConfig)gc;

        D3DGraphicsDevice d3dgd = d3dgc.getD3DDevice();

        String peerName = peer.getClass().getName();

        Rectangle r = peer.getBounds();

        Component target = (Component)peer.getTarget();

        Window fsw = d3dgd.getFullScreenWindow();

        return

            WindowsFlags.isD3DOnScreenEnabled() &&

            d3dgd.isD3DEnabledOnDevice() &&

            peer.isAccelCapable() &&

            (r.width > MIN_WIN_SIZE || r.height > MIN_WIN_SIZE) &&

            bbNum == 0 &&

            (fsw == null || (fsw == target && !hasHWChildren(target))) &&

            (peerName.equals("sun.awt.windows.WCanvasPeer") ||

             peerName.equals("sun.awt.windows.WDialogPeer") ||

             peerName.equals("sun.awt.windows.WPanelPeer")  ||

             peerName.equals("sun.awt.windows.WWindowPeer") ||

             peerName.equals("sun.awt.windows.WFramePeer")  ||

             peerName.equals("sun.awt.windows.WEmbeddedFramePeer"));

    }

    /**

     * Creates a graphics object for the passed in surface data. If

     * the surface is lost, it is restored.

     * If the surface wasn't lost or the restoration was successful

     * the surface is added to the list of maintained surfaces

     * (if it hasn't been already).

     *

     * If the updater thread hasn't been created yet , it will be created and

     * started.

     *

     * @param sd surface data for which to create SunGraphics2D

     * @param peer peer associated with the surface data

     * @param fgColor fg color to be used in graphics

     * @param bgColor bg color to be used in graphics

     * @param font font to be used in graphics

     * @return a SunGraphics2D object for the surface (or for temp GDI

     * surface data)

     */

    @Override

    public Graphics2D createGraphics(SurfaceData sd,

            WComponentPeer peer, Color fgColor, Color bgColor, Font font)

    {

        if (!done && sd instanceof D3DWindowSurfaceData) {

            D3DWindowSurfaceData d3dw = (D3DWindowSurfaceData)sd;

            if (!d3dw.isSurfaceLost() || validate(d3dw)) {

                trackScreenSurface(d3dw);

                return new SunGraphics2D(sd, fgColor, bgColor, font);

            }

            // could not restore the d3dw surface, use the cached gdi surface

            // instead for this graphics object; note that we do not track

            // this new gdi surface, it is only used for this graphics

            // object

            sd = getGdiSurface(d3dw);

        }

        return super.createGraphics(sd, peer, fgColor, bgColor, font);

    }

    /**

     * Posts a repaint event for the peer's target to the EDT

     * @param peer for which target's the repaint should be issued

     */

    private void repaintPeerTarget(WComponentPeer peer) {

        Component target = (Component)peer.getTarget();

        Rectangle bounds = AWTAccessor.getComponentAccessor().getBounds(target);

        // the system-level painting operations should call the handlePaint()

        // method of the WComponentPeer class to repaint the component;

        // calling repaint() forces AWT to make call to update()

        peer.handlePaint(0, 0, bounds.width, bounds.height);

    }

    /**

     * Adds a surface to the list of tracked surfaces.

     *

     * @param d3dw the surface to be added

     */

    private void trackScreenSurface(SurfaceData sd) {

        if (!done && sd instanceof D3DWindowSurfaceData) {

            synchronized (this) {

                if (d3dwSurfaces == null) {

                    d3dwSurfaces = new ArrayList<D3DWindowSurfaceData>();

                }

                D3DWindowSurfaceData d3dw = (D3DWindowSurfaceData)sd;

                if (!d3dwSurfaces.contains(d3dw)) {

                    d3dwSurfaces.add(d3dw);

                }

            }

            startUpdateThread();

        }

    }

    @Override

    public synchronized void dropScreenSurface(SurfaceData sd) {

        if (d3dwSurfaces != null && sd instanceof D3DWindowSurfaceData) {

            D3DWindowSurfaceData d3dw = (D3DWindowSurfaceData)sd;

            removeGdiSurface(d3dw);

            d3dwSurfaces.remove(d3dw);

        }

    }

    @Override

    public SurfaceData getReplacementScreenSurface(WComponentPeer peer,

                                                   SurfaceData sd)

    {

        SurfaceData newSurface = super.getReplacementScreenSurface(peer, sd);

        // if some outstanding graphics context wants to get a replacement we

        // need to make sure that the new surface (if it is accelerated) is

        // being tracked

        trackScreenSurface(newSurface);

        return newSurface;

    }

    /**

     * Remove the gdi surface corresponding to the passed d3dw surface

     * from list of the cached gdi surfaces.

     *

     * @param d3dw surface for which associated gdi surface is to be removed

     */

    private void removeGdiSurface(final D3DWindowSurfaceData d3dw) {

        if (gdiSurfaces != null) {

            GDIWindowSurfaceData gdisd = gdiSurfaces.get(d3dw);

            if (gdisd != null) {

                gdisd.invalidate();

                gdiSurfaces.remove(d3dw);

            }

        }

    }

    /**

     * If the update thread hasn't yet been created, it will be;

     * otherwise it is awaken

     */

    private synchronized void startUpdateThread() {

        if (screenUpdater == null) {

            screenUpdater = AccessController.doPrivileged(

                    (PrivilegedAction<Thread>) () -> {

                        ThreadGroup rootTG = ThreadGroupUtils.getRootThreadGroup();

                        Thread t = new Thread(rootTG,

                                D3DScreenUpdateManager.this,

                                "D3D Screen Updater");

                        // REMIND: should it be higher?

                        t.setPriority(Thread.NORM_PRIORITY + 2);

                        t.setDaemon(true);

                        return t;

                    });

            screenUpdater.start();

        } else {

            wakeUpUpdateThread();

        }

    }

    /**

     * Wakes up the screen updater thread.

     *

     * This method is not synchronous, it doesn't wait

     * for the updater thread to complete the updates.

     *

     * It should be used when it is not necessary to wait for the

     * completion, for example, when a new surface had been added

     * to the list of tracked surfaces (which means that it's about

     * to be rendered to).

     */

    public void wakeUpUpdateThread() {

        synchronized (runLock) {

            runLock.notifyAll();

        }

    }

    /**

     * Wakes up the screen updater thread and waits for the completion

     * of the update.

     *

     * This method is called from Toolkit.sync() or

     * when there was a copy from a VI to the screen

     * so that swing applications would not appear to be

     * sluggish.

     */

    public void runUpdateNow() {

        synchronized (this) {

            // nothing to do if the updater thread hadn't been started or if

            // there are no tracked surfaces

            if (done || screenUpdater == null ||

                d3dwSurfaces  == null || d3dwSurfaces.size() == 0)

            {

                return;

            }

        }

        synchronized (runLock) {

            needsUpdateNow = true;

            runLock.notifyAll();

            while (needsUpdateNow) {

                try {

                    runLock.wait();

                } catch (InterruptedException e) {}

            }

        }

    }

    public void run() {

        while (!done) {

            synchronized (runLock) {

                // If the list is empty, suspend the thread until a

                // new surface is added. Note that we have to check before

                // wait() (and inside the runLock), otherwise we could miss a

                // notify() when a new surface is added and sleep forever.

                long timeout = d3dwSurfaces.size() > 0 ? 100 : 0;

                // don't go to sleep if there's a thread waiting for an update

                if (!needsUpdateNow) {

                    try { runLock.wait(timeout); }

                        catch (InterruptedException e) {}

                }

                // if we were woken up, there are probably surfaces in the list,

                // no need to check if the list is empty

            }

            // make a copy to avoid synchronization during the loop

            D3DWindowSurfaceData surfaces[] = new D3DWindowSurfaceData[] {};

            synchronized (this) {

                surfaces = d3dwSurfaces.toArray(surfaces);

            }

            for (D3DWindowSurfaceData sd : surfaces) {

                // skip invalid surfaces (they could have become invalid

                // after we made a copy of the list) - just a precaution

                if (sd.isValid() && (sd.isDirty() || sd.isSurfaceLost())) {

                    if (!sd.isSurfaceLost()) {

                        // the flip and the clearing of the dirty state

                        // must be done under the lock, otherwise it's

                        // possible to miss an update to the surface

                        D3DRenderQueue rq = D3DRenderQueue.getInstance();

                        rq.lock();

                        try {

                            Rectangle r = sd.getBounds();

                            D3DSurfaceData.swapBuffers(sd, 0, 0,

                                                       r.width, r.height);

                            sd.markClean();

                        } finally {

                            rq.unlock();

                        }

                    } else if (!validate(sd)) {

                        // it is possible that the validation may never

                        // succeed, we need to detect this and replace

                        // the d3dw surface with gdi; the replacement of

                        // the surface will also trigger a repaint

                        sd.getPeer().replaceSurfaceDataLater();

                    }

                }

            }

            synchronized (runLock) {

                needsUpdateNow = false;

                runLock.notifyAll();

            }

        }

    }

    /**

     * Restores the passed surface if it was lost, resets the lost status.

     * @param sd surface to be validated

     * @return true if surface wasn't lost or if restoration was successful,

     * false otherwise

     */

    private boolean validate(D3DWindowSurfaceData sd) {

        if (sd.isSurfaceLost()) {

            try {

                sd.restoreSurface();

                // if succeeded, first fill the surface with bg color

                // note: use the non-synch method to avoid incorrect lock order

                Color bg = sd.getPeer().getBackgroundNoSync();

                SunGraphics2D sg2d = new SunGraphics2D(sd, bg, bg, null);

                sg2d.fillRect(0, 0, sd.getBounds().width, sd.getBounds().height);

                sg2d.dispose();

                // now clean the dirty status so that we don't flip it

                // next time before it gets repainted; it is safe

                // to do without the lock because we will issue a

                // repaint anyway so we will not lose any rendering

                sd.markClean();

                // since the surface was successfully restored we need to

                // repaint whole window to repopulate the back-buffer

                repaintPeerTarget(sd.getPeer());

            } catch (InvalidPipeException ipe) {

                return false;

            }

        }

        return true;

    }

    /**

     * Creates (or returns a cached one) gdi surface for the same peer as

     * the passed d3dw surface has.

     *

     * @param d3dw surface used as key into the cache

     * @return gdi window surface associated with the d3d window surfaces' peer

     */

    private synchronized SurfaceData getGdiSurface(D3DWindowSurfaceData d3dw) {

        if (gdiSurfaces == null) {

            gdiSurfaces =

                new HashMap<D3DWindowSurfaceData, GDIWindowSurfaceData>();

        }

        GDIWindowSurfaceData gdisd = gdiSurfaces.get(d3dw);

        if (gdisd == null) {

            gdisd = GDIWindowSurfaceData.createData(d3dw.getPeer());

            gdiSurfaces.put(d3dw, gdisd);

        }

        return gdisd;

    }

    /**

     * Returns true if the component has heavyweight children.

     *

     * @param comp component to check for hw children

     * @return true if Component has heavyweight children

     */