aboutsummaryrefslogtreecommitdiffstats
path: root/src/jogl/classes/com/jogamp/opengl/util/TileRendererBase.java
blob: 133c3866fe0858a73663ade8042bf0209a8ef34c (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
/**
 * Copyright 2013 JogAmp Community. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification, are
 * permitted provided that the following conditions are met:
 * 
 *    1. Redistributions of source code must retain the above copyright notice, this list of
 *       conditions and the following disclaimer.
 * 
 *    2. Redistributions in binary form must reproduce the above copyright notice, this list
 *       of conditions and the following disclaimer in the documentation and/or other materials
 *       provided with the distribution.
 * 
 * THIS SOFTWARE IS PROVIDED BY JogAmp Community ``AS IS'' AND ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
 * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL JogAmp Community OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 * 
 * The views and conclusions contained in the software and documentation are those of the
 * authors and should not be interpreted as representing official policies, either expressed
 * or implied, of JogAmp Community.
 * 
 * ---------------------
 * 
 * Based on Brian Paul's tile rendering library, found
 * at <a href = "http://www.mesa3d.org/brianp/TR.html">http://www.mesa3d.org/brianp/TR.html</a>.
 * 
 * Copyright (C) 1997-2005 Brian Paul. 
 * Licensed under BSD-compatible terms with permission of the author. 
 * See LICENSE.txt for license information.
 */
package com.jogamp.opengl.util;

import javax.media.nativewindow.util.Dimension;
import javax.media.nativewindow.util.DimensionImmutable;
import javax.media.opengl.GL;
import javax.media.opengl.GL2ES3;
import javax.media.opengl.GLAutoDrawable;
import javax.media.opengl.GLCapabilitiesImmutable;
import javax.media.opengl.GLDrawable;
import javax.media.opengl.GLEventListener;
import javax.media.opengl.GLException;
import javax.media.opengl.GLFBODrawable;
import jogamp.opengl.Debug;

/**
 * A fairly direct port of Brian Paul's tile rendering library, found
 * at <a href = "http://www.mesa3d.org/brianp/TR.html">
 * http://www.mesa3d.org/brianp/TR.html </a> . I've java-fied it, but
 * the functionality is the same.
 * <p>
 * Original code Copyright (C) 1997-2005 Brian Paul. Licensed under
 * BSD-compatible terms with permission of the author. See LICENSE.txt
 * for license information.
 * </p>
 * <p>
 * Enhanced for {@link GL} and {@link GL2ES3}, abstracted to suit {@link TileRenderer} and {@link RandomTileRenderer}.
 * </p>
 * <a name="pmvmatrix"><h5>PMV Matrix Considerations</h5></a>
 * <p>
 * The PMV matrix needs to be reshaped in user code
 * after calling {@link #beginTile(GL)}, See {@link #beginTile(GL)}.
 * </p>
 * <p> 
 * If {@link #attachToAutoDrawable(GLAutoDrawable) attaching to} an {@link GLAutoDrawable},
 * the {@link GLEventListener#reshape(GLAutoDrawable, int, int, int, int)} method
 * is being called after {@link #beginTile(GL)}.
 * It's implementation shall reshape the PMV matrix according to {@link #beginTile(GL)}. 
 * </p>
 * <a name="glprequirement"><h5>GL Profile Requirement</h5></a>
 * <p>
 * Note that {@link #setImageBuffer(GLPixelBuffer) image buffer} can only be used 
 * in conjunction w/ a {@link GL} instance &ge; {@link GL2ES3} passed to {@link #beginTile(GL)} and {@link #endTile(GL)}.<br>
 * This is due to setting up the {@link GL2ES3#GL_PACK_ROW_LENGTH pack row length} 
 * for an {@link #setImageSize(int, int) image width} != tile-width, which usually is the case.<br>
 * Hence a {@link GLException} is thrown in both methods,
 * if using an {@link #setImageBuffer(GLPixelBuffer) image buffer}
 * and passing a {@link GL} instance &lt; {@link GL2ES3}.
 * </p>
 * <p>
 * Further more, reading back of MSAA buffers is only supported since {@link GL2ES3}
 * since it requires to set the {@link GL2ES3#glReadBuffer(int) read-buffer}.
 * </p>
 * 
 * @author ryanm, sgothel
 */
public abstract class TileRendererBase {
    /**
     * The width of the final image. See {@link #getParam(int)}.
     */
    public static final int TR_IMAGE_WIDTH = 1;
    /**
     * The height of the final image. See {@link #getParam(int)}.
     */
    public static final int TR_IMAGE_HEIGHT = 2;
    /**
     * The x-pos of the current tile. See {@link #getParam(int)}.
     */
    public static final int TR_CURRENT_TILE_X_POS = 3;
    /**
     * The y-pos of the current tile. See {@link #getParam(int)}.
     */
    public static final int TR_CURRENT_TILE_Y_POS = 4;
    /**
     * The width of the current tile. See {@link #getParam(int)}.
     */
    public static final int TR_CURRENT_TILE_WIDTH = 5;
    /**
     * The height of the current tile. See {@link #getParam(int)}.
     */
    public static final int TR_CURRENT_TILE_HEIGHT = 6;
    
    /* pp */ static final boolean DEBUG = Debug.debug("TileRenderer");
    
    /** 
     * Notifies {@link GLEventListener} implementing this interface
     * that the owning {@link GLAutoDrawable} is {@link TileRendererBase#attachToAutoDrawable(GLAutoDrawable) attached} 
     * to a tile renderer or {@link TileRendererBase#detachFromAutoDrawable() detached} from it.
     */
    public static interface TileRendererNotify {
        /** The owning {@link GLAutoDrawable} is {@link TileRendererBase#attachToAutoDrawable(GLAutoDrawable) attached} to a {@link TileRendererBase}. */
        public void addTileRendererNotify(TileRendererBase tr);
        /** The owning {@link GLAutoDrawable} is {@link TileRendererBase#detachFromAutoDrawable() detached} from a {@link TileRendererBase}. */
        public void removeTileRendererNotify(TileRendererBase tr);
    }
    
    protected final Dimension imageSize = new Dimension(0, 0);
    protected final GLPixelStorageModes psm = new GLPixelStorageModes();
    protected GLPixelBuffer imageBuffer;
    protected GLPixelBuffer tileBuffer;
    protected boolean beginCalled = false;
    protected int currentTileXPos;
    protected int currentTileYPos;
    protected int currentTileWidth;
    protected int currentTileHeight;
    protected GLAutoDrawable glad;
    protected boolean gladRequiresPreSwap;
    protected boolean gladAutoSwapBufferMode = true;
    protected GLEventListener[] listeners;
    protected boolean[] listenersInit;
    protected GLEventListener glEventListenerPre = null;
    protected GLEventListener glEventListenerPost = null;

    private final String hashStr(Object o) {
        final int h = null != o ? o.hashCode() : 0;
        return "0x"+Integer.toHexString(h);
    }
    protected StringBuilder tileDetails(StringBuilder sb) {
        return sb.append("cur "+currentTileXPos+"/"+currentTileYPos+" "+currentTileWidth+"x"+currentTileHeight+", buffer "+hashStr(tileBuffer));
    }
    public StringBuilder toString(StringBuilder sb) {
        final int gladListenerCount = null != listeners ? listeners.length : 0;
        sb.append("tile[");
        tileDetails(sb);
        sb.append("], image[size "+imageSize+", buffer "+hashStr(imageBuffer)+"], glad["+
                gladListenerCount+" listener, pre "+(null!=glEventListenerPre)+", post "+(null!=glEventListenerPost)+", preSwap "+gladRequiresPreSwap+"]");
        return sb;
    }
    public String toString() {
        StringBuilder sb = new StringBuilder();
        return getClass().getSimpleName()+
                "["+toString(sb).toString()+"]";
    }
    
    protected TileRendererBase() {
    }

    /**
     * Gets the parameters of this TileRenderer object
     * 
     * @param pname The parameter name that is to be retrieved
     * @return the value of the parameter
     * @throws IllegalArgumentException if <code>pname</code> is not handled
     */
    public abstract int getParam(int pname) throws IllegalArgumentException;
    
    /**
     * Specify a buffer the tiles to be copied to. This is not
     * necessary for the creation of the final image, but useful if you
     * want to inspect each tile in turn.
     * 
     * @param buffer The buffer itself. Must be large enough to contain a random tile
     */
    public final void setTileBuffer(GLPixelBuffer buffer) {
        tileBuffer = buffer;
        if( DEBUG ) {
            System.err.println("TileRenderer: tile-buffer "+tileBuffer);
        }
    }

    /** @see #setTileBuffer(GLPixelBuffer) */
    public final GLPixelBuffer getTileBuffer() { return tileBuffer; }

    /**
     * Sets the desired size of the final image
     * 
     * @param width The width of the final image
     * @param height The height of the final image
     */
    public final void setImageSize(int width, int height) {
        imageSize.setWidth(width);
        imageSize.setHeight(height);
    }

    /** @see #setImageSize(int, int) */
    public final DimensionImmutable getImageSize() { return imageSize; }

    /**
     * Sets the buffer in which to store the final image
     * 
     * @param buffer the buffer itself, must be large enough to hold the final image
     */
    public final void setImageBuffer(GLPixelBuffer buffer) {
        imageBuffer = buffer;
        if( DEBUG ) {
            System.err.println("TileRenderer: image-buffer "+imageBuffer);
        }
    }

    /** @see #setImageBuffer(GLPixelBuffer) */
    public final GLPixelBuffer getImageBuffer() { return imageBuffer; }

    /* pp */ final void validateGL(GL gl) throws GLException {
        if( imageBuffer != null && !gl.isGL2ES3()) {
            throw new GLException("Using image-buffer w/ inssufficient GL context: "+gl.getContext().getGLVersion()+", "+gl.getGLProfile());
        }        
    }
    
    /**
     * Begins rendering a tile.
     * <p>
     * This method modifies the viewport, see below.
     * User shall reset the viewport when finishing all tile rendering,
     * i.e. after very last call of {@link #endTile(GL)}!
     * </p>
     * <p>
     * The <a href="#pmvmatrix">PMV Matrix</a>
     * must be reshaped after this call using:
     * <ul>
     *   <li>Current Viewport
     *   <ul>
     *      <li>x 0</li>
     *      <li>y 0</li>
     *      <li>{@link #TR_CURRENT_TILE_WIDTH tile width}</li>
     *      <li>{@link #TR_CURRENT_TILE_HEIGHT tile height}</li>
     *   </ul></li>
     *   <li>{@link #TR_CURRENT_TILE_X_POS tile x-pos}</li>
     *   <li>{@link #TR_CURRENT_TILE_Y_POS tile y-pos}</li>
     *   <li>{@link #TR_IMAGE_WIDTH image width}</li>
     *   <li>{@link #TR_IMAGE_HEIGHT image height}</li>
     * </ul>
     * </p>
     * <p>
     * Use shall render the scene afterwards, concluded with a call to
     * this renderer {@link #endTile(GL)}. 
     * </p>
     * <p>
     * User has to comply with the <a href="#glprequirement">GL profile requirement</a>.
     * </p>
     * 
     * @param gl The gl context
     * @throws IllegalStateException if image-size has not been set
     * @throws GLException if {@link #setImageBuffer(GLPixelBuffer) image buffer} is used but <code>gl</code> instance is &lt; {@link GL2ES3}
     */
    public abstract void beginTile(GL gl) throws IllegalStateException, GLException;
    
    /**
     * Must be called after rendering the scene,
     * see {@link #beginTile(GL)}.
     * <p>
     * Please consider {@link #reqPreSwapBuffers(GLCapabilitiesImmutable)} to determine
     * whether you need to perform {@link GLDrawable#swapBuffers() swap-buffers} before or after
     * calling this method!
     * </p>
     * <p>
     * User has to comply with the <a href="#glprequirement">GL profile requirement</a>.
     * </p>
     * 
     * @param gl the gl context
     * @throws IllegalStateException if beginTile(gl) has not been called
     * @throws GLException if {@link #setImageBuffer(GLPixelBuffer) image buffer} is used but <code>gl</code> instance is &lt; {@link GL2ES3}
     */
    public abstract void endTile( GL gl ) throws IllegalStateException, GLException;
    
    /**
     * Determines whether the chosen {@link GLCapabilitiesImmutable}
     * requires a <i>pre-{@link GLDrawable#swapBuffers() swap-buffers}</i>
     * before accessing the results, i.e. before {@link #endTile(GL)}.
     * <p>
     * Usually one uses the {@link GL#getDefaultReadBuffer() default-read-buffer}, i.e.
     * {@link GL#GL_FRONT} for single-buffer and {@link GL#GL_BACK} for double-buffer {@link GLDrawable}s
     * and {@link GL#GL_COLOR_ATTACHMENT0} for offscreen framebuffer objects.<br>
     * Here {@link GLDrawable#swapBuffers() swap-buffers} shall happen <b>after</b> calling {@link #endTile(GL)}, the default.
     * </p>
     * <p>
     * However, <i>multisampling</i> offscreen {@link GLFBODrawable}s 
     * utilize {@link GLDrawable#swapBuffers() swap-buffers} to <i>downsample</i>
     * the multisamples into the readable sampling sink.
     * In this case, we require a {@link GLDrawable#swapBuffers() swap-buffers} <b>before</b> calling {@link #endTile(GL)}. 
     * </p> 
     * @param chosenCaps the chosen {@link GLCapabilitiesImmutable} 
     * @return chosenCaps.isFBO() && chosenCaps.getSampleBuffers()
     */
    public final boolean reqPreSwapBuffers(GLCapabilitiesImmutable chosenCaps) {
        return chosenCaps.isFBO() && chosenCaps.getSampleBuffers();
    }
    
    /**
     * Attaches this renderer to the {@link GLAutoDrawable}.
     * <p>
     * The {@link GLAutoDrawable}'s original {@link GLEventListener} are moved to this tile renderer.<br>
     * It is <i>highly recommended</i> that the original {@link GLEventListener} implement 
     * {@link TileRendererNotify}, so they get {@link TileRendererNotify#addTileRendererNotify(TileRendererBase) notified}
     * about this event.
     * </p>
     * <p>
     * The {@link GLAutoDrawable}'s {@link GLAutoDrawable#getAutoSwapBufferMode() auto-swap mode} is cached
     * and set to <code>false</code>, since {@link GLAutoDrawable#swapBuffers() swapBuffers()} maybe issued before {@link #endTile(GL)},
     * see {@link #reqPreSwapBuffers(GLCapabilitiesImmutable)}.  
     * </p>
     * <p>
     * This tile renderer's {@link GLEventListener} is then added to handle the tile rendering,
     * replacing the original {@link GLEventListener}.<br>
     * This {@link GLEventListener#display(GLAutoDrawable) display} implementations issues:
     * <ul>
     *   <li>Optional {@link #setGLEventListener(GLEventListener, GLEventListener) pre-glel}.{@link GLEventListener#display(GLAutoDrawable) display(..)}</li>
     *   <li>{@link #beginTile(GL)}</li>
     *   <li>for all original {@link GLEventListener}:
     *   <ul> 
     *     <li>{@link GLEventListener#reshape(GLAutoDrawable, int, int, int, int) reshape(0, 0, tile-width, tile-height)}</li>
     *     <li>{@link GLEventListener#display(GLAutoDrawable) display(autoDrawable)}</li>
     *   </ul></li>
     *   <li>if ( {@link #reqPreSwapBuffers(GLCapabilitiesImmutable) pre-swap} ) { {@link GLAutoDrawable#swapBuffers() swapBuffers()} }</li>
     *   <li>{@link #endTile(GL)}</li>
     *   <li>if ( !{@link #reqPreSwapBuffers(GLCapabilitiesImmutable) pre-swap} ) { {@link GLAutoDrawable#swapBuffers() swapBuffers()} }</li>
     *   <li>Optional {@link #setGLEventListener(GLEventListener, GLEventListener) post-glel}.{@link GLEventListener#display(GLAutoDrawable) display(..)}</li>
     * </ul>
     * </p>
     * <p>
     * The <a href="#pmvmatrix">PMV Matrix</a> shall be reshaped in the 
     * original {@link GLEventListener}'s {@link GLEventListener#reshape(GLAutoDrawable, int, int, int, int) reshape} method
     * according to the tile-position, -size and image-size<br>
     * The {@link GLEventListener#reshape(GLAutoDrawable, int, int, int, int) reshape} method is called for each tile 
     * w/ the current viewport of tile-size, where the tile-position and image-size can be retrieved by this tile renderer,
     * see  details in {@link #beginTile(GL)}.<br>
     * The original {@link GLEventListener} implementing {@link TileRendererNotify} is aware of this
     * tile renderer instance.
     * </p>
     * <p>
     * Consider using {@link #setGLEventListener(GLEventListener, GLEventListener)} to add pre- and post
     * hooks to be performed on this renderer {@link GLEventListener}.<br>
     * The pre-hook is able to allocate memory and setup parameters, since it's called before {@link #beginTile(GL)}.<br>
     * The post-hook is able to use the rendering result and can even shutdown tile-rendering,
     * since it's called after {@link #endTile(GL)}.
     * </p>
     * <p>
     * Call {@link #detachFromAutoDrawable()} to remove this renderer from the {@link GLAutoDrawable} 
     * and to restore it's original {@link GLEventListener}.
     * </p>
     * @param glad
     * @throws IllegalStateException if an {@link GLAutoDrawable} is already attached
     */
    public void attachToAutoDrawable(GLAutoDrawable glad) throws IllegalStateException {
        if( null != this.glad ) {
            throw new IllegalStateException("GLAutoDrawable already attached");
        }
        this.glad = glad;
        
        final int aSz = glad.getGLEventListenerCount();
        listeners = new GLEventListener[aSz];
        listenersInit = new boolean[aSz];
        for(int i=0; i<aSz; i++) {
            final GLEventListener l = glad.getGLEventListener(0);
            listenersInit[i] = glad.getGLEventListenerInitState(l);
            listeners[i] = glad.removeGLEventListener( l );
            final boolean trn;
            if( listeners[i] instanceof TileRendererNotify ) {
                trn = true;
                ((TileRendererNotify)listeners[i]).addTileRendererNotify(this);
            } else {
                trn = false;
            }
            if( DEBUG ) {
                System.err.println("TileRenderer.attach["+i+"]: isInit "+listenersInit[i]+", isTRN "+trn+", "+listeners[i].getClass().getName());
            }
        }
        glad.addGLEventListener(tiledGLEL);
        gladAutoSwapBufferMode = glad.getAutoSwapBufferMode();
        gladRequiresPreSwap = this.reqPreSwapBuffers(glad.getChosenGLCapabilities());
        glad.setAutoSwapBufferMode(false);
        if( DEBUG ) {
            System.err.println("TileRenderer: attached: "+glad);
            System.err.println("TileRenderer: preSwap "+gladRequiresPreSwap+", "+glad.getChosenGLCapabilities()+", cached "+listeners.length+" listener");
        }
    }

    /**
     * Detaches this renderer from the {@link GLAutoDrawable}.
     * <p>
     * It is <i>highly recommended</i> that the original {@link GLEventListener} implement 
     * {@link TileRendererNotify}, so they get {@link TileRendererNotify#removeTileRendererNotify(TileRendererBase) notified}
     * about this event.
     * </p>
     * <p>
     * See {@link #attachToAutoDrawable(GLAutoDrawable)}.
     * </p>
     */
    public void detachFromAutoDrawable() {
        if( null != glad ) {
            glad.removeGLEventListener(tiledGLEL);
            final int aSz = listenersInit.length;
            for(int i=0; i<aSz; i++) {
                final GLEventListener l = listeners[i];
                if( l instanceof TileRendererNotify ) {
                    ((TileRendererNotify)l).removeTileRendererNotify(this);
                }
                glad.addGLEventListener(l);
                glad.setGLEventListenerInitState(l, listenersInit[i]);
            }
            glad.setAutoSwapBufferMode(gladAutoSwapBufferMode);
            if( DEBUG ) {
                System.err.println("TileRenderer: detached: "+glad);
                System.err.println("TileRenderer: "+glad.getChosenGLCapabilities());
            }
            
            listeners = null;
            listenersInit = null;
            glad = null;
        }
    }
    
    /**
     * Set {@link GLEventListener} for pre- and post operations when used w/
     * {@link #attachToAutoDrawable(GLAutoDrawable)} 
     * for each {@link GLEventListener} callback.
     * @param preTile the pre operations
     * @param postTile the post operations
     */
    public void setGLEventListener(GLEventListener preTile, GLEventListener postTile) {
        glEventListenerPre = preTile;
        glEventListenerPost = postTile;
    }
    
    /**
     * Rendering one tile, by simply calling {@link GLAutoDrawable#display()}.
     * 
     * @throws IllegalStateException if no {@link GLAutoDrawable} is {@link #attachToAutoDrawable(GLAutoDrawable) attached}
     *                               or imageSize is not set
     */
    public void display() throws IllegalStateException {
        if( null == glad ) {
            throw new IllegalStateException("No GLAutoDrawable attached");
        }
        glad.display();
    }
    
    private final GLEventListener tiledGLEL = new GLEventListener() {
        @Override
        public void init(GLAutoDrawable drawable) {
            if( null != glEventListenerPre ) {
                glEventListenerPre.init(drawable);
            }
            final int aSz = listenersInit.length;
            for(int i=0; i<aSz; i++) {
                final GLEventListener l = listeners[i];
                if( !listenersInit[i] ) {
                    l.init(drawable);
                    listenersInit[i] = true;
                }
            }
            if( null != glEventListenerPost ) {
                glEventListenerPost.init(drawable);
            }
        }
        @Override
        public void dispose(GLAutoDrawable drawable) {
            if( null != glEventListenerPre ) {
                glEventListenerPre.dispose(drawable);
            }
            final int aSz = listenersInit.length;
            for(int i=0; i<aSz; i++) {
                listeners[i].dispose(drawable);
            }
            if( null != glEventListenerPost ) {
                glEventListenerPost.dispose(drawable);
            }
        }
        @Override
        public void display(GLAutoDrawable drawable) {
            if( null != glEventListenerPre ) {
                glEventListenerPre.display(drawable);
            }
            final GL gl = drawable.getGL();

            beginTile(gl);

            final int aSz = listenersInit.length;
            for(int i=0; i<aSz; i++) {
                listeners[i].reshape(drawable, 0, 0, currentTileWidth, currentTileHeight);
                listeners[i].display(drawable);
            }
            
            if( gladRequiresPreSwap ) {
                glad.swapBuffers();
                endTile(gl);
            } else {
                endTile(gl);
                glad.swapBuffers();
            }
            
            if( null != glEventListenerPost ) {
                glEventListenerPost.display(drawable);
            }
        }
        @Override
        public void reshape(GLAutoDrawable drawable, int x, int y, int width, int height) {
            if( null != glEventListenerPre ) {
                glEventListenerPre.reshape(drawable, x, y, width, height);
            }
            final int aSz = listenersInit.length;
            for(int i=0; i<aSz; i++) {
                listeners[i].reshape(drawable, x, y, width, height);
            }
            if( null != glEventListenerPost ) {
                glEventListenerPost.reshape(drawable, x, y, width, height);
            }
        }
    };
}