Project

General

Profile

Download (22 KB) Statistics
| Branch: | Revision:

library / src / main / java / org / distorted / library / mesh / MeshBase.java @ e172985c

1
///////////////////////////////////////////////////////////////////////////////////////////////////
2
// Copyright 2016 Leszek Koltunski                                                               //
3
//                                                                                               //
4
// This file is part of Distorted.                                                               //
5
//                                                                                               //
6
// Distorted is free software: you can redistribute it and/or modify                             //
7
// it under the terms of the GNU General Public License as published by                          //
8
// the Free Software Foundation, either version 2 of the License, or                             //
9
// (at your option) any later version.                                                           //
10
//                                                                                               //
11
// Distorted is distributed in the hope that it will be useful,                                  //
12
// but WITHOUT ANY WARRANTY; without even the implied warranty of                                //
13
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the                                 //
14
// GNU General Public License for more details.                                                  //
15
//                                                                                               //
16
// You should have received a copy of the GNU General Public License                             //
17
// along with Distorted.  If not, see <http://www.gnu.org/licenses/>.                            //
18
///////////////////////////////////////////////////////////////////////////////////////////////////
19

    
20
package org.distorted.library.mesh;
21

    
22
import android.opengl.GLES31;
23
import android.opengl.Matrix;
24

    
25
import org.distorted.library.effect.MatrixEffect;
26
import org.distorted.library.main.DistortedLibrary;
27
import org.distorted.library.main.InternalBuffer;
28
import org.distorted.library.program.DistortedProgram;
29
import org.distorted.library.type.Static4D;
30

    
31
import java.util.ArrayList;
32

    
33
///////////////////////////////////////////////////////////////////////////////////////////////////
34
/**
35
 * Abstract class which represents a Mesh, ie an array of vertices (rendered as a TRIANGLE_STRIP).
36
 * <p>
37
 * If you want to render to a particular shape, extend from here, construct a float array
38
 * containing per-vertex attributes, and call back setAttribs().
39
 */
40
public abstract class MeshBase
41
   {
42
   // sizes of attributes of an individual vertex.
43
   private static final int POS_DATA_SIZE= 3; // vertex coordinates: x,y,z
44
   private static final int NOR_DATA_SIZE= 3; // normal vector: x,y,z
45
   private static final int INF_DATA_SIZE= 3; // 'inflate' vector: x,y,z
46
   private static final int TEX_DATA_SIZE= 2; // texture coordinates: s,t
47

    
48
   static final int POS_ATTRIB   = 0;
49
   static final int NOR_ATTRIB   = POS_DATA_SIZE;
50
   static final int INF_ATTRIB   = POS_DATA_SIZE + NOR_DATA_SIZE;
51
   static final int TEX_ATTRIB   = POS_DATA_SIZE + NOR_DATA_SIZE + INF_DATA_SIZE;
52
   static final int VERT_ATTRIBS = POS_DATA_SIZE + NOR_DATA_SIZE + INF_DATA_SIZE + TEX_DATA_SIZE;  // number of attributes of a 'normal' vertex
53
   static final int TRAN_ATTRIBS = POS_DATA_SIZE + POS_DATA_SIZE;                                  // number of attributes of a transform feedback vertex
54

    
55
   private static final int BYTES_PER_FLOAT = 4;
56

    
57
   private static final int OFFSET_POS = POS_ATTRIB*BYTES_PER_FLOAT;
58
   private static final int OFFSET_NOR = NOR_ATTRIB*BYTES_PER_FLOAT;
59
   private static final int OFFSET_INF = INF_ATTRIB*BYTES_PER_FLOAT;
60
   private static final int OFFSET_TEX = TEX_ATTRIB*BYTES_PER_FLOAT;
61
   private static final int TRAN_SIZE  = TRAN_ATTRIBS*BYTES_PER_FLOAT;
62
   private static final int VERT_SIZE  = VERT_ATTRIBS*BYTES_PER_FLOAT;
63

    
64
   private boolean mShowNormals;      // when rendering this mesh, draw normal vectors?
65
   private InternalBuffer mVBO, mTFO; // main vertex buffer and transform feedback buffer
66
   private int mNumVertices;
67
   private float[] mVertAttribs;      // packed: PosX,PosY,PosZ, NorX,NorY,NorZ, InfX,InfY,InfZ, TexS,TexT
68
   private float mInflate;
69
   private float mBoundingX, mBoundingY, mBoundingZ;
70
   private float mStretchX, mStretchY, mStretchZ;
71

    
72
   private static class Component
73
     {
74
     private int mEndIndex;
75
     private Static4D mTextureMap;
76

    
77
     Component(int end)
78
       {
79
       mEndIndex  = end;
80
       mTextureMap= new Static4D(0,0,1,1);
81
       }
82
     Component(Component original)
83
       {
84
       mEndIndex = original.mEndIndex;
85

    
86
       float x = original.mTextureMap.get0();
87
       float y = original.mTextureMap.get1();
88
       float z = original.mTextureMap.get2();
89
       float w = original.mTextureMap.get3();
90
       mTextureMap = new Static4D(x,y,z,w);
91
       }
92

    
93
     void setMap(Static4D map)
94
       {
95
       mTextureMap.set(map.get0(),map.get1(),map.get2(),map.get3());
96
       }
97
     }
98

    
99
   private ArrayList<Component> mComponent;
100

    
101
///////////////////////////////////////////////////////////////////////////////////////////////////
102

    
103
   MeshBase(float bx, float by, float bz)
104
     {
105
     mBoundingX = bx/2;
106
     mBoundingY = by/2;
107
     mBoundingZ = bz/2;
108

    
109
     mStretchX = 1.0f;
110
     mStretchY = 1.0f;
111
     mStretchZ = 1.0f;
112

    
113
     mShowNormals = false;
114
     mInflate     = 0.0f;
115
     mComponent   = new ArrayList<>();
116

    
117
     mVBO = new InternalBuffer(GLES31.GL_ARRAY_BUFFER             , GLES31.GL_STATIC_READ);
118
     mTFO = new InternalBuffer(GLES31.GL_TRANSFORM_FEEDBACK_BUFFER, GLES31.GL_STATIC_READ);
119
     }
120

    
121
///////////////////////////////////////////////////////////////////////////////////////////////////
122
// copy constructor
123

    
124
   MeshBase(MeshBase original)
125
     {
126
     mBoundingX = original.mBoundingX;
127
     mBoundingY = original.mBoundingY;
128
     mBoundingZ = original.mBoundingZ;
129

    
130
     mStretchX = original.mStretchX;
131
     mStretchY = original.mStretchY;
132
     mStretchZ = original.mStretchZ;
133

    
134
     mShowNormals = original.mShowNormals;
135
     mInflate     = original.mInflate;
136

    
137
     int size = original.mComponent.size();
138
     mComponent = new ArrayList<>();
139
     for(int i=0; i<size; i++)
140
       {
141
       Component comp = new Component(original.mComponent.get(i));
142
       mComponent.add(comp);
143
       }
144

    
145
     mVBO = new InternalBuffer(GLES31.GL_ARRAY_BUFFER             , GLES31.GL_STATIC_READ);
146
     mTFO = new InternalBuffer(GLES31.GL_TRANSFORM_FEEDBACK_BUFFER, GLES31.GL_STATIC_READ);
147

    
148
     System.arraycopy(original.mVertAttribs,0,mVertAttribs,0,original.mNumVertices*VERT_ATTRIBS);
149
     setAttribs(mVertAttribs);
150
     }
151

    
152
///////////////////////////////////////////////////////////////////////////////////////////////////
153

    
154
   int numComponents()
155
     {
156
     return mComponent.size();
157
     }
158

    
159
///////////////////////////////////////////////////////////////////////////////////////////////////
160

    
161
   void setBounding(float bx, float by, float bz)
162
     {
163
     mBoundingX = bx/2;
164
     mBoundingY = by/2;
165
     mBoundingZ = bz/2;
166
     }
167

    
168
///////////////////////////////////////////////////////////////////////////////////////////////////
169
// when a derived class is done computing its mesh, it has to call this method.
170

    
171
   void setAttribs(float[] vertexAttribs)
172
     {
173
     mNumVertices = vertexAttribs.length/VERT_ATTRIBS;
174
     mVertAttribs = vertexAttribs;
175

    
176
     mComponent.add(new Component(mNumVertices));
177

    
178
     mVBO.invalidate();
179
     mTFO.invalidate();
180
     }
181

    
182
///////////////////////////////////////////////////////////////////////////////////////////////////
183
// called from MeshJoined
184

    
185
   void join(MeshBase[] meshes)
186
     {
187
     MeshBase mesh;
188
     Component comp;
189
     int numComponents, numVertices, numMeshes = meshes.length;
190
     int origVertices = mNumVertices;
191

    
192
     // compute new numVertices; take care of Components
193

    
194
     if( origVertices>0 )
195
       {
196
       numComponents = mComponent.size();
197
       mNumVertices+= ( mNumVertices%2==1 ? 2:1 );
198
       mComponent.get(numComponents-1).mEndIndex = mNumVertices;
199
       }
200

    
201
     for(int i=0; i<numMeshes; i++)
202
       {
203
       mesh = meshes[i];
204
       numComponents = mesh.mComponent.size();
205

    
206
       for(int j=0; j<numComponents; j++)
207
         {
208
         comp = new Component(mesh.mComponent.get(j));
209
         comp.mEndIndex += mNumVertices;
210
         mComponent.add(comp);
211
         }
212

    
213
       numVertices = mesh.mNumVertices;
214

    
215
       if( mNumVertices==0 )
216
         {
217
         if( numMeshes>1 )
218
            mNumVertices += (numVertices%2==1 ? numVertices+2 : numVertices+1);
219
         else
220
            mNumVertices +=  numVertices;
221
         }
222
       else if( i==numMeshes-1 ) mNumVertices += (numVertices+1);
223
       else                      mNumVertices += (numVertices%2==1 ? numVertices+3 : numVertices+2);
224
       }
225

    
226
     // allocate new attrib array
227
     float[] newAttribs = new float[VERT_ATTRIBS*mNumVertices];
228
     numVertices = origVertices;
229

    
230
     if( origVertices>0 )
231
       {
232
       System.arraycopy(mVertAttribs,                             0, newAttribs,                         0, VERT_ATTRIBS*numVertices);
233
       System.arraycopy(mVertAttribs, VERT_ATTRIBS*(origVertices-1), newAttribs, VERT_ATTRIBS*origVertices, VERT_ATTRIBS    );
234
       origVertices++;
235

    
236
       if( numVertices%2==1 )
237
         {
238
         System.arraycopy(mVertAttribs, VERT_ATTRIBS*(origVertices-1), newAttribs, VERT_ATTRIBS*origVertices, VERT_ATTRIBS);
239
         origVertices++;
240
         }
241
       }
242

    
243
     for(int i=0; i<numMeshes; i++)
244
       {
245
       mesh = meshes[i];
246
       numVertices = mesh.mNumVertices;
247

    
248
       if( origVertices>0 )
249
         {
250
         System.arraycopy(mesh.mVertAttribs, 0, newAttribs, VERT_ATTRIBS*origVertices, VERT_ATTRIBS    );
251
         origVertices++;
252
         }
253
       System.arraycopy(mesh.mVertAttribs, 0, newAttribs, VERT_ATTRIBS*origVertices, VERT_ATTRIBS*numVertices);
254
       origVertices+=numVertices;
255

    
256
       if( i<numMeshes-1 )
257
         {
258
         System.arraycopy(mesh.mVertAttribs, VERT_ATTRIBS*(numVertices-1), newAttribs, VERT_ATTRIBS*origVertices, VERT_ATTRIBS);
259
         origVertices++;
260

    
261
         if( numVertices%2==1 )
262
           {
263
           System.arraycopy(mesh.mVertAttribs, VERT_ATTRIBS*(numVertices-1), newAttribs, VERT_ATTRIBS*origVertices, VERT_ATTRIBS);
264
           origVertices++;
265
           }
266
         }
267
       }
268

    
269
     if( origVertices!=mNumVertices )
270
       {
271
       android.util.Log.e("mesh", "join: origVertices: "+origVertices+" numVertices: "+mNumVertices);
272
       }
273

    
274
     mVertAttribs = newAttribs;
275

    
276
     mVBO.invalidate();
277
     }
278

    
279
///////////////////////////////////////////////////////////////////////////////////////////////////
280
/**
281
 * Not part of public API, do not document (public only because has to be used from the main package)
282
 *
283
 * @y.exclude
284
 */
285
   public int getTFO()
286
     {
287
     return mTFO.getIndex();
288
     }
289

    
290
///////////////////////////////////////////////////////////////////////////////////////////////////
291
/**
292
 * Not part of public API, do not document (public only because has to be used from the main package)
293
 *
294
 * @y.exclude
295
 */
296
   public int getNumVertices()
297
     {
298
     return mNumVertices;
299
     }
300

    
301
///////////////////////////////////////////////////////////////////////////////////////////////////
302
/**
303
 * Not part of public API, do not document (public only because has to be used from the main package)
304
 *
305
 * @y.exclude
306
 */
307
   public void bindVertexAttribs(DistortedProgram program)
308
     {
309
     int index = mVBO.createImmediately(mNumVertices*VERT_SIZE, mVertAttribs);
310

    
311
     GLES31.glBindBuffer(GLES31.GL_ARRAY_BUFFER, index );
312
     GLES31.glVertexAttribPointer(program.mAttribute[0], POS_DATA_SIZE, GLES31.GL_FLOAT, false, VERT_SIZE, OFFSET_POS);
313
     GLES31.glVertexAttribPointer(program.mAttribute[1], NOR_DATA_SIZE, GLES31.GL_FLOAT, false, VERT_SIZE, OFFSET_NOR);
314
     GLES31.glVertexAttribPointer(program.mAttribute[2], INF_DATA_SIZE, GLES31.GL_FLOAT, false, VERT_SIZE, OFFSET_INF);
315
     GLES31.glVertexAttribPointer(program.mAttribute[3], TEX_DATA_SIZE, GLES31.GL_FLOAT, false, VERT_SIZE, OFFSET_TEX);
316
     GLES31.glBindBuffer(GLES31.GL_ARRAY_BUFFER, 0);
317
     }
318

    
319
///////////////////////////////////////////////////////////////////////////////////////////////////
320
/**
321
 * Not part of public API, do not document (public only because has to be used from the main package)
322
 *
323
 * @y.exclude
324
 */
325
   public void bindTransformAttribs(DistortedProgram program)
326
     {
327
     int index = mTFO.createImmediately(mNumVertices*TRAN_SIZE, null);
328

    
329
     GLES31.glBindBuffer(GLES31.GL_ARRAY_BUFFER, index );
330
     GLES31.glVertexAttribPointer(program.mAttribute[0], POS_DATA_SIZE, GLES31.GL_FLOAT, false, 0, 0);
331
     GLES31.glBindBuffer(GLES31.GL_ARRAY_BUFFER, 0);
332
     }
333

    
334
///////////////////////////////////////////////////////////////////////////////////////////////////
335
/**
336
 * Not part of public API, do not document (public only because has to be used from the main package)
337
 *
338
 * @y.exclude
339
 */
340
   public void setInflate(float inflate)
341
     {
342
     mInflate = inflate;
343
     }
344

    
345
///////////////////////////////////////////////////////////////////////////////////////////////////
346
/**
347
 * Not part of public API, do not document (public only because has to be used from the main package)
348
 *
349
 * @y.exclude
350
 */
351
   public float getInflate()
352
     {
353
     return mInflate;
354
     }
355

    
356
///////////////////////////////////////////////////////////////////////////////////////////////////
357
// PUBLIC API
358
///////////////////////////////////////////////////////////////////////////////////////////////////
359
/**
360
 * When rendering this Mesh, do we want to render the Normal vectors as well?
361
 * <p>
362
 * Will work only on OpenGL ES >= 3.0 devices.
363
 *
364
 * @param show Controls if we render the Normal vectors or not.
365
 */
366
   public void setShowNormals(boolean show)
367
     {
368
     mShowNormals = (DistortedLibrary.GLSL >= 300 && show);
369
     }
370

    
371
///////////////////////////////////////////////////////////////////////////////////////////////////
372
/**
373
 * When rendering this mesh, should we also draw the normal vectors?
374
 *
375
 * @return <i>true</i> if we do render normal vectors
376
 */
377
   public boolean getShowNormals()
378
     {
379
     return mShowNormals;
380
     }
381

    
382
///////////////////////////////////////////////////////////////////////////////////////////////////
383
/**
384
 * Release all internal resources.
385
 */
386
   public void markForDeletion()
387
     {
388
     mVertAttribs = null;
389

    
390
     mVBO.markForDeletion();
391
     mTFO.markForDeletion();
392
     }
393

    
394
///////////////////////////////////////////////////////////////////////////////////////////////////
395
/**
396
 * Apply all Effects to the vertex mesh. Overwrite the mesh in place.
397
 * <p>
398
 * This is a static, permanent modification of the vertices contained in this Mesh. If the effects
399
 * contain any Dynamics, they will be evaluated at 0.
400
 *
401
 * Please note that calling this once with the complete list of Effects will be much faster than
402
 * calling it repeatedly with one Effect at a time, as we have to reallocate the array of vertices
403
 * each time.
404
 *
405
 * @param effects List of Matrix Effects to apply to the Mesh.
406
 */
407
   public void apply(MatrixEffect[] effects)
408
     {
409
     float[][] matrix = new float[effects.length][16];
410
     float[] tmp;
411
     float[] array = new float[7];
412
     float x,y,z;
413
     int numEffects = 0;
414

    
415
     for(MatrixEffect eff: effects)
416
       {
417
       if( eff!=null )
418
         {
419
         Matrix.setIdentityM(matrix[numEffects],0);
420
         eff.compute(array,0,0,0);
421
         eff.apply(matrix[numEffects], array, 0);
422
         numEffects++;
423
         }
424
       }
425

    
426
     for(int index=0; index<mNumVertices*VERT_ATTRIBS; index+=VERT_ATTRIBS )
427
       {
428
       for(int mat=0; mat<numEffects; mat++)
429
         {
430
         tmp = matrix[mat];
431

    
432
         x = mVertAttribs[index+POS_ATTRIB  ];
433
         y = mVertAttribs[index+POS_ATTRIB+1];
434
         z = mVertAttribs[index+POS_ATTRIB+2];
435

    
436
         mVertAttribs[index+POS_ATTRIB  ] = tmp[0]*x + tmp[4]*y + tmp[ 8]*z + tmp[12];
437
         mVertAttribs[index+POS_ATTRIB+1] = tmp[1]*x + tmp[5]*y + tmp[ 9]*z + tmp[13];
438
         mVertAttribs[index+POS_ATTRIB+2] = tmp[2]*x + tmp[6]*y + tmp[10]*z + tmp[14];
439

    
440
         x = mVertAttribs[index+NOR_ATTRIB  ];
441
         y = mVertAttribs[index+NOR_ATTRIB+1];
442
         z = mVertAttribs[index+NOR_ATTRIB+2];
443

    
444
         mVertAttribs[index+NOR_ATTRIB  ] = tmp[0]*x + tmp[4]*y + tmp[ 8]*z;
445
         mVertAttribs[index+NOR_ATTRIB+1] = tmp[1]*x + tmp[5]*y + tmp[ 9]*z;
446
         mVertAttribs[index+NOR_ATTRIB+2] = tmp[2]*x + tmp[6]*y + tmp[10]*z;
447

    
448
         x = mVertAttribs[index+INF_ATTRIB  ];
449
         y = mVertAttribs[index+INF_ATTRIB+1];
450
         z = mVertAttribs[index+INF_ATTRIB+2];
451

    
452
         mVertAttribs[index+INF_ATTRIB  ] = tmp[0]*x + tmp[4]*y + tmp[ 8]*z;
453
         mVertAttribs[index+INF_ATTRIB+1] = tmp[1]*x + tmp[5]*y + tmp[ 9]*z;
454
         mVertAttribs[index+INF_ATTRIB+2] = tmp[2]*x + tmp[6]*y + tmp[10]*z;
455
         }
456
       }
457

    
458
     mVBO.invalidate();
459
     }
460

    
461
///////////////////////////////////////////////////////////////////////////////////////////////////
462
/**
463
 * Sets texture maps for (some of) the components of this mesh.
464
 * <p>
465
 * Format: ( x of lower-left corner, y of lower-left corner, width, height ).
466
 * For example maps[0] = new Static4D( 0.0, 0.5, 0.5, 0.5 ) sets the 0th component texture map to the
467
 * upper-left quadrant of the texture.
468
 * <p>
469
 * Probably the most common user case would be sending as many maps as there are components in this
470
 * Mesh. One can also send less, or more (the extraneous ones will be ignored) and set some of them
471
 * to null (those will be ignored as well). So if there are 5 components, and we want to set the map
472
 * of the 2nd and 4rd one, call this with
473
 * maps = new Static4D[4]
474
 * maps[0] = null
475
 * maps[1] = the map for the 2nd component
476
 * maps[2] = null
477
 * maps[3] = the map for the 4th component
478
 *
479
 * A map's width and height have to be non-zero (but can be negative!)
480
 *
481
 * @param maps List of texture maps to apply to the texture's components.
482
 */
483
   public void setTextureMap(Static4D[] maps)
484
     {
485
     int num_comp = mComponent.size();
486
     int num_maps = maps.length;
487
     int min = Math.min(num_comp, num_maps);
488
     int vertex = 0;
489
     Static4D newMap, oldMap;
490
     Component comp;
491
     float newW, newH, ratW, ratH, movX, movY;
492

    
493
     for(int i=0; i<min; i++)
494
       {
495
       newMap = maps[i];
496
       comp = mComponent.get(i);
497

    
498
       if( newMap!=null )
499
         {
500
         newW = newMap.get2();
501
         newH = newMap.get3();
502

    
503
         if( newW!=0.0f && newH!=0.0f )
504
           {
505
           oldMap = comp.mTextureMap;
506
           ratW = newW/oldMap.get2();
507
           ratH = newH/oldMap.get3();
508
           movX = newMap.get0() - ratW*oldMap.get0();
509
           movY = newMap.get1() - ratH*oldMap.get1();
510

    
511
           for( int index=vertex*VERT_ATTRIBS+TEX_ATTRIB ; vertex<=comp.mEndIndex; vertex++, index+=VERT_ATTRIBS)
512
             {
513
             mVertAttribs[index  ] = ratW*mVertAttribs[index  ] + movX;
514
             mVertAttribs[index+1] = ratH*mVertAttribs[index+1] + movY;
515
             }
516
           comp.setMap(newMap);
517
           }
518
         }
519

    
520
       vertex= comp.mEndIndex+1;
521
       }
522

    
523
     mVBO.invalidate();
524
     }
525

    
526
///////////////////////////////////////////////////////////////////////////////////////////////////
527
/**
528
 * Return the texture map of one of the components.
529
 *
530
 * @param component The component number whose texture map we want to retrieve.
531
 */
532
   public Static4D getTextureMap(int component)
533
     {
534
     return (component>=0 && component<mComponent.size()) ? mComponent.get(component).mTextureMap : null;
535
     }
536

    
537
///////////////////////////////////////////////////////////////////////////////////////////////////
538
/**
539
 * Each mesh has its 'bounding box' - return half of its X-length.
540
 * <p>
541
 * In case of all 'simple' Meshes, the bounding box is always 1x1x1 (Sphere, Cubes) or 1x1x0
542
 * (Rectangles, Triangles, Quad - i.e. all 'flat' Meshes). But this can be something else in case of
543
 * MeshComponent.
544
 */
545
   public float getBoundingX()
546
    {
547
    return mBoundingX*mStretchX;
548
    }
549

    
550
///////////////////////////////////////////////////////////////////////////////////////////////////
551
/**
552
 * Each mesh has its 'bounding box' - return half of its Y-length.
553
 */
554
   public float getBoundingY()
555
    {
556
    return mBoundingY*mStretchY;
557
    }
558

    
559
///////////////////////////////////////////////////////////////////////////////////////////////////
560
/**
561
 * Each mesh has its 'bounding box' - return half of its Z-length.
562
 */
563
   public float getBoundingZ()
564
    {
565
    return mBoundingZ*mStretchZ;
566
    }
567

    
568
///////////////////////////////////////////////////////////////////////////////////////////////////
569
/**
570
 * Sometimes we want to display a Mesh on a rectangular screen. Then we need to stretch it by
571
 * different factors in x and y (or z) directions. If we also wanted do display some vertex effects
572
 * done on this mesh, let's say a bulge done by a Distort effect, and wanted the bulge to be round,
573
 * (i.e the same in x and y directions) then doing so without this method would be impossible.
574
 *
575
 * This sets 'stretch' factors in each 3 dimensions. All vertices of this Mesh will be premultiplied
576
 * by those factors in the very first line of the Vertex Shader, before any Effects are done on it.
577
 * Using this we can thus pre-stretch the mesh to aspect ratio equal to the surface we eventually
578
 * want to display the Mesh on, and this way we can achieve a round Distort bulge!
579
 *
580
 * This could also be used to pre-stretch a Rectangles Mesh to a size equal (in pixels) to the bitmap
581
 * this mesh is textured with - and this lets us work with all Effects in natural, pixel units.
582
 *
583
 * @param sx stretch factor in x.
584
 * @param sy stretch factor in y.
585
 * @param sz stretch factor in z.
586
 */
587
   public void setStretch(float sx, float sy, float sz)
588
     {
589
     mStretchX = sx;
590
     mStretchY = sy;
591
     mStretchZ = sz;
592
     }
593

    
594
///////////////////////////////////////////////////////////////////////////////////////////////////
595
/**
596
 * Returns the x-factor set by setStretch().
597
 */
598
   public float getStretchX()
599
     {
600
     return mStretchX;
601
     }
602

    
603
///////////////////////////////////////////////////////////////////////////////////////////////////
604
/**
605
 * Returns the y-factor set by setStretch().
606
 */
607
   public float getStretchY()
608
     {
609
     return mStretchY;
610
     }
611

    
612
///////////////////////////////////////////////////////////////////////////////////////////////////
613
/**
614
 * Returns the z-factor set by setStretch().
615
 */
616
   public float getStretchZ()
617
     {
618
     return mStretchZ;
619
     }
620
   }
621

    
622

    
623

    
(1-1/7)