Source

Coin / src / vrml97 / Billboard.cpp

Full commit
  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
/**************************************************************************\
 * Copyright (c) Kongsberg Oil & Gas Technologies AS
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 * 
 * Redistributions of source code must retain the above copyright notice,
 * this list of conditions and the following disclaimer.
 * 
 * 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.
 * 
 * Neither the name of the copyright holder nor the names of its
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "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 THE COPYRIGHT
 * HOLDER 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.
\**************************************************************************/

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif // HAVE_CONFIG_H

#ifdef HAVE_VRML97

/*!
  \class SoVRMLBillboard SoVRMLBillboard.h Inventor/VRMLnodes/SoVRMLBillboard.h
  \brief The SoVRMLBillboard class is used for rotating geometry towards the viewpoint.
  \ingroup VRMLnodes

  \WEB3DCOPYRIGHT

  \verbatim
  Billboard {
    eventIn      MFNode   addChildren
    eventIn      MFNode   removeChildren
    exposedField SFVec3f  axisOfRotation 0 1 0     # (-inf, inf)
    exposedField MFNode   children       []
    field        SFVec3f  bboxCenter     0 0 0     # (-inf, inf)
    field        SFVec3f  bboxSize       -1 -1 -1  # (0, inf) or -1,-1,-1
  }
  \endverbatim

  The Billboard node is a grouping node which modifies its coordinate
  system so that the Billboard node's local Z-axis turns to point at
  the viewer.  The Billboard node has children which may be other
  children nodes.  The axisOfRotation field specifies which axis to
  use to perform the rotation. This axis is defined in the local
  coordinate system.  When the axisOfRotation field is not (0, 0, 0),
  the following steps describe how to rotate the billboard to face the
  viewer:

  \li a. Compute the vector from the Billboard node's origin to the
  viewer's position. This vector is called the billboard-to-viewer
  vector.

  \li b. Compute the plane defined by the axisOfRotation and the
  billboard-to-viewer vector.

  \li c. Rotate the local Z-axis of the billboard into the plane from b., pivoting
  around the axisOfRotation.

  When the axisOfRotation field is set to (0, 0, 0), the special case
  of viewer-alignment is indicated. In this case, the object rotates
  to keep the billboard's local Y-axis parallel with the Y-axis of the
  viewer.  This special case is distinguished by setting the
  axisOfRotation to (0, 0, 0). The following steps describe how to
  align the billboard's Y-axis to the Y-axis of the viewer:

  \li d. Compute the billboard-to-viewer vector.

  \li e. Rotate the Z-axis of the billboard to be collinear with the
  billboard-to-viewer vector and pointing towards the viewer's
  position.

  \li f. Rotate the Y-axis of the billboard to be parallel and
  oriented in the same direction as the Y-axis of the viewer.

  If the axisOfRotation and the billboard-to-viewer line are
  coincident, the plane cannot be established and the resulting
  rotation of the billboard is undefined. For example, if the
  axisOfRotation is set to (0,1,0) (Y-axis) and the viewer flies over
  the billboard and peers directly down the Y-axis, the results are
  undefined.  Multiple instances of Billboard nodes (DEF/USE) operate
  as expected: each instance rotates in its unique coordinate system
  to face the viewer.  Subclause 4.6.5, Grouping and children nodes
  (<http://www.web3d.org/x3d/specifications/vrml/ISO-IEC-14772-VRML97/part1/concepts.html#4.6.5>),
  provides a description of the children, addChildren, and
  removeChildren fields and eventIns.  The bboxCenter and bboxSize
  fields specify a bounding box that encloses the Billboard node's
  children. This is a hint that may be used for optimization
  purposes. The results are undefined if the specified bounding box is
  smaller than the actual bounding box of the children at any time. A
  default bboxSize value, (-1, -1, -1), implies that the bounding box
  is not specified and if needed shall be calculated by the browser. A
  description of the bboxCenter and bboxSize fields is contained in
  4.6.4, Bounding boxes
  (<http://www.web3d.org/x3d/specifications/vrml/ISO-IEC-14772-VRML97/part1/concepts.html#4.6.4>),

  \ENDWEB3D

  The following example VRML scene is a simple illustration of how
  SoVRMLBillboard::axisOfRotation constrains rotation around the given
  vector:

  \verbatim
  #VRML V2.0 utf8
  
  Transform {
     translation -2 0 0
     children [
        Billboard {
          children [ Box { } ]
        }
     ]
  }
  
  Transform {
     translation 2 0 0
     children [
        Billboard {
          axisOfRotation 0 1 0
          children [ Box { } ]
        }
     ]
  }
  
  Transform {
     translation 0 -2 0
     children [ Box { size 10 0.1 10 } ]
  }
  \endverbatim

*/

// *************************************************************************

/*!
  \var SoSFVec3f SoVRMLBillboard::axisOfRotation

  The axis of rotation for the geometry.
*/

/*!
  \var SoSFVec3f SoVRMLBillboard::bboxCenter
  The bounding box center hint. Default value is (0, 0, 0).
*/

/*!
  \var SoSFVec3f SoVRMLBillboard::bboxSize
  The bounding box size hint. Default value is (-1, -1, -1).
*/

// *************************************************************************

#include <Inventor/VRMLnodes/SoVRMLBillboard.h>

#include <math.h>
#include <float.h>

#include <Inventor/VRMLnodes/SoVRMLMacros.h>
#include <Inventor/actions/SoSearchAction.h>
#include <Inventor/actions/SoGLRenderAction.h>
#include <Inventor/actions/SoWriteAction.h>
#include <Inventor/actions/SoGetBoundingBoxAction.h>
#include <Inventor/elements/SoViewVolumeElement.h>
#include <Inventor/elements/SoModelMatrixElement.h>
#include <Inventor/elements/SoViewingMatrixElement.h>
#include <Inventor/elements/SoCacheElement.h>
#include <Inventor/SbPlane.h>
#include <Inventor/misc/SoState.h>
#include <Inventor/misc/SoChildList.h>
#include <Inventor/SbRotation.h>
#include <Inventor/errors/SoDebugError.h>
#include <Inventor/system/gl.h>

#include "nodes/SoSubNodeP.h"
#include "rendering/SoGL.h"
#include "glue/glp.h"
#include "profiler/SoNodeProfiling.h"

// *************************************************************************

SO_NODE_SOURCE(SoVRMLBillboard);

// *************************************************************************

// Doc in parent
void
SoVRMLBillboard::initClass(void)
{
  SO_NODE_INTERNAL_INIT_CLASS(SoVRMLBillboard, SO_VRML97_NODE_TYPE);
}

/*!
  Constructor.
*/
SoVRMLBillboard::SoVRMLBillboard(void)
{
  SO_VRMLNODE_INTERNAL_CONSTRUCTOR(SoVRMLBillboard);

  SO_VRMLNODE_ADD_EXPOSED_FIELD(axisOfRotation, (0.0f, 0.0f, 0.0f));
  SO_VRMLNODE_ADD_FIELD(bboxCenter, (0.0f, 0.0f, 0.0f));
  SO_VRMLNODE_ADD_FIELD(bboxSize, (-1.0f, -1.0f, -1.0f));
}

/*!
  Constructor. \a numchildren is the expected number of children.
*/
SoVRMLBillboard::SoVRMLBillboard(int numchildren)
  : inherited(numchildren)
{
}

/*!
  Destructor.
*/
SoVRMLBillboard::~SoVRMLBillboard()
{
}

// *************************************************************************

// Doc in parent
void
SoVRMLBillboard::doAction(SoAction * action)
{
  SoState * state = action->getState();
  state->push();
  this->performRotation(state);
  SoGroup::doAction(action);
  state->pop();
}

// Doc in parent
void
SoVRMLBillboard::callback(SoCallbackAction * action)
{
  SoVRMLBillboard::doAction((SoAction*) action);
}

// Doc in parent
void
SoVRMLBillboard::GLRender(SoGLRenderAction * action)
{
  switch (action->getCurPathCode()) {
  case SoAction::NO_PATH:
  case SoAction::BELOW_PATH:
    this->GLRenderBelowPath(action);
    break;
  case SoAction::OFF_PATH:
    // do nothing. Separator will reset state.
    break;
  case SoAction::IN_PATH:
    this->GLRenderInPath(action);
    break;
  }
}

// Doc in parent
void
SoVRMLBillboard::getBoundingBox(SoGetBoundingBoxAction * action)
{
  SoState * state = action->getState();
  state->push();
  this->performRotation(state);
  SoGroup::getBoundingBox(action);
  state->pop();
}

// Doc in parent
void
SoVRMLBillboard::getMatrix(SoGetMatrixAction * COIN_UNUSED_ARG(action))
{
  // FIXME: hmmm, what should I do here. pederb, 2001-10-30
}

// Doc in parent
void
SoVRMLBillboard::pick(SoPickAction * action)
{
  SoVRMLBillboard::doAction((SoAction*) action);
}

// Doc in parent
void
SoVRMLBillboard::search(SoSearchAction * action)
{
  SoNode::search(action);
  if (action->isFound()) return;
  SoGroup::doAction(action);
}

// Doc in parent
void
SoVRMLBillboard::GLRenderBelowPath(SoGLRenderAction * action)
{
  SoState * state = action->getState();

  // never cache this node
  SoCacheElement::invalidate(state);

  state->push();
  this->performRotation(state);

  int n = this->getChildren()->getLength();
  SoNode ** childarray = (SoNode**) this->getChildren()->getArrayPtr();

  action->pushCurPath();
  for (int i = 0; i < n && !action->hasTerminated(); i++) {
    action->popPushCurPath(i, childarray[i]);
    if (action->abortNow()) {
      // only cache if we do a full traversal
      break;
    }
    SoNodeProfiling profiling;
    profiling.preTraversal(action);
    childarray[i]->GLRenderBelowPath(action);
    profiling.postTraversal(action);

#if COIN_DEBUG
    // The GL error test is default disabled for this optimized
    // path.  If you get a GL error reporting an error in the
    // Separator node, enable this code by setting the environment
    // variable COIN_GLERROR_DEBUGGING to "1" to see exactly which
    // node caused the error.
    static SbBool chkglerr = sogl_glerror_debugging();
    if (chkglerr) {
      cc_string str;
      cc_string_construct(&str);
      const unsigned int errs = coin_catch_gl_errors(&str);
      if (errs > 0) {
        SoDebugError::post("SoVRMLBillboard::GLRenderBelowPath",
                           "GL error: '%s', nodetype: %s",
                           cc_string_get_text(&str),
                           (*this->getChildren())[i]->getTypeId().getName().getString());
      }
      cc_string_clean(&str);
    }
#endif // COIN_DEBUG
  }
  action->popCurPath();
  state->pop();
}

// Doc in parent
void
SoVRMLBillboard::GLRenderInPath(SoGLRenderAction * action )
{
  int numindices;
  const int * indices;

  SoAction::PathCode pathcode = action->getPathCode(numindices, indices);

  if (pathcode == SoAction::IN_PATH) {
    SoState * state = action->getState();
    SoCacheElement::invalidate(state);
    SoNode ** childarray = (SoNode**) this->getChildren()->getArrayPtr();
    state->push();
    this->performRotation(state);

    int childidx = 0;
    for (int i = 0; i < numindices; i++) {
      for (; childidx < indices[i] && !action->hasTerminated(); childidx++) {
        SoNode * offpath = childarray[childidx];
        if (offpath->affectsState()) {
          action->pushCurPath(childidx, offpath);
          if (!action->abortNow()) {
            SoNodeProfiling profiling;
            profiling.preTraversal(action);
            offpath->GLRenderOffPath(action);
            profiling.postTraversal(action);
          }
          action->popCurPath(pathcode);
        }
      }
      SoNode * inpath = childarray[childidx];
      action->pushCurPath(childidx, inpath);
      if (!action->abortNow()) {
        SoNodeProfiling profiling;
        profiling.preTraversal(action);
        inpath->GLRenderInPath(action);
        profiling.postTraversal(action);
      }
      action->popCurPath(pathcode);
      childidx++;
    }
    state->pop();
  }
  else {
    // we got to the end of the path
    assert(action->getCurPathCode() == SoAction::BELOW_PATH);
    this->GLRenderBelowPath(action);
  }
}

// Doc in parent
void
SoVRMLBillboard::GLRenderOffPath(SoGLRenderAction * COIN_UNUSED_ARG(action))
{
  // do nothing
}

// Doc in parent
void
SoVRMLBillboard::notify(SoNotList * list)
{
  inherited::notify(list);
}

//
// private method that appends the needed rotation to the state
//
void
SoVRMLBillboard::performRotation(SoState * state) const
{
  SbVec3f rotaxis = this->axisOfRotation.getValue();

  SbMatrix imm = SoModelMatrixElement::get(state).inverse();
  const SbViewVolume & vv = SoViewVolumeElement::get(state);
  SbVec3f up, look, right;
  
  imm.multDirMatrix(vv.getViewUp(), up);
  imm.multDirMatrix(-vv.getProjectionDirection(), look);

  if (rotaxis == SbVec3f(0.0f, 0.0f, 0.0f)) {
    // always orient the billboard towards the viewer
    right = up.cross(look);
    up = look.cross(right);
  } else { 
    // The VRML97 spec calls for rotating the local z-axis of the
    // billboard to face the viewer, pivoting around the axis of
    // rotation. If the axis of rotation is the z axis, this angle
    // will be zero, and no rotation can happen. We don't actually
    // bother to compute this angle at all, but set up = rotaxis and
    // use cross products from there to construct the rotation matrix.
    // This is more numerically stable, more general, and the code is
    // much nicer, but it also means that we must check specifically
    // for this case.
    if (rotaxis == SbVec3f(0.0f, 0.0f, 1.0f)) { return; }
    
    up = rotaxis;
    right = up.cross(look);
    look = right.cross(up);
  }

  // construct the rotation matrix with the vectors defining the
  // desired orientation
  SbMatrix matrix = SbMatrix::identity();

  right.normalize();
  up.normalize();
  look.normalize();
  
  matrix[0][0] = right[0];
  matrix[0][1] = right[1];
  matrix[0][2] = right[2];
  
  matrix[1][0] = up[0];
  matrix[1][1] = up[1];
  matrix[1][2] = up[2];
  
  matrix[2][0] = look[0];
  matrix[2][1] = look[1];
  matrix[2][2] = look[2];
  
  // append the desired rotation to the state
  SoModelMatrixElement::rotateBy(state, (SoNode*) this, SbRotation(matrix));
}

#endif // HAVE_VRML97