src/Main/CameraGroup.cxx

   1 // Copyright (C) 2008  Tim Moore
   2 // Copyright (C) 2011  Mathias Froehlich
   3 //
   4 // This program is free software; you can redistribute it and/or
   5 // modify it under the terms of the GNU General Public License as
   6 // published by the Free Software Foundation; either version 2 of the
   7 // License, or (at your option) any later version.
   8 //
   9 // This program is distributed in the hope that it will be useful, but
  10 // WITHOUT ANY WARRANTY; without even the implied warranty of
  11 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12 // General Public License for more details.
  13 //
  14 // You should have received a copy of the GNU General Public License
  15 // along with this program; if not, write to the Free Software
  16 // Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  17
  18 #ifdef HAVE_CONFIG_H
  19 #  include <config.h>
  20 #endif
  21
  22 #include "CameraGroup.hxx"
  23
  24 #include "fg_props.hxx"
  25 #include "globals.hxx"
  26 #include "renderer.hxx"
  27 #include "FGEventHandler.hxx"
  28 #include "WindowBuilder.hxx"
  29 #include "WindowSystemAdapter.hxx"
  30 #include <simgear/props/props.hxx>
  31 #include <simgear/structure/OSGUtils.hxx>
  32 #include <simgear/structure/OSGVersion.hxx>
  33 #include <simgear/scene/material/EffectCullVisitor.hxx>
  34 #include <simgear/scene/util/RenderConstants.hxx>
  35
  36 #include <algorithm>
  37 #include <cstring>
  38 #include <string>
  39
  40 #include <osg/Camera>
  41 #include <osg/Geometry>
  42 #include <osg/GraphicsContext>
  43 #include <osg/io_utils>
  44 #include <osg/Math>
  45 #include <osg/Matrix>
  46 #include <osg/Notify>
  47 #include <osg/Program>
  48 #include <osg/Quat>
  49 #include <osg/TexMat>
  50 #include <osg/Vec3d>
  51 #include <osg/Viewport>
  52
  53 #include <osgUtil/IntersectionVisitor>
  54
  55 #include <osgViewer/GraphicsWindow>
  56 #include <osgViewer/Renderer>
  57
  58 static osg::Matrix
  59 invert(const osg::Matrix& matrix)
  60 {
  61     return osg::Matrix::inverse(matrix);
  62 }
  63
  64 /// Returns the zoom factor of the master camera.
  65 /// The reference fov is the historic 55 deg
  66 static double
  67 zoomFactor()
  68 {
  69     double fov = fgGetDouble("/sim/current-view/field-of-view", 55);
  70     if (fov < 1)
  71         fov = 1;
  72     return tan(55*0.5*SG_DEGREES_TO_RADIANS)/tan(fov*0.5*SG_DEGREES_TO_RADIANS);
  73 }
  74
  75 static osg::Vec2d
  76 preMult(const osg::Vec2d& v, const osg::Matrix& m)
  77 {
  78   osg::Vec3d tmp = m.preMult(osg::Vec3(v, 0));
  79   return osg::Vec2d(tmp[0], tmp[1]);
  80 }
  81
  82 static osg::Matrix
  83 relativeProjection(const osg::Matrix& P0, const osg::Matrix& R, const osg::Vec2d ref[2],
  84                    const osg::Matrix& pP, const osg::Matrix& pR, const osg::Vec2d pRef[2])
  85 {
  86   // Track the way from one projection space to the other:
  87   // We want
  88   //  P = T*S*P0
  89   // where P0 is the projection template sensible for the given window size,
  90   // T is a translation matrix and S a scale matrix.
  91   // We need to determine T and S so that the reference points in the parents
  92   // projection space match the two reference points in this cameras projection space.
  93
  94   // Starting from the parents camera projection space, we get into this cameras
  95   // projection space by the transform matrix:
  96   //  P*R*inv(pP*pR) = T*S*P0*R*inv(pP*pR)
  97   // So, at first compute that matrix without T*S and determine S and T from that
  98
  99   // Ok, now osg uses the inverse matrix multiplication order, thus:
 100   osg::Matrix PtoPwithoutTS = invert(pR*pP)*R*P0;
 101   // Compute the parents reference points in the current projection space
 102   // without the yet unknown T and S
 103   osg::Vec2d pRefInThis[2] = {
 104     preMult(pRef[0], PtoPwithoutTS),
 105     preMult(pRef[1], PtoPwithoutTS)
 106   };
 107
 108   // To get the same zoom, rescale to match the parents size
 109   double s = (ref[0] - ref[1]).length()/(pRefInThis[0] - pRefInThis[1]).length();
 110   osg::Matrix S = osg::Matrix::scale(s, s, 1);
 111
 112   // For the translation offset, incorporate the now known scale
 113   // and recompute the position ot the first reference point in the
 114   // currents projection space without the yet unknown T.
 115   pRefInThis[0] = preMult(pRef[0], PtoPwithoutTS*S);
 116   // The translation is then the difference of the reference points
 117   osg::Matrix T = osg::Matrix::translate(osg::Vec3d(ref[0] - pRefInThis[0], 0));
 118
 119   // Compose and return the desired final projection matrix
 120   return P0*S*T;
 121 }
 122
 123 namespace flightgear
 124 {
 125 using namespace osg;
 126
 127 using std::strcmp;
 128 using std::string;
 129
 130 ref_ptr<CameraGroup> CameraGroup::_defaultGroup;
 131
 132 CameraGroup::CameraGroup(osgViewer::Viewer* viewer) :
 133     _viewer(viewer)
 134 {
 135 }
 136
 137 }
 138
 139 namespace
 140 {
 141 using namespace osg;
 142
 143 // Given a projection matrix, return a new one with the same frustum
 144 // sides and new near / far values.
 145
 146 void makeNewProjMat(Matrixd& oldProj, double znear,
 147                                        double zfar, Matrixd& projection)
 148 {
 149     projection = oldProj;
 150     // Slightly inflate the near & far planes to avoid objects at the
 151     // extremes being clipped out.
 152     znear *= 0.999;
 153     zfar *= 1.001;
 154
 155     // Clamp the projection matrix z values to the range (near, far)
 156     double epsilon = 1.0e-6;
 157     if (fabs(projection(0,3)) < epsilon &&
 158         fabs(projection(1,3)) < epsilon &&
 159         fabs(projection(2,3)) < epsilon) {
 160         // Projection is Orthographic
 161         epsilon = -1.0/(zfar - znear); // Used as a temp variable
 162         projection(2,2) = 2.0*epsilon;
 163         projection(3,2) = (zfar + znear)*epsilon;
 164     } else {
 165         // Projection is Perspective
 166         double trans_near = (-znear*projection(2,2) + projection(3,2)) /
 167             (-znear*projection(2,3) + projection(3,3));
 168         double trans_far = (-zfar*projection(2,2) + projection(3,2)) /
 169             (-zfar*projection(2,3) + projection(3,3));
 170         double ratio = fabs(2.0/(trans_near - trans_far));
 171         double center = -0.5*(trans_near + trans_far);
 172
 173         projection.postMult(osg::Matrixd(1.0, 0.0, 0.0, 0.0,
 174                                          0.0, 1.0, 0.0, 0.0,
 175                                          0.0, 0.0, ratio, 0.0,
 176                                          0.0, 0.0, center*ratio, 1.0));
 177     }
 178 }
 179
 180 void installCullVisitor(Camera* camera)
 181 {
 182     osgViewer::Renderer* renderer
 183         = static_cast<osgViewer::Renderer*>(camera->getRenderer());
 184     for (int i = 0; i < 2; ++i) {
 185         osgUtil::SceneView* sceneView = renderer->getSceneView(i);
 186 #if SG_OSG_VERSION_LESS_THAN(3,0,0)
 187         sceneView->setCullVisitor(new simgear::EffectCullVisitor);
 188 #else
 189         osg::ref_ptr<osgUtil::CullVisitor::Identifier> identifier;
 190         identifier = sceneView->getCullVisitor()->getIdentifier();
 191         sceneView->setCullVisitor(new simgear::EffectCullVisitor);
 192         sceneView->getCullVisitor()->setIdentifier(identifier.get());
 193
 194         identifier = sceneView->getCullVisitorLeft()->getIdentifier();
 195         sceneView->setCullVisitorLeft(sceneView->getCullVisitor()->clone());
 196         sceneView->getCullVisitorLeft()->setIdentifier(identifier.get());
 197
 198         identifier = sceneView->getCullVisitorRight()->getIdentifier();
 199         sceneView->setCullVisitorRight(sceneView->getCullVisitor()->clone());
 200         sceneView->getCullVisitorRight()->setIdentifier(identifier.get());
 201 #endif
 202     }
 203 }
 204 }
 205
 206 namespace flightgear
 207 {
 208 void updateCameras(const CameraInfo* info)
 209 {
 210     if (info->camera.valid())
 211         info->camera->getViewport()->setViewport(info->x, info->y,
 212                                                  info->width, info->height);
 213     if (info->farCamera.valid())
 214         info->farCamera->getViewport()->setViewport(info->x, info->y,
 215                                                     info->width, info->height);
 216 }
 217
 218 CameraInfo* CameraGroup::addCamera(unsigned flags, Camera* camera,
 219                                    const Matrix& view,
 220                                    const Matrix& projection,
 221                                    bool useMasterSceneData)
 222 {
 223     CameraInfo* info = new CameraInfo(flags);
 224     // The camera group will always update the camera
 225     camera->setReferenceFrame(Transform::ABSOLUTE_RF);
 226
 227     Camera* farCamera = 0;
 228     if ((flags & (GUI | ORTHO)) == 0) {
 229         farCamera = new Camera;
 230         farCamera->setAllowEventFocus(camera->getAllowEventFocus());
 231         farCamera->setGraphicsContext(camera->getGraphicsContext());
 232         farCamera->setCullingMode(camera->getCullingMode());
 233         farCamera->setInheritanceMask(camera->getInheritanceMask());
 234         farCamera->setReferenceFrame(Transform::ABSOLUTE_RF);
 235         // Each camera's viewport is written when the window is
 236         // resized; if the the viewport isn't copied here, it gets updated
 237         // twice and ends up with the wrong value.
 238         farCamera->setViewport(simgear::clone(camera->getViewport()));
 239         farCamera->setDrawBuffer(camera->getDrawBuffer());
 240         farCamera->setReadBuffer(camera->getReadBuffer());
 241         farCamera->setRenderTargetImplementation(
 242             camera->getRenderTargetImplementation());
 243         const Camera::BufferAttachmentMap& bufferMap
 244             = camera->getBufferAttachmentMap();
 245         if (bufferMap.count(Camera::COLOR_BUFFER) != 0) {
 246             farCamera->attach(
 247                 Camera::COLOR_BUFFER,
 248                 bufferMap.find(Camera::COLOR_BUFFER)->second._texture.get());
 249         }
 250         _viewer->addSlave(farCamera, projection, view, useMasterSceneData);
 251         installCullVisitor(farCamera);
 252         info->farCamera = farCamera;
 253         info->farSlaveIndex = _viewer->getNumSlaves() - 1;
 254         farCamera->setRenderOrder(Camera::POST_RENDER, info->farSlaveIndex);
 255         camera->setCullMask(camera->getCullMask() & ~simgear::BACKGROUND_BIT);
 256         camera->setClearMask(GL_DEPTH_BUFFER_BIT);
 257     }
 258     _viewer->addSlave(camera, projection, view, useMasterSceneData);
 259     installCullVisitor(camera);
 260     info->camera = camera;
 261     info->slaveIndex = _viewer->getNumSlaves() - 1;
 262     camera->setRenderOrder(Camera::POST_RENDER, info->slaveIndex);
 263     _cameras.push_back(info);
 264     return info;
 265 }
 266
 267 void CameraGroup::update(const osg::Vec3d& position,
 268                          const osg::Quat& orientation)
 269 {
 270     const Matrix masterView(osg::Matrix::translate(-position)
 271                             * osg::Matrix::rotate(orientation.inverse()));
 272     _viewer->getCamera()->setViewMatrix(masterView);
 273     const Matrix& masterProj = _viewer->getCamera()->getProjectionMatrix();
 274     double masterZoomFactor = zoomFactor();
 275     for (CameraList::iterator i = _cameras.begin(); i != _cameras.end(); ++i) {
 276         const CameraInfo* info = i->get();
 277         const View::Slave& slave = _viewer->getSlave(info->slaveIndex);
 278 #if SG_OSG_VERSION_LESS_THAN(3,0,0)
 279         // refreshes camera viewports (for now)
 280         updateCameras(info);
 281 #endif
 282         Camera* camera = info->camera.get();
 283         Matrix viewMatrix;
 284         if ((info->flags & VIEW_ABSOLUTE) != 0)
 285             viewMatrix = slave._viewOffset;
 286         else
 287             viewMatrix = masterView * slave._viewOffset;
 288         camera->setViewMatrix(viewMatrix);
 289         Matrix projectionMatrix;
 290         if ((info->flags & PROJECTION_ABSOLUTE) != 0) {
 291             if (info->flags & ENABLE_MASTER_ZOOM) {
 292                 if (info->relativeCameraParent < _cameras.size()) {
 293                     // template projection matrix and view matrix of the current camera
 294                     osg::Matrix P0 = slave._projectionOffset;
 295                     osg::Matrix R = viewMatrix;
 296
 297                     // The already known projection and view matrix of the parent camera
 298                     const CameraInfo* parentInfo = _cameras[info->relativeCameraParent].get();
 299                     osg::Matrix pP = parentInfo->camera->getProjectionMatrix();
 300                     osg::Matrix pR = parentInfo->camera->getViewMatrix();
 301
 302                     // And the projection matrix derived from P0 so that the reference points match
 303                     projectionMatrix = relativeProjection(P0, R, info->thisReference,
 304                                                           pP, pR, info->parentReference);
 305
 306                 } else {
 307                     // We want to zoom, so take the original matrix and apply the zoom to it.
 308                     projectionMatrix = slave._projectionOffset;
 309                     projectionMatrix.postMultScale(osg::Vec3d(masterZoomFactor, masterZoomFactor, 1));
 310                 }
 311             } else {
 312                 projectionMatrix = slave._projectionOffset;
 313             }
 314         } else {
 315             projectionMatrix = masterProj * slave._projectionOffset;
 316         }
 317
 318         if (!info->farCamera.valid()) {
 319             camera->setProjectionMatrix(projectionMatrix);
 320         } else {
 321             Camera* farCamera = info->farCamera.get();
 322             farCamera->setViewMatrix(viewMatrix);
 323             double left, right, bottom, top, parentNear, parentFar;
 324             projectionMatrix.getFrustum(left, right, bottom, top,
 325                                         parentNear, parentFar);
 326             if ((info->flags & FIXED_NEAR_FAR) == 0) {
 327                 parentNear = _zNear;
 328                 parentFar = _zFar;
 329             }
 330             if (parentFar < _nearField || _nearField == 0.0f) {
 331                 camera->setProjectionMatrix(projectionMatrix);
 332                 camera->setCullMask(camera->getCullMask()
 333                                     | simgear::BACKGROUND_BIT);
 334                 camera->setClearMask(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT | GL_STENCIL_BUFFER_BIT);
 335                 farCamera->setNodeMask(0);
 336             } else {
 337                 Matrix nearProj, farProj;
 338                 makeNewProjMat(projectionMatrix, parentNear, _nearField,
 339                                nearProj);
 340                 makeNewProjMat(projectionMatrix, _nearField, parentFar,
 341                                farProj);
 342                 camera->setProjectionMatrix(nearProj);
 343                 camera->setCullMask(camera->getCullMask()
 344                                     & ~simgear::BACKGROUND_BIT);
 345                 camera->setClearMask(GL_DEPTH_BUFFER_BIT);
 346                 farCamera->setProjectionMatrix(farProj);
 347                 farCamera->setNodeMask(camera->getNodeMask());
 348             }
 349         }
 350     }
 351 }
 352
 353 void CameraGroup::setCameraParameters(float vfov, float aspectRatio)
 354 {
 355     if (vfov != 0.0f && aspectRatio != 0.0f)
 356         _viewer->getCamera()
 357             ->setProjectionMatrixAsPerspective(vfov,
 358                                                1.0f / aspectRatio,
 359                                                _zNear, _zFar);
 360 }
 361
 362 double CameraGroup::getMasterAspectRatio() const
 363 {
 364     if (_cameras.empty())
 365         return 0.0;
 366
 367     const CameraInfo* info = _cameras.front();
 368
 369     const osg::Viewport* viewport = info->camera->getViewport();
 370     if (!viewport) {
 371         return 0.0;
 372     }
 373
 374     return static_cast<double>(viewport->height()) / viewport->width();
 375 }
 376
 377 }
 378
 379 namespace
 380 {
 381 // A raw value for property nodes that references a class member via
 382 // an osg::ref_ptr.
 383 template<class C, class T>
 384 class RefMember : public SGRawValue<T>
 385 {
 386 public:
 387     RefMember (C *obj, T C::*ptr)
 388         : _obj(obj), _ptr(ptr) {}
 389     virtual ~RefMember () {}
 390     virtual T getValue () const
 391     {
 392         return _obj.get()->*_ptr;
 393     }
 394     virtual bool setValue (T value)
 395     {
 396         _obj.get()->*_ptr = value;
 397         return true;
 398     }
 399     virtual SGRawValue<T> * clone () const
 400     {
 401         return new RefMember(_obj.get(), _ptr);
 402     }
 403 private:
 404     ref_ptr<C> _obj;
 405     T C::* const _ptr;
 406 };
 407
 408 template<typename C, typename T>
 409 RefMember<C, T> makeRefMember(C *obj, T C::*ptr)
 410 {
 411     return RefMember<C, T>(obj, ptr);
 412 }
 413
 414 template<typename C, typename T>
 415 void bindMemberToNode(SGPropertyNode* parent, const char* childName,
 416                       C* obj, T C::*ptr, T value)
 417 {
 418     SGPropertyNode* valNode = parent->getNode(childName);
 419     RefMember<C, T> refMember = makeRefMember(obj, ptr);
 420     if (!valNode) {
 421         valNode = parent->getNode(childName, true);
 422         valNode->tie(refMember, false);
 423         setValue(valNode, value);
 424     } else {
 425         valNode->tie(refMember, true);
 426     }
 427 }
 428
 429 void buildViewport(flightgear::CameraInfo* info, SGPropertyNode* viewportNode,
 430                    const osg::GraphicsContext::Traits *traits)
 431 {
 432     using namespace flightgear;
 433     bindMemberToNode(viewportNode, "x", info, &CameraInfo::x, 0.0);
 434     bindMemberToNode(viewportNode, "y", info, &CameraInfo::y, 0.0);
 435     bindMemberToNode(viewportNode, "width", info, &CameraInfo::width,
 436                      static_cast<double>(traits->width));
 437     bindMemberToNode(viewportNode, "height", info, &CameraInfo::height,
 438                      static_cast<double>(traits->height));
 439 }
 440 }
 441
 442 namespace flightgear
 443 {
 444
 445 // Mostly copied from osg's osgViewer/View.cpp
 446
 447 static osg::Geometry* createParoramicSphericalDisplayDistortionMesh(
 448     const Vec3& origin, const Vec3& widthVector, const Vec3& heightVector,
 449     double sphere_radius, double collar_radius,
 450     Image* intensityMap = 0, const Matrix& projectorMatrix = Matrix())
 451 {
 452     osg::Vec3d center(0.0,0.0,0.0);
 453     osg::Vec3d eye(0.0,0.0,0.0);
 454
 455     double distance = sqrt(sphere_radius*sphere_radius - collar_radius*collar_radius);
 456     bool flip = false;
 457     bool texcoord_flip = false;
 458
 459 #if 0
 460     osg::Vec3d projector = eye - osg::Vec3d(0.0,0.0, distance);
 461
 462     OSG_INFO<<"createParoramicSphericalDisplayDistortionMesh : Projector position = "<<projector<<std::endl;
 463     OSG_INFO<<"createParoramicSphericalDisplayDistortionMesh : distance = "<<distance<<std::endl;
 464 #endif
 465     // create the quad to visualize.
 466     osg::Geometry* geometry = new osg::Geometry();
 467
 468     geometry->setSupportsDisplayList(false);
 469
 470     osg::Vec3 xAxis(widthVector);
 471     float width = widthVector.length();
 472     xAxis /= width;
 473
 474     osg::Vec3 yAxis(heightVector);
 475     float height = heightVector.length();
 476     yAxis /= height;
 477
 478     int noSteps = 160;
 479
 480     osg::Vec3Array* vertices = new osg::Vec3Array;
 481     osg::Vec2Array* texcoords0 = new osg::Vec2Array;
 482     osg::Vec2Array* texcoords1 = intensityMap==0 ? new osg::Vec2Array : 0;
 483     osg::Vec4Array* colors = new osg::Vec4Array;
 484
 485 #if 0
 486     osg::Vec3 bottom = origin;
 487     osg::Vec3 dx = xAxis*(width/((float)(noSteps-2)));
 488     osg::Vec3 dy = yAxis*(height/((float)(noSteps-1)));
 489 #endif
 490     osg::Vec3 top = origin + yAxis*height;
 491
 492     osg::Vec3 screenCenter = origin + widthVector*0.5f + heightVector*0.5f;
 493     float screenRadius = heightVector.length() * 0.5f;
 494
 495     geometry->getOrCreateStateSet()->setMode(GL_CULL_FACE, osg::StateAttribute::OFF | osg::StateAttribute::PROTECTED);
 496
 497     for(int i=0;i<noSteps;++i)
 498     {
 499         //osg::Vec3 cursor = bottom+dy*(float)i;
 500         for(int j=0;j<noSteps;++j)
 501         {
 502             osg::Vec2 texcoord(double(i)/double(noSteps-1), double(j)/double(noSteps-1));
 503             double theta = texcoord.x() * 2.0 * osg::PI;
 504             double phi = (1.0-texcoord.y()) * osg::PI;
 505
 506             if (texcoord_flip) texcoord.y() = 1.0f - texcoord.y();
 507
 508             osg::Vec3 pos(sin(phi)*sin(theta), sin(phi)*cos(theta), cos(phi));
 509             pos = pos*projectorMatrix;
 510
 511             double alpha = atan2(pos.x(), pos.y());
 512             if (alpha<0.0) alpha += 2.0*osg::PI;
 513
 514             double beta = atan2(sqrt(pos.x()*pos.x() + pos.y()*pos.y()), pos.z());
 515             if (beta<0.0) beta += 2.0*osg::PI;
 516
 517             double gamma = atan2(sqrt(double(pos.x()*pos.x() + pos.y()*pos.y())), double(pos.z()+distance));
 518             if (gamma<0.0) gamma += 2.0*osg::PI;
 519
 520
 521             osg::Vec3 v = screenCenter + osg::Vec3(sin(alpha)*gamma*2.0/osg::PI, -cos(alpha)*gamma*2.0/osg::PI, 0.0f)*screenRadius;
 522
 523             if (flip)
 524                 vertices->push_back(osg::Vec3(v.x(), top.y()-(v.y()-origin.y()),v.z()));
 525             else
 526                 vertices->push_back(v);
 527
 528             texcoords0->push_back( texcoord );
 529
 530             osg::Vec2 texcoord1(alpha/(2.0*osg::PI), 1.0f - beta/osg::PI);
 531             if (intensityMap)
 532             {
 533                 colors->push_back(intensityMap->getColor(texcoord1));
 534             }
 535             else
 536             {
 537                 colors->push_back(osg::Vec4(1.0f,1.0f,1.0f,1.0f));
 538                 if (texcoords1) texcoords1->push_back( texcoord1 );
 539             }
 540
 541
 542         }
 543     }
 544
 545
 546     // pass the created vertex array to the points geometry object.
 547     geometry->setVertexArray(vertices);
 548
 549     geometry->setColorArray(colors);
 550     geometry->setColorBinding(osg::Geometry::BIND_PER_VERTEX);
 551
 552     geometry->setTexCoordArray(0,texcoords0);
 553     if (texcoords1) geometry->setTexCoordArray(1,texcoords1);
 554
 555     osg::DrawElementsUShort* elements = new osg::DrawElementsUShort(osg::PrimitiveSet::TRIANGLES);
 556     geometry->addPrimitiveSet(elements);
 557
 558     for(int i=0;i<noSteps-1;++i)
 559     {
 560         for(int j=0;j<noSteps-1;++j)
 561         {
 562             int i1 = j+(i+1)*noSteps;
 563             int i2 = j+(i)*noSteps;
 564             int i3 = j+1+(i)*noSteps;
 565             int i4 = j+1+(i+1)*noSteps;
 566
 567             osg::Vec3& v1 = (*vertices)[i1];
 568             osg::Vec3& v2 = (*vertices)[i2];
 569             osg::Vec3& v3 = (*vertices)[i3];
 570             osg::Vec3& v4 = (*vertices)[i4];
 571
 572             if ((v1-screenCenter).length()>screenRadius) continue;
 573             if ((v2-screenCenter).length()>screenRadius) continue;
 574             if ((v3-screenCenter).length()>screenRadius) continue;
 575             if ((v4-screenCenter).length()>screenRadius) continue;
 576
 577             elements->push_back(i1);
 578             elements->push_back(i2);
 579             elements->push_back(i3);
 580
 581             elements->push_back(i1);
 582             elements->push_back(i3);
 583             elements->push_back(i4);
 584         }
 585     }
 586
 587     return geometry;
 588 }
 589
 590 void CameraGroup::buildDistortionCamera(const SGPropertyNode* psNode,
 591                                         Camera* camera)
 592 {
 593     const SGPropertyNode* texNode = psNode->getNode("texture");
 594     if (!texNode) {
 595         // error
 596         return;
 597     }
 598     string texName = texNode->getStringValue();
 599     TextureMap::iterator itr = _textureTargets.find(texName);
 600     if (itr == _textureTargets.end()) {
 601         // error
 602         return;
 603     }
 604     Viewport* viewport = camera->getViewport();
 605     float width = viewport->width();
 606     float height = viewport->height();
 607     TextureRectangle* texRect = itr->second.get();
 608     double radius = psNode->getDoubleValue("radius", 1.0);
 609     double collar = psNode->getDoubleValue("collar", 0.45);
 610     Geode* geode = new Geode();
 611     geode->addDrawable(createParoramicSphericalDisplayDistortionMesh(
 612                            Vec3(0.0f,0.0f,0.0f), Vec3(width,0.0f,0.0f),
 613                            Vec3(0.0f,height,0.0f), radius, collar));
 614
 615     // new we need to add the texture to the mesh, we do so by creating a
 616     // StateSet to contain the Texture StateAttribute.
 617     StateSet* stateset = geode->getOrCreateStateSet();
 618     stateset->setTextureAttributeAndModes(0, texRect, StateAttribute::ON);
 619     stateset->setMode(GL_LIGHTING, StateAttribute::OFF);
 620
 621     TexMat* texmat = new TexMat;
 622     texmat->setScaleByTextureRectangleSize(true);
 623     stateset->setTextureAttributeAndModes(0, texmat, osg::StateAttribute::ON);
 624 #if 0
 625     if (!applyIntensityMapAsColours && intensityMap)
 626     {
 627         stateset->setTextureAttributeAndModes(1, new osg::Texture2D(intensityMap), osg::StateAttribute::ON);
 628     }
 629 #endif
 630     // add subgraph to render
 631     camera->addChild(geode);
 632     camera->setClearMask(GL_DEPTH_BUFFER_BIT | GL_COLOR_BUFFER_BIT);
 633     camera->setClearColor(osg::Vec4(0.0, 0.0, 0.0, 1.0));
 634     camera->setComputeNearFarMode(osg::CullSettings::DO_NOT_COMPUTE_NEAR_FAR);
 635     camera->setCullingMode(osg::CullSettings::NO_CULLING);
 636     camera->setName("DistortionCorrectionCamera");
 637 }
 638
 639 CameraInfo* CameraGroup::buildCamera(SGPropertyNode* cameraNode)
 640 {
 641     WindowBuilder *wBuild = WindowBuilder::getWindowBuilder();
 642     const SGPropertyNode* windowNode = cameraNode->getNode("window");
 643     GraphicsWindow* window = 0;
 644     int cameraFlags = DO_INTERSECTION_TEST;
 645     if (windowNode) {
 646         // New style window declaration / definition
 647         window = wBuild->buildWindow(windowNode);
 648     } else {
 649         // Old style: suck window params out of camera block
 650         window = wBuild->buildWindow(cameraNode);
 651     }
 652     if (!window) {
 653         return 0;
 654     }
 655     Camera* camera = new Camera;
 656     camera->setAllowEventFocus(false);
 657     camera->setGraphicsContext(window->gc.get());
 658     camera->setViewport(new Viewport);
 659     camera->setCullingMode(CullSettings::SMALL_FEATURE_CULLING
 660                            | CullSettings::VIEW_FRUSTUM_CULLING);
 661     camera->setInheritanceMask(CullSettings::ALL_VARIABLES
 662                                & ~(CullSettings::CULL_MASK
 663                                    | CullSettings::CULLING_MODE
 664 #if defined(HAVE_CULLSETTINGS_CLEAR_MASK)
 665                                    | CullSettings::CLEAR_MASK
 666 #endif
 667                                    ));
 668
 669     osg::Matrix vOff;
 670     const SGPropertyNode* viewNode = cameraNode->getNode("view");
 671     if (viewNode) {
 672         double heading = viewNode->getDoubleValue("heading-deg", 0.0);
 673         double pitch = viewNode->getDoubleValue("pitch-deg", 0.0);
 674         double roll = viewNode->getDoubleValue("roll-deg", 0.0);
 675         double x = viewNode->getDoubleValue("x", 0.0);
 676         double y = viewNode->getDoubleValue("y", 0.0);
 677         double z = viewNode->getDoubleValue("z", 0.0);
 678         // Build a view matrix, which is the inverse of a model
 679         // orientation matrix.
 680         vOff = (Matrix::translate(-x, -y, -z)
 681                 * Matrix::rotate(-DegreesToRadians(heading),
 682                                  Vec3d(0.0, 1.0, 0.0),
 683                                  -DegreesToRadians(pitch),
 684                                  Vec3d(1.0, 0.0, 0.0),
 685                                  -DegreesToRadians(roll),
 686                                  Vec3d(0.0, 0.0, 1.0)));
 687         if (viewNode->getBoolValue("absolute", false))
 688             cameraFlags |= VIEW_ABSOLUTE;
 689     } else {
 690         // Old heading parameter, works in the opposite direction
 691         double heading = cameraNode->getDoubleValue("heading-deg", 0.0);
 692         vOff.makeRotate(DegreesToRadians(heading), osg::Vec3(0, 1, 0));
 693     }
 694     // Configuring the physical dimensions of a monitor
 695     SGPropertyNode* viewportNode = cameraNode->getNode("viewport", true);
 696     double physicalWidth = viewportNode->getDoubleValue("width", 1024);
 697     double physicalHeight = viewportNode->getDoubleValue("height", 768);
 698     double bezelHeightTop = 0;
 699     double bezelHeightBottom = 0;
 700     double bezelWidthLeft = 0;
 701     double bezelWidthRight = 0;
 702     const SGPropertyNode* physicalDimensionsNode = 0;
 703     if ((physicalDimensionsNode = cameraNode->getNode("physical-dimensions")) != 0) {
 704         physicalWidth = physicalDimensionsNode->getDoubleValue("width", physicalWidth);
 705         physicalHeight = physicalDimensionsNode->getDoubleValue("height", physicalHeight);
 706         const SGPropertyNode* bezelNode = 0;
 707         if ((bezelNode = physicalDimensionsNode->getNode("bezel")) != 0) {
 708             bezelHeightTop = bezelNode->getDoubleValue("top", bezelHeightTop);
 709             bezelHeightBottom = bezelNode->getDoubleValue("bottom", bezelHeightBottom);
 710             bezelWidthLeft = bezelNode->getDoubleValue("left", bezelWidthLeft);
 711             bezelWidthRight = bezelNode->getDoubleValue("right", bezelWidthRight);
 712         }
 713     }
 714     osg::Matrix pOff;
 715     unsigned parentCameraIndex = ~0u;
 716     osg::Vec2d parentReference[2];
 717     osg::Vec2d thisReference[2];
 718     SGPropertyNode* projectionNode = 0;
 719     if ((projectionNode = cameraNode->getNode("perspective")) != 0) {
 720         double fovy = projectionNode->getDoubleValue("fovy-deg", 55.0);
 721         double aspectRatio = projectionNode->getDoubleValue("aspect-ratio",
 722                                                             1.0);
 723         double zNear = projectionNode->getDoubleValue("near", 0.0);
 724         double zFar = projectionNode->getDoubleValue("far", zNear + 20000);
 725         double offsetX = projectionNode->getDoubleValue("offset-x", 0.0);
 726         double offsetY = projectionNode->getDoubleValue("offset-y", 0.0);
 727         double tan_fovy = tan(DegreesToRadians(fovy*0.5));
 728         double right = tan_fovy * aspectRatio * zNear + offsetX;
 729         double left = -tan_fovy * aspectRatio * zNear + offsetX;
 730         double top = tan_fovy * zNear + offsetY;
 731         double bottom = -tan_fovy * zNear + offsetY;
 732         pOff.makeFrustum(left, right, bottom, top, zNear, zFar);
 733         cameraFlags |= PROJECTION_ABSOLUTE;
 734         if (projectionNode->getBoolValue("fixed-near-far", true))
 735             cameraFlags |= FIXED_NEAR_FAR;
 736     } else if ((projectionNode = cameraNode->getNode("frustum")) != 0
 737                || (projectionNode = cameraNode->getNode("ortho")) != 0) {
 738         double top = projectionNode->getDoubleValue("top", 0.0);
 739         double bottom = projectionNode->getDoubleValue("bottom", 0.0);
 740         double left = projectionNode->getDoubleValue("left", 0.0);
 741         double right = projectionNode->getDoubleValue("right", 0.0);
 742         double zNear = projectionNode->getDoubleValue("near", 0.0);
 743         double zFar = projectionNode->getDoubleValue("far", zNear + 20000);
 744         if (cameraNode->getNode("frustum")) {
 745             pOff.makeFrustum(left, right, bottom, top, zNear, zFar);
 746             cameraFlags |= PROJECTION_ABSOLUTE;
 747         } else {
 748             pOff.makeOrtho(left, right, bottom, top, zNear, zFar);
 749             cameraFlags |= (PROJECTION_ABSOLUTE | ORTHO);
 750         }
 751         if (projectionNode->getBoolValue("fixed-near-far", true))
 752             cameraFlags |= FIXED_NEAR_FAR;
 753     } else if ((projectionNode = cameraNode->getNode("master-perspective")) != 0) {
 754         double zNear = projectionNode->getDoubleValue("eye-distance", 0.4*physicalWidth);
 755         double xoff = projectionNode->getDoubleValue("x-offset", 0);
 756         double yoff = projectionNode->getDoubleValue("y-offset", 0);
 757         double left = -0.5*physicalWidth - xoff;
 758         double right = 0.5*physicalWidth - xoff;
 759         double bottom = -0.5*physicalHeight - yoff;
 760         double top = 0.5*physicalHeight - yoff;
 761         pOff.makeFrustum(left, right, bottom, top, zNear, zNear*1000);
 762         cameraFlags |= PROJECTION_ABSOLUTE | ENABLE_MASTER_ZOOM;
 763     } else if ((projectionNode = cameraNode->getNode("right-of-perspective"))
 764                || (projectionNode = cameraNode->getNode("left-of-perspective"))
 765                || (projectionNode = cameraNode->getNode("above-perspective"))
 766                || (projectionNode = cameraNode->getNode("below-perspective"))
 767                || (projectionNode = cameraNode->getNode("reference-points-perspective"))) {
 768         std::string name = projectionNode->getStringValue("parent-camera");
 769         for (unsigned i = 0; i < _cameras.size(); ++i) {
 770             if (_cameras[i]->name != name)
 771                 continue;
 772             parentCameraIndex = i;
 773         }
 774         if (_cameras.size() <= parentCameraIndex) {
 775             SG_LOG(SG_VIEW, SG_ALERT, "CameraGroup::buildCamera: "
 776                    "failed to find parent camera for relative camera!");
 777             return 0;
 778         }
 779         const CameraInfo* parentInfo = _cameras[parentCameraIndex].get();
 780         if (projectionNode->getNameString() == "right-of-perspective") {
 781             double tmp = (parentInfo->physicalWidth + 2*parentInfo->bezelWidthRight)/parentInfo->physicalWidth;
 782             parentReference[0] = osg::Vec2d(tmp, -1);
 783             parentReference[1] = osg::Vec2d(tmp, 1);
 784             tmp = (physicalWidth + 2*bezelWidthLeft)/physicalWidth;
 785             thisReference[0] = osg::Vec2d(-tmp, -1);
 786             thisReference[1] = osg::Vec2d(-tmp, 1);
 787         } else if (projectionNode->getNameString() == "left-of-perspective") {
 788             double tmp = (parentInfo->physicalWidth + 2*parentInfo->bezelWidthLeft)/parentInfo->physicalWidth;
 789             parentReference[0] = osg::Vec2d(-tmp, -1);
 790             parentReference[1] = osg::Vec2d(-tmp, 1);
 791             tmp = (physicalWidth + 2*bezelWidthRight)/physicalWidth;
 792             thisReference[0] = osg::Vec2d(tmp, -1);
 793             thisReference[1] = osg::Vec2d(tmp, 1);
 794         } else if (projectionNode->getNameString() == "above-perspective") {
 795             double tmp = (parentInfo->physicalHeight + 2*parentInfo->bezelHeightTop)/parentInfo->physicalHeight;
 796             parentReference[0] = osg::Vec2d(-1, tmp);
 797             parentReference[1] = osg::Vec2d(1, tmp);
 798             tmp = (physicalHeight + 2*bezelHeightBottom)/physicalHeight;
 799             thisReference[0] = osg::Vec2d(-1, -tmp);
 800             thisReference[1] = osg::Vec2d(1, -tmp);
 801         } else if (projectionNode->getNameString() == "below-perspective") {
 802             double tmp = (parentInfo->physicalHeight + 2*parentInfo->bezelHeightBottom)/parentInfo->physicalHeight;
 803             parentReference[0] = osg::Vec2d(-1, -tmp);
 804             parentReference[1] = osg::Vec2d(1, -tmp);
 805             tmp = (physicalHeight + 2*bezelHeightTop)/physicalHeight;
 806             thisReference[0] = osg::Vec2d(-1, tmp);
 807             thisReference[1] = osg::Vec2d(1, tmp);
 808         } else if (projectionNode->getNameString() == "reference-points-perspective") {
 809             SGPropertyNode* parentNode = projectionNode->getNode("parent", true);
 810             SGPropertyNode* thisNode = projectionNode->getNode("this", true);
 811             SGPropertyNode* pointNode;
 812
 813             pointNode = parentNode->getNode("point", 0, true);
 814             parentReference[0][0] = pointNode->getDoubleValue("x", 0)*2/parentInfo->physicalWidth;
 815             parentReference[0][1] = pointNode->getDoubleValue("y", 0)*2/parentInfo->physicalHeight;
 816             pointNode = parentNode->getNode("point", 1, true);
 817             parentReference[1][0] = pointNode->getDoubleValue("x", 0)*2/parentInfo->physicalWidth;
 818             parentReference[1][1] = pointNode->getDoubleValue("y", 0)*2/parentInfo->physicalHeight;
 819
 820             pointNode = thisNode->getNode("point", 0, true);
 821             thisReference[0][0] = pointNode->getDoubleValue("x", 0)*2/physicalWidth;
 822             thisReference[0][1] = pointNode->getDoubleValue("y", 0)*2/physicalHeight;
 823             pointNode = thisNode->getNode("point", 1, true);
 824             thisReference[1][0] = pointNode->getDoubleValue("x", 0)*2/physicalWidth;
 825             thisReference[1][1] = pointNode->getDoubleValue("y", 0)*2/physicalHeight;
 826         }
 827
 828         pOff = osg::Matrix::perspective(45, physicalWidth/physicalHeight, 1, 20000);
 829         cameraFlags |= PROJECTION_ABSOLUTE | ENABLE_MASTER_ZOOM;
 830     } else {
 831         // old style shear parameters
 832         double shearx = cameraNode->getDoubleValue("shear-x", 0);
 833         double sheary = cameraNode->getDoubleValue("shear-y", 0);
 834         pOff.makeTranslate(-shearx, -sheary, 0);
 835     }
 836     const SGPropertyNode* textureNode = cameraNode->getNode("texture");
 837     if (textureNode) {
 838         string texName = textureNode->getStringValue("name");
 839         int tex_width = textureNode->getIntValue("width");
 840         int tex_height = textureNode->getIntValue("height");
 841         TextureRectangle* texture = new TextureRectangle;
 842
 843         texture->setTextureSize(tex_width, tex_height);
 844         texture->setInternalFormat(GL_RGB);
 845         texture->setFilter(Texture::MIN_FILTER, Texture::LINEAR);
 846         texture->setFilter(Texture::MAG_FILTER, Texture::LINEAR);
 847         texture->setWrap(Texture::WRAP_S, Texture::CLAMP_TO_EDGE);
 848         texture->setWrap(Texture::WRAP_T, Texture::CLAMP_TO_EDGE);
 849         camera->setDrawBuffer(GL_FRONT);
 850         camera->setReadBuffer(GL_FRONT);
 851         camera->setRenderTargetImplementation(Camera::FRAME_BUFFER_OBJECT);
 852         camera->attach(Camera::COLOR_BUFFER, texture);
 853         _textureTargets[texName] = texture;
 854     } else {
 855         camera->setDrawBuffer(GL_BACK);
 856         camera->setReadBuffer(GL_BACK);
 857     }
 858     const SGPropertyNode* psNode = cameraNode->getNode("panoramic-spherical");
 859     bool useMasterSceneGraph = !psNode;
 860     CameraInfo* info = addCamera(cameraFlags, camera, vOff, pOff,
 861                                  useMasterSceneGraph);
 862     info->name = cameraNode->getStringValue("name");
 863     info->physicalWidth = physicalWidth;
 864     info->physicalHeight = physicalHeight;
 865     info->bezelHeightTop = bezelHeightTop;
 866     info->bezelHeightBottom = bezelHeightBottom;
 867     info->bezelWidthLeft = bezelWidthLeft;
 868     info->bezelWidthRight = bezelWidthRight;
 869     info->relativeCameraParent = parentCameraIndex;
 870     info->parentReference[0] = parentReference[0];
 871     info->parentReference[1] = parentReference[1];
 872     info->thisReference[0] = thisReference[0];
 873     info->thisReference[1] = thisReference[1];
 874     // If a viewport isn't set on the camera, then it's hard to dig it
 875     // out of the SceneView objects in the viewer, and the coordinates
 876     // of mouse events are somewhat bizzare.
 877     buildViewport(info, viewportNode, window->gc->getTraits());
 878     updateCameras(info);
 879     // Distortion camera needs the viewport which is created by addCamera().
 880     if (psNode) {
 881         info->flags = info->flags | VIEW_ABSOLUTE;
 882         buildDistortionCamera(psNode, camera);
 883     }
 884     return info;
 885 }
 886
 887 CameraInfo* CameraGroup::buildGUICamera(SGPropertyNode* cameraNode,
 888                                         GraphicsWindow* window)
 889 {
 890     WindowBuilder *wBuild = WindowBuilder::getWindowBuilder();
 891     const SGPropertyNode* windowNode = (cameraNode
 892                                         ? cameraNode->getNode("window")
 893                                         : 0);
 894     if (!window && windowNode) {
 895       // New style window declaration / definition
 896       window = wBuild->buildWindow(windowNode);
 897     }
 898
 899     if (!window) { // buildWindow can fail
 900       SG_LOG(SG_VIEW, SG_WARN, "CameraGroup::buildGUICamera: failed to build a window");
 901       return NULL;
 902     }
 903
 904     Camera* camera = new Camera;
 905     camera->setAllowEventFocus(false);
 906     camera->setGraphicsContext(window->gc.get());
 907     camera->setViewport(new Viewport);
 908     // XXX Camera needs to be drawn last; eventually the render order
 909     // should be assigned by a camera manager.
 910     camera->setRenderOrder(osg::Camera::POST_RENDER, 100);
 911         camera->setClearMask(0);
 912     camera->setInheritanceMask(CullSettings::ALL_VARIABLES
 913                                & ~(CullSettings::COMPUTE_NEAR_FAR_MODE
 914                                    | CullSettings::CULLING_MODE
 915 #if defined(HAVE_CULLSETTINGS_CLEAR_MASK)
 916                                    | CullSettings::CLEAR_MASK
 917 #endif
 918                                    ));
 919     camera->setComputeNearFarMode(osg::CullSettings::DO_NOT_COMPUTE_NEAR_FAR);
 920     camera->setCullingMode(osg::CullSettings::NO_CULLING);
 921     camera->setProjectionResizePolicy(Camera::FIXED);
 922     camera->setReferenceFrame(Transform::ABSOLUTE_RF);
 923     const int cameraFlags = GUI;
 924     CameraInfo* result = addCamera(cameraFlags, camera, Matrixd::identity(),
 925                                    Matrixd::identity(), false);
 926     SGPropertyNode* viewportNode = cameraNode->getNode("viewport", true);
 927     buildViewport(result, viewportNode, window->gc->getTraits());
 928
 929     // Disable statistics for the GUI camera.
 930     result->camera->setStats(0);
 931     updateCameras(result);
 932     return result;
 933 }
 934
 935 CameraGroup* CameraGroup::buildCameraGroup(osgViewer::Viewer* viewer,
 936                                            SGPropertyNode* gnode)
 937 {
 938     CameraGroup* cgroup = new CameraGroup(viewer);
 939     for (int i = 0; i < gnode->nChildren(); ++i) {
 940         SGPropertyNode* pNode = gnode->getChild(i);
 941         const char* name = pNode->getName();
 942         if (!strcmp(name, "camera")) {
 943             cgroup->buildCamera(pNode);
 944         } else if (!strcmp(name, "window")) {
 945             WindowBuilder::getWindowBuilder()->buildWindow(pNode);
 946         } else if (!strcmp(name, "gui")) {
 947             cgroup->buildGUICamera(pNode);
 948         }
 949     }
 950     bindMemberToNode(gnode, "znear", cgroup, &CameraGroup::_zNear, .1f);
 951     bindMemberToNode(gnode, "zfar", cgroup, &CameraGroup::_zFar, 120000.0f);
 952     bindMemberToNode(gnode, "near-field", cgroup, &CameraGroup::_nearField,
 953                      100.0f);
 954     return cgroup;
 955 }
 956
 957 void CameraGroup::setCameraCullMasks(Node::NodeMask nm)
 958 {
 959     for (CameraIterator i = camerasBegin(), e = camerasEnd(); i != e; ++i) {
 960         CameraInfo* info = i->get();
 961         if (info->flags & GUI)
 962             continue;
 963         if (info->farCamera.valid() && info->farCamera->getNodeMask() != 0) {
 964             info->camera->setCullMask(nm & ~simgear::BACKGROUND_BIT);
 965             info->camera->setCullMaskLeft(nm & ~simgear::BACKGROUND_BIT);
 966             info->camera->setCullMaskRight(nm & ~simgear::BACKGROUND_BIT);
 967             info->farCamera->setCullMask(nm);
 968             info->farCamera->setCullMaskLeft(nm);
 969             info->farCamera->setCullMaskRight(nm);
 970         } else {
 971             info->camera->setCullMask(nm);
 972             info->camera->setCullMaskLeft(nm);
 973             info->camera->setCullMaskRight(nm);
 974         }
 975     }
 976 }
 977
 978 void CameraGroup::resized()
 979 {
 980     for (CameraIterator i = camerasBegin(), e = camerasEnd(); i != e; ++i) {
 981         CameraInfo *info = i->get();
 982         const Viewport* viewport = info->camera->getViewport();
 983         info->x = viewport->x();
 984         info->y = viewport->y();
 985         info->width = viewport->width();
 986         info->height = viewport->height();
 987     }
 988 }
 989
 990 Camera* getGUICamera(CameraGroup* cgroup)
 991 {
 992     CameraGroup::CameraIterator end = cgroup->camerasEnd();
 993     CameraGroup::CameraIterator result
 994         = std::find_if(cgroup->camerasBegin(), end,
 995                        FlagTester<CameraInfo>(CameraGroup::GUI));
 996     if (result != end)
 997         return (*result)->camera.get();
 998     else
 999         return 0;
1000 }
1001
1002 bool computeIntersections(const CameraGroup* cgroup,
1003                           const osgGA::GUIEventAdapter* ea,
1004                           osgUtil::LineSegmentIntersector::Intersections& intersections)
1005 {
1006     using osgUtil::Intersector;
1007     using osgUtil::LineSegmentIntersector;
1008     double x, y;
1009     eventToWindowCoords(ea, x, y);
1010     // Find camera that contains event
1011     for (CameraGroup::ConstCameraIterator iter = cgroup->camerasBegin(),
1012              e = cgroup->camerasEnd();
1013          iter != e;
1014          ++iter) {
1015         const CameraInfo* cinfo = iter->get();
1016         if ((cinfo->flags & CameraGroup::DO_INTERSECTION_TEST) == 0)
1017             continue;
1018         const Camera* camera = cinfo->camera.get();
1019         if (camera->getGraphicsContext() != ea->getGraphicsContext())
1020             continue;
1021         const Viewport* viewport = camera->getViewport();
1022         double epsilon = 0.5;
1023         if (!(x >= viewport->x() - epsilon
1024               && x < viewport->x() + viewport->width() -1.0 + epsilon
1025               && y >= viewport->y() - epsilon
1026               && y < viewport->y() + viewport->height() -1.0 + epsilon))
1027             continue;
1028         Vec4d start(x, y, 0.0, 1.0);
1029         Vec4d end(x, y, 1.0, 1.0);
1030         Matrix windowMat = viewport->computeWindowMatrix();
1031         Matrix startPtMat = Matrix::inverse(camera->getProjectionMatrix()
1032                                             * windowMat);
1033         Matrix endPtMat;
1034         if (!cinfo->farCamera.valid() || cinfo->farCamera->getNodeMask() == 0)
1035             endPtMat = startPtMat;
1036         else
1037             endPtMat = Matrix::inverse(cinfo->farCamera->getProjectionMatrix()
1038                                        * windowMat);
1039         start = start * startPtMat;
1040         start /= start.w();
1041         end = end * endPtMat;
1042         end /= end.w();
1043         ref_ptr<LineSegmentIntersector> picker
1044             = new LineSegmentIntersector(Intersector::VIEW,
1045                                          Vec3d(start.x(), start.y(), start.z()),
1046                                          Vec3d(end.x(), end.y(), end.z()));
1047         osgUtil::IntersectionVisitor iv(picker.get());
1048         const_cast<Camera*>(camera)->accept(iv);
1049         if (picker->containsIntersections()) {
1050             intersections = picker->getIntersections();
1051             return true;
1052         } else {
1053             break;
1054         }
1055     }
1056     intersections.clear();
1057     return false;
1058 }
1059
1060 void warpGUIPointer(CameraGroup* cgroup, int x, int y)
1061 {
1062     using osgViewer::GraphicsWindow;
1063     Camera* guiCamera = getGUICamera(cgroup);
1064     if (!guiCamera)
1065         return;
1066     Viewport* vport = guiCamera->getViewport();
1067     GraphicsWindow* gw
1068         = dynamic_cast<GraphicsWindow*>(guiCamera->getGraphicsContext());
1069     if (!gw)
1070         return;
1071     globals->get_renderer()->getEventHandler()->setMouseWarped();
1072     // Translate the warp request into the viewport of the GUI camera,
1073     // send the request to the window, then transform the coordinates
1074     // for the Viewer's event queue.
1075     double wx = x + vport->x();
1076     double wyUp = vport->height() + vport->y() - y;
1077     double wy;
1078     const GraphicsContext::Traits* traits = gw->getTraits();
1079     if (gw->getEventQueue()->getCurrentEventState()->getMouseYOrientation()
1080         == osgGA::GUIEventAdapter::Y_INCREASING_DOWNWARDS) {
1081         wy = traits->height - wyUp;
1082     } else {
1083         wy = wyUp;
1084     }
1085     gw->getEventQueue()->mouseWarped(wx, wy);
1086     gw->requestWarpPointer(wx, wy);
1087     osgGA::GUIEventAdapter* eventState
1088         = cgroup->getViewer()->getEventQueue()->getCurrentEventState();
1089     double viewerX
1090         = (eventState->getXmin()
1091            + ((wx / double(traits->width))
1092               * (eventState->getXmax() - eventState->getXmin())));
1093     double viewerY
1094         = (eventState->getYmin()
1095            + ((wyUp / double(traits->height))
1096               * (eventState->getYmax() - eventState->getYmin())));
1097     cgroup->getViewer()->getEventQueue()->mouseWarped(viewerX, viewerY);
1098 }
1099 }