src/Main/CameraGroup.cxx

   1 // Copyright (C) 2008  Tim Moore
   2 //
   3 // This program is free software; you can redistribute it and/or
   4 // modify it under the terms of the GNU General Public License as
   5 // published by the Free Software Foundation; either version 2 of the
   6 // License, or (at your option) any later version.
   7 //
   8 // This program is distributed in the hope that it will be useful, but
   9 // WITHOUT ANY WARRANTY; without even the implied warranty of
  10 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  11 // General Public License for more details.
  12 //
  13 // You should have received a copy of the GNU General Public License
  14 // along with this program; if not, write to the Free Software
  15 // Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  16
  17 #include "CameraGroup.hxx"
  18
  19 #include "globals.hxx"
  20 #include "renderer.hxx"
  21 #include "FGEventHandler.hxx"
  22 #include "WindowBuilder.hxx"
  23 #include "WindowSystemAdapter.hxx"
  24 #include <simgear/props/props.hxx>
  25 #include <simgear/structure/OSGUtils.hxx>
  26 #include <simgear/scene/util/RenderConstants.hxx>
  27
  28 #include <algorithm>
  29 #include <cstring>
  30 #include <string>
  31
  32 #include <osg/Camera>
  33 #include <osg/GraphicsContext>
  34 #include <osg/Math>
  35 #include <osg/Matrix>
  36 #include <osg/Quat>
  37 #include <osg/Vec3d>
  38 #include <osg/Viewport>
  39
  40 #include <osgUtil/IntersectionVisitor>
  41
  42 #include <osgViewer/GraphicsWindow>
  43
  44 namespace flightgear
  45 {
  46 using namespace osg;
  47
  48 using std::strcmp;
  49 using std::string;
  50
  51 ref_ptr<CameraGroup> CameraGroup::_defaultGroup;
  52
  53 CameraGroup::CameraGroup(osgViewer::Viewer* viewer) :
  54     _viewer(viewer)
  55 {
  56 }
  57
  58 }
  59
  60 namespace
  61 {
  62 using namespace osg;
  63
  64 // Given a projection matrix, return a new one with the same frustum
  65 // sides and new near / far values.
  66
  67 void makeNewProjMat(Matrixd& oldProj, double znear,
  68                                        double zfar, Matrixd& projection)
  69 {
  70     projection = oldProj;
  71     // Slightly inflate the near & far planes to avoid objects at the
  72     // extremes being clipped out.
  73     znear *= 0.999;
  74     zfar *= 1.001;
  75
  76     // Clamp the projection matrix z values to the range (near, far)
  77     double epsilon = 1.0e-6;
  78     if (fabs(projection(0,3)) < epsilon &&
  79         fabs(projection(1,3)) < epsilon &&
  80         fabs(projection(2,3)) < epsilon) {
  81         // Projection is Orthographic
  82         epsilon = -1.0/(zfar - znear); // Used as a temp variable
  83         projection(2,2) = 2.0*epsilon;
  84         projection(3,2) = (zfar + znear)*epsilon;
  85     } else {
  86         // Projection is Perspective
  87         double trans_near = (-znear*projection(2,2) + projection(3,2)) /
  88             (-znear*projection(2,3) + projection(3,3));
  89         double trans_far = (-zfar*projection(2,2) + projection(3,2)) /
  90             (-zfar*projection(2,3) + projection(3,3));
  91         double ratio = fabs(2.0/(trans_near - trans_far));
  92         double center = -0.5*(trans_near + trans_far);
  93
  94         projection.postMult(osg::Matrixd(1.0, 0.0, 0.0, 0.0,
  95                                          0.0, 1.0, 0.0, 0.0,
  96                                          0.0, 0.0, ratio, 0.0,
  97                                          0.0, 0.0, center*ratio, 1.0));
  98     }
  99 }
 100
 101 void installCullVisitor(Camera* camera)
 102 {
 103 #if 0 // Not yet
 104     osgViewer::Renderer* renderer
 105         = static_cast<osgViewer::Renderer*>(camera->getRenderer());
 106     for (int i = 0; i < 2; ++i) {
 107         osgUtil::SceneView* sceneView = renderer->getSceneView(i);
 108         sceneView->setCullVisitor(new simgear::EffectCullVisitor);
 109     }
 110 #endif
 111 }
 112 }
 113
 114 namespace flightgear
 115 {
 116 void updateCameras(const CameraInfo* info)
 117 {
 118     if (info->camera.valid())
 119         info->camera->getViewport()->setViewport(info->x, info->y,
 120                                                  info->width, info->height);
 121     if (info->farCamera.valid())
 122         info->farCamera->getViewport()->setViewport(info->x, info->y,
 123                                                     info->width, info->height);
 124 }
 125
 126 CameraInfo* CameraGroup::addCamera(unsigned flags, Camera* camera,
 127                                    const Matrix& view,
 128                                    const Matrix& projection,
 129                                    bool useMasterSceneData)
 130 {
 131     CameraInfo* info = new CameraInfo(flags);
 132     // The camera group will always update the camera
 133     camera->setReferenceFrame(Transform::ABSOLUTE_RF);
 134
 135     Camera* farCamera = 0;
 136     if ((flags & (GUI | ORTHO)) == 0) {
 137         farCamera = simgear::clone(camera);
 138         farCamera->setGraphicsContext(camera->getGraphicsContext());
 139         // Each camera's viewport is written when the window is
 140         // resized; if the the viewport isn't copied here, it gets updated
 141         // twice and ends up with the wrong value.
 142         farCamera->setViewport(simgear::clone(camera->getViewport()));
 143         _viewer->addSlave(farCamera, view, projection, useMasterSceneData);
 144         installCullVisitor(farCamera);
 145         info->farCamera = farCamera;
 146         info->farSlaveIndex = _viewer->getNumSlaves() - 1;
 147         farCamera->setRenderOrder(Camera::NESTED_RENDER, info->farSlaveIndex);
 148         camera->setCullMask(camera->getCullMask() & ~simgear::BACKGROUND_BIT);
 149         camera->setClearMask(GL_DEPTH_BUFFER_BIT);
 150     }
 151     _viewer->addSlave(camera, view, projection, useMasterSceneData);
 152     installCullVisitor(camera);
 153     info->camera = camera;
 154     info->slaveIndex = _viewer->getNumSlaves() - 1;
 155     camera->setRenderOrder(Camera::NESTED_RENDER, info->slaveIndex);
 156     _cameras.push_back(info);
 157     return info;
 158 }
 159
 160 void CameraGroup::update(const osg::Vec3d& position,
 161                          const osg::Quat& orientation)
 162 {
 163     const Matrix masterView(osg::Matrix::translate(-position)
 164                             * osg::Matrix::rotate(orientation.inverse()));
 165     _viewer->getCamera()->setViewMatrix(masterView);
 166     const Matrix& masterProj = _viewer->getCamera()->getProjectionMatrix();
 167     for (CameraList::iterator i = _cameras.begin(); i != _cameras.end(); ++i) {
 168         const CameraInfo* info = i->get();
 169         const View::Slave& slave = _viewer->getSlave(info->slaveIndex);
 170         // refreshes camera viewports (for now)
 171         updateCameras(info);
 172         Camera* camera = info->camera.get();
 173         Matrix viewMatrix;
 174         if ((info->flags & VIEW_ABSOLUTE) != 0)
 175             viewMatrix = slave._viewOffset;
 176         else
 177             viewMatrix = masterView * slave._viewOffset;
 178         camera->setViewMatrix(viewMatrix);
 179         Matrix projectionMatrix;
 180         if ((info->flags & PROJECTION_ABSOLUTE) != 0)
 181             projectionMatrix = slave._projectionOffset;
 182         else
 183             projectionMatrix = masterProj * slave._projectionOffset;
 184
 185         if (!info->farCamera.valid()) {
 186             camera->setProjectionMatrix(projectionMatrix);
 187         } else {
 188             Camera* farCamera = info->farCamera.get();
 189             farCamera->setViewMatrix(viewMatrix);
 190             double left, right, bottom, top, parentNear, parentFar;
 191             projectionMatrix.getFrustum(left, right, bottom, top,
 192                                         parentNear, parentFar);
 193             if (parentFar < _nearField || _nearField == 0.0f) {
 194                 camera->setProjectionMatrix(projectionMatrix);
 195                 camera->setCullMask(camera->getCullMask()
 196                                     | simgear::BACKGROUND_BIT);
 197                 camera->setClearMask(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
 198                 farCamera->setNodeMask(0);
 199             } else {
 200                 Matrix nearProj, farProj;
 201                 makeNewProjMat(projectionMatrix, parentNear, _nearField,
 202                                nearProj);
 203                 makeNewProjMat(projectionMatrix, _nearField, parentFar,
 204                                farProj);
 205                 camera->setProjectionMatrix(nearProj);
 206                 camera->setCullMask(camera->getCullMask()
 207                                     & ~simgear::BACKGROUND_BIT);
 208                 camera->setClearMask(GL_DEPTH_BUFFER_BIT);
 209                 farCamera->setProjectionMatrix(farProj);
 210                 farCamera->setNodeMask(camera->getNodeMask());
 211             }
 212         }
 213     }
 214 }
 215
 216 void CameraGroup::setCameraParameters(float vfov, float aspectRatio)
 217 {
 218     _viewer->getCamera()->setProjectionMatrixAsPerspective(vfov,
 219                                                            1.0f / aspectRatio,
 220                                                            _zNear, _zFar);
 221 }
 222 }
 223
 224 namespace
 225 {
 226 // A raw value for property nodes that references a class member via
 227 // an osg::ref_ptr.
 228 template<class C, class T>
 229 class RefMember : public SGRawValue<T>
 230 {
 231 public:
 232     RefMember (C *obj, T C::*ptr)
 233         : _obj(obj), _ptr(ptr) {}
 234     virtual ~RefMember () {}
 235     virtual T getValue () const
 236     {
 237         return _obj.get()->*_ptr;
 238     }
 239     virtual bool setValue (T value)
 240     {
 241         _obj.get()->*_ptr = value;
 242         return true;
 243     }
 244     virtual SGRawValue<T> * clone () const
 245     {
 246         return new RefMember(_obj.get(), _ptr);
 247     }
 248 private:
 249     ref_ptr<C> _obj;
 250     T C::* const _ptr;
 251 };
 252
 253 template<typename C, typename T>
 254 RefMember<C, T> makeRefMember(C *obj, T C::*ptr)
 255 {
 256     return RefMember<C, T>(obj, ptr);
 257 }
 258
 259 template<typename C, typename T>
 260 void bindMemberToNode(SGPropertyNode* parent, const char* childName,
 261                       C* obj, T C::*ptr, T value)
 262 {
 263     SGPropertyNode* valNode = parent->getNode(childName);
 264     RefMember<C, T> refMember = makeRefMember(obj, ptr);
 265     if (!valNode) {
 266         valNode = parent->getNode(childName, true);
 267         valNode->tie(refMember, false);
 268         setValue(valNode, value);
 269     } else {
 270         valNode->tie(refMember, true);
 271     }
 272 }
 273
 274 void buildViewport(flightgear::CameraInfo* info, SGPropertyNode* viewportNode,
 275                    const osg::GraphicsContext::Traits *traits)
 276 {
 277     using namespace flightgear;
 278     bindMemberToNode(viewportNode, "x", info, &CameraInfo::x, 0.0);
 279     bindMemberToNode(viewportNode, "y", info, &CameraInfo::y, 0.0);
 280     bindMemberToNode(viewportNode, "width", info, &CameraInfo::width,
 281                      static_cast<double>(traits->width));
 282     bindMemberToNode(viewportNode, "height", info, &CameraInfo::height,
 283                      static_cast<double>(traits->height));
 284 }
 285 }
 286
 287 namespace flightgear
 288 {
 289
 290 CameraInfo* CameraGroup::buildCamera(SGPropertyNode* cameraNode)
 291 {
 292     WindowBuilder *wBuild = WindowBuilder::getWindowBuilder();
 293     const SGPropertyNode* windowNode = cameraNode->getNode("window");
 294     GraphicsWindow* window = 0;
 295     static int cameraNum = 0;
 296     int cameraFlags = DO_INTERSECTION_TEST;
 297     if (windowNode) {
 298         // New style window declaration / definition
 299         window = wBuild->buildWindow(windowNode);
 300     } else {
 301         // Old style: suck window params out of camera block
 302         window = wBuild->buildWindow(cameraNode);
 303     }
 304     if (!window) {
 305         return 0;
 306     }
 307     Camera* camera = new Camera;
 308     camera->setAllowEventFocus(false);
 309     camera->setGraphicsContext(window->gc.get());
 310     camera->setViewport(new Viewport);
 311     camera->setCullingMode(CullSettings::SMALL_FEATURE_CULLING
 312                            | CullSettings::VIEW_FRUSTUM_CULLING);
 313     camera->setInheritanceMask(CullSettings::ALL_VARIABLES
 314                                & ~(CullSettings::CULL_MASK
 315                                    | CullSettings::CULLING_MODE));
 316
 317     osg::Matrix pOff;
 318     osg::Matrix vOff;
 319     const SGPropertyNode* viewNode = cameraNode->getNode("view");
 320     if (viewNode) {
 321         double heading = viewNode->getDoubleValue("heading-deg", 0.0);
 322         double pitch = viewNode->getDoubleValue("pitch-deg", 0.0);
 323         double roll = viewNode->getDoubleValue("roll-deg", 0.0);
 324         double x = viewNode->getDoubleValue("x", 0.0);
 325         double y = viewNode->getDoubleValue("y", 0.0);
 326         double z = viewNode->getDoubleValue("z", 0.0);
 327         // Build a view matrix, which is the inverse of a model
 328         // orientation matrix.
 329         vOff = (Matrix::translate(-x, -y, -z)
 330                 * Matrix::rotate(-DegreesToRadians(heading),
 331                                  Vec3d(0.0, 1.0, 0.0),
 332                                  -DegreesToRadians(pitch),
 333                                  Vec3d(1.0, 0.0, 0.0),
 334                                  -DegreesToRadians(roll),
 335                                  Vec3d(0.0, 0.0, 1.0)));
 336         if (viewNode->getBoolValue("absolute", false))
 337             cameraFlags |= VIEW_ABSOLUTE;
 338     } else {
 339         // Old heading parameter, works in the opposite direction
 340         double heading = cameraNode->getDoubleValue("heading-deg", 0.0);
 341         vOff.makeRotate(DegreesToRadians(heading), osg::Vec3(0, 1, 0));
 342     }
 343     const SGPropertyNode* projectionNode = 0;
 344     if ((projectionNode = cameraNode->getNode("perspective")) != 0) {
 345         double fovy = projectionNode->getDoubleValue("fovy-deg", 55.0);
 346         double aspectRatio = projectionNode->getDoubleValue("aspect-ratio",
 347                                                             1.0);
 348         double zNear = projectionNode->getDoubleValue("near", 0.0);
 349         double zFar = projectionNode->getDoubleValue("far", 0.0);
 350         double offsetX = projectionNode->getDoubleValue("offset-x", 0.0);
 351         double offsetY = projectionNode->getDoubleValue("offset-y", 0.0);
 352         double tan_fovy = tan(DegreesToRadians(fovy*0.5));
 353         double right = tan_fovy * aspectRatio * zNear + offsetX;
 354         double left = -tan_fovy * aspectRatio * zNear + offsetX;
 355         double top = tan_fovy * zNear + offsetY;
 356         double bottom = -tan_fovy * zNear + offsetY;
 357         pOff.makeFrustum(left, right, bottom, top, zNear, zFar);
 358         cameraFlags |= PROJECTION_ABSOLUTE;
 359     } else if ((projectionNode = cameraNode->getNode("frustum")) != 0
 360                || (projectionNode = cameraNode->getNode("ortho")) != 0) {
 361         double top = projectionNode->getDoubleValue("top", 0.0);
 362         double bottom = projectionNode->getDoubleValue("bottom", 0.0);
 363         double left = projectionNode->getDoubleValue("left", 0.0);
 364         double right = projectionNode->getDoubleValue("right", 0.0);
 365         double zNear = projectionNode->getDoubleValue("near", 0.0);
 366         double zFar = projectionNode->getDoubleValue("far", 0.0);
 367         if (cameraNode->getNode("frustum")) {
 368             pOff.makeFrustum(left, right, bottom, top, zNear, zFar);
 369             cameraFlags |= PROJECTION_ABSOLUTE;
 370         } else {
 371             pOff.makeOrtho(left, right, bottom, top, zNear, zFar);
 372             cameraFlags |= (PROJECTION_ABSOLUTE | ORTHO);
 373         }
 374     } else {
 375         // old style shear parameters
 376         double shearx = cameraNode->getDoubleValue("shear-x", 0);
 377         double sheary = cameraNode->getDoubleValue("shear-y", 0);
 378         pOff.makeTranslate(-shearx, -sheary, 0);
 379     }
 380     CameraInfo* info = addCamera(cameraFlags, camera, pOff, vOff);
 381     // If a viewport isn't set on the camera, then it's hard to dig it
 382     // out of the SceneView objects in the viewer, and the coordinates
 383     // of mouse events are somewhat bizzare.
 384     SGPropertyNode* viewportNode = cameraNode->getNode("viewport", true);
 385     buildViewport(info, viewportNode, window->gc->getTraits());
 386     updateCameras(info);
 387     return info;
 388 }
 389
 390 CameraInfo* CameraGroup::buildGUICamera(SGPropertyNode* cameraNode,
 391                                         GraphicsWindow* window)
 392 {
 393     WindowBuilder *wBuild = WindowBuilder::getWindowBuilder();
 394     const SGPropertyNode* windowNode = (cameraNode
 395                                         ? cameraNode->getNode("window")
 396                                         : 0);
 397     static int cameraNum = 0;
 398     if (!window) {
 399         if (windowNode) {
 400             // New style window declaration / definition
 401             window = wBuild->buildWindow(windowNode);
 402
 403         } else {
 404             return 0;
 405         }
 406     }
 407     Camera* camera = new Camera;
 408     camera->setAllowEventFocus(false);
 409     camera->setGraphicsContext(window->gc.get());
 410     camera->setViewport(new Viewport);
 411     // XXX Camera needs to be drawn last; eventually the render order
 412     // should be assigned by a camera manager.
 413     camera->setRenderOrder(osg::Camera::POST_RENDER, 100);
 414         camera->setClearMask(0);
 415     camera->setInheritanceMask(CullSettings::ALL_VARIABLES
 416                                & ~(CullSettings::COMPUTE_NEAR_FAR_MODE
 417                                    | CullSettings::CULLING_MODE));
 418     camera->setComputeNearFarMode(osg::CullSettings::DO_NOT_COMPUTE_NEAR_FAR);
 419     camera->setCullingMode(osg::CullSettings::NO_CULLING);
 420     camera->setProjectionResizePolicy(Camera::FIXED);
 421     camera->setReferenceFrame(Transform::ABSOLUTE_RF);
 422     const int cameraFlags = GUI;
 423     CameraInfo* result = addCamera(cameraFlags, camera, Matrixd::identity(),
 424                                    Matrixd::identity(), false);
 425     SGPropertyNode* viewportNode = cameraNode->getNode("viewport", true);
 426     buildViewport(result, viewportNode, window->gc->getTraits());
 427
 428     // Disable statistics for the GUI camera.
 429     result->camera->setStats(0);
 430     updateCameras(result);
 431     return result;
 432 }
 433
 434 CameraGroup* CameraGroup::buildCameraGroup(osgViewer::Viewer* viewer,
 435                                            SGPropertyNode* gnode)
 436 {
 437     CameraGroup* cgroup = new CameraGroup(viewer);
 438     for (int i = 0; i < gnode->nChildren(); ++i) {
 439         SGPropertyNode* pNode = gnode->getChild(i);
 440         const char* name = pNode->getName();
 441         if (!strcmp(name, "camera")) {
 442             cgroup->buildCamera(pNode);
 443         } else if (!strcmp(name, "window")) {
 444             WindowBuilder::getWindowBuilder()->buildWindow(pNode);
 445         } else if (!strcmp(name, "gui")) {
 446             cgroup->buildGUICamera(pNode);
 447         }
 448     }
 449     bindMemberToNode(gnode, "znear", cgroup, &CameraGroup::_zNear, .4f);
 450     bindMemberToNode(gnode, "zfar", cgroup, &CameraGroup::_zFar, 120000.0f);
 451     bindMemberToNode(gnode, "near-field", cgroup, &CameraGroup::_nearField,
 452                      100.0f);
 453     return cgroup;
 454 }
 455
 456 void CameraGroup::setCameraCullMasks(Node::NodeMask nm)
 457 {
 458     for (CameraIterator i = camerasBegin(), e = camerasEnd(); i != e; ++i) {
 459         CameraInfo* info = i->get();
 460         if (info->flags & GUI)
 461             continue;
 462         if (info->farCamera.valid() && info->farCamera->getNodeMask() != 0) {
 463             info->camera->setCullMask(nm & ~simgear::BACKGROUND_BIT);
 464             info->farCamera->setCullMask(nm);
 465         } else {
 466             info->camera->setCullMask(nm);
 467         }
 468     }
 469 }
 470
 471 void CameraGroup::resized()
 472 {
 473     for (CameraIterator i = camerasBegin(), e = camerasEnd(); i != e; ++i) {
 474         CameraInfo *info = i->get();
 475         const Viewport* viewport = info->camera->getViewport();
 476         info->x = viewport->x();
 477         info->y = viewport->y();
 478         info->width = viewport->width();
 479         info->height = viewport->height();
 480     }
 481 }
 482
 483 Camera* getGUICamera(CameraGroup* cgroup)
 484 {
 485     CameraGroup::CameraIterator end = cgroup->camerasEnd();
 486     CameraGroup::CameraIterator result
 487         = std::find_if(cgroup->camerasBegin(), end,
 488                        FlagTester<CameraInfo>(CameraGroup::GUI));
 489     if (result != end)
 490         return (*result)->camera.get();
 491     else
 492         return 0;
 493 }
 494
 495 bool computeIntersections(const CameraGroup* cgroup,
 496                           const osgGA::GUIEventAdapter* ea,
 497                           osgUtil::LineSegmentIntersector::Intersections& intersections)
 498 {
 499     using osgUtil::Intersector;
 500     using osgUtil::LineSegmentIntersector;
 501     double x, y;
 502     eventToWindowCoords(ea, x, y);
 503     // Find camera that contains event
 504     for (CameraGroup::ConstCameraIterator iter = cgroup->camerasBegin(),
 505              e = cgroup->camerasEnd();
 506          iter != e;
 507          ++iter) {
 508         const CameraInfo* cinfo = iter->get();
 509         if ((cinfo->flags & CameraGroup::DO_INTERSECTION_TEST) == 0)
 510             continue;
 511         const Camera* camera = cinfo->camera.get();
 512         if (camera->getGraphicsContext() != ea->getGraphicsContext())
 513             continue;
 514         const Viewport* viewport = camera->getViewport();
 515         double epsilon = 0.5;
 516         if (!(x >= viewport->x() - epsilon
 517               && x < viewport->x() + viewport->width() -1.0 + epsilon
 518               && y >= viewport->y() - epsilon
 519               && y < viewport->y() + viewport->height() -1.0 + epsilon))
 520             continue;
 521         Vec4d start(x, y, 0.0, 1.0);
 522         Vec4d end(x, y, 1.0, 1.0);
 523         Matrix windowMat = viewport->computeWindowMatrix();
 524         Matrix startPtMat = Matrix::inverse(camera->getProjectionMatrix()
 525                                             * windowMat);
 526         Matrix endPtMat;
 527         if (!cinfo->farCamera.valid() || cinfo->farCamera->getNodeMask() == 0)
 528             endPtMat = startPtMat;
 529         else
 530             endPtMat = Matrix::inverse(cinfo->farCamera->getProjectionMatrix()
 531                                        * windowMat);
 532         start = start * startPtMat;
 533         start /= start.w();
 534         end = end * endPtMat;
 535         end /= end.w();
 536         ref_ptr<LineSegmentIntersector> picker
 537             = new LineSegmentIntersector(Intersector::VIEW,
 538                                          Vec3d(start.x(), start.y(), start.z()),
 539                                          Vec3d(end.x(), end.y(), end.z()));
 540         osgUtil::IntersectionVisitor iv(picker.get());
 541         const_cast<Camera*>(camera)->accept(iv);
 542         if (picker->containsIntersections()) {
 543             intersections = picker->getIntersections();
 544             return true;
 545         } else {
 546             break;
 547         }
 548     }
 549     intersections.clear();
 550     return false;
 551 }
 552
 553 void warpGUIPointer(CameraGroup* cgroup, int x, int y)
 554 {
 555     using osgViewer::GraphicsWindow;
 556     Camera* guiCamera = getGUICamera(cgroup);
 557     if (!guiCamera)
 558         return;
 559     Viewport* vport = guiCamera->getViewport();
 560     GraphicsWindow* gw
 561         = dynamic_cast<GraphicsWindow*>(guiCamera->getGraphicsContext());
 562     if (!gw)
 563         return;
 564     globals->get_renderer()->getEventHandler()->setMouseWarped();
 565     // Translate the warp request into the viewport of the GUI camera,
 566     // send the request to the window, then transform the coordinates
 567     // for the Viewer's event queue.
 568     double wx = x + vport->x();
 569     double wyUp = vport->height() + vport->y() - y;
 570     double wy;
 571     const GraphicsContext::Traits* traits = gw->getTraits();
 572     if (gw->getEventQueue()->getCurrentEventState()->getMouseYOrientation()
 573         == osgGA::GUIEventAdapter::Y_INCREASING_DOWNWARDS) {
 574         wy = traits->height - wyUp;
 575     } else {
 576         wy = wyUp;
 577     }
 578     gw->getEventQueue()->mouseWarped(wx, wy);
 579     gw->requestWarpPointer(wx, wy);
 580     osgGA::GUIEventAdapter* eventState
 581         = cgroup->getViewer()->getEventQueue()->getCurrentEventState();
 582     double viewerX
 583         = (eventState->getXmin()
 584            + ((wx / double(traits->width))
 585               * (eventState->getXmax() - eventState->getXmin())));
 586     double viewerY
 587         = (eventState->getYmin()
 588            + ((wyUp / double(traits->height))
 589               * (eventState->getYmax() - eventState->getYmin())));
 590     cgroup->getViewer()->getEventQueue()->mouseWarped(viewerX, viewerY);
 591 }
 592 }