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     }
 150     camera->setClearMask(GL_DEPTH_BUFFER_BIT);
 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 < 100.0) {
 194                 camera->setProjectionMatrix(projectionMatrix);
 195                 camera->setCullMask(camera->getCullMask()
 196                                     | simgear::BACKGROUND_BIT);
 197                 farCamera->setNodeMask(0);
 198             } else {
 199                 Matrix nearProj, farProj;
 200                 makeNewProjMat(projectionMatrix, parentNear, 100.0, nearProj);
 201                 makeNewProjMat(projectionMatrix, 100.0, parentFar, farProj);
 202                 camera->setProjectionMatrix(nearProj);
 203                 camera->setCullMask(camera->getCullMask()
 204                                     & ~simgear::BACKGROUND_BIT);
 205                 farCamera->setProjectionMatrix(farProj);
 206                 farCamera->setNodeMask(camera->getNodeMask());
 207             }
 208         }
 209     }
 210 }
 211
 212 void CameraGroup::setCameraParameters(float vfov, float aspectRatio)
 213 {
 214     const float zNear = .1f;
 215     const float zFar = 120000.0f;
 216     _viewer->getCamera()->setProjectionMatrixAsPerspective(vfov,
 217                                                            1.0f / aspectRatio,
 218                                                            zNear, zFar);
 219 }
 220 }
 221
 222 namespace
 223 {
 224 // A raw value for property nodes that references a class member via
 225 // an osg::ref_ptr.
 226 template<class C, class T>
 227 class RefMember : public SGRawValue<T>
 228 {
 229 public:
 230     RefMember (C *obj, T C::*ptr)
 231         : _obj(obj), _ptr(ptr) {}
 232     virtual ~RefMember () {}
 233     virtual T getValue () const
 234     {
 235         return _obj.get()->*_ptr;
 236     }
 237     virtual bool setValue (T value)
 238     {
 239         _obj.get()->*_ptr = value;
 240         return true;
 241     }
 242     virtual SGRawValue<T> * clone () const
 243     {
 244         return new RefMember(_obj.get(), _ptr);
 245     }
 246 private:
 247     ref_ptr<C> _obj;
 248     T C::* const _ptr;
 249 };
 250
 251 template<typename C, typename T>
 252 RefMember<C, T> makeRefMember(C *obj, T C::*ptr)
 253 {
 254     return RefMember<C, T>(obj, ptr);
 255 }
 256
 257 template<typename C, typename T>
 258 void bindMemberToNode(SGPropertyNode* parent, const char* childName,
 259                       C* obj, T C::*ptr, T value)
 260 {
 261     SGPropertyNode* valNode = parent->getNode(childName);
 262     RefMember<C, T> refMember = makeRefMember(obj, ptr);
 263     if (!valNode) {
 264         valNode = parent->getNode(childName, true);
 265         valNode->tie(refMember, false);
 266         setValue(valNode, value);
 267     } else {
 268         valNode->tie(refMember, true);
 269     }
 270 }
 271
 272 void buildViewport(flightgear::CameraInfo* info, SGPropertyNode* viewportNode,
 273                    const osg::GraphicsContext::Traits *traits)
 274 {
 275     using namespace flightgear;
 276     bindMemberToNode(viewportNode, "x", info, &CameraInfo::x, 0.0);
 277     bindMemberToNode(viewportNode, "y", info, &CameraInfo::y, 0.0);
 278     bindMemberToNode(viewportNode, "width", info, &CameraInfo::width,
 279                      static_cast<double>(traits->width));
 280     bindMemberToNode(viewportNode, "height", info, &CameraInfo::height,
 281                      static_cast<double>(traits->height));
 282 }
 283 }
 284
 285 namespace flightgear
 286 {
 287
 288 CameraInfo* CameraGroup::buildCamera(SGPropertyNode* cameraNode)
 289 {
 290     WindowBuilder *wBuild = WindowBuilder::getWindowBuilder();
 291     const SGPropertyNode* windowNode = cameraNode->getNode("window");
 292     GraphicsWindow* window = 0;
 293     static int cameraNum = 0;
 294     int cameraFlags = DO_INTERSECTION_TEST;
 295     if (windowNode) {
 296         // New style window declaration / definition
 297         window = wBuild->buildWindow(windowNode);
 298     } else {
 299         // Old style: suck window params out of camera block
 300         window = wBuild->buildWindow(cameraNode);
 301     }
 302     if (!window) {
 303         return 0;
 304     }
 305     Camera* camera = new Camera;
 306     camera->setAllowEventFocus(false);
 307     camera->setGraphicsContext(window->gc.get());
 308     camera->setViewport(new Viewport);
 309     camera->setCullingMode(CullSettings::SMALL_FEATURE_CULLING
 310                            | CullSettings::VIEW_FRUSTUM_CULLING);
 311     camera->setInheritanceMask(CullSettings::ALL_VARIABLES
 312                                & ~(CullSettings::CULL_MASK
 313                                    | CullSettings::CULLING_MODE));
 314
 315     osg::Matrix pOff;
 316     osg::Matrix vOff;
 317     const SGPropertyNode* viewNode = cameraNode->getNode("view");
 318     if (viewNode) {
 319         double heading = viewNode->getDoubleValue("heading-deg", 0.0);
 320         double pitch = viewNode->getDoubleValue("pitch-deg", 0.0);
 321         double roll = viewNode->getDoubleValue("roll-deg", 0.0);
 322         double x = viewNode->getDoubleValue("x", 0.0);
 323         double y = viewNode->getDoubleValue("y", 0.0);
 324         double z = viewNode->getDoubleValue("z", 0.0);
 325         // Build a view matrix, which is the inverse of a model
 326         // orientation matrix.
 327         vOff = (Matrix::translate(-x, -y, -z)
 328                 * Matrix::rotate(-DegreesToRadians(heading),
 329                                  Vec3d(0.0, 1.0, 0.0),
 330                                  -DegreesToRadians(pitch),
 331                                  Vec3d(1.0, 0.0, 0.0),
 332                                  -DegreesToRadians(roll),
 333                                  Vec3d(0.0, 0.0, 1.0)));
 334         if (viewNode->getBoolValue("absolute", false))
 335             cameraFlags |= VIEW_ABSOLUTE;
 336     } else {
 337         // Old heading parameter, works in the opposite direction
 338         double heading = cameraNode->getDoubleValue("heading-deg", 0.0);
 339         vOff.makeRotate(DegreesToRadians(heading), osg::Vec3(0, 1, 0));
 340     }
 341     const SGPropertyNode* projectionNode = 0;
 342     if ((projectionNode = cameraNode->getNode("perspective")) != 0) {
 343         double fovy = projectionNode->getDoubleValue("fovy-deg", 55.0);
 344         double aspectRatio = projectionNode->getDoubleValue("aspect-ratio",
 345                                                             1.0);
 346         double zNear = projectionNode->getDoubleValue("near", 0.0);
 347         double zFar = projectionNode->getDoubleValue("far", 0.0);
 348         double offsetX = projectionNode->getDoubleValue("offset-x", 0.0);
 349         double offsetY = projectionNode->getDoubleValue("offset-y", 0.0);
 350         double tan_fovy = tan(DegreesToRadians(fovy*0.5));
 351         double right = tan_fovy * aspectRatio * zNear + offsetX;
 352         double left = -tan_fovy * aspectRatio * zNear + offsetX;
 353         double top = tan_fovy * zNear + offsetY;
 354         double bottom = -tan_fovy * zNear + offsetY;
 355         pOff.makeFrustum(left, right, bottom, top, zNear, zFar);
 356         cameraFlags |= PROJECTION_ABSOLUTE;
 357     } else if ((projectionNode = cameraNode->getNode("frustum")) != 0
 358                || (projectionNode = cameraNode->getNode("ortho")) != 0) {
 359         double top = projectionNode->getDoubleValue("top", 0.0);
 360         double bottom = projectionNode->getDoubleValue("bottom", 0.0);
 361         double left = projectionNode->getDoubleValue("left", 0.0);
 362         double right = projectionNode->getDoubleValue("right", 0.0);
 363         double zNear = projectionNode->getDoubleValue("near", 0.0);
 364         double zFar = projectionNode->getDoubleValue("far", 0.0);
 365         if (cameraNode->getNode("frustum")) {
 366             pOff.makeFrustum(left, right, bottom, top, zNear, zFar);
 367             cameraFlags |= PROJECTION_ABSOLUTE;
 368         } else {
 369             pOff.makeOrtho(left, right, bottom, top, zNear, zFar);
 370             cameraFlags |= (PROJECTION_ABSOLUTE | ORTHO);
 371         }
 372     } else {
 373         // old style shear parameters
 374         double shearx = cameraNode->getDoubleValue("shear-x", 0);
 375         double sheary = cameraNode->getDoubleValue("shear-y", 0);
 376         pOff.makeTranslate(-shearx, -sheary, 0);
 377     }
 378     CameraInfo* info = addCamera(cameraFlags, camera, pOff, vOff);
 379     // If a viewport isn't set on the camera, then it's hard to dig it
 380     // out of the SceneView objects in the viewer, and the coordinates
 381     // of mouse events are somewhat bizzare.
 382     SGPropertyNode* viewportNode = cameraNode->getNode("viewport", true);
 383     buildViewport(info, viewportNode, window->gc->getTraits());
 384     updateCameras(info);
 385     return info;
 386 }
 387
 388 CameraInfo* CameraGroup::buildGUICamera(SGPropertyNode* cameraNode,
 389                                         GraphicsWindow* window)
 390 {
 391     WindowBuilder *wBuild = WindowBuilder::getWindowBuilder();
 392     const SGPropertyNode* windowNode = (cameraNode
 393                                         ? cameraNode->getNode("window")
 394                                         : 0);
 395     static int cameraNum = 0;
 396     if (!window) {
 397         if (windowNode) {
 398             // New style window declaration / definition
 399             window = wBuild->buildWindow(windowNode);
 400
 401         } else {
 402             return 0;
 403         }
 404     }
 405     Camera* camera = new Camera;
 406     camera->setAllowEventFocus(false);
 407     camera->setGraphicsContext(window->gc.get());
 408     camera->setViewport(new Viewport);
 409     // XXX Camera needs to be drawn last; eventually the render order
 410     // should be assigned by a camera manager.
 411     camera->setRenderOrder(osg::Camera::POST_RENDER, 100);
 412         camera->setClearMask(0);
 413     camera->setInheritanceMask(CullSettings::ALL_VARIABLES
 414                                & ~(CullSettings::COMPUTE_NEAR_FAR_MODE
 415                                    | CullSettings::CULLING_MODE));
 416     camera->setComputeNearFarMode(osg::CullSettings::DO_NOT_COMPUTE_NEAR_FAR);
 417     camera->setCullingMode(osg::CullSettings::NO_CULLING);
 418     camera->setProjectionResizePolicy(Camera::FIXED);
 419     camera->setReferenceFrame(Transform::ABSOLUTE_RF);
 420     const int cameraFlags = GUI;
 421     CameraInfo* result = addCamera(cameraFlags, camera, Matrixd::identity(),
 422                                    Matrixd::identity(), false);
 423     SGPropertyNode* viewportNode = cameraNode->getNode("viewport", true);
 424     buildViewport(result, viewportNode, window->gc->getTraits());
 425
 426     // Disable statistics for the GUI camera.
 427     result->camera->setStats(0);
 428     updateCameras(result);
 429     return result;
 430 }
 431
 432 CameraGroup* CameraGroup::buildCameraGroup(osgViewer::Viewer* viewer,
 433                                            SGPropertyNode* gnode)
 434 {
 435     CameraGroup* cgroup = new CameraGroup(viewer);
 436     for (int i = 0; i < gnode->nChildren(); ++i) {
 437         SGPropertyNode* pNode = gnode->getChild(i);
 438         const char* name = pNode->getName();
 439         if (!strcmp(name, "camera")) {
 440             cgroup->buildCamera(pNode);
 441         } else if (!strcmp(name, "window")) {
 442             WindowBuilder::getWindowBuilder()->buildWindow(pNode);
 443         } else if (!strcmp(name, "gui")) {
 444             cgroup->buildGUICamera(pNode);
 445         }
 446     }
 447     return cgroup;
 448 }
 449
 450 void CameraGroup::setCameraCullMasks(Node::NodeMask nm)
 451 {
 452     for (CameraIterator i = camerasBegin(), e = camerasEnd(); i != e; ++i) {
 453         if ((*i)->flags & GUI)
 454             continue;
 455         (*i)->camera->setCullMask(nm & ~simgear::BACKGROUND_BIT);
 456         (*i)->farCamera->setCullMask(nm);
 457     }
 458 }
 459
 460 void CameraGroup::resized()
 461 {
 462     for (CameraIterator i = camerasBegin(), e = camerasEnd(); i != e; ++i) {
 463         CameraInfo *info = i->get();
 464         const Viewport* viewport = info->camera->getViewport();
 465         info->x = viewport->x();
 466         info->y = viewport->y();
 467         info->width = viewport->width();
 468         info->height = viewport->height();
 469     }
 470 }
 471
 472 Camera* getGUICamera(CameraGroup* cgroup)
 473 {
 474     CameraGroup::CameraIterator end = cgroup->camerasEnd();
 475     CameraGroup::CameraIterator result
 476         = std::find_if(cgroup->camerasBegin(), end,
 477                        FlagTester<CameraInfo>(CameraGroup::GUI));
 478     if (result != end)
 479         return (*result)->camera.get();
 480     else
 481         return 0;
 482 }
 483
 484 bool computeIntersections(const CameraGroup* cgroup,
 485                           const osgGA::GUIEventAdapter* ea,
 486                           osgUtil::LineSegmentIntersector::Intersections& intersections)
 487 {
 488     using osgUtil::Intersector;
 489     using osgUtil::LineSegmentIntersector;
 490     double x, y;
 491     eventToWindowCoords(ea, x, y);
 492     // Find camera that contains event
 493     for (CameraGroup::ConstCameraIterator iter = cgroup->camerasBegin(),
 494              e = cgroup->camerasEnd();
 495          iter != e;
 496          ++iter) {
 497         const CameraInfo* cinfo = iter->get();
 498         if ((cinfo->flags & CameraGroup::DO_INTERSECTION_TEST) == 0)
 499             continue;
 500         const Camera* camera = cinfo->camera.get();
 501         if (camera->getGraphicsContext() != ea->getGraphicsContext())
 502             continue;
 503         const Viewport* viewport = camera->getViewport();
 504         double epsilon = 0.5;
 505         if (!(x >= viewport->x() - epsilon
 506               && x < viewport->x() + viewport->width() -1.0 + epsilon
 507               && y >= viewport->y() - epsilon
 508               && y < viewport->y() + viewport->height() -1.0 + epsilon))
 509             continue;
 510         LineSegmentIntersector::CoordinateFrame cf = Intersector::WINDOW;
 511         ref_ptr<LineSegmentIntersector> picker
 512             = new LineSegmentIntersector(cf, x, y);
 513         osgUtil::IntersectionVisitor iv(picker.get());
 514         const_cast<Camera*>(camera)->accept(iv);
 515         if (picker->containsIntersections()) {
 516             intersections = picker->getIntersections();
 517             return true;
 518         } else {
 519             break;
 520         }
 521     }
 522     intersections.clear();
 523     return false;
 524 }
 525
 526 void warpGUIPointer(CameraGroup* cgroup, int x, int y)
 527 {
 528     using osgViewer::GraphicsWindow;
 529     Camera* guiCamera = getGUICamera(cgroup);
 530     if (!guiCamera)
 531         return;
 532     Viewport* vport = guiCamera->getViewport();
 533     GraphicsWindow* gw
 534         = dynamic_cast<GraphicsWindow*>(guiCamera->getGraphicsContext());
 535     if (!gw)
 536         return;
 537     globals->get_renderer()->getEventHandler()->setMouseWarped();
 538     // Translate the warp request into the viewport of the GUI camera,
 539     // send the request to the window, then transform the coordinates
 540     // for the Viewer's event queue.
 541     double wx = x + vport->x();
 542     double wyUp = vport->height() + vport->y() - y;
 543     double wy;
 544     const GraphicsContext::Traits* traits = gw->getTraits();
 545     if (gw->getEventQueue()->getCurrentEventState()->getMouseYOrientation()
 546         == osgGA::GUIEventAdapter::Y_INCREASING_DOWNWARDS) {
 547         wy = traits->height - wyUp;
 548     } else {
 549         wy = wyUp;
 550     }
 551     gw->getEventQueue()->mouseWarped(wx, wy);
 552     gw->requestWarpPointer(wx, wy);
 553     osgGA::GUIEventAdapter* eventState
 554         = cgroup->getViewer()->getEventQueue()->getCurrentEventState();
 555     double viewerX
 556         = (eventState->getXmin()
 557            + ((wx / double(traits->width))
 558               * (eventState->getXmax() - eventState->getXmin())));
 559     double viewerY
 560         = (eventState->getYmin()
 561            + ((wyUp / double(traits->height))
 562               * (eventState->getYmax() - eventState->getYmin())));
 563     cgroup->getViewer()->getEventQueue()->mouseWarped(viewerX, viewerY);
 564 }
 565 }