Modified Files:

Makefile.am
Added Files:
	SGClipGroup.cxx SGClipGroup.hxx: Add helper group node for reuse
	of clipping planes. Will be used for the panel code.

simgear/scene/model/Makefile.am

@@ -13,6 +13,7 @@ include_HEADERS = \
 	persparam.hxx \
 	placement.hxx \
 	placementtrans.hxx \
+	SGClipGroup.hxx \
 	SGMaterialAnimation.hxx \
 	SGOffsetTransform.hxx \
 	SGRotateTransform.hxx \
@@ -29,6 +30,7 @@ libsgmodel_a_SOURCES = \
 	placement.cxx \
 	placementtrans.cxx \
 	shadanim.cxx \
+	SGClipGroup.cxx \
 	SGMaterialAnimation.cxx \
 	SGOffsetTransform.cxx \
 	SGRotateTransform.cxx \

simgear/scene/model/SGClipGroup.cxx

@@ -0,0 +1,159 @@
+/* -*-c++-*-
+ *
+ * Copyright (C) 2006-2007 Mathias Froehlich 
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+ * MA 02110-1301, USA.
+ *
+ */
+
+#include "SGClipGroup.hxx"
+
+#include <osg/ClipPlane>
+#include <osg/NodeCallback>
+#include <osg/StateSet>
+#include <osg/Version>
+
+#include <osgUtil/RenderBin>
+#include <osgUtil/RenderLeaf>
+#include <osgUtil/CullVisitor>
+
+class SGClipGroup::ClipRenderBin : public osgUtil::RenderBin {
+public:
+  virtual osg::Object* cloneType() const
+  { return new ClipRenderBin(); }
+  virtual osg::Object* clone(const osg::CopyOp& copyop) const
+  { return new ClipRenderBin; }
+  virtual bool isSameKindAs(const osg::Object* obj) const
+  { return dynamic_cast<const ClipRenderBin*>(obj)!=0L; }
+  virtual const char* libraryName() const
+  { return "SimGear"; }
+  virtual const char* className() const
+  { return "ClipRenderBin"; }
+
+  virtual void drawImplementation(osg::RenderInfo& renderInfo,
+                                  osgUtil::RenderLeaf*& previous)
+  {
+    osg::State* state = renderInfo.getState();
+
+    glPushAttrib(GL_TRANSFORM_BIT);
+
+    state->applyModelViewMatrix(mModelView.get());
+    for (unsigned i = 0; i < mClipPlanes.size(); ++i)
+      mClipPlanes[i]->apply(*state);
+
+    osgUtil::RenderBin::drawImplementation(renderInfo, previous);
+
+    glPopAttrib();
+  }
+
+  virtual void reset()
+  { mClipPlanes.resize(0); }
+ 
+  std::vector<osg::ref_ptr<osg::ClipPlane> > mClipPlanes;
+  osg::ref_ptr<osg::RefMatrix> mModelView;
+};
+
+osgUtil::RegisterRenderBinProxy
+SGClipGroup::clipBinProxy("ClipRenderBin", new SGClipGroup::ClipRenderBin);
+
+class SGClipGroup::CullCallback : public osg::NodeCallback {
+public:
+  virtual void operator()(osg::Node* node, osg::NodeVisitor* nv)
+  {
+    osgUtil::CullVisitor* cullVisitor;
+    cullVisitor = dynamic_cast<osgUtil::CullVisitor*>(nv);
+    
+    if (cullVisitor) {
+      osgUtil::RenderBin* renderBin = cullVisitor->getCurrentRenderBin();
+      ClipRenderBin* clipBin = dynamic_cast<ClipRenderBin*>(renderBin);
+      SGClipGroup* clipGroup;
+      clipGroup = dynamic_cast<SGClipGroup*>(node);
+      if (clipGroup && clipBin) {
+        clipBin->mClipPlanes = clipGroup->mClipPlanes;
+        clipBin->mModelView = cullVisitor->getModelViewMatrix();
+      }
+    }
+    
+    // note, callback is responsible for scenegraph traversal so
+    // they must call traverse(node,nv) to ensure that the
+    // scene graph subtree (and associated callbacks) are traversed.
+    traverse(node, nv);
+  }
+};
+
+static osg::Vec4d clipPlane(const osg::Vec2& p0, const osg::Vec2& p1)
+{
+  osg::Vec2d v(p1[0] - p0[0], p1[1] - p0[1]);
+  return osg::Vec4d(v[1], -v[0], 0, v[0]*p0[1] - v[1]*p0[0]);
+}
+
+SGClipGroup::SGClipGroup()
+{
+  getOrCreateStateSet()->setRenderBinDetails(0, "ClipRenderBin");
+  setCullCallback(new CullCallback);
+}
+
+osg::BoundingSphere
+SGClipGroup::computeBound() const
+{
+  return _initialBound;
+}
+
+void
+SGClipGroup::addClipPlane(unsigned num, const SGVec2d& p0,
+                          const SGVec2d& p1)
+{
+  osg::Vec2d v(p1[0] - p0[0], p1[1] - p0[1]);
+  osg::Vec4d planeEquation(v[1], -v[0], 0, v[0]*p0[1] - v[1]*p0[0]);
+  osg::ClipPlane* clipPlane = new osg::ClipPlane(num, planeEquation);
+  getStateSet()->setAssociatedModes(clipPlane, osg::StateAttribute::ON);
+  mClipPlanes.push_back(clipPlane);
+}
+
+void
+SGClipGroup::setDrawArea(const SGVec2d& lowerLeft,
+                         const SGVec2d& upperRight)
+{
+  setDrawArea(lowerLeft,
+              SGVec2d(lowerLeft[0], upperRight[1]),
+              SGVec2d(upperRight[0], lowerLeft[1]),
+              upperRight);
+}
+
+void
+SGClipGroup::setDrawArea(const SGVec2d& bottomLeft,
+                         const SGVec2d& topLeft,
+                         const SGVec2d& bottomRight,
+                         const SGVec2d& topRight)
+{
+#if (OPENSCENEGRAPH_MAJOR_VERSION > 2) || (OPENSCENEGRAPH_MINOR_VERSION > 2)
+  for (unsigned i = 0; i < mClipPlanes.size(); ++i)
+    getStateSet()->removeAssociatedModes(mClipPlanes[i].get());
+#endif
+  mClipPlanes.resize(0);
+  addClipPlane(2, bottomLeft, topLeft);
+  addClipPlane(3, topLeft, topRight);
+  addClipPlane(4, topRight, bottomRight);
+  addClipPlane(5, bottomRight, bottomLeft);
+  _initialBound.init();
+  _initialBound.expandBy(osg::Vec3(bottomLeft[0], bottomLeft[1], 0));
+  _initialBound.expandBy(osg::Vec3(topLeft[0], topLeft[1], 0));
+  _initialBound.expandBy(osg::Vec3(bottomRight[0], bottomRight[1], 0));
+  _initialBound.expandBy(osg::Vec3(topRight[0], topRight[1], 0));
+  _boundingSphere = _initialBound;
+  _boundingSphereComputed = true;
+}
+

simgear/scene/model/SGClipGroup.hxx

@@ -0,0 +1,55 @@
+/* -*-c++-*-
+ *
+ * Copyright (C) 2006-2007 Mathias Froehlich 
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+ * MA 02110-1301, USA.
+ *
+ */
+
+#ifndef SG_CLIP_GROUP_HXX
+#define SG_CLIP_GROUP_HXX
+
+#include <vector>
+#include <osg/ref_ptr>
+#include <osg/ClipPlane>
+#include <osg/Group>
+#include <osgUtil/RenderBin>
+
+#include <simgear/math/SGMath.hxx>
+
+class SGClipGroup : public osg::Group {
+public:
+  SGClipGroup();
+
+  virtual osg::BoundingSphere computeBound() const;
+
+  void addClipPlane(unsigned num, const SGVec2d& p0, const SGVec2d& p1);
+  void setDrawArea(const SGVec2d& lowerLeft, const SGVec2d& upperRight);
+  void setDrawArea(const SGVec2d& bottomLeft,
+                   const SGVec2d& topLeft,
+                   const SGVec2d& bottomRight,
+                   const SGVec2d& topRight);
+
+protected:
+  class CullCallback;
+  class ClipRenderBin;
+
+  std::vector<osg::ref_ptr<osg::ClipPlane> > mClipPlanes;
+
+  static osgUtil::RegisterRenderBinProxy clipBinProxy;
+};
+
+#endif