415 lines
14 KiB
C++
415 lines
14 KiB
C++
#include <osg/ArgumentParser>
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#include <osg/LightModel>
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#include <osg/Depth>
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#include <osg/BlendFunc>
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#include <osg/Camera>
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#include <osg/Stencil>
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#include <osg/CullFace>
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#include <osg/Geometry>
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#include <osgGA/TrackballManipulator>
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#include <osgViewer/Viewer>
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#include <osgShadow/OccluderGeometry>
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#include <osgDB/ReadFile>
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#include <iostream>
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class ComputeBoundingBoxVisitor : public osg::NodeVisitor
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{
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public:
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ComputeBoundingBoxVisitor():
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osg::NodeVisitor(osg::NodeVisitor::TRAVERSE_ALL_CHILDREN)
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{
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}
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virtual void reset()
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{
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_matrixStack.clear();
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_bb.init();
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}
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osg::BoundingBox& getBoundingBox() { return _bb; }
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void getPolytope(osg::Polytope& polytope, float margin=0.1) const
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{
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float delta = _bb.radius()*margin;
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polytope.add( osg::Plane(0.0, 0.0, 1.0, -(_bb.zMin()-delta)) );
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polytope.add( osg::Plane(0.0, 0.0, -1.0, (_bb.zMax()+delta)) );
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polytope.add( osg::Plane(1.0, 0.0, 0.0, -(_bb.xMin()-delta)) );
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polytope.add( osg::Plane(-1.0, 0.0, 0.0, (_bb.xMax()+delta)) );
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polytope.add( osg::Plane(0.0, 1.0, 0.0, -(_bb.yMin()-delta)) );
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polytope.add( osg::Plane(0.0, -1.0, 0.0, (_bb.yMax()+delta)) );
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}
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void apply(osg::Node& node)
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{
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traverse(node);
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}
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void apply(osg::Transform& transform)
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{
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osg::Matrix matrix;
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if (!_matrixStack.empty()) matrix = _matrixStack.back();
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transform.computeLocalToWorldMatrix(matrix,this);
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pushMatrix(matrix);
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traverse(transform);
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popMatrix();
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}
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void apply(osg::Geode& geode)
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{
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for(unsigned int i=0; i<geode.getNumDrawables(); ++i)
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{
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apply(geode.getDrawable(i));
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}
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}
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void pushMatrix(osg::Matrix& matrix)
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{
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_matrixStack.push_back(matrix);
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}
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void popMatrix()
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{
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_matrixStack.pop_back();
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}
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void apply(osg::Drawable* drawable)
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{
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if (_matrixStack.empty()) _bb.expandBy(drawable->getBound());
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else
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{
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osg::Matrix& matrix = _matrixStack.back();
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const osg::BoundingBox& dbb = drawable->getBound();
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if (dbb.valid())
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{
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_bb.expandBy(dbb.corner(0) * matrix);
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_bb.expandBy(dbb.corner(1) * matrix);
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_bb.expandBy(dbb.corner(2) * matrix);
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_bb.expandBy(dbb.corner(3) * matrix);
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_bb.expandBy(dbb.corner(4) * matrix);
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_bb.expandBy(dbb.corner(5) * matrix);
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_bb.expandBy(dbb.corner(6) * matrix);
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_bb.expandBy(dbb.corner(7) * matrix);
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}
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}
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}
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protected:
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typedef std::vector<osg::Matrix> MatrixStack;
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MatrixStack _matrixStack;
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osg::BoundingBox _bb;
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};
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int main(int argc, char** argv)
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{
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// use an ArgumentParser object to manage the program arguments.
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osg::ArgumentParser arguments(&argc, argv);
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// set up the usage document, in case we need to print out how to use this program.
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arguments.getApplicationUsage()->setDescription(arguments.getApplicationName() + " is the example which demonstrates using of GL_ARB_shadow extension implemented in osg::Texture class");
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arguments.getApplicationUsage()->setCommandLineUsage(arguments.getApplicationName());
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arguments.getApplicationUsage()->addCommandLineOption("-h or --help", "Display this information");
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arguments.getApplicationUsage()->addCommandLineOption("--with-base-texture", "Adde base texture to shadowed model.");
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arguments.getApplicationUsage()->addCommandLineOption("--no-base-texture", "Adde base texture to shadowed model.");
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// construct the viewer.
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osgViewer::Viewer viewer;
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// if user request help write it out to cout.
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if (arguments.read("-h") || arguments.read("--help"))
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{
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arguments.getApplicationUsage()->write(std::cout);
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return 1;
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}
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bool postionalLight = false;
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while (arguments.read("--positionalLight")) postionalLight = true;
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while (arguments.read("--directionalLight")) postionalLight = false;
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bool addOccluderToScene = false;
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while (arguments.read("--addOccluderToScene")) addOccluderToScene = true;
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bool updateLightPosition = true;
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while (arguments.read("--noUpdate")) updateLightPosition = false;
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bool createBase = false;
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while (arguments.read("--base")) createBase = true;
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bool doShadow = true;
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while (arguments.read("--noShadow")) doShadow = false;
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// any option left unread are converted into errors to write out later.
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arguments.reportRemainingOptionsAsUnrecognized();
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// report any errors if they have occured when parsing the program aguments.
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if (arguments.errors())
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{
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arguments.writeErrorMessages(std::cout);
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return 1;
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}
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osg::ref_ptr<osg::Node> model = osgDB::readNodeFiles(arguments);
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if (!model)
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{
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osg::notify(osg::NOTICE)<<"No model loaded, please specify a model to load."<<std::endl;
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return 1;
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}
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// get the bounds of the model.
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ComputeBoundingBoxVisitor cbbv;
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model->accept(cbbv);
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osg::BoundingBox bb = cbbv.getBoundingBox();
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if (createBase)
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{
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osg::ref_ptr<osg::Group> newGroup = new osg::Group;
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newGroup->addChild(model.get());
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osg::Geode* geode = new osg::Geode;
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osg::Vec3 widthVec(bb.radius(), 0.0f, 0.0f);
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osg::Vec3 depthVec(0.0f, bb.radius(), 0.0f);
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osg::Vec3 centerBase( (bb.xMin()+bb.xMax())*0.5f, (bb.yMin()+bb.yMax())*0.5f, bb.zMin()-bb.radius()*0.1f );
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geode->addDrawable( osg::createTexturedQuadGeometry( centerBase-widthVec*1.5f-depthVec*1.5f,
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widthVec*3.0f, depthVec*3.0f) );
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newGroup->addChild(geode);
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model = newGroup.get();
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}
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// get the bounds of the model.
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cbbv.reset();
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model->accept(cbbv);
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bb = cbbv.getBoundingBox();
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osg::ref_ptr<osg::Group> group = new osg::Group;
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// set up the occluder
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osg::ref_ptr<osgShadow::OccluderGeometry> occluder = new osgShadow::OccluderGeometry;
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occluder->computeOccluderGeometry(model.get());
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cbbv.getPolytope(occluder->getBoundingPolytope(),0.001);
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if (addOccluderToScene)
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{
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osg::ref_ptr<osg::Geode> geode = new osg::Geode;
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geode->addDrawable(occluder.get());
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group->addChild(geode.get());
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}
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osg::ref_ptr<osgShadow::ShadowVolumeGeometry> shadowVolume = new osgShadow::ShadowVolumeGeometry;
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shadowVolume->setUseDisplayList(!updateLightPosition);
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osg::Vec4 lightpos;
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if (postionalLight)
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{
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lightpos.set(bb.center().x(), bb.center().y(), bb.zMax() + bb.radius() ,1.0f);
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}
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else
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{
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lightpos.set(0.5f,0.25f,0.8f,0.0f);
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}
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osg::ref_ptr<osg::Light> light = new osg::Light;
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if (!doShadow)
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{
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group->addChild(model.get());
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osg::ref_ptr<osg::Geode> geode = new osg::Geode;
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occluder->computeShadowVolumeGeometry(lightpos, *shadowVolume);
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geode->addDrawable(shadowVolume.get());
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group->addChild(geode.get());
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osg::StateSet* ss = geode->getOrCreateStateSet();
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ss->setAttributeAndModes(new osg::CullFace(osg::CullFace::BACK), osg::StateAttribute::ON | osg::StateAttribute::OVERRIDE);
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}
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else
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{
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osg::Vec4 ambient(0.2,0.2,0.2,1.0);
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osg::Vec4 diffuse(0.8,0.8,0.8,1.0);
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osg::Vec4 zero_colour(0.0,0.0,0.0,1.0);
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// first group
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{
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osg::Group* first_model_group = new osg::Group;
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first_model_group->addChild(model.get());
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group->addChild(first_model_group);
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osg::StateSet* ss1 = first_model_group->getOrCreateStateSet();
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osg::LightModel* lm1 = new osg::LightModel;
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lm1->setAmbientIntensity(ambient);
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ss1->setAttribute(lm1);
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osg::Light* light1 = new osg::Light;
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light1->setAmbient(ambient);
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light1->setDiffuse(zero_colour);
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light1->setPosition(lightpos);
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ss1->setAttributeAndModes(light1, osg::StateAttribute::ON | osg::StateAttribute::OVERRIDE);
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ss1->setMode(GL_LIGHTING, osg::StateAttribute::ON | osg::StateAttribute::OVERRIDE);
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}
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// second group
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{
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// use a camera here just to implement a seperate post rendering stage.
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osg::Camera* camera = new osg::Camera;
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camera->setRenderOrder(osg::Camera::POST_RENDER);
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camera->setClearMask(GL_STENCIL_BUFFER_BIT);
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group->addChild(camera);
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osg::StateSet* ss_camera = camera->getOrCreateStateSet();
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osg::Depth* depth = new osg::Depth;
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depth->setWriteMask(false);
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depth->setFunction(osg::Depth::LEQUAL);
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ss_camera->setAttribute(depth);
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{
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osg::ref_ptr<osg::Geode> geode = new osg::Geode;
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occluder->computeShadowVolumeGeometry(lightpos, *shadowVolume);
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geode->addDrawable(shadowVolume.get());
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// switch off the writing to the color bit planes.
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osg::ColorMask* colourMask = new osg::ColorMask;
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colourMask->setMask(false,false,false,false);
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osg::Stencil* stencil = new osg::Stencil;
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stencil->setFunction(osg::Stencil::ALWAYS,0,~0u);
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stencil->setOperation(osg::Stencil::KEEP, osg::Stencil::KEEP, osg::Stencil::INCR);
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osg::StateSet* ss_sv1 = geode->getOrCreateStateSet();
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ss_sv1->setRenderBinDetails(0, "RenderBin");
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ss_sv1->setAttributeAndModes(stencil,osg::StateAttribute::ON);
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ss_sv1->setAttribute(colourMask);
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ss_sv1->setAttributeAndModes(new osg::CullFace(osg::CullFace::BACK), osg::StateAttribute::ON | osg::StateAttribute::OVERRIDE);
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camera->addChild(geode.get());
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}
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if (true)
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{
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osg::ref_ptr<osg::Geode> geode = new osg::Geode;
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occluder->computeShadowVolumeGeometry(lightpos, *shadowVolume);
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geode->addDrawable(shadowVolume.get());
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// switch off the writing to the color bit planes.
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osg::ColorMask* colourMask = new osg::ColorMask;
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colourMask->setMask(false,false,false,false);
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osg::Stencil* stencil = new osg::Stencil;
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stencil->setFunction(osg::Stencil::ALWAYS,0,~0u);
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stencil->setOperation(osg::Stencil::KEEP, osg::Stencil::KEEP, osg::Stencil::DECR);
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osg::StateSet* ss_sv1 = geode->getOrCreateStateSet();
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ss_sv1->setRenderBinDetails(1, "RenderBin");
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ss_sv1->setAttributeAndModes(stencil,osg::StateAttribute::ON);
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ss_sv1->setAttribute(colourMask);
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ss_sv1->setAttributeAndModes(new osg::CullFace(osg::CullFace::FRONT), osg::StateAttribute::ON | osg::StateAttribute::OVERRIDE);
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camera->addChild(geode.get());
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}
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{
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osg::Group* second_model_group = new osg::Group;
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second_model_group->addChild(model.get());
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osg::StateSet* ss1 = second_model_group->getOrCreateStateSet();
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ss1->setRenderBinDetails(5, "RenderBin");
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osg::LightModel* lm1 = new osg::LightModel;
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lm1->setAmbientIntensity(zero_colour);
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ss1->setAttribute(lm1);
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osg::LightSource* lightsource = new osg::LightSource;
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lightsource->setLight(light.get());
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light->setAmbient(zero_colour);
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light->setDiffuse(diffuse);
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light->setPosition(lightpos);
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second_model_group->addChild(lightsource);
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ss1->setMode(GL_LIGHT0, osg::StateAttribute::ON | osg::StateAttribute::OVERRIDE);
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// set up the stencil ops so that only operator on this mirrors stencil value.
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osg::Stencil* stencil = new osg::Stencil;
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stencil->setFunction(osg::Stencil::EQUAL,0,~0u);
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stencil->setOperation(osg::Stencil::KEEP, osg::Stencil::KEEP, osg::Stencil::KEEP);
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ss1->setAttributeAndModes(stencil,osg::StateAttribute::ON);
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osg::BlendFunc* blend = new osg::BlendFunc;
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blend->setFunction(osg::BlendFunc::ONE, osg::BlendFunc::ONE);
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ss1->setAttributeAndModes(blend, osg::StateAttribute::ON | osg::StateAttribute::OVERRIDE);
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ss1->setMode(GL_LIGHTING, osg::StateAttribute::ON | osg::StateAttribute::OVERRIDE);
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camera->addChild(second_model_group);
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}
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}
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}
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osg::DisplaySettings::instance()->setMinimumNumStencilBits(8);
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viewer.setSceneData(group.get());
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viewer.setCameraManipulator(new osgGA::TrackballManipulator());
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osg::notify(osg::NOTICE)<<"Warning: Stencil buffer required, but not yet switched on."<<std::endl;
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// create the windows and run the threads.
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viewer.realize();
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while (!viewer.done())
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{
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if (updateLightPosition)
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{
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float t = viewer.getFrameStamp()->getReferenceTime();
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if (postionalLight)
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{
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lightpos.set(bb.center().x()+sinf(t)*bb.radius(), bb.center().y() + cosf(t)*bb.radius(), bb.zMax() + bb.radius() ,1.0f);
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}
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else
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{
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lightpos.set(sinf(t),cosf(t),0.8f,0.0f);
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}
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light->setPosition(lightpos);
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occluder->computeShadowVolumeGeometry(lightpos, *shadowVolume);
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}
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viewer.frame();
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}
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return 0;
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}
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