OpenSceneGraph/examples/osgdistortion/osgdistortion.cpp

334 lines
10 KiB
C++

#include <osg/GLExtensions>
#include <osg/Node>
#include <osg/Geometry>
#include <osg/Notify>
#include <osg/MatrixTransform>
#include <osg/Texture2D>
#include <osg/Stencil>
#include <osg/ColorMask>
#include <osg/Depth>
#include <osg/Billboard>
#include <osg/Material>
#include <osg/Projection>
#include <osgGA/TrackballManipulator>
#include <osgGA/FlightManipulator>
#include <osgGA/DriveManipulator>
#include <osgUtil/TransformCallback>
#include <osgUtil/RenderToTextureStage>
#include <osgUtil/SmoothingVisitor>
#include <osgDB/Registry>
#include <osgDB/ReadFile>
#include <osgProducer/Viewer>
using namespace osg;
class DistortionNode : public osg::Group
{
public:
DistortionNode();
DistortionNode(const DistortionNode& rhs,const osg::CopyOp& copyop=osg::CopyOp::SHALLOW_COPY):
osg::Group(rhs,copyop) {}
META_Node(osgDistortion, DistortionNode);
virtual void traverse(osg::NodeVisitor& nv);
protected:
void createHUDSubgraph();
void preRender(osgUtil::CullVisitor& nv);
osg::ref_ptr<osg::Node> _hudSubgraph;
osg::ref_ptr<osg::Texture2D> _texture;
osg::ref_ptr<osg::StateSet> _localStateSet;
};
DistortionNode::DistortionNode()
{
setCullingActive(false);
createHUDSubgraph();
}
void DistortionNode::createHUDSubgraph()
{
// create the quad to visualize.
osg::Geometry* polyGeom = new osg::Geometry();
polyGeom->setSupportsDisplayList(false);
osg::Vec3 origin(0.0f,0.0f,0.0f);
osg::Vec3 xAxis(1.0f,0.0f,0.0f);
osg::Vec3 yAxis(0.0f,1.0f,0.0f);
osg::Vec3 zAxis(0.0f,0.0f,1.0f);
float height = 1024.0f;
float width = 1280.0f;
int noSteps = 50;
osg::Vec3Array* vertices = new osg::Vec3Array;
osg::Vec2Array* texcoords = new osg::Vec2Array;
osg::Vec4Array* colors = new osg::Vec4Array;
osg::Vec3 bottom = origin;
osg::Vec3 dx = xAxis*(width/((float)(noSteps-1)));
osg::Vec3 dy = yAxis*(height/((float)(noSteps-1)));
osg::Vec2 bottom_texcoord(0.0f,0.0f);
osg::Vec2 dx_texcoord(1.0f/(float)(noSteps-1),0.0f);
osg::Vec2 dy_texcoord(0.0f,1.0f/(float)(noSteps-1));
osg::Vec3 cursor = bottom;
osg::Vec2 texcoord = bottom_texcoord;
int i,j;
for(i=0;i<noSteps;++i)
{
osg::Vec3 cursor = bottom+dy*(float)i;
osg::Vec2 texcoord = bottom_texcoord+dy_texcoord*(float)i;
for(j=0;j<noSteps;++j)
{
vertices->push_back(cursor);
texcoords->push_back(osg::Vec2((sin(texcoord.x()*osg::PI-osg::PI*0.5)+1.0f)*0.5f,(sin(texcoord.y()*osg::PI-osg::PI*0.5)+1.0f)*0.5f));
colors->push_back(osg::Vec4(1.0f,1.0f,1.0f,1.0f));
cursor += dx;
texcoord += dx_texcoord;
}
}
// pass the created vertex array to the points geometry object.
polyGeom->setVertexArray(vertices);
polyGeom->setColorArray(colors);
polyGeom->setColorBinding(osg::Geometry::BIND_PER_VERTEX);
polyGeom->setTexCoordArray(0,texcoords);
for(i=0;i<noSteps-1;++i)
{
osg::DrawElementsUShort* elements = new osg::DrawElementsUShort(osg::PrimitiveSet::QUAD_STRIP);
for(j=0;j<noSteps;++j)
{
elements->push_back(j+(i+1)*noSteps);
elements->push_back(j+(i)*noSteps);
}
polyGeom->addPrimitiveSet(elements);
}
// new we need to add the texture to the Drawable, we do so by creating a
// StateSet to contain the Texture StateAttribute.
osg::StateSet* stateset = new osg::StateSet;
osg::Texture2D* texture = new osg::Texture2D;
// texture->setFilter(osg::Texture2D::MIN_FILTER,osg::Texture2D::NEAREST);
// texture->setFilter(osg::Texture2D::MAG_FILTER,osg::Texture2D::NEAREST);
texture->setFilter(osg::Texture2D::MIN_FILTER,osg::Texture2D::LINEAR);
texture->setFilter(osg::Texture2D::MAG_FILTER,osg::Texture2D::LINEAR);
stateset->setTextureAttributeAndModes(0, texture,osg::StateAttribute::ON);
stateset->setMode(GL_LIGHTING,osg::StateAttribute::OFF);
polyGeom->setStateSet(stateset);
_texture = texture;
osg::Geode* geode = new osg::Geode();
geode->addDrawable(polyGeom);
// create the hud.
osg::MatrixTransform* modelview_abs = new osg::MatrixTransform;
modelview_abs->setReferenceFrame(osg::Transform::ABSOLUTE_RF);
modelview_abs->setMatrix(osg::Matrix::identity());
modelview_abs->addChild(geode);
osg::Projection* projection = new osg::Projection;
projection->setMatrix(osg::Matrix::ortho2D(0,1280,0,1024));
projection->addChild(modelview_abs);
_hudSubgraph = projection;
_localStateSet = new osg::StateSet;
}
void DistortionNode::traverse(osg::NodeVisitor& nv)
{
if (nv.getVisitorType()==osg::NodeVisitor::CULL_VISITOR)
{
osgUtil::CullVisitor* cullVisitor = dynamic_cast<osgUtil::CullVisitor*>(&nv);
if (cullVisitor && _texture.valid() && _hudSubgraph.valid())
{
preRender(*cullVisitor);
_hudSubgraph->accept(nv);
return;
}
}
Group::traverse(nv);
}
void DistortionNode::preRender(osgUtil::CullVisitor& cv)
{
// create the render to texture stage.
osg::ref_ptr<osgUtil::RenderToTextureStage> rtts = new osgUtil::RenderToTextureStage;
// set up lighting.
// currently ignore lights in the scene graph itself..
// will do later.
osgUtil::RenderStage* previous_stage = cv.getCurrentRenderBin()->getStage();
// set up the background color and clear mask.
rtts->setClearColor(osg::Vec4(0.1f,0.1f,0.3f,1.0f));
rtts->setClearMask(previous_stage->getClearMask());
// set up to charge the same RenderStageLighting is the parent previous stage.
rtts->setRenderStageLighting(previous_stage->getRenderStageLighting());
// record the render bin, to be restored after creation
// of the render to text
osgUtil::RenderBin* previousRenderBin = cv.getCurrentRenderBin();
// set the current renderbin to be the newly created stage.
cv.setCurrentRenderBin(rtts.get());
cv.pushStateSet(_localStateSet.get());
{
// traverse the subgraph
Group::traverse(cv);
}
cv.popStateSet();
// restore the previous renderbin.
cv.setCurrentRenderBin(previousRenderBin);
if (rtts->getRenderGraphList().size()==0 && rtts->getRenderBinList().size()==0)
{
// getting to this point means that all the subgraph has been
// culled by small feature culling or is beyond LOD ranges.
return;
}
int height = 1024;
int width = 1024;
const osg::Viewport& viewport = *cv.getViewport();
// offset the impostor viewport from the center of the main window
// viewport as often the edges of the viewport might be obscured by
// other windows, which can cause image/reading writing problems.
int center_x = viewport.x()+viewport.width()/2;
int center_y = viewport.y()+viewport.height()/2;
osg::Viewport* new_viewport = new osg::Viewport;
new_viewport->setViewport(center_x-width/2,center_y-height/2,width,height);
rtts->setViewport(new_viewport);
_localStateSet->setAttribute(new_viewport);
// and the render to texture stage to the current stages
// dependancy list.
cv.getCurrentRenderBin()->getStage()->addToDependencyList(rtts.get());
// if one exist attach texture to the RenderToTextureStage.
if (_texture.valid()) rtts->setTexture(_texture.get());
}
int main( int argc, char **argv )
{
// use an ArgumentParser object to manage the program arguments.
osg::ArgumentParser arguments(&argc,argv);
// set up the usage document, in case we need to print out how to use this program.
arguments.getApplicationUsage()->setDescription(arguments.getApplicationName()+" is the example which demonstrates pre rendering of scene to a texture, and then apply this texture to geometry.");
arguments.getApplicationUsage()->setCommandLineUsage(arguments.getApplicationName()+" [options] filename ...");
arguments.getApplicationUsage()->addCommandLineOption("-h or --help","Display this information");
// construct the viewer.
osgProducer::Viewer viewer(arguments);
// set up the value with sensible default event handlers.
viewer.setUpViewer(osgProducer::Viewer::STANDARD_SETTINGS);
// get details on keyboard and mouse bindings used by the viewer.
viewer.getUsage(*arguments.getApplicationUsage());
// if user request help write it out to cout.
if (arguments.read("-h") || arguments.read("--help"))
{
arguments.getApplicationUsage()->write(std::cout);
return 1;
}
// any option left unread are converted into errors to write out later.
arguments.reportRemainingOptionsAsUnrecognized();
// report any errors if they have occured when parsing the program aguments.
if (arguments.errors())
{
arguments.writeErrorMessages(std::cout);
return 1;
}
if (arguments.argc()<=1)
{
arguments.getApplicationUsage()->write(std::cout,osg::ApplicationUsage::COMMAND_LINE_OPTION);
return 1;
}
// load the nodes from the commandline arguments.
osg::Node* loadedModel = osgDB::readNodeFiles(arguments);
if (!loadedModel)
{
// write_usage(osg::notify(osg::NOTICE),argv[0]);
return 1;
}
// create a transform to spin the model.
DistortionNode* distortionNode = new DistortionNode;
distortionNode->addChild(loadedModel);
// add model to the viewer.
viewer.setSceneData( distortionNode );
// create the windows and run the threads.
viewer.realize();
while( !viewer.done() )
{
// wait for all cull and draw threads to complete.
viewer.sync();
// update the scene by traversing it with the the update visitor which will
// call all node update callbacks and animations.
viewer.update();
// fire off the cull and draw traversals of the scene.
viewer.frame();
}
// wait for all cull and draw threads to complete before exit.
viewer.sync();
return 0;
}