OpenSceneGraph/examples/osgmultiplecameras/osgmultiplecameras.cpp
Robert Osfield 682b867e4f From Marco Jez, moved the rear view camera's viewport to the bottom left of window to accomdate a greater range of display sizes.
From Robert Osfield, made the background colour of the intersted camera a scaled down verson of the main background colour to make it more obvious.
2005-11-02 14:22:31 +00:00

141 lines
4.7 KiB
C++

/* -*-c++-*- OpenSceneGraph - Copyright (C) 1998-2003 Robert Osfield
*
* This library is open source and may be redistributed and/or modified under
* the terms of the OpenSceneGraph Public License (OSGPL) version 0.0 or
* (at your option) any later version. The full license is in LICENSE file
* included with this distribution, and on the openscenegraph.org website.
*
* This library 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
* OpenSceneGraph Public License for more details.
*/
#include <osgUtil/Optimizer>
#include <osgDB/ReadFile>
#include <osgProducer/Viewer>
#include <osg/Material>
#include <osg/Geode>
#include <osg/BlendFunc>
#include <osg/Depth>
#include <osg/Projection>
#include <osg/PolygonOffset>
#include <osg/MatrixTransform>
#include <osg/CameraNode>
#include <osg/FrontFace>
#include <osgText/Text>
osg::Node* createRearView(osg::Node* subgraph, const osg::Vec4& clearColour)
{
osg::CameraNode* camera = new osg::CameraNode;
// set the viewport
camera->setViewport(10,10,400,200);
// set the view matrix
camera->setCullingActive(false);
camera->setReferenceFrame(osg::Transform::RELATIVE_RF);
camera->setTransformOrder(osg::CameraNode::POST_MULTIPLE);
camera->setProjectionMatrix(osg::Matrixd::scale(-1.0f,1.0f,1.0f));
camera->setViewMatrix(osg::Matrixd::rotate(osg::inDegrees(180.0f),0.0f,1.0f,0.0f));
// set clear the color and depth buffer
camera->setClearColor(clearColour);
camera->setClearMask(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);
// draw subgraph after main camera view.
camera->setRenderOrder(osg::CameraNode::POST_RENDER);
// add the subgraph to draw.
camera->addChild(subgraph);
// switch of back face culling as we've swapped over the projection matrix making back faces become front faces.
camera->getOrCreateStateSet()->setAttribute(new osg::FrontFace(osg::FrontFace::CLOCKWISE));
return camera;
}
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 how to do Head Up Displays.");
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;
}
// read the scene from the list of file specified commandline args.
osg::ref_ptr<osg::Node> scene = osgDB::readNodeFiles(arguments);
osg::ref_ptr<osg::Group> group = new osg::Group;
// add the HUD subgraph.
if (scene.valid()) group->addChild(scene.get());
osg::Vec4 colour = viewer.getClearColor();
colour.r() *= 0.5f;
colour.g() *= 0.5f;
colour.b() *= 0.5f;
// note tone down the normal back ground colour to make it obvious that there is a seperate camera inserted.
group->addChild(createRearView(scene.get(), colour));
// set the scene to render
viewer.setSceneData(group.get());
// 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;
}