OpenSceneGraph/examples/osghud/osghud.cpp
Robert Osfield dd996a3289 Introduced CMake option OSG_PROVIDE_READFILE option that defaults to ON, but when switched to OFF disables the building of the osgDB::read*File() methods,
forcing users to use osgDB::readRef*File() methods.  The later is preferable as it closes a potential threading bug when using paging databases in conjunction
with the osgDB::Registry Object Cache.  This threading bug occurs when one thread gets an object from the Cache via an osgDB::read*File() call where only
a pointer to the object is passed back, so taking a reference to the object is delayed till it gets reassigned to a ref_ptr<>, but at the same time another
thread calls a flush of the Object Cache deleting this object as it's referenceCount is now zero.  Using osgDB::readREf*File() makes sure the a ref_ptr<> is
passed back and the referenceCount never goes to zero.

To ensure the OSG builds when OSG_PROVIDE_READFILE is to OFF the many cases of osgDB::read*File() usage had to be replaced with a ref_ptr<> osgDB::readRef*File()
usage.  The avoid this change causing lots of other client code to be rewritten to handle the use of ref_ptr<> in place of C pointer I introduced a serious of
templte methods in various class to adapt ref_ptr<> to the underly C pointer to be passed to old OSG API's, example of this is found in include/osg/Group:

    bool addChild(Node* child); // old method which can only be used with a Node*

    tempalte<class T> bool addChild(const osg::ref_ptr<T>& child) { return addChild(child.get()); } // adapter template method

These changes together cover 149 modified files, so it's a large submission. This extent of changes are warrent to make use of the Object Cache
and multi-threaded loaded more robust.



git-svn-id: http://svn.openscenegraph.org/osg/OpenSceneGraph/trunk@15164 16af8721-9629-0410-8352-f15c8da7e697
2015-10-22 13:42:19 +00:00

388 lines
12 KiB
C++

/* OpenSceneGraph example, osghud.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include <osgUtil/Optimizer>
#include <osgDB/ReadFile>
#include <osgViewer/Viewer>
#include <osgViewer/CompositeViewer>
#include <osgGA/TrackballManipulator>
#include <osg/Material>
#include <osg/Geode>
#include <osg/BlendFunc>
#include <osg/Depth>
#include <osg/PolygonOffset>
#include <osg/MatrixTransform>
#include <osg/Camera>
#include <osg/RenderInfo>
#include <osgDB/WriteFile>
#include <osgText/Text>
osg::Camera* createHUD()
{
// create a camera to set up the projection and model view matrices, and the subgraph to draw in the HUD
osg::Camera* camera = new osg::Camera;
// set the projection matrix
camera->setProjectionMatrix(osg::Matrix::ortho2D(0,1280,0,1024));
// set the view matrix
camera->setReferenceFrame(osg::Transform::ABSOLUTE_RF);
camera->setViewMatrix(osg::Matrix::identity());
// only clear the depth buffer
camera->setClearMask(GL_DEPTH_BUFFER_BIT);
// draw subgraph after main camera view.
camera->setRenderOrder(osg::Camera::POST_RENDER);
// we don't want the camera to grab event focus from the viewers main camera(s).
camera->setAllowEventFocus(false);
// add to this camera a subgraph to render
{
osg::Geode* geode = new osg::Geode();
std::string timesFont("fonts/arial.ttf");
// turn lighting off for the text and disable depth test to ensure it's always ontop.
osg::StateSet* stateset = geode->getOrCreateStateSet();
stateset->setMode(GL_LIGHTING,osg::StateAttribute::OFF);
osg::Vec3 position(150.0f,800.0f,0.0f);
osg::Vec3 delta(0.0f,-120.0f,0.0f);
{
osgText::Text* text = new osgText::Text;
geode->addDrawable( text );
text->setFont(timesFont);
text->setPosition(position);
text->setText("Head Up Displays are simple :-)");
position += delta;
}
{
osgText::Text* text = new osgText::Text;
geode->addDrawable( text );
text->setFont(timesFont);
text->setPosition(position);
text->setText("All you need to do is create your text in a subgraph.");
position += delta;
}
{
osgText::Text* text = new osgText::Text;
geode->addDrawable( text );
text->setFont(timesFont);
text->setPosition(position);
text->setText("Then place an osg::Camera above the subgraph\n"
"to create an orthographic projection.\n");
position += delta;
}
{
osgText::Text* text = new osgText::Text;
geode->addDrawable( text );
text->setFont(timesFont);
text->setPosition(position);
text->setText("Set the Camera's ReferenceFrame to ABSOLUTE_RF to ensure\n"
"it remains independent from any external model view matrices.");
position += delta;
}
{
osgText::Text* text = new osgText::Text;
geode->addDrawable( text );
text->setFont(timesFont);
text->setPosition(position);
text->setText("And set the Camera's clear mask to just clear the depth buffer.");
position += delta;
}
{
osgText::Text* text = new osgText::Text;
geode->addDrawable( text );
text->setFont(timesFont);
text->setPosition(position);
text->setText("And finally set the Camera's RenderOrder to POST_RENDER\n"
"to make sure it's drawn last.");
position += delta;
}
{
osg::BoundingBox bb;
for(unsigned int i=0;i<geode->getNumDrawables();++i)
{
bb.expandBy(geode->getDrawable(i)->getBoundingBox());
}
osg::Geometry* geom = new osg::Geometry;
osg::Vec3Array* vertices = new osg::Vec3Array;
float depth = bb.zMin()-0.1;
vertices->push_back(osg::Vec3(bb.xMin(),bb.yMax(),depth));
vertices->push_back(osg::Vec3(bb.xMin(),bb.yMin(),depth));
vertices->push_back(osg::Vec3(bb.xMax(),bb.yMin(),depth));
vertices->push_back(osg::Vec3(bb.xMax(),bb.yMax(),depth));
geom->setVertexArray(vertices);
osg::Vec3Array* normals = new osg::Vec3Array;
normals->push_back(osg::Vec3(0.0f,0.0f,1.0f));
geom->setNormalArray(normals, osg::Array::BIND_OVERALL);
osg::Vec4Array* colors = new osg::Vec4Array;
colors->push_back(osg::Vec4(1.0f,1.0,0.8f,0.2f));
geom->setColorArray(colors, osg::Array::BIND_OVERALL);
geom->addPrimitiveSet(new osg::DrawArrays(GL_QUADS,0,4));
osg::StateSet* stateset = geom->getOrCreateStateSet();
stateset->setMode(GL_BLEND,osg::StateAttribute::ON);
//stateset->setAttribute(new osg::PolygonOffset(1.0f,1.0f),osg::StateAttribute::ON);
stateset->setRenderingHint(osg::StateSet::TRANSPARENT_BIN);
geode->addDrawable(geom);
}
camera->addChild(geode);
}
return camera;
}
struct SnapImage : public osg::Camera::DrawCallback
{
SnapImage(const std::string& filename):
_filename(filename),
_snapImage(false)
{
_image = new osg::Image;
}
virtual void operator () (osg::RenderInfo& renderInfo) const
{
if (!_snapImage) return;
osg::notify(osg::NOTICE)<<"Camera callback"<<std::endl;
osg::Camera* camera = renderInfo.getCurrentCamera();
osg::Viewport* viewport = camera ? camera->getViewport() : 0;
osg::notify(osg::NOTICE)<<"Camera callback "<<camera<<" "<<viewport<<std::endl;
if (viewport && _image.valid())
{
_image->readPixels(int(viewport->x()),int(viewport->y()),int(viewport->width()),int(viewport->height()),
GL_RGBA,
GL_UNSIGNED_BYTE);
osgDB::writeImageFile(*_image, _filename);
osg::notify(osg::NOTICE)<<"Taken screenshot, and written to '"<<_filename<<"'"<<std::endl;
}
_snapImage = false;
}
std::string _filename;
mutable bool _snapImage;
mutable osg::ref_ptr<osg::Image> _image;
};
struct SnapeImageHandler : public osgGA::GUIEventHandler
{
SnapeImageHandler(int key,SnapImage* si):
_key(key),
_snapImage(si) {}
bool handle(const osgGA::GUIEventAdapter& ea, osgGA::GUIActionAdapter& aa)
{
if (ea.getHandled()) return false;
switch(ea.getEventType())
{
case(osgGA::GUIEventAdapter::KEYUP):
{
if (ea.getKey() == 'o' )
{
osgViewer::View* view = dynamic_cast<osgViewer::View*>(&aa);
osg::Node* node = view ? view->getSceneData() : 0;
if (node)
{
osgDB::writeNodeFile(*node, "hud.osgt");
osgDB::writeNodeFile(*node, "hud.osgb");
}
return true;
}
if (ea.getKey() == _key)
{
osg::notify(osg::NOTICE)<<"event handler"<<std::endl;
_snapImage->_snapImage = true;
return true;
}
break;
}
default:
break;
}
return false;
}
int _key;
osg::ref_ptr<SnapImage> _snapImage;
};
int main( int argc, char **argv )
{
// use an ArgumentParser object to manage the program arguments.
osg::ArgumentParser arguments(&argc,argv);
// read the scene from the list of file specified commandline args.
osg::ref_ptr<osg::Node> scene = osgDB::readRefNodeFiles(arguments);
// if not loaded assume no arguments passed in, try use default model instead.
if (!scene) scene = osgDB::readRefNodeFile("dumptruck.osgt");
if (!scene)
{
osg::notify(osg::NOTICE)<<"No model loaded"<<std::endl;
return 1;
}
if (arguments.read("--Viewer"))
{
// construct the viewer.
osgViewer::Viewer viewer;
// create a HUD as slave camera attached to the master view.
viewer.setUpViewAcrossAllScreens();
osgViewer::Viewer::Windows windows;
viewer.getWindows(windows);
if (windows.empty()) return 1;
osg::Camera* hudCamera = createHUD();
// set up cameras to render on the first window available.
hudCamera->setGraphicsContext(windows[0]);
hudCamera->setViewport(0,0,windows[0]->getTraits()->width, windows[0]->getTraits()->height);
viewer.addSlave(hudCamera, false);
// set the scene to render
viewer.setSceneData(scene);
return viewer.run();
}
if (arguments.read("--CompositeViewer"))
{
// construct the viewer.
osgViewer::CompositeViewer viewer;
// create the main 3D view
osgViewer::View* view = new osgViewer::View;
viewer.addView(view);
view->setSceneData(scene);
view->setUpViewAcrossAllScreens();;
view->setCameraManipulator(new osgGA::TrackballManipulator);
// now create the HUD camera's view
osgViewer::Viewer::Windows windows;
viewer.getWindows(windows);
if (windows.empty()) return 1;
osg::Camera* hudCamera = createHUD();
// set up cameras to render on the first window available.
hudCamera->setGraphicsContext(windows[0]);
hudCamera->setViewport(0,0,windows[0]->getTraits()->width, windows[0]->getTraits()->height);
osgViewer::View* hudView = new osgViewer::View;
hudView->setCamera(hudCamera);
viewer.addView(hudView);
return viewer.run();
}
else
{
// construct the viewer.
osgViewer::Viewer viewer;
SnapImage* postDrawCallback = new SnapImage("PostDrawCallback.png");
viewer.getCamera()->setPostDrawCallback(postDrawCallback);
viewer.addEventHandler(new SnapeImageHandler('p',postDrawCallback));
SnapImage* finalDrawCallback = new SnapImage("FinalDrawCallback.png");
viewer.getCamera()->setFinalDrawCallback(finalDrawCallback);
viewer.addEventHandler(new SnapeImageHandler('f',finalDrawCallback));
osg::ref_ptr<osg::Group> group = new osg::Group;
// add the HUD subgraph.
if (scene.valid()) group->addChild(scene);
group->addChild(createHUD());
// set the scene to render
viewer.setSceneData(group);
return viewer.run();
}
}