OpenSceneGraph/examples/osgfadetext/osgfadetext.cpp
Robert Osfield 6a67be2e32 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/branches/OpenSceneGraph-3.4@15165 16af8721-9629-0410-8352-f15c8da7e697
2015-10-22 14:14:53 +00:00

151 lines
4.7 KiB
C++

/* OpenSceneGraph example, osgfadetext.
*
* 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 <osgViewer/Viewer>
#include <osg/Group>
#include <osg/Geode>
#include <osg/ShapeDrawable>
#include <osg/Texture2D>
#include <osg/PositionAttitudeTransform>
#include <osg/MatrixTransform>
#include <osg/CoordinateSystemNode>
#include <osg/ClusterCullingCallback>
#include <osgDB/FileUtils>
#include <osgDB/ReadFile>
#include <osgText/FadeText>
#include <osgSim/OverlayNode>
#include <osgSim/SphereSegment>
#include <osgGA/TerrainManipulator>
#include <iostream>
osg::Node* createEarth()
{
osg::TessellationHints* hints = new osg::TessellationHints;
hints->setDetailRatio(5.0f);
osg::ShapeDrawable* sd = new osg::ShapeDrawable(new osg::Sphere(osg::Vec3(0.0,0.0,0.0), osg::WGS_84_RADIUS_POLAR), hints);
osg::Geode* geode = new osg::Geode;
geode->addDrawable(sd);
std::string filename = osgDB::findDataFile("Images/land_shallow_topo_2048.jpg");
geode->getOrCreateStateSet()->setTextureAttributeAndModes(0, new osg::Texture2D(osgDB::readRefImageFile(filename)));
osg::CoordinateSystemNode* csn = new osg::CoordinateSystemNode;
csn->setEllipsoidModel(new osg::EllipsoidModel());
csn->addChild(geode);
return csn;
}
osgText::Text* createText(osg::EllipsoidModel* ellipsoid, double latitude, double longitude, double height, const std::string& str)
{
double X,Y,Z;
ellipsoid->convertLatLongHeightToXYZ( osg::DegreesToRadians(latitude), osg::DegreesToRadians(longitude), height, X, Y, Z);
osgText::Text* text = new osgText::FadeText;
osg::Vec3 normal = ellipsoid->computeLocalUpVector( X, Y, Z);
text->setCullCallback(new osg::ClusterCullingCallback(osg::Vec3(X,Y,Z), normal, 0.0));
text->setText(str);
text->setFont("fonts/arial.ttf");
text->setPosition(osg::Vec3(X,Y,Z));
text->setCharacterSize(300000.0f);
text->setCharacterSizeMode(osgText::Text::OBJECT_COORDS_WITH_MAXIMUM_SCREEN_SIZE_CAPPED_BY_FONT_HEIGHT);
text->setAutoRotateToScreen(true);
return text;
}
osg::Node* createFadeText(osg::EllipsoidModel* ellipsoid)
{
osg::Group* group = new osg::Group;
group->getOrCreateStateSet()->setMode(GL_DEPTH_TEST,osg::StateAttribute::OFF);
osg::Geode* geode = new osg::Geode;
group->addChild(geode);
std::vector<std::string> textList;
textList.push_back("Town");
textList.push_back("City");
textList.push_back("Village");
textList.push_back("River");
textList.push_back("Mountain");
textList.push_back("Road");
textList.push_back("Lake");
unsigned int numLat = 15;
unsigned int numLong = 20;
double latitude = 0.0;
double longitude = -100.0;
double deltaLatitude = 1.0f;
double deltaLongitude = 1.0f;
unsigned int t = 0;
for(unsigned int i = 0; i < numLat; ++i, latitude += deltaLatitude)
{
double lgnt = longitude;
for(unsigned int j = 0; j < numLong; ++j, ++t, lgnt += deltaLongitude)
{
geode->addDrawable( createText( ellipsoid, latitude, lgnt, 0, textList[t % textList.size()]) );
}
}
return group;
}
int main(int, char**)
{
// construct the viewer.
osgViewer::Viewer viewer;
viewer.getCamera()->setComputeNearFarMode(osg::CullSettings::COMPUTE_NEAR_FAR_USING_PRIMITIVES);
viewer.getCamera()->setNearFarRatio(0.00001f);
// read the scene from the list of file specified commandline args.
osg::ref_ptr<osg::Node> root = createEarth();
if (!root) return 0;
// add a viewport to the viewer and attach the scene graph.
viewer.setSceneData(root.get());
osg::CoordinateSystemNode* csn = dynamic_cast<osg::CoordinateSystemNode*>(root.get());
if (csn)
{
// add fade text around the globe
csn->addChild(createFadeText(csn->getEllipsoidModel()));
}
viewer.setCameraManipulator(new osgGA::TerrainManipulator);
return viewer.run();
}