FGFS-4.1/OpenSceneGraph
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Added code in hangglide to move the earth sky around with the eye point,

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use osg::Transform::ComputeTransformCallback.
This commit is contained in:
Robert Osfield
2002-04-22 19:41:33 +00:00
parent 56dc083330
commit 8b30a10375
2 changed files with 56 additions and 7 deletions
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9
include/osgUtil/CullVisitor
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@@ -175,6 +175,11 @@ class OSGUTIL_EXPORT CullVisitor : public osg::NodeVisitor
const float getCalculatedFarPlane() const { return _computed_zfar; }
inline const osg::Vec3& getEyeLocal() const
{
return _eyePointStack.back();
}
protected:
/** prevent unwanted copy construction.*/
@@ -197,10 +202,6 @@ class OSGUTIL_EXPORT CullVisitor : public osg::NodeVisitor
else acceptNode->accept(*this);
}
inline const osg::Vec3& getEyeLocal() const
{
return _eyePointStack.back();
}
inline const osg::Vec3 getUpLocal() const
{

54
src/Demos/hangglide/hangglide.cpp
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@@ -3,6 +3,9 @@
#include <osg/Depth>
#include <osg/StateSet>
#include <osg/EarthSky>
#include <osg/Transform>
#include <osgUtil/CullVisitor>
#include <osgDB/Registry>
#include <osgDB/ReadFile>
@@ -22,6 +25,31 @@ extern osg::Node *makeSky( void );
extern osg::Node *makeBase( void );
extern osg::Node *makeClouds( void );
struct MoveEarthySkyWithEyePointCallback : public osg::Transform::ComputeTransformCallback
{
/** Get the transformation matrix which moves from local coords to world coords.*/
virtual const bool computeLocalToWorldMatrix(osg::Matrix& matrix,const osg::Transform* transform, osg::NodeVisitor* nv) const
{
osgUtil::CullVisitor* cv = dynamic_cast<osgUtil::CullVisitor*>(nv);
if (cv)
{
osg::Vec3 eyePointLocal = cv->getEyeLocal();
matrix.preMult(osg::Matrix::translate(eyePointLocal.x(),eyePointLocal.y(),0.0f));
}
}
/** Get the transformation matrix which moves from world coords to local coords.*/
virtual const bool computeWorldToLocalMatrix(osg::Matrix& matrix,const osg::Transform* transform, osg::NodeVisitor* nv) const
{
osgUtil::CullVisitor* cv = dynamic_cast<osgUtil::CullVisitor*>(nv);
if (cv)
{
osg::Vec3 eyePointLocal = cv->getEyeLocal();
matrix.postMult(osg::Matrix::translate(-eyePointLocal.x(),-eyePointLocal.y(),0.0f));
}
}
};
int main( int argc, char **argv )
{
@@ -56,11 +84,31 @@ int main( int argc, char **argv )
// osg::Depth, and setting their bin numbers to less than 0,
// to force them to draw before the rest of the scene.
osg::EarthSky* earthSky = new osg::EarthSky;
osg::EarthSky* earthSky = osgNew osg::EarthSky;
earthSky->setRequiresClear(false); // we've got base and sky to do it.
earthSky->addChild(makeSky()); // bin number -2 so drawn first.
earthSky->addChild(makeBase()); // bin number -1 so draw second.
// use a transform to make the sky and base around with the eye point.
osg::Transform* transform = osgNew osg::Transform;
// transform's value isn't knowm until in the cull traversal so its bounding
// volume is can't be determined, therefore culling will be invalid,
// so switch it off, this cause all our paresnts to switch culling
// off as well. But don't worry culling will be back on once underneath
// this node or any other branch above this transform.
transform->setCullingActive(false);
// set the compute transform callback to do all the work of
// determining the transform according to the current eye point.
transform->setComputeTransformCallback(osgNew MoveEarthySkyWithEyePointCallback);
// add the sky and base layer.
transform->addChild(makeSky()); // bin number -2 so drawn first.
transform->addChild(makeBase()); // bin number -1 so draw second.
// add the transform to the earth sky.
earthSky->addChild(transform);
// add to earth sky to the scene.
group->addChild(earthSky);
// the rest of the scene drawn after the base and sky above.