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From Michael McDonnell, Merged enchancements to osgtesselationshader example from OSG-svn/trunk to OSG-3.2 branch.

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git-svn-id: http://svn.openscenegraph.org/osg/OpenSceneGraph/branches/OpenSceneGraph-3.2@14746 16af8721-9629-0410-8352-f15c8da7e697
This commit is contained in:
Robert Osfield
2015-03-02 11:08:59 +00:00
parent 4c9e17fcc7
commit c8d8a051ad
1 changed files with 77 additions and 24 deletions
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101
examples/osgtessellationshaders/osgtessellationshaders.cpp
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@@ -1,6 +1,13 @@
/* A demonstration of Tessellation Shaders in OpenScenegraph.
*
* Instructions:
* Press plus to increase tesselation and minus to decrease it.
* Press right arrow to increase inner tesselation and left arrow to decrease it.
* Press up arrow to increase outer tesselation and down arrow to decrease it.
*
* Original code by Philip Rideout
* Adapted to OpenScenegraph by John Kaniarz
* Additional work by Michael Mc Donnell
*/
#include <osg/Program>
@@ -113,7 +120,8 @@ static const char* fragSource = {
"}\n"
};
osg::ref_ptr<osg::Geode> CreateIcosahedron(osg::Program *program){
osg::ref_ptr<osg::Geode> CreateIcosahedron(osg::Program *program)
{
osg::Geode *geode=new osg::Geode();
osg::Geometry *geometry = new osg::Geometry();
const unsigned int Faces[] = {
@@ -163,10 +171,16 @@ osg::ref_ptr<osg::Geode> CreateIcosahedron(osg::Program *program){
geometry->setVertexArray(vertices);
geometry->addPrimitiveSet(new osg::DrawElementsUInt(osg::PrimitiveSet::PATCHES,IndexCount,Faces));
// Expand the bounding box, otherwise the geometry is clipped in front when tessellating.
osg::BoundingBox bbox(osg::Vec3(-1.0f, -1.9f, -1.0f), osg::Vec3(1.0f, 1.0f, 1.0f));
geometry->setInitialBound(bbox);
geode->addDrawable(geometry);
return geode;
}
osg::ref_ptr<osg::Program> createProgram(){
osg::ref_ptr<osg::Program> createProgram()
{
osg::Program *program = new osg::Program();
program->addShader(new osg::Shader(osg::Shader::VERTEX,vertSource));
program->addShader(new osg::Shader(osg::Shader::TESSCONTROL,tessControlSource));
@@ -179,38 +193,74 @@ osg::ref_ptr<osg::Program> createProgram(){
return program;
}
float tessInner=1.0f;
float tessOuter=1.0f;
osg::ref_ptr<osg::Uniform> tessInnerU = new osg::Uniform("TessLevelInner",tessInner);
osg::ref_ptr<osg::Uniform> tessOuterU = new osg::Uniform("TessLevelOuter",tessOuter);
class KeyboardEventHandler : public osgGA::GUIEventHandler {
class KeyboardEventHandler : public osgGA::GUIEventHandler
{
public:
KeyboardEventHandler():osgGA::GUIEventHandler(){}
virtual bool handle(const osgGA::GUIEventAdapter& ea,osgGA::GUIActionAdapter& gaa){
KeyboardEventHandler(osg::ref_ptr<osg::Uniform> tessInnerU, osg::ref_ptr<osg::Uniform> tessOuterU):
_tessInnerU(tessInnerU),
_tessOuterU(tessOuterU)
{
tessInnerU->get(_tessInner);
tessOuterU->get(_tessOuter);
}
virtual bool handle(const osgGA::GUIEventAdapter& ea,osgGA::GUIActionAdapter& gaa)
{
if(ea.getEventType()==osgGA::GUIEventAdapter::KEYDOWN){
switch (ea.getKey()){
case osgGA::GUIEventAdapter::KEY_Up:
tessOuter++;
tessOuterU->set(tessOuter);
increaseOuterTesselation();
return true;
case osgGA::GUIEventAdapter::KEY_Down:
tessOuter--;
tessOuter=std::max(1.0f,tessOuter);
tessOuterU->set(tessOuter);
decreaseOuterTesselation();
return true;
case osgGA::GUIEventAdapter::KEY_Left:
tessInner--;
tessInner=std::max(1.0f,tessInner);
tessInnerU->set(tessInner);
decreaseInnerTesselation();
return true;
case osgGA::GUIEventAdapter::KEY_Right:
tessInner++;
tessInnerU->set(tessInner);
increaseInnerTesselation();
return true;
case osgGA::GUIEventAdapter::KEY_Plus:
case osgGA::GUIEventAdapter::KEY_KP_Add:
increaseInnerTesselation();
increaseOuterTesselation();
return true;
case osgGA::GUIEventAdapter::KEY_Minus:
case osgGA::GUIEventAdapter::KEY_KP_Subtract:
decreaseInnerTesselation();
decreaseOuterTesselation();
return true;
}
}
return osgGA::GUIEventHandler::handle(ea,gaa);
return osgGA::GUIEventHandler::handle(ea, gaa);
}
private:
osg::ref_ptr<osg::Uniform> _tessInnerU;
osg::ref_ptr<osg::Uniform> _tessOuterU;
float _tessInner;
float _tessOuter;
void increaseInnerTesselation()
{
_tessInnerU->set(++_tessInner);
}
void decreaseInnerTesselation()
{
_tessInner = std::max(1.0f, _tessInner-1.0f);
_tessInnerU->set(_tessInner);
}
void increaseOuterTesselation()
{
_tessOuterU->set(++_tessOuter);
}
void decreaseOuterTesselation()
{
_tessOuter = std::max(1.0f, _tessOuter-1.0f);
_tessOuterU->set(_tessOuter);
}
};
@@ -220,6 +270,9 @@ int main(int argc, char* argv[])
viewer.setUpViewInWindow(100,100,800,600);
osg::ref_ptr<osg::Program> program = createProgram();
osg::ref_ptr<osg::Geode> geode = CreateIcosahedron(program.get());
osg::ref_ptr<osg::Uniform> tessInnerU = new osg::Uniform("TessLevelInner", 1.0f);
osg::ref_ptr<osg::Uniform> tessOuterU = new osg::Uniform("TessLevelOuter", 1.0f);
osg::StateSet *state;
state = geode->getOrCreateStateSet();
state->addUniform(new osg::Uniform("AmbientMaterial",osg::Vec3(0.04f, 0.04f, 0.04f)));
@@ -229,7 +282,7 @@ int main(int argc, char* argv[])
state->addUniform(tessOuterU.get());
state->setAttribute(new osg::PatchParameter(3));
state->setAttribute(program.get());
// switch on the uniforms that track the modelview and projection matrices
osgViewer::Viewer::Windows windows;
viewer.getWindows(windows);
@@ -241,8 +294,8 @@ int main(int argc, char* argv[])
s->setUseModelViewAndProjectionUniforms(true);
s->setUseVertexAttributeAliasing(true);
}
viewer.addEventHandler(new KeyboardEventHandler());
viewer.addEventHandler(new KeyboardEventHandler(tessInnerU, tessOuterU));
viewer.setSceneData(geode.get());
return viewer.run();
}