OpenSceneGraph/examples/osgtexture3D/osgtexture3D.cpp

289 lines
10 KiB
C++

#include <osg/Node>
#include <osg/Geometry>
#include <osg/Notify>
#include <osg/Texture3D>
#include <osg/TexGen>
#include <osg/Geode>
#include <osgDB/Registry>
#include <osgDB/ReadFile>
#include <osgProducer/Viewer>
//
// A simple demo demonstrating different texturing modes,
// including using of texture extensions.
//
typedef std::vector< osg::ref_ptr<osg::Image> > ImageList;
class ConstructStateCallback : public osgProducer::OsgCameraGroup::RealizeCallback
{
public:
ConstructStateCallback(osg::Node* node):_node(node),_initialized(false) {}
osg::StateSet* constructState()
{
// read 4 2d images
osg::ref_ptr<osg::Image> image_0 = osgDB::readImageFile("Images/lz.rgb");
osg::ref_ptr<osg::Image> image_1 = osgDB::readImageFile("Images/reflect.rgb");
osg::ref_ptr<osg::Image> image_2 = osgDB::readImageFile("Images/tank.rgb");
osg::ref_ptr<osg::Image> image_3 = osgDB::readImageFile("Images/skymap.jpg");
if (!image_0 || !image_1 || !image_2 || !image_3)
{
std::cout << "Warning: could not open files."<<std::endl;
return new osg::StateSet;
}
if (image_0->getPixelFormat()!=image_1->getPixelFormat() || image_0->getPixelFormat()!=image_2->getPixelFormat() || image_0->getPixelFormat()!=image_3->getPixelFormat())
{
std::cout << "Warning: image pixel formats not compatible."<<std::endl;
return new osg::StateSet;
}
// get max 3D texture size
GLint textureSize = osg::Texture3D::getExtensions(0,true)->maxTexture3DSize();
if (textureSize > 256)
textureSize = 256;
// scale them all to the same size.
image_0->scaleImage(textureSize,textureSize,1);
image_1->scaleImage(textureSize,textureSize,1);
image_2->scaleImage(textureSize,textureSize,1);
image_3->scaleImage(textureSize,textureSize,1);
// then allocated a 3d image to use for texturing.
osg::Image* image_3d = new osg::Image;
image_3d->allocateImage(textureSize,textureSize,4,
image_0->getPixelFormat(),image_0->getDataType());
// copy the 2d images into the 3d image.
image_3d->copySubImage(0,0,0,image_0.get());
image_3d->copySubImage(0,0,1,image_1.get());
image_3d->copySubImage(0,0,2,image_2.get());
image_3d->copySubImage(0,0,3,image_3.get());
image_3d->setInternalTextureFormat(image_0->getInternalTextureFormat());
// set up the 3d texture itself,
// note, well set the filtering up so that mip mapping is disabled,
// gluBuild3DMipsmaps doesn't do a very good job of handled the
// inbalanced dimensions of the 256x256x4 texture.
osg::Texture3D* texture3D = new osg::Texture3D;
texture3D->setFilter(osg::Texture3D::MIN_FILTER,osg::Texture3D::LINEAR);
texture3D->setFilter(osg::Texture3D::MAG_FILTER,osg::Texture3D::LINEAR);
texture3D->setWrap(osg::Texture3D::WRAP_R,osg::Texture3D::REPEAT);
texture3D->setImage(image_3d);
// create a texgen to generate a R texture coordinate, the geometry
// itself will supply the S & T texture coordinates.
// in the animateStateSet callback well alter this R value to
// move the texture through the 3d texture, 3d texture filtering
// will do the blending for us.
osg::TexGen* texgen = new osg::TexGen;
texgen->setMode(osg::TexGen::OBJECT_LINEAR);
texgen->setPlane(osg::TexGen::R, osg::Vec4(0.0f,0.0f,0.0f,0.2f));
// create the StateSet to store the texture data
osg::StateSet* stateset = new osg::StateSet;
stateset->setTextureMode(0,GL_TEXTURE_GEN_R,osg::StateAttribute::ON);
stateset->setTextureAttribute(0,texgen);
stateset->setTextureAttributeAndModes(0,texture3D,osg::StateAttribute::ON);
return stateset;
}
virtual void operator()( osgProducer::OsgCameraGroup&, osgProducer::OsgSceneHandler& sh, const Producer::RenderSurface& )
{
if (!_initialized)
{
// only initialize state once, only need for cases where multiple graphics contexts are
// if which case this callback can get called multiple times.
_initialized = true;
if (_node) _node->setStateSet(constructState());
}
// now safe to con
sh.init();
}
osg::Node* _node;
bool _initialized;
};
class UpdateStateCallback : public osg::NodeCallback
{
public:
UpdateStateCallback() {}
void animateState(osg::StateSet* stateset)
{
// here we simply get any existing texgen, and then increment its
// plane, pushing the R coordinate through the texture.
osg::StateAttribute* attribute = stateset->getTextureAttribute(0,osg::StateAttribute::TEXGEN);
osg::TexGen* texgen = dynamic_cast<osg::TexGen*>(attribute);
if (texgen)
{
texgen->getPlane(osg::TexGen::R)[3] += 0.001f;
}
}
virtual void operator()(osg::Node* node, osg::NodeVisitor* nv)
{
osg::StateSet* stateset = node->getStateSet();
if (stateset)
{
// we have an exisitng stateset, so lets animate it.
animateState(stateset);
}
// note, callback is repsonsible for scenegraph traversal so
// should always include call the traverse(node,nv) to ensure
// that the rest of cullbacks and the scene graph are traversed.
traverse(node,nv);
}
};
/** create 2,2 square with center at 0,0,0 and aligned along the XZ plan */
osg::Drawable* createSquare(float textureCoordMax=1.0f)
{
// set up the Geometry.
osg::Geometry* geom = new osg::Geometry;
osg::Vec3Array* coords = new osg::Vec3Array(4);
(*coords)[0].set(-1.0f,0.0f,1.0f);
(*coords)[1].set(-1.0f,0.0f,-1.0f);
(*coords)[2].set(1.0f,0.0f,-1.0f);
(*coords)[3].set(1.0f,0.0f,1.0f);
geom->setVertexArray(coords);
osg::Vec3Array* norms = new osg::Vec3Array(1);
(*norms)[0].set(0.0f,-1.0f,0.0f);
geom->setNormalArray(norms);
geom->setNormalBinding(osg::Geometry::BIND_OVERALL);
osg::Vec2Array* tcoords = new osg::Vec2Array(4);
(*tcoords)[0].set(0.0f,textureCoordMax);
(*tcoords)[1].set(0.0f,0.0f);
(*tcoords)[2].set(textureCoordMax,0.0f);
(*tcoords)[3].set(textureCoordMax,textureCoordMax);
geom->setTexCoordArray(0,tcoords);
geom->addPrimitiveSet(new osg::DrawArrays(osg::PrimitiveSet::QUADS,0,4));
return geom;
}
osg::Node* createModel()
{
// create the geometry of the model, just a simple 2d quad right now.
osg::Geode* geode = new osg::Geode;
geode->addDrawable(createSquare());
// normally we'd create the stateset's to contain all the textures
// etc here, but, the above technique uses osg::Image::scaleImage and
// osg::Image::copySubImage() which are implemented with OpenGL utility
// library, which unfortunately can't be used until we have a valid
// OpenGL context, and at this point in initilialization we don't have
// a valid OpenGL context, so we have to delay creation of state until
// there is a valid OpenGL context. I'll manage this by using an
// app callback which will create the state during the first traversal.
// A bit hacky, and my plan is to reimplement the osg::scaleImage and
// osg::Image::copySubImage() without using GLU which will get round
// this current limitation.
geode->setUpdateCallback(new UpdateStateCallback());
return geode;
}
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()->setCommandLineUsage(arguments.getProgramName()+" [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;
}
// create a model from the images.
osg::Node* rootNode = createModel();
if (rootNode)
{
// set the scene to render
viewer.setSceneData(rootNode);
// the construct state uses gl commands to resize images so we are forced
// to only call it once a valid graphics context has been established,
// for that we use a realize callback.
viewer.setRealizeCallback(new ConstructStateCallback(rootNode));
// create the windows and run the threads.
viewer.realize(Producer::CameraGroup::ThreadPerCamera);
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;
}