Hi list,
attached there should be a .cpp file intended to replace the
osgtexture1D.cpp example, since the current one doesn't produces
visually different results when switching from the OBJECT_LINEAR to
the EYE_LINEAR mode, because, as Robert has written twice in the users
list, EYE_LINEAR is only relative to the eye when you use a identiy
modelview matrix.
My submission uses a TexGenNode that sets the reference frame to
ABSOLUTE_RF to solve the problem, as suggested in the users list. It
is based on the example from OSG 2.4, but apparently this file is the
same as the one in OSG 2.8 .
This is actually the second time I sent this e-mail, since the first
time I send this message, since it doesn't shows in the mailing list
archives, and I wasn't registered to the mailing list, so I guess it
rejected my e-mail.
- Coz
/* OpenSceneGraph example, osgtexture1D.
*
* 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 <osg/Notify>
#include <osg/Texture1D>
#include <osg/TexGenNode>
#include <osg/Material>
#include <osgDB/Registry>
#include <osgDB/ReadFile>
#include <osgViewer/Viewer>
#include <iostream>
// Creates a stateset which contains a 1D texture which is populated by contour banded color,
// and allows tex gen to override the S texture coordinate
osg::StateSet* create1DTextureStateToDecorate(osg::Node* loadedModel)
{
osg::Image* image = new osg::Image;
int noPixels = 1024;
// allocate the image data, noPixels x 1 x 1 with 4 rgba floats - equivalent to a Vec4!
image->allocateImage(noPixels,1,1,GL_RGBA,GL_FLOAT);
image->setInternalTextureFormat(GL_RGBA);
typedef std::vector<osg::Vec4> ColorBands;
ColorBands colorbands;
colorbands.push_back(osg::Vec4(0.0f,0.0,0.0,1.0f));
colorbands.push_back(osg::Vec4(1.0f,0.0,0.0,1.0f));
colorbands.push_back(osg::Vec4(1.0f,1.0,0.0,1.0f));
colorbands.push_back(osg::Vec4(0.0f,1.0,0.0,1.0f));
colorbands.push_back(osg::Vec4(0.0f,1.0,1.0,1.0f));
colorbands.push_back(osg::Vec4(0.0f,0.0,1.0,1.0f));
colorbands.push_back(osg::Vec4(1.0f,0.0,1.0,1.0f));
colorbands.push_back(osg::Vec4(1.0f,1.0,1.0,1.0f));
float nobands = colorbands.size();
float delta = nobands/(float)noPixels;
float pos = 0.0f;
// fill in the image data.
osg::Vec4* dataPtr = (osg::Vec4*)image->data();
for(int i=0;i<noPixels;++i,pos+=delta)
{
//float p = floorf(pos);
//float r = pos-p;
//osg::Vec4 color = colorbands[(int)p]*(1.0f-r);
//if (p+1<colorbands.size()) color += colorbands[(int)p+1]*r;
osg::Vec4 color = colorbands[(int)pos];
*dataPtr++ = color;
}
osg::Texture1D* texture = new osg::Texture1D;
texture->setWrap(osg::Texture1D::WRAP_S,osg::Texture1D::MIRROR);
texture->setFilter(osg::Texture1D::MIN_FILTER,osg::Texture1D::LINEAR);
texture->setImage(image);
osg::Material* material = new osg::Material;
osg::StateSet* stateset = new osg::StateSet;
stateset->setTextureAttribute(0,texture,osg::StateAttribute::OVERRIDE);
stateset->setTextureMode(0,GL_TEXTURE_1D,osg::StateAttribute::ON|osg::StateAttribute::OVERRIDE);
stateset->setTextureMode(0,GL_TEXTURE_2D,osg::StateAttribute::OFF|osg::StateAttribute::OVERRIDE);
stateset->setTextureMode(0,GL_TEXTURE_3D,osg::StateAttribute::OFF|osg::StateAttribute::OVERRIDE);
stateset->setTextureMode(0,GL_TEXTURE_GEN_S,osg::StateAttribute::ON|osg::StateAttribute::OVERRIDE);
stateset->setAttribute(material,osg::StateAttribute::OVERRIDE);
return stateset;
}
// An app callback which alternates the tex gen mode between object linear and eye linear to illustrate what differences it makes.
class AnimateTexGenCallback : public osg::NodeCallback
{
public:
AnimateTexGenCallback() {}
void animateTexGen(osg::TexGenNode* texgenNode,double time)
{
// here we simply get any existing texgen, and then increment its
// plane, pushing the R coordinate through the texture.
const double timeInterval = 2.0f;
static double previousTime = time;
static bool state = false;
while (time>previousTime+timeInterval)
{
previousTime+=timeInterval;
state = !state;
}
if (state)
{
texgenNode->getTexGen()->setMode(osg::TexGen::OBJECT_LINEAR);
}
else
{
texgenNode->getTexGen()->setMode(osg::TexGen::EYE_LINEAR);
}
}
virtual void operator()(osg::Node* node, osg::NodeVisitor* nv)
{
osg::TexGenNode* texgenNode = dynamic_cast<osg::TexGenNode*>(node);
if (texgenNode && nv->getFrameStamp())
{
// we have an exisitng stateset, so lets animate it.
animateTexGen(texgenNode,nv->getFrameStamp()->getSimulationTime());
}
// 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);
}
};
int main( int argc, char **argv )
{
// use an ArgumentParser object to manage the program arguments.
osg::ArgumentParser arguments(&argc,argv);
// construct the viewer.
osgViewer::Viewer viewer;
// load the images specified on command line
osg::Node* loadedModel = osgDB::readNodeFiles(arguments);
// if not loaded assume no arguments passed in, try use default mode instead.
if (!loadedModel) loadedModel = osgDB::readNodeFile("dumptruck.osg");
if (!loadedModel)
{
osg::notify(osg::NOTICE)<<arguments.getApplicationUsage()->getCommandLineUsage()<<std::endl;
return 0;
}
osg::StateSet* stateset = create1DTextureStateToDecorate(loadedModel);
if (!stateset)
{
std::cout<<"Error: failed to create 1D texture state."<<std::endl;
return 1;
}
loadedModel->setStateSet(stateset);
osg:: Group *root = new osg:: Group;
root -> addChild( loadedModel );
// The contour banded color texture is used in conjunction with TexGenNode
// to create contoured models, either in object linear coords - like
// contours on a map, or eye linear which contour the distance from
// the eye. An app callback toggles between the two tex gen modes.
osg::TexGenNode* texgenNode = new osg::TexGenNode;
texgenNode->setReferenceFrame( osg::TexGenNode::ABSOLUTE_RF );
texgenNode->getTexGen()->setMode( osg::TexGen::OBJECT_LINEAR );
const osg::BoundingSphere& bs = loadedModel->getBound();
float zBase = bs.center().z()-bs.radius();
float zScale = 2.0f/bs.radius();
texgenNode->getTexGen()->setPlane(osg::TexGen::S,osg::Plane(0.0f,0.0f,zScale,-zBase));
texgenNode->setUpdateCallback(new AnimateTexGenCallback());
root -> addChild( texgenNode );
viewer.setSceneData( root );
return viewer.run();
}
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