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/* OpenSceneGraph example, osgpointsprite.
*
* 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/PointSprite>
#include <osg/BlendFunc>
#include <osg/StateAttribute>
#include <osg/Point>
#include <osg/Geometry>
#include <osg/Texture2D>
#include <osg/TexEnv>
#include <osg/GLExtensions>
#include <osg/TexEnv>
#include <osgDB/ReadFile>
#include <osgViewer/Viewer>
osg::Geode *makeGalaxy(unsigned nvertices)
{
osg::Geode *geode = new osg::Geode();
osg::Geometry *galaxy = new osg::Geometry();
osg::Vec3Array *vertices = new osg::Vec3Array();
osg::Vec4Array *colors = new osg::Vec4Array();
osg::Vec4 ini(1,1,0,1);
osg::Vec4 fin(0,0,1,1);
/** Formula for the two spirals */
for (unsigned i=0;i<nvertices/2;i++) {
float val = (i*2/(float)nvertices * 2 * 3.14159265359);
float modx1 = rand() / (float)RAND_MAX*2;
float mody1 = rand() / (float)RAND_MAX*2;
float modx2 = rand() / (float)RAND_MAX*2;
float mody2 = rand() / (float)RAND_MAX*2;
float modz1 = ((rand()-RAND_MAX/2) / (float)(RAND_MAX))*3/(val+1);
float modz2 = ((rand()-RAND_MAX/2) / (float)(RAND_MAX))*3/(val+1);
vertices->push_back(osg::Vec3(cos(val)*val+modx1, sin(val)*val+mody1, modz1));
vertices->push_back(osg::Vec3(-cos(val)*val+modx2, -sin(val)*val+mody2, modz2));
colors->push_back(ini+(fin-ini)*(i*2/(float)nvertices));
colors->push_back(ini+(fin-ini)*(i*2/(float)nvertices));
}
galaxy->setVertexArray(vertices);
galaxy->setColorArray(colors, osg::Array::BIND_PER_VERTEX);
galaxy->addPrimitiveSet(new osg::DrawArrays(osg::PrimitiveSet::POINTS, 0, nvertices));
geode->addDrawable(galaxy);
return geode;
}
osg::StateSet* makeStateSet(float size)
{
osg::StateSet *set = new osg::StateSet();
/// Setup cool blending
set->setMode(GL_BLEND, osg::StateAttribute::ON);
osg::BlendFunc *fn = new osg::BlendFunc();
fn->setFunction(osg::BlendFunc::SRC_ALPHA, osg::BlendFunc::DST_ALPHA);
set->setAttributeAndModes(fn, osg::StateAttribute::ON);
/// Setup the point sprites
osg::PointSprite *sprite = new osg::PointSprite();
set->setTextureAttributeAndModes(0, sprite, osg::StateAttribute::ON);
/// Give some size to the points to be able to see the sprite
osg::Point *point = new osg::Point();
point->setSize(size);
set->setAttribute(point);
/// Disable depth test to avoid sort problems and Lighting
set->setMode(GL_DEPTH_TEST, osg::StateAttribute::OFF);
set->setMode(GL_LIGHTING, osg::StateAttribute::OFF);
/// The texture for the sprites
osg::Texture2D *tex = new osg::Texture2D();
tex->setImage(osgDB::readImageFile("Images/particle.rgb"));
set->setTextureAttributeAndModes(0, tex, osg::StateAttribute::ON);
return set;
}
int main(int, char *[])
{
osgViewer::Viewer viewer;
/// Make the galaxy of points
osg::Node *node = makeGalaxy(5000);
node->setStateSet(makeStateSet(10.0f));
viewer.setSceneData(node);
return viewer.run();
}
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