final.

gistfile1.cpp

/* -*-c++-*- */
/* osgEarth - Dynamic map generation toolkit for OpenSceneGraph
* Copyright 2008-2014 Pelican Mapping
* http://osgearth.org
*
* osgEarth is free software; you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program.  If not, see <http://www.gnu.org/licenses/>
*/

#include <osgViewer/Viewer>
#include <osgEarth/Notify>
#include <osgEarthUtil/EarthManipulator>
#include <osgEarthUtil/ExampleResources>
#include <osgEarth/ShaderLoader>
#include <osgEarth/VirtualProgram>
#include <osg/Uniform>

const char* vs = OE_MULTILINE(
    #pragma vp_entryPoint "oe_grid_vertex"\n
    #pragma vp_location   "vertex_view"\n

    uniform vec4 oe_tile_key;
    varying vec4 oe_layer_tilec;
    varying vec2 oe_grid_coord;

    void oe_grid_vertex(inout vec4 vertex)
    {
        // calculate long and lat from [0..1] across the profile:
        vec2 r = (oe_tile_key.xy + oe_layer_tilec.xy)/exp2(oe_tile_key.z);
        oe_grid_coord = vec2(0.5*r.x, r.y);
    }
);

const char* fs = OE_MULTILINE(
    #pragma vp_entryPoint "oe_grid_fragment"\n
    #pragma vp_location   "fragment_coloring"\n
    uniform float gridLineWidth;
    uniform float gridResolution;
    uniform float gridAlpha;
    varying vec2 oe_grid_coord;
    void oe_grid_fragment(inout vec4 color)
    {
        // double the effective res for longitude since it has twice the span
        vec2 gr = vec2(0.5*gridResolution, gridResolution);
        vec2 distanceToLine = mod(oe_grid_coord, gr);
        vec2 dx = abs(dFdx(oe_grid_coord));
        vec2 dy = abs(dFdy(oe_grid_coord));
        vec2 dF = vec2(max(dx.s, dy.s), max(dx.t, dy.t)) * gridLineWidth;
        
        if ( any(lessThan(distanceToLine, dF)) )
        {
            color.rgb = mix(color.rgb, vec3(1,1,0), gridAlpha);
        }
    }
);


#define LC "[viewer] "

using namespace osgEarth;
using namespace osgEarth::Util;

int
usage(const char* name)
{
    OE_NOTICE 
        << "\nUsage: " << name << " file.earth" << std::endl
        << MapNodeHelper().usage() << std::endl;

    return 0;
}

int
main(int argc, char** argv)
{
    osg::ArgumentParser arguments(&argc,argv);

    // help?
    if ( arguments.read("--help") )
        return usage(argv[0]);

    if ( arguments.read("--stencil") )
        osg::DisplaySettings::instance()->setMinimumNumStencilBits( 8 );

    // create a viewer:
    osgViewer::Viewer viewer(arguments);

    // Tell the database pager to not modify the unref settings
    viewer.getDatabasePager()->setUnrefImageDataAfterApplyPolicy( false, false );

    // install our default manipulator (do this before calling load)
    viewer.setCameraManipulator( new EarthManipulator() );

    // load an earth file, and support all or our example command-line options
    // and earth file <external> tags    
    osg::Node* node = MapNodeHelper().load( arguments, &viewer );
    if ( node )
    {
        viewer.setSceneData( node );

        osg::StateSet* ss = MapNode::get(node)->getTerrainEngine()->getOrCreateStateSet();
        VirtualProgram* vp = VirtualProgram::getOrCreate(ss);

        ShaderPackage sp;
        sp.add( "Vertex", vs );
        sp.add( "Fragment", fs );
        sp.loadFunction( vp, "Vertex" );
        sp.loadFunction( vp, "Fragment" );

        const SpatialReference* srs = SpatialReference::get("wgs84");
        osg::Vec3f escale(
            1.0/srs->getEllipsoid()->getRadiusEquator(),
            1.0/srs->getEllipsoid()->getRadiusEquator(),
            1.0/srs->getEllipsoid()->getRadiusPolar());

        ss->addUniform(new osg::Uniform("oe_grid_ellipsoidScale", escale));
        ss->addUniform(new osg::Uniform("gridLineWidth", 3.0f));
        ss->addUniform(new osg::Uniform("gridResolution", 0.125f));
        ss->addUniform(new osg::Uniform("gridAlpha", 0.5f));

        //viewer.getCamera()->setNearFarRatio(0.00002);
        viewer.getCamera()->setSmallFeatureCullingPixelSize(-1.0f);

        return viewer.run();
    }
    else
    {
        return usage(argv[0]);
    }
}