官方示例代码
/* -*-c++-*- */
/* osgEarth - Dynamic map generation toolkit for OpenSceneGraph
* Copyright 2016 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.
*
* 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.
*
* 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 <osg/Notify>
#include <osgGA/StateSetManipulator>
#include <osgViewer/Viewer>
#include <osgViewer/ViewerEventHandlers>
#include <osgEarth/Map>
#include <osgEarth/MapNode>
#include <osgEarth/ImageLayer>
#include <osgEarth/ModelLayer>
#include <osgEarthUtil/ExampleResources>
#include <osgEarthUtil/EarthManipulator>
#include <osgEarthUtil/AutoClipPlaneHandler>
#include <osgEarthSymbology/Style>
#include <osgEarthFeatures/FeatureModelLayer>
#include <osgEarthFeatures/ConvertTypeFilter>
#include <osgEarthDrivers/engine_rex/RexTerrainEngineOptions>
#include <osgEarthDrivers/gdal/GDALOptions>
#include <osgEarthDrivers/feature_ogr/OGRFeatureOptions>
#include <osgEarthDrivers/agglite/AGGLiteOptions>
#include <osgEarthDrivers/model_feature_geom/FeatureGeomModelOptions>
#include <osgDB/WriteFile>
using namespace osgEarth;
using namespace osgEarth::Features;
using namespace osgEarth::Drivers;
using namespace osgEarth::Symbology;
using namespace osgEarth::Util;
int usage(const std::string& app)
{
OE_NOTICE "\n" << app << "\n"
<< " --rasterize : draw features as rasterized image tiles \n"
<< " --overlay : draw features as projection texture \n"
<< " --mem : load features from memory \n"
<< " --labels : add feature labels \n"
<< "\n"
<< MapNodeHelper().usage();
return -1;
}
//
// NOTE: run this sample from the repo/tests directory.
//
int main(int argc, char** argv)
{
osg::ArgumentParser arguments(&argc, argv);
if (arguments.read("--help"))
return usage(argv[0]);
bool useRaster = arguments.read("--rasterize");
bool useOverlay = arguments.read("--overlay");
bool useMem = arguments.read("--mem");
bool useLabels = arguments.read("--labels");
osgViewer::Viewer viewer(arguments);
// Start by creating the map:
Map* map = new Map();
// Start with a basemap imagery layer; we'll be using the GDAL driver
// to load a local GeoTIFF file:
GDALOptions basemap;
basemap.url() = "E:/temp/OE/data/world.tif";
map->addLayer(new ImageLayer(ImageLayerOptions("basemap", basemap)));
// Next we add a feature layer.
OGRFeatureOptions ogrData;
if (!useMem)
{
// Configures the feature driver to load the vectors from a shapefile:
ogrData.url() = "E:/temp/OE/data/world.shp";
}
else
{
// the --mem options tells us to just make an in-memory geometry:
Ring* line = new Ring();
line->push_back(osg::Vec3d(-60, 20, 0));
line->push_back(osg::Vec3d(-120, 20, 0));
line->push_back(osg::Vec3d(-120, 60, 0));
line->push_back(osg::Vec3d(-60, 60, 0));
ogrData.geometry() = line;
}
// Make a feature source layer and add it to the Map:
FeatureSourceLayerOptions ogrLayer;
ogrLayer.name() = "vector-data";
ogrLayer.featureSource() = ogrData;
map->addLayer(new FeatureSourceLayer(ogrLayer));
// Define a style for the feature data. Since we are going to render the
// vectors as lines, configure the line symbolizer:
Style style;
LineSymbol* ls = style.getOrCreateSymbol<LineSymbol>();
ls->stroke()->color() = Color::Yellow;
ls->stroke()->width() = 2.0f;
// That's it, the map is ready; now create a MapNode to render the Map:
osgEarth::Drivers::RexTerrainEngine::RexTerrainEngineOptions rex;
MapNodeOptions mapNodeOptions;
mapNodeOptions.enableLighting() = false;
mapNodeOptions.setTerrainOptions(rex);
MapNode* mapNode = new MapNode(map, mapNodeOptions);
osg::Group* root = new osg::Group();
root->addChild(mapNode);
viewer.setSceneData(root);
viewer.setCameraManipulator(new EarthManipulator());
// Process cmdline args
MapNodeHelper().parse(mapNode, arguments, &viewer, root, new LabelControl("Features Demo"));
if (useRaster)
{
AGGLiteOptions rasterOptions;
rasterOptions.featureOptions() = ogrData;
rasterOptions.styles() = new StyleSheet();
rasterOptions.styles()->addStyle(style);
map->addLayer(new ImageLayer("My Features", rasterOptions));
}
else //if (useGeom || useOverlay)
{
FeatureModelLayerOptions fml;
fml.name() = "My Features";
fml.featureSourceLayer() = "vector-data";
fml.styles() = new StyleSheet();
fml.styles()->addStyle(style);
fml.enableLighting() = false;
map->addLayer(new FeatureModelLayer(fml));
}
if (useLabels)
{
// set up symbology for drawing labels. We're pulling the label
// text from the name attribute, and its draw priority from the
// population attribute.
Style labelStyle;
TextSymbol* text = labelStyle.getOrCreateSymbol<TextSymbol>();
text->content() = StringExpression("[cntry_name]");
text->priority() = NumericExpression("[pop_cntry]");
text->size() = 16.0f;
text->alignment() = TextSymbol::ALIGN_CENTER_CENTER;
text->fill()->color() = Color::White;
text->halo()->color() = Color::DarkGray;
// and configure a model layer:
FeatureModelLayerOptions fml;
fml.name() = "Labels";
fml.featureSourceLayer() = "vector-data";
//fml.featureSource() = featureOptions;
fml.styles() = new StyleSheet();
fml.styles()->addStyle(labelStyle);
map->addLayer(new FeatureModelLayer(fml));
}
// add some stock OSG handlers:
viewer.addEventHandler(new osgViewer::StatsHandler());
viewer.addEventHandler(new osgViewer::WindowSizeHandler());
viewer.addEventHandler(new osgGA::StateSetManipulator(viewer.getCamera()->getOrCreateStateSet()));
osg::ref_ptr<osg::GraphicsContext::Traits> traits = new osg::GraphicsContext::Traits;
traits->x = 200;
traits->y = 200;
traits->width = 800;
traits->height = 680;
traits->windowDecoration = true;
traits->doubleBuffer = true;
traits->sharedContext = 0;
osg::ref_ptr<osg::GraphicsContext> gc = osg::GraphicsContext::createGraphicsContext(traits.get());
osg::ref_ptr<osg::Camera> camera = new osg::Camera;
camera->setGraphicsContext(gc.get());
camera->setViewport(new osg::Viewport(0, 0, traits->width, traits->height));
GLenum buffer = traits->doubleBuffer ? GL_BACK : GL_FRONT;
camera->setDrawBuffer(buffer);
camera->setReadBuffer(buffer);
viewer.addSlave(camera);
return viewer.run();
}