simgear/scene/tgdb/ReaderWriterSPT.cxx

   1 // ReaderWriterSPT.cxx -- Provide a paged database for flightgear scenery.
   2 //
   3 // Copyright (C) 2010 - 2011  Mathias Froehlich
   4 //
   5 // This program is free software; you can redistribute it and/or
   6 // modify it under the terms of the GNU General Public License as
   7 // published by the Free Software Foundation; either version 2 of the
   8 // License, or (at your option) any later version.
   9 //
  10 // This program is distributed in the hope that it will be useful, but
  11 // WITHOUT ANY WARRANTY; without even the implied warranty of
  12 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13 // General Public License for more details.
  14 //
  15 // You should have received a copy of the GNU General Public License
  16 // along with this program; if not, write to the Free Software
  17 // Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  18 //
  19
  20 #ifdef HAVE_CONFIG_H
  21 #  include <simgear_config.h>
  22 #endif
  23
  24 #include "ReaderWriterSPT.hxx"
  25
  26 #include <cassert>
  27
  28 #include <osg/CullFace>
  29 #include <osg/PagedLOD>
  30 #include <osg/Texture2D>
  31
  32 #include <osgDB/FileNameUtils>
  33 #include <osgDB/ReadFile>
  34
  35 #include "BucketBox.hxx"
  36
  37 namespace simgear {
  38
  39 ReaderWriterSPT::ReaderWriterSPT()
  40 {
  41     supportsExtension("spt", "SimGear paged terrain meta database.");
  42 }
  43
  44 ReaderWriterSPT::~ReaderWriterSPT()
  45 {
  46 }
  47
  48 const char*
  49 ReaderWriterSPT::className() const
  50 {
  51     return "simgear::ReaderWriterSPT";
  52 }
  53
  54 osgDB::ReaderWriter::ReadResult
  55 ReaderWriterSPT::readObject(const std::string& fileName, const osgDB::Options* options) const
  56 {
  57     if (fileName != "state.spt")
  58         return ReadResult(osgDB::ReaderWriter::ReadResult::FILE_NOT_FOUND);
  59
  60     osg::StateSet* stateSet = new osg::StateSet;
  61     stateSet->setAttributeAndModes(new osg::CullFace);
  62
  63     std::string imageFileName = options->getPluginStringData("SimGear::FG_WORLD_TEXTURE");
  64     if (osg::Image* image = osgDB::readImageFile(imageFileName, options)) {
  65         osg::Texture2D* texture = new osg::Texture2D;
  66         texture->setImage(image);
  67         texture->setWrap(osg::Texture2D::WRAP_S, osg::Texture2D::REPEAT);
  68         texture->setWrap(osg::Texture2D::WRAP_T, osg::Texture2D::CLAMP);
  69         stateSet->setTextureAttributeAndModes(0, texture);
  70     }
  71
  72     return stateSet;
  73 }
  74
  75 osgDB::ReaderWriter::ReadResult
  76 ReaderWriterSPT::readNode(const std::string& fileName, const osgDB::Options* options) const
  77 {
  78     // The file name without path and without the spt extension
  79     std::string strippedFileName = osgDB::getStrippedName(fileName);
  80     if (strippedFileName == "earth")
  81         return createTree(BucketBox(0, -90, 360, 180), options, true);
  82
  83     std::stringstream ss(strippedFileName);
  84     BucketBox bucketBox;
  85     ss >> bucketBox;
  86     if (ss.fail())
  87         return osgDB::ReaderWriter::ReadResult::FILE_NOT_FOUND;
  88
  89     BucketBox bucketBoxList[2];
  90     unsigned bucketBoxListSize = bucketBox.periodicSplit(bucketBoxList);
  91     if (bucketBoxListSize == 0)
  92         return osgDB::ReaderWriter::ReadResult::FILE_NOT_FOUND;
  93
  94     if (bucketBoxListSize == 1)
  95         return createTree(bucketBoxList[0], options, true);
  96
  97     assert(bucketBoxListSize == 2);
  98     osg::ref_ptr<osg::Group> group = new osg::Group;
  99     group->addChild(createTree(bucketBoxList[0], options, true));
 100     group->addChild(createTree(bucketBoxList[1], options, true));
 101     return group.release();
 102 }
 103
 104 osg::Node*
 105 ReaderWriterSPT::createTree(const BucketBox& bucketBox, const osgDB::Options* options, bool topLevel) const
 106 {
 107     if (bucketBox.getIsBucketSize()) {
 108         return createPagedLOD(bucketBox, options);
 109     } else if (!topLevel && bucketBox.getStartLevel() == 4) {
 110         // We want an other level of indirection for paging
 111         return createPagedLOD(bucketBox, options);
 112     } else {
 113         BucketBox bucketBoxList[100];
 114         unsigned numTiles = bucketBox.getSubDivision(bucketBoxList, 100);
 115         if (numTiles == 0)
 116             return 0;
 117
 118         if (numTiles == 1)
 119             return createTree(bucketBoxList[0], options, false);
 120
 121         osg::ref_ptr<osg::Group> group = new osg::Group;
 122         for (unsigned i = 0; i < numTiles; ++i) {
 123             osg::Node* node = createTree(bucketBoxList[i], options, false);
 124             if (!node)
 125                 continue;
 126             group->addChild(node);
 127         }
 128         if (!group->getNumChildren())
 129             return 0;
 130
 131         return group.release();
 132     }
 133 }
 134
 135 osg::Node*
 136 ReaderWriterSPT::createPagedLOD(const BucketBox& bucketBox, const osgDB::Options* options) const
 137 {
 138     osg::PagedLOD* pagedLOD = new osg::PagedLOD;
 139
 140     pagedLOD->setCenterMode(osg::PagedLOD::USER_DEFINED_CENTER);
 141     SGSpheref sphere = bucketBox.getBoundingSphere();
 142     pagedLOD->setCenter(toOsg(sphere.getCenter()));
 143     pagedLOD->setRadius(sphere.getRadius());
 144
 145     osg::ref_ptr<osgDB::Options> localOptions;
 146     localOptions = static_cast<osgDB::Options*>(options->clone(osg::CopyOp()));
 147     pagedLOD->setDatabaseOptions(localOptions.get());
 148
 149     float range;
 150     if (bucketBox.getIsBucketSize())
 151         range = 200e3;
 152     else
 153         range = 1e6;
 154
 155     // Add the static sea level textured shell
 156     if (osg::Node* tile = createSeaLevelTile(bucketBox, options))
 157         pagedLOD->addChild(tile, range, std::numeric_limits<float>::max());
 158
 159     // Add the paged file name that creates the subtrees on demand
 160     if (bucketBox.getIsBucketSize()) {
 161         std::string fileName;
 162         fileName = bucketBox.getBucket().gen_index_str() + std::string(".stg");
 163         pagedLOD->setFileName(pagedLOD->getNumChildren(), fileName);
 164     } else {
 165         std::stringstream ss;
 166         ss << bucketBox << ".spt";
 167         pagedLOD->setFileName(pagedLOD->getNumChildren(), ss.str());
 168     }
 169     pagedLOD->setRange(pagedLOD->getNumChildren(), 0.0, range);
 170
 171     return pagedLOD;
 172 }
 173
 174 osg::Node*
 175 ReaderWriterSPT::createSeaLevelTile(const BucketBox& bucketBox, const osgDB::Options* options) const
 176 {
 177     if (options->getPluginStringData("SimGear::FG_EARTH") != "ON")
 178         return 0;
 179
 180     osg::Vec3Array* vertices = new osg::Vec3Array;
 181     osg::Vec3Array* normals = new osg::Vec3Array;
 182     osg::Vec2Array* texCoords = new osg::Vec2Array;
 183
 184     unsigned widthLevel = bucketBox.getWidthLevel();
 185     unsigned heightLevel = bucketBox.getHeightLevel();
 186
 187     unsigned incx = bucketBox.getWidthIncrement(widthLevel + 2);
 188     incx = std::min(incx, bucketBox.getSize(0));
 189     for (unsigned i = 0; incx != 0;) {
 190         unsigned incy = bucketBox.getHeightIncrement(heightLevel + 2);
 191         incy = std::min(incy, bucketBox.getSize(1));
 192         for (unsigned j = 0; incy != 0;) {
 193             SGVec3f v[6], n[6];
 194             SGVec2f t[6];
 195             unsigned num = bucketBox.getTileTriangles(i, j, incx, incy, v, n, t);
 196             for (unsigned k = 0; k < num; ++k) {
 197                 vertices->push_back(toOsg(v[k]));
 198                 normals->push_back(toOsg(n[k]));
 199                 texCoords->push_back(toOsg(t[k]));
 200             }
 201             j += incy;
 202             incy = std::min(incy, bucketBox.getSize(1) - j);
 203         }
 204         i += incx;
 205         incx = std::min(incx, bucketBox.getSize(0) - i);
 206     }
 207
 208     osg::Vec4Array* colors = new osg::Vec4Array;
 209     colors->push_back(osg::Vec4(1, 1, 1, 1));
 210
 211     osg::Geometry* geometry = new osg::Geometry;
 212     geometry->setVertexArray(vertices);
 213     geometry->setNormalArray(normals);
 214     geometry->setNormalBinding(osg::Geometry::BIND_PER_VERTEX);
 215     geometry->setColorArray(colors);
 216     geometry->setColorBinding(osg::Geometry::BIND_OVERALL);
 217     geometry->setTexCoordArray(0, texCoords);
 218
 219     geometry->addPrimitiveSet(new osg::DrawArrays(osg::DrawArrays::TRIANGLES, 0, vertices->size()));
 220
 221     osg::Geode* geode = new osg::Geode;
 222     geode->addDrawable(geometry);
 223     geode->setStateSet(getLowLODStateSet(options));
 224
 225     return geode;
 226 }
 227
 228 osg::StateSet*
 229 ReaderWriterSPT::getLowLODStateSet(const osgDB::Options* options) const
 230 {
 231     osg::ref_ptr<osgDB::Options> localOptions;
 232     localOptions = static_cast<osgDB::Options*>(options->clone(osg::CopyOp()));
 233     localOptions->setObjectCacheHint(osgDB::Options::CACHE_ALL);
 234
 235     osg::ref_ptr<osg::Object> object = osgDB::readObjectFile("state.spt", localOptions.get());
 236     if (!dynamic_cast<osg::StateSet*>(object.get()))
 237         return 0;
 238
 239     return static_cast<osg::StateSet*>(object.release());
 240 }
 241
 242 } // namespace simgear
 243