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 <simgear/scene/util/OsgMath.hxx>
  36
  37 #include "BucketBox.hxx"
  38
  39 namespace simgear {
  40
  41 ReaderWriterSPT::ReaderWriterSPT()
  42 {
  43     supportsExtension("spt", "SimGear paged terrain meta database.");
  44 }
  45
  46 ReaderWriterSPT::~ReaderWriterSPT()
  47 {
  48 }
  49
  50 const char*
  51 ReaderWriterSPT::className() const
  52 {
  53     return "simgear::ReaderWriterSPT";
  54 }
  55
  56 osgDB::ReaderWriter::ReadResult
  57 ReaderWriterSPT::readObject(const std::string& fileName, const osgDB::Options* options) const
  58 {
  59     // We get called with different extensions. To make sure search continues,
  60     // we need to return FILE_NOT_HANDLED in this case.
  61     if (osgDB::getLowerCaseFileExtension(fileName) != "spt")
  62         return ReadResult(osgDB::ReaderWriter::ReadResult::FILE_NOT_HANDLED);
  63     if (fileName != "state.spt")
  64         return ReadResult(osgDB::ReaderWriter::ReadResult::FILE_NOT_FOUND);
  65
  66     osg::StateSet* stateSet = new osg::StateSet;
  67     stateSet->setAttributeAndModes(new osg::CullFace);
  68
  69     std::string imageFileName = options->getPluginStringData("SimGear::FG_WORLD_TEXTURE");
  70     if (osg::Image* image = osgDB::readImageFile(imageFileName, options)) {
  71         osg::Texture2D* texture = new osg::Texture2D;
  72         texture->setImage(image);
  73         texture->setWrap(osg::Texture2D::WRAP_S, osg::Texture2D::REPEAT);
  74         texture->setWrap(osg::Texture2D::WRAP_T, osg::Texture2D::CLAMP);
  75         stateSet->setTextureAttributeAndModes(0, texture);
  76     }
  77
  78     return stateSet;
  79 }
  80
  81 osgDB::ReaderWriter::ReadResult
  82 ReaderWriterSPT::readNode(const std::string& fileName, const osgDB::Options* options) const
  83 {
  84     // The file name without path and without the spt extension
  85     std::string strippedFileName = osgDB::getStrippedName(fileName);
  86     if (strippedFileName == "earth")
  87         return createTree(BucketBox(0, -90, 360, 180), options, true);
  88
  89     std::stringstream ss(strippedFileName);
  90     BucketBox bucketBox;
  91     ss >> bucketBox;
  92     if (ss.fail())
  93         return osgDB::ReaderWriter::ReadResult::FILE_NOT_FOUND;
  94
  95     BucketBox bucketBoxList[2];
  96     unsigned bucketBoxListSize = bucketBox.periodicSplit(bucketBoxList);
  97     if (bucketBoxListSize == 0)
  98         return osgDB::ReaderWriter::ReadResult::FILE_NOT_FOUND;
  99
 100     if (bucketBoxListSize == 1)
 101         return createTree(bucketBoxList[0], options, true);
 102
 103     assert(bucketBoxListSize == 2);
 104     osg::ref_ptr<osg::Group> group = new osg::Group;
 105     group->addChild(createTree(bucketBoxList[0], options, true));
 106     group->addChild(createTree(bucketBoxList[1], options, true));
 107     return group.release();
 108 }
 109
 110 osg::Node*
 111 ReaderWriterSPT::createTree(const BucketBox& bucketBox, const osgDB::Options* options, bool topLevel) const
 112 {
 113     if (bucketBox.getIsBucketSize()) {
 114         return createPagedLOD(bucketBox, options);
 115     } else if (!topLevel && bucketBox.getStartLevel() == 4) {
 116         // We want an other level of indirection for paging
 117         return createPagedLOD(bucketBox, options);
 118     } else {
 119         BucketBox bucketBoxList[100];
 120         unsigned numTiles = bucketBox.getSubDivision(bucketBoxList, 100);
 121         if (numTiles == 0)
 122             return 0;
 123
 124         if (numTiles == 1)
 125             return createTree(bucketBoxList[0], options, false);
 126
 127         osg::ref_ptr<osg::Group> group = new osg::Group;
 128         for (unsigned i = 0; i < numTiles; ++i) {
 129             osg::Node* node = createTree(bucketBoxList[i], options, false);
 130             if (!node)
 131                 continue;
 132             group->addChild(node);
 133         }
 134         if (!group->getNumChildren())
 135             return 0;
 136
 137         return group.release();
 138     }
 139 }
 140
 141 osg::Node*
 142 ReaderWriterSPT::createPagedLOD(const BucketBox& bucketBox, const osgDB::Options* options) const
 143 {
 144     osg::PagedLOD* pagedLOD = new osg::PagedLOD;
 145
 146     pagedLOD->setCenterMode(osg::PagedLOD::USER_DEFINED_CENTER);
 147     SGSpheref sphere = bucketBox.getBoundingSphere();
 148     pagedLOD->setCenter(toOsg(sphere.getCenter()));
 149     pagedLOD->setRadius(sphere.getRadius());
 150
 151     osg::ref_ptr<osgDB::Options> localOptions;
 152     localOptions = static_cast<osgDB::Options*>(options->clone(osg::CopyOp()));
 153     pagedLOD->setDatabaseOptions(localOptions.get());
 154
 155     float range;
 156     if (bucketBox.getIsBucketSize())
 157         range = 200e3;
 158     else
 159         range = 1e6;
 160
 161     // Add the static sea level textured shell
 162     if (osg::Node* tile = createSeaLevelTile(bucketBox, options))
 163         pagedLOD->addChild(tile, range, std::numeric_limits<float>::max());
 164
 165     // Add the paged file name that creates the subtrees on demand
 166     if (bucketBox.getIsBucketSize()) {
 167         std::string fileName;
 168         fileName = bucketBox.getBucket().gen_index_str() + std::string(".stg");
 169         pagedLOD->setFileName(pagedLOD->getNumChildren(), fileName);
 170     } else {
 171         std::stringstream ss;
 172         ss << bucketBox << ".spt";
 173         pagedLOD->setFileName(pagedLOD->getNumChildren(), ss.str());
 174     }
 175     pagedLOD->setRange(pagedLOD->getNumChildren(), 0.0, range);
 176
 177     return pagedLOD;
 178 }
 179
 180 osg::Node*
 181 ReaderWriterSPT::createSeaLevelTile(const BucketBox& bucketBox, const osgDB::Options* options) const
 182 {
 183     if (options->getPluginStringData("SimGear::FG_EARTH") != "ON")
 184         return 0;
 185
 186     osg::Vec3Array* vertices = new osg::Vec3Array;
 187     osg::Vec3Array* normals = new osg::Vec3Array;
 188     osg::Vec2Array* texCoords = new osg::Vec2Array;
 189
 190     unsigned widthLevel = bucketBox.getWidthLevel();
 191     unsigned heightLevel = bucketBox.getHeightLevel();
 192
 193     unsigned incx = bucketBox.getWidthIncrement(widthLevel + 2);
 194     incx = std::min(incx, bucketBox.getSize(0));
 195     for (unsigned i = 0; incx != 0;) {
 196         unsigned incy = bucketBox.getHeightIncrement(heightLevel + 2);
 197         incy = std::min(incy, bucketBox.getSize(1));
 198         for (unsigned j = 0; incy != 0;) {
 199             SGVec3f v[6], n[6];
 200             SGVec2f t[6];
 201             unsigned num = bucketBox.getTileTriangles(i, j, incx, incy, v, n, t);
 202             for (unsigned k = 0; k < num; ++k) {
 203                 vertices->push_back(toOsg(v[k]));
 204                 normals->push_back(toOsg(n[k]));
 205                 texCoords->push_back(toOsg(t[k]));
 206             }
 207             j += incy;
 208             incy = std::min(incy, bucketBox.getSize(1) - j);
 209         }
 210         i += incx;
 211         incx = std::min(incx, bucketBox.getSize(0) - i);
 212     }
 213
 214     osg::Vec4Array* colors = new osg::Vec4Array;
 215     colors->push_back(osg::Vec4(1, 1, 1, 1));
 216
 217     osg::Geometry* geometry = new osg::Geometry;
 218     geometry->setVertexArray(vertices);
 219     geometry->setNormalArray(normals);
 220     geometry->setNormalBinding(osg::Geometry::BIND_PER_VERTEX);
 221     geometry->setColorArray(colors);
 222     geometry->setColorBinding(osg::Geometry::BIND_OVERALL);
 223     geometry->setTexCoordArray(0, texCoords);
 224
 225     geometry->addPrimitiveSet(new osg::DrawArrays(osg::DrawArrays::TRIANGLES, 0, vertices->size()));
 226
 227     osg::Geode* geode = new osg::Geode;
 228     geode->addDrawable(geometry);
 229     geode->setStateSet(getLowLODStateSet(options));
 230
 231     return geode;
 232 }
 233
 234 osg::StateSet*
 235 ReaderWriterSPT::getLowLODStateSet(const osgDB::Options* options) const
 236 {
 237     osg::ref_ptr<osgDB::Options> localOptions;
 238     localOptions = static_cast<osgDB::Options*>(options->clone(osg::CopyOp()));
 239     localOptions->setObjectCacheHint(osgDB::Options::CACHE_ALL);
 240
 241     osg::ref_ptr<osg::Object> object = osgDB::readObjectFile("state.spt", localOptions.get());
 242     if (!dynamic_cast<osg::StateSet*>(object.get()))
 243         return 0;
 244
 245     return static_cast<osg::StateSet*>(object.release());
 246 }
 247
 248 } // namespace simgear
 249