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