3 * Copyright (C) 2008 Stuart Buchanan
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.
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.
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,
23 # include <simgear_config.h>
31 #include <boost/tuple/tuple_comparison.hpp>
34 #include <osg/Geometry>
36 #include <osg/MatrixTransform>
38 #include <osg/NodeVisitor>
40 #include <osgDB/ReadFile>
41 #include <osgDB/FileUtils>
43 #include <simgear/debug/logstream.hxx>
44 #include <simgear/math/sg_random.h>
45 #include <simgear/misc/sg_path.hxx>
46 #include <simgear/scene/material/Effect.hxx>
47 #include <simgear/scene/material/EffectGeode.hxx>
48 #include <simgear/props/props.hxx>
49 #include <simgear/scene/util/QuadTreeBuilder.hxx>
50 #include <simgear/scene/util/RenderConstants.hxx>
51 #include <simgear/scene/util/StateAttributeFactory.hxx>
52 #include <simgear/structure/OSGUtils.hxx>
54 #include "ShaderGeometry.hxx"
55 #include "TreeBin.hxx"
57 #define SG_TREE_QUAD_TREE_DEPTH 3
58 #define SG_TREE_FADE_OUT_LEVELS 10
65 // Tree instance scheme:
66 // vertex - local position of quad vertex.
67 // normal - x y scaling, z number of varieties
68 // fog coord - rotation
69 // color - xyz of tree quad origin, replicated 4 times.
71 // The tree quad is rendered twice, with different rotations, to
72 // create the crossed tree geometry.
74 struct TreesBoundingBoxCallback : public Drawable::ComputeBoundingBoxCallback
76 TreesBoundingBoxCallback() {}
77 TreesBoundingBoxCallback(const TreesBoundingBoxCallback&, const CopyOp&) {}
78 META_Object(simgear, TreesBoundingBoxCallback);
79 virtual BoundingBox computeBound(const Drawable&) const;
83 TreesBoundingBoxCallback::computeBound(const Drawable& drawable) const
86 const Geometry* geom = static_cast<const Geometry*>(&drawable);
87 const Vec3Array* v = static_cast<const Vec3Array*>(geom->getVertexArray());
88 const Vec3Array* pos = static_cast<const Vec3Array*>(geom->getColorArray());
89 const Vec3Array* params
90 = static_cast<const Vec3Array*>(geom->getNormalArray());
92 = static_cast<const FloatArray*>(geom->getFogCoordArray());
93 float w = (*params)[0].x();
94 float h = (*params)[0].y();
95 Geometry::PrimitiveSetList primSets = geom->getPrimitiveSetList();
96 FloatArray::const_iterator rotitr = rot->begin();
97 for (Geometry::PrimitiveSetList::const_iterator psitr = primSets.begin(),
98 psend = primSets.end();
101 Matrixd trnsfrm = (Matrixd::scale(w, w, h)
102 * Matrixd::rotate(*rotitr, Vec3(0.0f, 0.0f, 1.0f)));
103 DrawArrays* da = static_cast<DrawArrays*>(psitr->get());
104 GLint psFirst = da->getFirst();
105 GLint psEndVert = psFirst + da->getCount();
106 for (GLint i = psFirst;i < psEndVert; ++i) {
116 Geometry* makeSharedTreeGeometry(int numQuads)
118 // generate a repeatable random seed
120 mt_init(&seed, unsigned(123));
122 osg::Vec3Array* v = new osg::Vec3Array;
123 osg::Vec2Array* t = new osg::Vec2Array;
124 v->reserve(numQuads * 4);
125 t->reserve(numQuads * 4);
126 for (int i = 0; i < numQuads; ++i) {
127 // Apply a random scaling factor and texture index.
128 float h = (mt_rand(&seed) + mt_rand(&seed)) / 2.0f + 0.5f;
130 v->push_back(Vec3(0.0f, -cw, 0.0f));
131 v->push_back(Vec3(0.0f, cw, 0.0f));
132 v->push_back(Vec3(0.0f, cw, h));
133 v->push_back(Vec3(0.0f,-cw, h));
134 // The texture coordinate range is not the entire coordinate
135 // space, as the texture has a number of different trees on
136 // it. Here we assign random coordinates and let the shader
137 // choose the variety.
138 float variety = mt_rand(&seed);
139 t->push_back(Vec2(variety, 0.0f));
140 t->push_back(Vec2(variety + 1.0f, 0.0f));
141 t->push_back(Vec2(variety + 1.0f, 0.234f));
142 t->push_back(Vec2(variety, 0.234f));
144 Geometry* result = new Geometry;
145 result->setVertexArray(v);
146 result->setTexCoordArray(0, t);
147 result->setComputeBoundingBoxCallback(new TreesBoundingBoxCallback);
148 result->setUseDisplayList(false);
152 ref_ptr<Geometry> sharedTreeGeometry;
154 Geometry* createTreeGeometry(float width, float height, int varieties)
156 if (!sharedTreeGeometry)
157 sharedTreeGeometry = makeSharedTreeGeometry(1600);
158 Geometry* quadGeom = simgear::clone(sharedTreeGeometry.get(),
159 CopyOp::SHALLOW_COPY);
160 Vec3Array* params = new Vec3Array;
161 params->push_back(Vec3(width, height, (float)varieties));
162 quadGeom->setNormalArray(params);
163 quadGeom->setNormalBinding(Geometry::BIND_OVERALL);
165 quadGeom->setColorArray(new Vec3Array);
166 quadGeom->setColorBinding(Geometry::BIND_PER_VERTEX);
167 FloatArray* rotation = new FloatArray(2);
168 (*rotation)[0] = 0.0;
169 (*rotation)[1] = PI_2;
170 quadGeom->setFogCoordArray(rotation);
171 quadGeom->setFogCoordBinding(Geometry::BIND_PER_PRIMITIVE_SET);
172 // The primitive sets render the same geometry, but the second
173 // will rotated 90 degrees by the vertex shader, which uses the
174 // fog coordinate as a rotation.
175 for (int i = 0; i < 2; ++i)
176 quadGeom->addPrimitiveSet(new DrawArrays(PrimitiveSet::QUADS));
180 EffectGeode* createTreeGeode(float width, float height, int varieties)
182 EffectGeode* result = new EffectGeode;
183 result->addDrawable(createTreeGeometry(width, height, varieties));
187 void addTreeToLeafGeode(Geode* geode, const SGVec3f& p)
190 unsigned int numDrawables = geode->getNumDrawables();
192 = static_cast<Geometry*>(geode->getDrawable(numDrawables - 1));
193 Vec3Array* posArray = static_cast<Vec3Array*>(geom->getColorArray());
195 >= static_cast<Vec3Array*>(geom->getVertexArray())->size()) {
196 Vec3Array* paramsArray
197 = static_cast<Vec3Array*>(geom->getNormalArray());
198 Vec3 params = (*paramsArray)[0];
199 geom = createTreeGeometry(params.x(), params.y(), params.z());
200 posArray = static_cast<Vec3Array*>(geom->getColorArray());
201 geode->addDrawable(geom);
203 posArray->insert(posArray->end(), 4, pos);
204 size_t numVerts = posArray->size();
205 for (int i = 0; i < 2; ++i) {
207 = static_cast<DrawArrays*>(geom->getPrimitiveSet(i));
208 primSet->setCount(numVerts);
212 typedef std::map<std::string, osg::observer_ptr<Effect> > EffectMap;
214 static EffectMap treeEffectMap;
216 // Helper classes for creating the quad tree
221 MakeTreesLeaf(float range, int varieties, float width, float height,
223 _range(range), _varieties(varieties),
224 _width(width), _height(height), _effect(effect) {}
226 MakeTreesLeaf(const MakeTreesLeaf& rhs) :
228 _varieties(rhs._varieties), _width(rhs._width), _height(rhs._height),
232 LOD* operator() () const
234 LOD* result = new LOD;
236 // Create a series of LOD nodes so trees cover decreases slightly
237 // gradually with distance from _range to 2*_range
238 for (float i = 0.0; i < SG_TREE_FADE_OUT_LEVELS; i++)
240 EffectGeode* geode = createTreeGeode(_width, _height, _varieties);
241 geode->setEffect(_effect.get());
242 result->addChild(geode, 0, _range * (1.0 + i / (SG_TREE_FADE_OUT_LEVELS - 1.0)));
250 ref_ptr<Effect> _effect;
253 struct AddTreesLeafObject
255 void operator() (LOD* lod, const TreeBin::Tree& tree) const
257 Geode* geode = static_cast<Geode*>(lod->getChild(int(tree.position.x() * 10.0f) % lod->getNumChildren()));
258 addTreeToLeafGeode(geode, tree.position);
264 Vec3 operator() (const TreeBin::Tree& tree) const
266 return toOsg(tree.position);
270 typedef QuadTreeBuilder<LOD*, TreeBin::Tree, MakeTreesLeaf, AddTreesLeafObject,
271 GetTreeCoord> ShaderGeometryQuadtree;
274 struct TreeTransformer
276 TreeTransformer(Matrix& mat_) : mat(mat_) {}
277 TreeBin::Tree operator()(const TreeBin::Tree& tree) const
279 Vec3 pos = toOsg(tree.position);
280 return TreeBin::Tree(toSG(pos * mat));
285 // We may end up with a quadtree with many empty leaves. One might say
286 // that we should avoid constructing the leaves in the first place,
287 // but this node visitor tries to clean up after the fact.
289 struct QuadTreeCleaner : public osg::NodeVisitor
291 QuadTreeCleaner() : NodeVisitor(NodeVisitor::TRAVERSE_ALL_CHILDREN)
296 for (int i = lod.getNumChildren() - 1; i >= 0; --i) {
297 EffectGeode* geode = dynamic_cast<EffectGeode*>(lod.getChild(i));
300 bool geodeEmpty = true;
301 for (unsigned j = 0; j < geode->getNumDrawables(); ++j) {
302 const Geometry* geom = dynamic_cast<Geometry*>(geode->getDrawable(j));
307 for (unsigned k = 0; k < geom->getNumPrimitiveSets(); k++) {
308 const PrimitiveSet* ps = geom->getPrimitiveSet(k);
309 if (ps->getNumIndices() > 0) {
316 lod.removeChildren(i, 1);
321 // This actually returns a MatrixTransform node. If we rotate the whole
322 // forest into the local Z-up coordinate system we can reuse the
323 // primitive tree geometry for all the forests of the same type.
325 osg::Group* createForest(SGTreeBinList& forestList, const osg::Matrix& transform,
326 const SGReaderWriterOptions* options)
328 Matrix transInv = Matrix::inverse(transform);
330 // Set up some shared structures.
331 ref_ptr<Group> group;
332 MatrixTransform* mt = new MatrixTransform(transform);
334 SGTreeBinList::iterator i;
336 for (i = forestList.begin(); i != forestList.end(); ++i) {
337 TreeBin* forest = *i;
339 ref_ptr<Effect> effect;
340 EffectMap::iterator iter = treeEffectMap.find(forest->texture);
342 if ((iter == treeEffectMap.end())||
343 (!iter->second.lock(effect)))
345 SGPropertyNode_ptr effectProp = new SGPropertyNode;
346 makeChild(effectProp, "inherits-from")->setStringValue("Effects/tree");
347 SGPropertyNode* params = makeChild(effectProp, "parameters");
349 params->getChild("texture", 0, true)->getChild("image", 0, true)
350 ->setStringValue(forest->texture);
351 effect = makeEffect(effectProp, true, options);
352 if (iter == treeEffectMap.end())
353 treeEffectMap.insert(EffectMap::value_type(forest->texture, effect));
355 iter->second = effect; // update existing, but empty observer
358 // Now, create a quadtree for the forest.
359 ShaderGeometryQuadtree
360 quadtree(GetTreeCoord(), AddTreesLeafObject(),
361 SG_TREE_QUAD_TREE_DEPTH,
362 MakeTreesLeaf(forest->range, forest->texture_varieties,
363 forest->width, forest->height, effect));
364 // Transform tree positions from the "geocentric" positions we
365 // get from the scenery polys into the local Z-up coordinate
367 std::vector<TreeBin::Tree> rotatedTrees;
368 rotatedTrees.reserve(forest->_trees.size());
369 std::transform(forest->_trees.begin(), forest->_trees.end(),
370 std::back_inserter(rotatedTrees),
371 TreeTransformer(transInv));
372 quadtree.buildQuadTree(rotatedTrees.begin(), rotatedTrees.end());
373 group = quadtree.getRoot();
375 for (size_t i = 0; i < group->getNumChildren(); ++i)
376 mt->addChild(group->getChild(i));
382 QuadTreeCleaner cleaner;