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>
39 #include <osgDB/ReadFile>
40 #include <osgDB/FileUtils>
42 #include <simgear/debug/logstream.hxx>
43 #include <simgear/math/sg_random.h>
44 #include <simgear/misc/sg_path.hxx>
45 #include <simgear/scene/material/Effect.hxx>
46 #include <simgear/scene/material/EffectGeode.hxx>
47 #include <simgear/props/props.hxx>
48 #include <simgear/scene/util/QuadTreeBuilder.hxx>
49 #include <simgear/scene/util/RenderConstants.hxx>
50 #include <simgear/scene/util/StateAttributeFactory.hxx>
51 #include <simgear/structure/OSGUtils.hxx>
53 #include "ShaderGeometry.hxx"
54 #include "TreeBin.hxx"
56 #define SG_TREE_QUAD_TREE_DEPTH 3
63 // Tree instance scheme:
64 // vertex - local position of quad vertex.
65 // normal - x y scaling, z number of varieties
66 // fog coord - rotation
67 // color - xyz of tree quad origin, replicated 4 times.
69 // The tree quad is rendered twice, with different rotations, to
70 // create the crossed tree geometry.
72 struct TreesBoundingBoxCallback : public Drawable::ComputeBoundingBoxCallback
74 TreesBoundingBoxCallback() {}
75 TreesBoundingBoxCallback(const TreesBoundingBoxCallback&, const CopyOp&) {}
76 META_Object(simgear, TreesBoundingBoxCallback);
77 virtual BoundingBox computeBound(const Drawable&) const;
81 TreesBoundingBoxCallback::computeBound(const Drawable& drawable) const
84 const Geometry* geom = static_cast<const Geometry*>(&drawable);
85 const Vec3Array* v = static_cast<const Vec3Array*>(geom->getVertexArray());
86 const Vec3Array* pos = static_cast<const Vec3Array*>(geom->getColorArray());
87 const Vec3Array* params
88 = static_cast<const Vec3Array*>(geom->getNormalArray());
90 = static_cast<const FloatArray*>(geom->getFogCoordArray());
91 float w = (*params)[0].x();
92 float h = (*params)[0].y();
93 Geometry::PrimitiveSetList primSets = geom->getPrimitiveSetList();
94 FloatArray::const_iterator rotitr = rot->begin();
95 for (Geometry::PrimitiveSetList::const_iterator psitr = primSets.begin(),
96 psend = primSets.end();
99 Matrixd trnsfrm = (Matrixd::scale(w, w, h)
100 * Matrixd::rotate(*rotitr, Vec3(0.0f, 0.0f, 1.0f)));
101 DrawArrays* da = static_cast<DrawArrays*>(psitr->get());
102 GLint psFirst = da->getFirst();
103 GLint psEndVert = psFirst + da->getCount();
104 for (GLint i = psFirst;i < psEndVert; ++i) {
114 Geometry* makeSharedTreeGeometry(int numQuads)
116 // generate a repeatable random seed
118 mt_init(&seed, unsigned(123));
120 osg::Vec3Array* v = new osg::Vec3Array;
121 osg::Vec2Array* t = new osg::Vec2Array;
122 v->reserve(numQuads * 4);
123 t->reserve(numQuads * 4);
124 for (int i = 0; i < numQuads; ++i) {
125 // Apply a random scaling factor and texture index.
126 float h = (mt_rand(&seed) + mt_rand(&seed)) / 2.0f + 0.5f;
128 v->push_back(Vec3(0.0f, -cw, 0.0f));
129 v->push_back(Vec3(0.0f, cw, 0.0f));
130 v->push_back(Vec3(0.0f, cw, h));
131 v->push_back(Vec3(0.0f,-cw, h));
132 // The texture coordinate range is not the entire coordinate
133 // space, as the texture has a number of different trees on
134 // it. Here we assign random coordinates and let the shader
135 // choose the variety.
136 float variety = mt_rand(&seed);
137 t->push_back(Vec2(variety, 0.0f));
138 t->push_back(Vec2(variety + 1.0f, 0.0f));
139 t->push_back(Vec2(variety + 1.0f, 1.0f));
140 t->push_back(Vec2(variety, 1.0f));
142 Geometry* result = new Geometry;
143 result->setVertexArray(v);
144 result->setTexCoordArray(0, t);
145 result->setComputeBoundingBoxCallback(new TreesBoundingBoxCallback);
146 result->setUseDisplayList(false);
150 ref_ptr<Geometry> sharedTreeGeometry;
152 Geometry* createTreeGeometry(float width, float height, int varieties)
154 if (!sharedTreeGeometry)
155 sharedTreeGeometry = makeSharedTreeGeometry(1600);
156 Geometry* quadGeom = simgear::clone(sharedTreeGeometry.get(),
157 CopyOp::SHALLOW_COPY);
158 Vec3Array* params = new Vec3Array;
159 params->push_back(Vec3(width, height, (float)varieties));
160 quadGeom->setNormalArray(params);
161 quadGeom->setNormalBinding(Geometry::BIND_OVERALL);
163 quadGeom->setColorArray(new Vec3Array);
164 quadGeom->setColorBinding(Geometry::BIND_PER_VERTEX);
165 FloatArray* rotation = new FloatArray(2);
166 (*rotation)[0] = 0.0;
167 (*rotation)[1] = PI_2;
168 quadGeom->setFogCoordArray(rotation);
169 quadGeom->setFogCoordBinding(Geometry::BIND_PER_PRIMITIVE_SET);
170 // The primitive sets render the same geometry, but the second
171 // will rotated 90 degrees by the vertex shader, which uses the
172 // fog coordinate as a rotation.
173 for (int i = 0; i < 2; ++i)
174 quadGeom->addPrimitiveSet(new DrawArrays(PrimitiveSet::QUADS));
178 EffectGeode* createTreeGeode(float width, float height, int varieties)
180 EffectGeode* result = new EffectGeode;
181 result->addDrawable(createTreeGeometry(width, height, varieties));
185 void addTreeToLeafGeode(Geode* geode, const SGVec3f& p)
188 unsigned int numDrawables = geode->getNumDrawables();
190 = static_cast<Geometry*>(geode->getDrawable(numDrawables - 1));
191 Vec3Array* posArray = static_cast<Vec3Array*>(geom->getColorArray());
193 >= static_cast<Vec3Array*>(geom->getVertexArray())->size()) {
194 Vec3Array* paramsArray
195 = static_cast<Vec3Array*>(geom->getNormalArray());
196 Vec3 params = (*paramsArray)[0];
197 geom = createTreeGeometry(params.x(), params.y(), params.z());
198 posArray = static_cast<Vec3Array*>(geom->getColorArray());
199 geode->addDrawable(geom);
201 posArray->insert(posArray->end(), 4, pos);
202 size_t numVerts = posArray->size();
203 for (int i = 0; i < 2; ++i) {
205 = static_cast<DrawArrays*>(geom->getPrimitiveSet(i));
206 primSet->setCount(numVerts);
210 typedef std::map<std::string, osg::ref_ptr<Effect> > EffectMap;
212 static EffectMap treeEffectMap;
214 // Helper classes for creating the quad tree
219 MakeTreesLeaf(float range, int varieties, float width, float height,
221 _range(range), _varieties(varieties),
222 _width(width), _height(height), _effect(effect) {}
224 MakeTreesLeaf(const MakeTreesLeaf& rhs) :
226 _varieties(rhs._varieties), _width(rhs._width), _height(rhs._height),
230 LOD* operator() () const
232 LOD* result = new LOD;
233 EffectGeode* geode = createTreeGeode(_width, _height, _varieties);
234 geode->setEffect(_effect.get());
235 result->addChild(geode, 0, _range);
242 ref_ptr<Effect> _effect;
245 struct AddTreesLeafObject
247 void operator() (LOD* lod, const TreeBin::Tree& tree) const
249 Geode* geode = static_cast<Geode*>(lod->getChild(0));
250 addTreeToLeafGeode(geode, tree.position);
256 Vec3 operator() (const TreeBin::Tree& tree) const
258 return toOsg(tree.position);
262 typedef QuadTreeBuilder<LOD*, TreeBin::Tree, MakeTreesLeaf, AddTreesLeafObject,
263 GetTreeCoord> ShaderGeometryQuadtree;
266 struct TreeTransformer
268 TreeTransformer(Matrix& mat_) : mat(mat_) {}
269 TreeBin::Tree operator()(const TreeBin::Tree& tree) const
271 Vec3 pos = toOsg(tree.position);
272 return TreeBin::Tree(toSG(pos * mat));
277 // This actually returns a MatrixTransform node. If we rotate the whole
278 // forest into the local Z-up coordinate system we can reuse the
279 // primitive tree geometry for all the forests of the same type.
281 osg::Group* createForest(TreeBin& forest, const osg::Matrix& transform)
283 Matrix transInv = Matrix::inverse(transform);
285 // Set up some shared structures.
286 ref_ptr<Group> group;
289 EffectMap::iterator iter = treeEffectMap.find(forest.texture);
290 if (iter == treeEffectMap.end()) {
291 SGPropertyNode_ptr effectProp = new SGPropertyNode;
292 makeChild(effectProp, "inherits-from")->setStringValue("Effects/tree");
293 SGPropertyNode* params = makeChild(effectProp, "parameters");
295 params->getChild("texture", 0, true)->getChild("image", 0, true)
296 ->setStringValue(forest.texture);
297 effect = makeEffect(effectProp, true);
298 treeEffectMap.insert(EffectMap::value_type(forest.texture, effect));
300 effect = iter->second.get();
302 // Now, create a quadtree for the forest.
304 ShaderGeometryQuadtree
305 quadtree(GetTreeCoord(), AddTreesLeafObject(),
306 SG_TREE_QUAD_TREE_DEPTH,
307 MakeTreesLeaf(forest.range, forest.texture_varieties,
308 forest.width, forest.height, effect));
309 // Transform tree positions from the "geocentric" positions we
310 // get from the scenery polys into the local Z-up coordinate
312 std::vector<TreeBin::Tree> rotatedTrees;
313 rotatedTrees.reserve(forest._trees.size());
314 std::transform(forest._trees.begin(), forest._trees.end(),
315 std::back_inserter(rotatedTrees),
316 TreeTransformer(transInv));
317 quadtree.buildQuadTree(rotatedTrees.begin(), rotatedTrees.end());
318 group = quadtree.getRoot();
320 MatrixTransform* mt = new MatrixTransform(transform);
321 for (size_t i = 0; i < group->getNumChildren(); ++i)
322 mt->addChild(group->getChild(i));