OpenSceneGraph/include/osgUtil/MeshOptimizers
2018-08-17 09:21:31 +01:00

147 lines
4.4 KiB
C++

/* -*-c++-*- OpenSceneGraph - Copyright (C) 1998-2006 Robert Osfield
*
* This library is open source and may be redistributed and/or modified under
* the terms of the OpenSceneGraph Public License (OSGPL) version 0.0 or
* (at your option) any later version. The full license is in LICENSE file
* included with this distribution, and on the openscenegraph.org website.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* OpenSceneGraph Public License for more details.
*/
#ifndef OSGUTIL_MESHOPTIMIZERS
#define OSGUTIL_MESHOPTIMIZERS 1
#include <set>
#include <vector>
#include <osg/Geode>
#include <osg/Geometry>
#include <osg/NodeVisitor>
#include <osgUtil/Optimizer>
namespace osgUtil
{
// Helper that collects all the unique Geometry objects in a subgraph.
class OSGUTIL_EXPORT GeometryCollector : public BaseOptimizerVisitor
{
public:
GeometryCollector(Optimizer* optimizer,
Optimizer::OptimizationOptions options)
: BaseOptimizerVisitor(optimizer, options) {}
void reset();
void apply(osg::Geometry& geom);
typedef std::set<osg::Geometry*> GeometryList;
GeometryList& getGeometryList() { return _geometryList; };
protected:
GeometryList _geometryList;
};
// Convert geometry that uses DrawArrays to DrawElements i.e.,
// construct a real mesh. This removes duplicate vertices.
class OSGUTIL_EXPORT IndexMeshVisitor : public GeometryCollector
{
public:
IndexMeshVisitor(Optimizer* optimizer = 0)
: GeometryCollector(optimizer, Optimizer::INDEX_MESH), _isForcedReindexationEnable(false)
{
}
inline void setGenerateNewIndicesOnAllGeometries(bool b) { _generateNewIndicesOnAllGeometries = b; }
inline bool getGenerateNewIndicesOnAllGeometries() const { return _generateNewIndicesOnAllGeometries; }
void makeMesh(osg::Geometry& geom);
void makeMesh();
protected:
bool _generateNewIndicesOnAllGeometries;
};
// Optimize the triangle order in a mesh for best use of the GPU's
// post-transform cache. This uses Tom Forsyth's algorithm described
// at http://home.comcast.net/~tom_forsyth/papers/fast_vert_cache_opt.html
class OSGUTIL_EXPORT VertexCacheVisitor : public GeometryCollector
{
public:
VertexCacheVisitor(Optimizer* optimizer = 0)
: GeometryCollector(optimizer, Optimizer::VERTEX_POSTTRANSFORM)
{
}
void optimizeVertices(osg::Geometry& geom);
void optimizeVertices();
private:
void doVertexOptimization(osg::Geometry& geom,
std::vector<unsigned>& vertDrawList);
};
// Gather statistics on post-transform cache misses for geometry
class OSGUTIL_EXPORT VertexCacheMissVisitor : public osg::NodeVisitor
{
public:
VertexCacheMissVisitor(unsigned cacheSize = 16);
void reset();
virtual void apply(osg::Geometry& geom);
void doGeometry(osg::Geometry& geom);
unsigned misses;
unsigned triangles;
protected:
const unsigned _cacheSize;
};
// Optimize the use of the GPU pre-transform cache by arranging vertex
// attributes in the order they are used.
class OSGUTIL_EXPORT VertexAccessOrderVisitor : public GeometryCollector
{
struct OrderByPrimitiveMode
{
inline bool operator() (const osg::ref_ptr<osg::PrimitiveSet>& prim1, const osg::ref_ptr<osg::PrimitiveSet>& prim2)
{
if(prim1 && prim2) {
return prim1->getMode() > prim2->getMode();
}
else if(prim1) {
return true;
}
return false;
}
} order_by_primitive_mode;
public:
VertexAccessOrderVisitor(Optimizer* optimizer = 0)
: GeometryCollector(optimizer, Optimizer::VERTEX_PRETRANSFORM)
{
}
void optimizeOrder();
void optimizeOrder(osg::Geometry& geom);
};
class OSGUTIL_EXPORT SharedArrayOptimizer
{
public:
void findDuplicatedUVs(const osg::Geometry& geometry);
void deduplicateUVs(osg::Geometry& geometry);
protected:
std::map<unsigned int, unsigned int> _deduplicateUvs;
}; // SharedArrayOptimizer
inline void optimizeMesh(osg::Node* node)
{
IndexMeshVisitor imv;
node->accept(imv);
imv.makeMesh();
VertexCacheVisitor vcv;
node->accept(vcv);
vcv.optimizeVertices();
VertexAccessOrderVisitor vaov;
node->accept(vaov);
vaov.optimizeOrder();
}
}
#endif