Port createForsythOptimizedMesh from Irrlicht 1.8
authorRealBadAngel <maciej.kasatkin@o2.pl>
Fri, 21 Nov 2014 07:41:21 +0000 (08:41 +0100)
committerRealBadAngel <maciej.kasatkin@o2.pl>
Sat, 22 Nov 2014 23:51:08 +0000 (00:51 +0100)
Mesh rotation helpers.

src/mesh.cpp
src/mesh.h

index 38b3d97bc44d0bde6d6b9322c2c631e681bb699c..e021e4c923718d8e16ef4a075e408663e8bdf11b 100644 (file)
@@ -20,6 +20,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "mesh.h"
 #include "debug.h"
 #include "log.h"
+#include "irrMap.h"
 #include <iostream>
 #include <IAnimatedMesh.h>
 #include <SAnimatedMesh.h>
@@ -197,6 +198,51 @@ void setMeshColorByNormalXYZ(scene::IMesh *mesh,
        }
 }
 
+void rotateMeshXYby (scene::IMesh *mesh, f64 degrees) 
+{      
+       u16 mc = mesh->getMeshBufferCount();
+       for(u16 j = 0; j < mc; j++)
+       {
+               scene::IMeshBuffer *buf = mesh->getMeshBuffer(j);
+               video::S3DVertex *vertices = (video::S3DVertex*)buf->getVertices();
+               u16 vc = buf->getVertexCount();
+               for(u16 i = 0; i < vc; i++)
+               {
+                       vertices[i].Pos.rotateXYBy(degrees);
+               }
+       }
+}
+
+void rotateMeshXZby (scene::IMesh *mesh, f64 degrees) 
+{      
+       u16 mc = mesh->getMeshBufferCount();
+       for(u16 j = 0; j < mc; j++)
+       {
+               scene::IMeshBuffer *buf = mesh->getMeshBuffer(j);
+               video::S3DVertex *vertices = (video::S3DVertex*)buf->getVertices();
+               u16 vc = buf->getVertexCount();
+               for(u16 i = 0; i < vc; i++)
+               {
+                       vertices[i].Pos.rotateXZBy(degrees);
+               }
+       }
+}
+
+void rotateMeshYZby (scene::IMesh *mesh, f64 degrees) 
+{      
+       u16 mc = mesh->getMeshBufferCount();
+       for(u16 j = 0; j < mc; j++)
+       {
+               scene::IMeshBuffer *buf = mesh->getMeshBuffer(j);
+               video::S3DVertex *vertices = (video::S3DVertex*)buf->getVertices();
+               u16 vc = buf->getVertexCount();
+               for(u16 i = 0; i < vc; i++)
+               {
+                       vertices[i].Pos.rotateYZBy(degrees);
+               }
+       }
+}
+
 void rotateMeshBy6dFacedir(scene::IMesh *mesh, int facedir)
 {              
        int axisdir = facedir>>2;
@@ -414,3 +460,597 @@ scene::IMesh* convertNodeboxNodeToMesh(ContentFeatures *f)
        }
        return dst_mesh;                                        
 }
+
+struct vcache
+{
+       core::array<u32> tris;
+       float score;
+       s16 cachepos;
+       u16 NumActiveTris;
+};
+
+struct tcache
+{
+       u16 ind[3];
+       float score;
+       bool drawn;
+};
+
+const u16 cachesize = 32;
+
+float FindVertexScore(vcache *v)
+{
+       const float CacheDecayPower = 1.5f;
+       const float LastTriScore = 0.75f;
+       const float ValenceBoostScale = 2.0f;
+       const float ValenceBoostPower = 0.5f;
+       const float MaxSizeVertexCache = 32.0f;
+
+       if (v->NumActiveTris == 0)
+       {
+               // No tri needs this vertex!
+               return -1.0f;
+       }
+
+       float Score = 0.0f;
+       int CachePosition = v->cachepos;
+       if (CachePosition < 0)
+       {
+               // Vertex is not in FIFO cache - no score.
+       }
+       else
+       {
+               if (CachePosition < 3)
+               {
+                       // This vertex was used in the last triangle,
+                       // so it has a fixed score.
+                       Score = LastTriScore;
+               }
+               else
+               {
+                       // Points for being high in the cache.
+                       const float Scaler = 1.0f / (MaxSizeVertexCache - 3);
+                       Score = 1.0f - (CachePosition - 3) * Scaler;
+                       Score = powf(Score, CacheDecayPower);
+               }
+       }
+
+       // Bonus points for having a low number of tris still to
+       // use the vert, so we get rid of lone verts quickly.
+       float ValenceBoost = powf(v->NumActiveTris,
+                               -ValenceBoostPower);
+       Score += ValenceBoostScale * ValenceBoost;
+
+       return Score;
+}
+
+/*
+       A specialized LRU cache for the Forsyth algorithm.
+*/
+
+class f_lru
+{
+
+public:
+       f_lru(vcache *v, tcache *t): vc(v), tc(t)
+       {
+               for (u16 i = 0; i < cachesize; i++)
+               {
+                       cache[i] = -1;
+               }
+       }
+
+       // Adds this vertex index and returns the highest-scoring triangle index
+       u32 add(u16 vert, bool updatetris = false)
+       {
+               bool found = false;
+
+               // Mark existing pos as empty
+               for (u16 i = 0; i < cachesize; i++)
+               {
+                       if (cache[i] == vert)
+                       {
+                               // Move everything down
+                               for (u16 j = i; j; j--)
+                               {
+                                       cache[j] = cache[j - 1];
+                               }
+
+                               found = true;
+                               break;
+                       }
+               }
+
+               if (!found)
+               {
+                       if (cache[cachesize-1] != -1)
+                               vc[cache[cachesize-1]].cachepos = -1;
+
+                       // Move everything down
+                       for (u16 i = cachesize - 1; i; i--)
+                       {
+                               cache[i] = cache[i - 1];
+                       }
+               }
+
+               cache[0] = vert;
+
+               u32 highest = 0;
+               float hiscore = 0;
+
+               if (updatetris)
+               {
+                       // Update cache positions
+                       for (u16 i = 0; i < cachesize; i++)
+                       {
+                               if (cache[i] == -1)
+                                       break;
+
+                               vc[cache[i]].cachepos = i;
+                               vc[cache[i]].score = FindVertexScore(&vc[cache[i]]);
+                       }
+
+                       // Update triangle scores
+                       for (u16 i = 0; i < cachesize; i++)
+                       {
+                               if (cache[i] == -1)
+                                       break;
+
+                               const u16 trisize = vc[cache[i]].tris.size();
+                               for (u16 t = 0; t < trisize; t++)
+                               {
+                                       tcache *tri = &tc[vc[cache[i]].tris[t]];
+
+                                       tri->score =
+                                               vc[tri->ind[0]].score +
+                                               vc[tri->ind[1]].score +
+                                               vc[tri->ind[2]].score;
+
+                                       if (tri->score > hiscore)
+                                       {
+                                               hiscore = tri->score;
+                                               highest = vc[cache[i]].tris[t];
+                                       }
+                               }
+                       }
+               }
+
+               return highest;
+       }
+
+private:
+       s32 cache[cachesize];
+       vcache *vc;
+       tcache *tc;
+};
+
+/**
+Vertex cache optimization according to the Forsyth paper:
+http://home.comcast.net/~tom_forsyth/papers/fast_vert_cache_opt.html
+
+The function is thread-safe (read: you can optimize several meshes in different threads)
+
+\param mesh Source mesh for the operation.  */
+scene::IMesh* createForsythOptimizedMesh(const scene::IMesh *mesh)
+{
+       if (!mesh)
+               return 0;
+
+       scene::SMesh *newmesh = new scene::SMesh();
+       newmesh->BoundingBox = mesh->getBoundingBox();
+
+       const u32 mbcount = mesh->getMeshBufferCount();
+
+       for (u32 b = 0; b < mbcount; ++b)
+       {
+               const scene::IMeshBuffer *mb = mesh->getMeshBuffer(b);
+
+               if (mb->getIndexType() != video::EIT_16BIT)
+               {
+                       //os::Printer::log("Cannot optimize a mesh with 32bit indices", ELL_ERROR);
+                       newmesh->drop();
+                       return 0;
+               }
+
+               const u32 icount = mb->getIndexCount();
+               const u32 tcount = icount / 3;
+               const u32 vcount = mb->getVertexCount();
+               const u16 *ind = mb->getIndices();
+
+               vcache *vc = new vcache[vcount];
+               tcache *tc = new tcache[tcount];
+
+               f_lru lru(vc, tc);
+
+               // init
+               for (u16 i = 0; i < vcount; i++)
+               {
+                       vc[i].score = 0;
+                       vc[i].cachepos = -1;
+                       vc[i].NumActiveTris = 0;
+               }
+
+               // First pass: count how many times a vert is used
+               for (u32 i = 0; i < icount; i += 3)
+               {
+                       vc[ind[i]].NumActiveTris++;
+                       vc[ind[i + 1]].NumActiveTris++;
+                       vc[ind[i + 2]].NumActiveTris++;
+
+                       const u32 tri_ind = i/3;
+                       tc[tri_ind].ind[0] = ind[i];
+                       tc[tri_ind].ind[1] = ind[i + 1];
+                       tc[tri_ind].ind[2] = ind[i + 2];
+               }
+
+               // Second pass: list of each triangle
+               for (u32 i = 0; i < tcount; i++)
+               {
+                       vc[tc[i].ind[0]].tris.push_back(i);
+                       vc[tc[i].ind[1]].tris.push_back(i);
+                       vc[tc[i].ind[2]].tris.push_back(i);
+
+                       tc[i].drawn = false;
+               }
+
+               // Give initial scores
+               for (u16 i = 0; i < vcount; i++)
+               {
+                       vc[i].score = FindVertexScore(&vc[i]);
+               }
+               for (u32 i = 0; i < tcount; i++)
+               {
+                       tc[i].score =
+                                       vc[tc[i].ind[0]].score +
+                                       vc[tc[i].ind[1]].score +
+                                       vc[tc[i].ind[2]].score;
+               }
+
+               switch(mb->getVertexType())
+               {
+                       case video::EVT_STANDARD:
+                       {
+                               video::S3DVertex *v = (video::S3DVertex *) mb->getVertices();
+
+                               scene::SMeshBuffer *buf = new scene::SMeshBuffer();
+                               buf->Material = mb->getMaterial();
+
+                               buf->Vertices.reallocate(vcount);
+                               buf->Indices.reallocate(icount);
+
+                               core::map<const video::S3DVertex, const u16> sind; // search index for fast operation
+                               typedef core::map<const video::S3DVertex, const u16>::Node snode;
+
+                               // Main algorithm
+                               u32 highest = 0;
+                               u32 drawcalls = 0;
+                               for (;;)
+                               {
+                                       if (tc[highest].drawn)
+                                       {
+                                               bool found = false;
+                                               float hiscore = 0;
+                                               for (u32 t = 0; t < tcount; t++)
+                                               {
+                                                       if (!tc[t].drawn)
+                                                       {
+                                                               if (tc[t].score > hiscore)
+                                                               {
+                                                                       highest = t;
+                                                                       hiscore = tc[t].score;
+                                                                       found = true;
+                                                               }
+                                                       }
+                                               }
+                                               if (!found)
+                                                       break;
+                                       }
+
+                                       // Output the best triangle
+                                       u16 newind = buf->Vertices.size();
+
+                                       snode *s = sind.find(v[tc[highest].ind[0]]);
+
+                                       if (!s)
+                                       {
+                                               buf->Vertices.push_back(v[tc[highest].ind[0]]);
+                                               buf->Indices.push_back(newind);
+                                               sind.insert(v[tc[highest].ind[0]], newind);
+                                               newind++;
+                                       }
+                                       else
+                                       {
+                                               buf->Indices.push_back(s->getValue());
+                                       }
+
+                                       s = sind.find(v[tc[highest].ind[1]]);
+
+                                       if (!s)
+                                       {
+                                               buf->Vertices.push_back(v[tc[highest].ind[1]]);
+                                               buf->Indices.push_back(newind);
+                                               sind.insert(v[tc[highest].ind[1]], newind);
+                                               newind++;
+                                       }
+                                       else
+                                       {
+                                               buf->Indices.push_back(s->getValue());
+                                       }
+
+                                       s = sind.find(v[tc[highest].ind[2]]);
+
+                                       if (!s)
+                                       {
+                                               buf->Vertices.push_back(v[tc[highest].ind[2]]);
+                                               buf->Indices.push_back(newind);
+                                               sind.insert(v[tc[highest].ind[2]], newind);
+                                       }
+                                       else
+                                       {
+                                               buf->Indices.push_back(s->getValue());
+                                       }
+
+                                       vc[tc[highest].ind[0]].NumActiveTris--;
+                                       vc[tc[highest].ind[1]].NumActiveTris--;
+                                       vc[tc[highest].ind[2]].NumActiveTris--;
+
+                                       tc[highest].drawn = true;
+
+                                       for (u16 j = 0; j < 3; j++)
+                                       {
+                                               vcache *vert = &vc[tc[highest].ind[j]];
+                                               for (u16 t = 0; t < vert->tris.size(); t++)
+                                               {
+                                                       if (highest == vert->tris[t])
+                                                       {
+                                                               vert->tris.erase(t);
+                                                               break;
+                                                       }
+                                               }
+                                       }
+
+                                       lru.add(tc[highest].ind[0]);
+                                       lru.add(tc[highest].ind[1]);
+                                       highest = lru.add(tc[highest].ind[2], true);
+                                       drawcalls++;
+                               }
+
+                               buf->setBoundingBox(mb->getBoundingBox());
+                               newmesh->addMeshBuffer(buf);
+                               buf->drop();
+                       }
+                       break;
+                       case video::EVT_2TCOORDS:
+                       {
+                               video::S3DVertex2TCoords *v = (video::S3DVertex2TCoords *) mb->getVertices();
+
+                               scene::SMeshBufferLightMap *buf = new scene::SMeshBufferLightMap();
+                               buf->Material = mb->getMaterial();
+
+                               buf->Vertices.reallocate(vcount);
+                               buf->Indices.reallocate(icount);
+
+                               core::map<const video::S3DVertex2TCoords, const u16> sind; // search index for fast operation
+                               typedef core::map<const video::S3DVertex2TCoords, const u16>::Node snode;
+
+                               // Main algorithm
+                               u32 highest = 0;
+                               u32 drawcalls = 0;
+                               for (;;)
+                               {
+                                       if (tc[highest].drawn)
+                                       {
+                                               bool found = false;
+                                               float hiscore = 0;
+                                               for (u32 t = 0; t < tcount; t++)
+                                               {
+                                                       if (!tc[t].drawn)
+                                                       {
+                                                               if (tc[t].score > hiscore)
+                                                               {
+                                                                       highest = t;
+                                                                       hiscore = tc[t].score;
+                                                                       found = true;
+                                                               }
+                                                       }
+                                               }
+                                               if (!found)
+                                                       break;
+                                       }
+
+                                       // Output the best triangle
+                                       u16 newind = buf->Vertices.size();
+
+                                       snode *s = sind.find(v[tc[highest].ind[0]]);
+
+                                       if (!s)
+                                       {
+                                               buf->Vertices.push_back(v[tc[highest].ind[0]]);
+                                               buf->Indices.push_back(newind);
+                                               sind.insert(v[tc[highest].ind[0]], newind);
+                                               newind++;
+                                       }
+                                       else
+                                       {
+                                               buf->Indices.push_back(s->getValue());
+                                       }
+
+                                       s = sind.find(v[tc[highest].ind[1]]);
+
+                                       if (!s)
+                                       {
+                                               buf->Vertices.push_back(v[tc[highest].ind[1]]);
+                                               buf->Indices.push_back(newind);
+                                               sind.insert(v[tc[highest].ind[1]], newind);
+                                               newind++;
+                                       }
+                                       else
+                                       {
+                                               buf->Indices.push_back(s->getValue());
+                                       }
+
+                                       s = sind.find(v[tc[highest].ind[2]]);
+
+                                       if (!s)
+                                       {
+                                               buf->Vertices.push_back(v[tc[highest].ind[2]]);
+                                               buf->Indices.push_back(newind);
+                                               sind.insert(v[tc[highest].ind[2]], newind);
+                                       }
+                                       else
+                                       {
+                                               buf->Indices.push_back(s->getValue());
+                                       }
+
+                                       vc[tc[highest].ind[0]].NumActiveTris--;
+                                       vc[tc[highest].ind[1]].NumActiveTris--;
+                                       vc[tc[highest].ind[2]].NumActiveTris--;
+
+                                       tc[highest].drawn = true;
+
+                                       for (u16 j = 0; j < 3; j++)
+                                       {
+                                               vcache *vert = &vc[tc[highest].ind[j]];
+                                               for (u16 t = 0; t < vert->tris.size(); t++)
+                                               {
+                                                       if (highest == vert->tris[t])
+                                                       {
+                                                               vert->tris.erase(t);
+                                                               break;
+                                                       }
+                                               }
+                                       }
+
+                                       lru.add(tc[highest].ind[0]);
+                                       lru.add(tc[highest].ind[1]);
+                                       highest = lru.add(tc[highest].ind[2]);
+                                       drawcalls++;
+                               }
+
+                               buf->setBoundingBox(mb->getBoundingBox());
+                               newmesh->addMeshBuffer(buf);
+                               buf->drop();
+
+                       }
+                       break;
+                       case video::EVT_TANGENTS:
+                       {
+                               video::S3DVertexTangents *v = (video::S3DVertexTangents *) mb->getVertices();
+
+                               scene::SMeshBufferTangents *buf = new scene::SMeshBufferTangents();
+                               buf->Material = mb->getMaterial();
+
+                               buf->Vertices.reallocate(vcount);
+                               buf->Indices.reallocate(icount);
+
+                               core::map<const video::S3DVertexTangents, const u16> sind; // search index for fast operation
+                               typedef core::map<const video::S3DVertexTangents, const u16>::Node snode;
+
+                               // Main algorithm
+                               u32 highest = 0;
+                               u32 drawcalls = 0;
+                               for (;;)
+                               {
+                                       if (tc[highest].drawn)
+                                       {
+                                               bool found = false;
+                                               float hiscore = 0;
+                                               for (u32 t = 0; t < tcount; t++)
+                                               {
+                                                       if (!tc[t].drawn)
+                                                       {
+                                                               if (tc[t].score > hiscore)
+                                                               {
+                                                                       highest = t;
+                                                                       hiscore = tc[t].score;
+                                                                       found = true;
+                                                               }
+                                                       }
+                                               }
+                                               if (!found)
+                                                       break;
+                                       }
+
+                                       // Output the best triangle
+                                       u16 newind = buf->Vertices.size();
+
+                                       snode *s = sind.find(v[tc[highest].ind[0]]);
+
+                                       if (!s)
+                                       {
+                                               buf->Vertices.push_back(v[tc[highest].ind[0]]);
+                                               buf->Indices.push_back(newind);
+                                               sind.insert(v[tc[highest].ind[0]], newind);
+                                               newind++;
+                                       }
+                                       else
+                                       {
+                                               buf->Indices.push_back(s->getValue());
+                                       }
+
+                                       s = sind.find(v[tc[highest].ind[1]]);
+
+                                       if (!s)
+                                       {
+                                               buf->Vertices.push_back(v[tc[highest].ind[1]]);
+                                               buf->Indices.push_back(newind);
+                                               sind.insert(v[tc[highest].ind[1]], newind);
+                                               newind++;
+                                       }
+                                       else
+                                       {
+                                               buf->Indices.push_back(s->getValue());
+                                       }
+
+                                       s = sind.find(v[tc[highest].ind[2]]);
+
+                                       if (!s)
+                                       {
+                                               buf->Vertices.push_back(v[tc[highest].ind[2]]);
+                                               buf->Indices.push_back(newind);
+                                               sind.insert(v[tc[highest].ind[2]], newind);
+                                       }
+                                       else
+                                       {
+                                               buf->Indices.push_back(s->getValue());
+                                       }
+
+                                       vc[tc[highest].ind[0]].NumActiveTris--;
+                                       vc[tc[highest].ind[1]].NumActiveTris--;
+                                       vc[tc[highest].ind[2]].NumActiveTris--;
+
+                                       tc[highest].drawn = true;
+
+                                       for (u16 j = 0; j < 3; j++)
+                                       {
+                                               vcache *vert = &vc[tc[highest].ind[j]];
+                                               for (u16 t = 0; t < vert->tris.size(); t++)
+                                               {
+                                                       if (highest == vert->tris[t])
+                                                       {
+                                                               vert->tris.erase(t);
+                                                               break;
+                                                       }
+                                               }
+                                       }
+
+                                       lru.add(tc[highest].ind[0]);
+                                       lru.add(tc[highest].ind[1]);
+                                       highest = lru.add(tc[highest].ind[2]);
+                                       drawcalls++;
+                               }
+
+                               buf->setBoundingBox(mb->getBoundingBox());
+                               newmesh->addMeshBuffer(buf);
+                               buf->drop();
+                       }
+                       break;
+               }
+
+               delete [] vc;
+               delete [] tc;
+
+       } // for each meshbuffer
+
+       return newmesh;
+}
index 29f5ec76ca6aae178c61e5978d7972f382364d62..761842b0d744c618634802a4731c3f0aff499f8b 100644 (file)
@@ -64,6 +64,13 @@ void setMeshColorByNormalXYZ(scene::IMesh *mesh,
 */
 void rotateMeshBy6dFacedir(scene::IMesh *mesh, int facedir);
 
+/*
+       Rotate the mesh around the axis and given angle in degrees.
+*/
+void rotateMeshXYby (scene::IMesh *mesh, f64 degrees);
+void rotateMeshXZby (scene::IMesh *mesh, f64 degrees);
+void rotateMeshYZby (scene::IMesh *mesh, f64 degrees); 
 /*
        Clone the mesh.
 */
@@ -79,4 +86,11 @@ scene::IMesh* convertNodeboxNodeToMesh(ContentFeatures *f);
 */
 void recalculateBoundingBox(scene::IMesh *src_mesh);
 
+/*
+       Vertex cache optimization according to the Forsyth paper:
+       http://home.comcast.net/~tom_forsyth/papers/fast_vert_cache_opt.html
+       Ported from irrlicht 1.8
+*/
+scene::IMesh* createForsythOptimizedMesh(const scene::IMesh *mesh);
+
 #endif