kaori says

void Object::renderstencilshadow_fast ( int slot, Light *l, bool reverse ) {  int i,j;    StartCounter ("10stencil render");       // vertex setup: all original vertices with w=1, followed by all original vertices with w=0   if ( instancebase ) {    stencilvarhandle = instancebase->stencilvarhandle;    if ( !stencilvarhandle ) {      stencilvarhandle = renderer->AllocVarBufferHandle( nv*2*4*4 ); // every vertex twice, four floats per vertex      if ( !stencilvarhandle ) return;      instancebase->stencilvarhandle = stencilvarhandle;    }    // is vertex buffer still valid?    if ( !renderer->IsVarBufferStillValid( stencilvarhandle ) ) stencilreloadneeded = true;      } else {    // std behaviour    // alloc vertex buffer    if ( !stencilvarhandle ) {      stencilvarhandle = renderer->AllocVarBufferHandle( nv*2*4*4 );      if ( !stencilvarhandle ) return;    }  }  // is vertex buffer still valid?  if ( !renderer->IsVarBufferStillValid( stencilvarhandle ) ) stencilreloadneeded = true;  void *vbuffer = renderer->LockVarBuffer( stencilvarhandle );  	if ( stencilreloadneeded ) {	        StartCounter ("92Stencil Geometry reload");          Object *src = instancebase?instancebase:this;    float *dest = (float*)vbuffer;    for ( i=0; i<src->nv; i++ ) {      dest[0] = src->v[i].os.longvec[0];      dest[1] = src->v[i].os.longvec[1];      dest[2] = src->v[i].os.longvec[2];      dest[3] = 1.0f;      dest+=4;    }    for ( i=0; i<src->nv; i++ ) {      dest[0] = src->v[i].os.longvec[0];      dest[1] = src->v[i].os.longvec[1];      dest[2] = src->v[i].os.longvec[2];      dest[3] = 0.0f;      dest+=4;    }        StopCounter ("92Stencil Geometry reload");      stencilreloadneeded = false;	}   // build indices (or should they be built during object update?)   int nind[3]; // slots: extrude, frontfacing, backfacing  int indbase[3];  // better use one scratch pool... or combine it with some very clever caching...     unsigned short *stencilindexlist = renderer->scratchindices;  // unsigned shorts.. humz.. this reduces effective max vertex count down to a mere 32k per object..   if ( nv>=(0x10000>>1) ) {    printf ("too many vertices in object for stenciling.\n");  }  // built extrusion indices  int mask = 1<<slot;  int ol_nind = outlines->nindices[slot];  unsigned short *ol_ind = outlines->indices[slot];  j=0;  indbase[0] = 0;  for ( i=0; i<ol_nind-1; i+=2 ) {                        stencilindexlist[j++] = ol_ind[i];    stencilindexlist[j++] = ol_ind[i+1];    stencilindexlist[j++] = ol_ind[i+1] + nv;        stencilindexlist[j++] = ol_ind[i] + nv;                            }  nind[0] = j;  if ( !reverse ) {    // todo  } else {    indbase[1] = j;      indbase[2] = j+nf*3;      nind[1] = 0;    nind[2] = 0;    for ( i=0; i<nf; i++ ) {      if ( (f[i].flags&mask)!=0 ) {        (stencilindexlist+indbase[1])[nind[1]++] = f[i].v[0];        (stencilindexlist+indbase[1])[nind[1]++] = f[i].v[1];        (stencilindexlist+indbase[1])[nind[1]++] = f[i].v[2];      } else {        (stencilindexlist+indbase[2])[nind[2]++] = f[i].v[0]+nv;        (stencilindexlist+indbase[2])[nind[2]++] = f[i].v[1]+nv;        (stencilindexlist+indbase[2])[nind[2]++] = f[i].v[2]+nv;      }    }        }        // render	m.Gl (glm);	glMatrixMode (GL_MODELVIEW); // is assumed to be set to camera matrix			glPushMatrix ();		glMultMatrixf (glm);  Vector osl = l->pos * mi;  osl.w = 1.0f;  glProgramParameter4fvNV ( GL_VERTEX_PROGRAM_NV, 16, osl.longvec );  // setup vertices  // vp and matrix tacking assumed to be active...    glVertexPointer ( 4, GL_FLOAT, 4*sizeof(float), vbuffer );  #ifdef _DEBUG  renderer->CheckVAR();  #endif       if ( reverse ) {    glCullFace ( GL_BACK );      glStencilOp ( GL_KEEP, GL_INCR_WRAP_EXT, GL_KEEP );        for ( int side=0; side<2; side++ ) {            if ( glDrawRangeElementsEXT ) {        // todo: maybe make first quad set a quad strip...        glDrawRangeElementsEXT (GL_QUADS, 0, nv<<1, nind[0], GL_UNSIGNED_SHORT, stencilindexlist+indbase[0]);                glDrawRangeElementsEXT (GL_TRIANGLES, 0, nv<<1, nind[2], GL_UNSIGNED_SHORT, stencilindexlist+indbase[2]);                glDisable ( GL_VERTEX_PROGRAM_NV );        glDrawRangeElementsEXT (GL_TRIANGLES, 0, nv, nind[1], GL_UNSIGNED_SHORT, stencilindexlist+indbase[1]);                glEnable ( GL_VERTEX_PROGRAM_NV );              } else {                glDrawElements (GL_QUADS, nind[0],GL_UNSIGNED_SHORT, stencilindexlist+indbase[0]);                                    glDrawElements (GL_TRIANGLES, nind[2],GL_UNSIGNED_SHORT, stencilindexlist+indbase[2]);                        glDisable ( GL_VERTEX_PROGRAM_NV );        glDrawElements (GL_TRIANGLES, nind[1],GL_UNSIGNED_SHORT, stencilindexlist+indbase[1]);                        glEnable ( GL_VERTEX_PROGRAM_NV );                      }            glCullFace ( GL_FRONT );          glStencilOp ( GL_KEEP, GL_DECR_WRAP_EXT, GL_KEEP );        }  } else {    glCullFace ( GL_BACK );      glStencilOp ( GL_KEEP, GL_KEEP, GL_INCR_WRAP_EXT );        for ( int side=0; side<2; side++ ) {      if ( glDrawRangeElementsEXT ) {        glDrawRangeElementsEXT (GL_QUADS, 0, nv, nind[0], GL_UNSIGNED_SHORT, stencilindexlist+indbase[0]);        glDisable ( GL_VERTEX_PROGRAM_NV );        glDrawRangeElementsEXT (GL_TRIANGLES, 0, nv, nind[1], GL_UNSIGNED_SHORT, stencilindexlist+indbase[1]);                glEnable ( GL_VERTEX_PROGRAM_NV );       } else {        glDrawElements (GL_QUADS, nind[0],GL_UNSIGNED_SHORT, stencilindexlist+indbase[0]);        glDisable ( GL_VERTEX_PROGRAM_NV );        glDrawElements (GL_TRIANGLES, nind[1],GL_UNSIGNED_SHORT, stencilindexlist+indbase[1]);                glEnable ( GL_VERTEX_PROGRAM_NV );       }            glCullFace ( GL_FRONT );          glStencilOp ( GL_KEEP, GL_KEEP, GL_DECR_WRAP_EXT );        }  }	glPopMatrix ();  renderer->UnlockVarBuffer( stencilvarhandle );    StopCounter ("10stencil render");        }