Issue "Wrapping" Decals

...updated code in next post

void DecalManager::addWrapDecal(const Point3F& pos,
                            Point3F normal,
                            Point3F impactNormal,
                            DecalData *decalData)
{
   ...
   DecalExData *exData=new DecalExData;
   newDecal->exData=exData;

   // construct matrix
   Point3F x,y,z;
   y=impactNormal;
   if (mFabs(y.z)>0.001f)
   {
      //mCross(y,Point3F(1,0,0),&z);
      z.set(0,y.z,-y.x);
      z.normalizeSafe();
      mCross(y,z,&x);
      x.normalizeSafe();
   }
   else
   {
      //mCross(y,Point3F(0,0,1),&x);
      x.set(y.y,-y.x,0);
      x.normalizeSafe();
      mCross(x,y,&z);
      z.normalizeSafe();
   }

   // backup a bit (for the transforms) so that we can "see" all the polys
   Point3F position = Point3F(pos.x + (-impactNormal.x * decalData->sizeX*2), pos.y + (-impactNormal.y * decalData->sizeY*2), pos.z + (-impactNormal.z * decalData->sizeX*2));

   MatrixF decalToWorld(true);
   decalToWorld.setColumn(0,x);
   decalToWorld.setColumn(1,y);
   decalToWorld.setColumn(2,z);
   decalToWorld.setColumn(3,position);

   exData->mTransform=decalToWorld;

   MatrixF worldToDecal=decalToWorld;
   worldToDecal.inverse();

   // setup depth sort list
   // expanded to allow the image to stretch
   Point3F extent(decalData->sizeX*5,decalData->sizeY*5,decalData->sizeX*5);
   smDepthSortList.clear();
   smDepthSortList.set(worldToDecal,extent);
   smDepthSortList.setInterestNormal(impactNormal);

   // build world space box and sphere around decal
   x *= decalData->sizeX*2;
   y *= decalData->sizeX*2;
   z *= decalData->sizeY*2;
   gDecalBox.max.set(mFabs(x.x)+mFabs(y.x)+mFabs(z.x),
                     mFabs(x.y)+mFabs(y.y)+mFabs(z.y),
                     mFabs(x.z)+mFabs(y.z)+mFabs(z.z));
   gDecalSphere.radius = gDecalBox.max.len();
   gDecalSphere.center = pos;
   gDecalBox.min  = pos - gDecalBox.max;
   gDecalBox.max += pos;

   // get polys
   gClientContainer.findObjects(smDecalMask,DecalManager::collisionCallback,this);

   // setup partition list
   gDecalPoly[0].set(-decalData->sizeX,0,-decalData->sizeY);
   gDecalPoly[1].set(-decalData->sizeX,0,decalData->sizeY);
   gDecalPoly[2].set(decalData->sizeX,0,decalData->sizeY);
   gDecalPoly[3].set(decalData->sizeX,0,-decalData->sizeY);

   exData->mPartition.clear();
   exData->mPartitionVerts.clear();
   smDepthSortList.depthPartition(gDecalPoly,4,exData->mPartition,exData->mPartitionVerts);

   if (exData->mPartitionVerts.size()>0)
   {
      // now set up tverts
      exData->mPartitionTVerts.setSize(exData->mPartitionVerts.size());
      F32 invSizeX = 1.0f / (decalData->sizeX);
      F32 invSizeY = 1.0f / (decalData->sizeY);
      for (S32 i=0; i<exData->mPartitionVerts.size(); i++)
         exData->mPartitionTVerts[i].set(0.5f + 0.5f * exData->mPartitionVerts[i].x * invSizeX,0.5f + 0.5f * exData->mPartitionVerts[i].z * invSizeY);
   }
   else
   {
      delete exData;
      newDecal->exData=NULL;
      // do it the old fashioned way
      ...
   }
   ...
}