Method createTangents

Engine/source/ts/tsMesh.cpp:3018–3096

----------------------------------------------------------------------------- create array of tangent vectors -----------------------------------------------------------------------------

// create array of tangent vectors
//-----------------------------------------------------------------------------
void TSMesh::createTangents(const Vector<Point3F> &_verts, const Vector<Point3F> &_norms)
{
   if (_verts.size() == 0) // can only be done in editable mode
      return;

   U32 numVerts = _verts.size();
   U32 numNorms = _norms.size();
   if ( numVerts <= 0 || numNorms <= 0 )
      return;

   if( numVerts != numNorms)
      return;

   Vector<Point3F> tan0;
   tan0.setSize( numVerts * 2 );

   Point3F *tan1 = tan0.address() + numVerts;
   dMemset( tan0.address(), 0, sizeof(Point3F) * 2 * numVerts );
   
   U32   numPrimatives = mPrimitives.size();

   for (S32 i = 0; i < numPrimatives; i++ )
   {
      const TSDrawPrimitive & draw = mPrimitives[i];
      GFXPrimitiveType drawType = getDrawType( draw.matIndex >> 30 );

      U32 p1Index = 0;
      U32 p2Index = 0;

      U32 *baseIdx = &mIndices[draw.start];

      const U32 numElements = (U32)draw.numElements;

      switch( drawType )
      {
      case GFXTriangleList:
         {
            for( U32 j = 0; j < numElements; j += 3 )
               findTangent( baseIdx[j], baseIdx[j + 1], baseIdx[j + 2], tan0.address(), tan1, _verts );
            break;
         }

      case GFXTriangleStrip:
         {
            p1Index = baseIdx[0];
            p2Index = baseIdx[1];
            for( U32 j = 2; j < numElements; j++ )
            {
               findTangent( p1Index, p2Index, baseIdx[j], tan0.address(), tan1, _verts );
               p1Index = p2Index;
               p2Index = baseIdx[j];
            }
            break;
         }

      default:
         AssertFatal( false, "TSMesh::createTangents: unknown primitive type!" );
      }