1 files changed, 181 insertions, 38 deletions

diff --git a/indra/llmath/llvolume.cpp b/indra/llmath/llvolume.cpp
index 14cebfe5aa..a030d889af 100755
--- a/indra/llmath/llvolume.cpp
+++ b/indra/llmath/llvolume.cpp
@@ -136,6 +136,82 @@ BOOL LLLineSegmentBoxIntersect(const F32* start, const F32* end, const F32* cent
 	return true;
 }
 
+// Finds tangent vec based on three vertices with texture coordinates.
+// Fills in dummy values if the triangle has degenerate texture coordinates.
+void calc_tangent_from_triangle(
+	LLVector4a&			normal,
+	LLVector4a&			tangent_out,
+	const LLVector4a& v1,
+	const LLVector2&  w1,
+	const LLVector4a& v2,
+	const LLVector2&  w2,
+	const LLVector4a& v3,
+	const LLVector2&  w3)
+{
+	const F32* v1ptr = v1.getF32ptr();
+	const F32* v2ptr = v2.getF32ptr();
+	const F32* v3ptr = v3.getF32ptr();
+
+	float x1 = v2ptr[0] - v1ptr[0];
+	float x2 = v3ptr[0] - v1ptr[0];
+	float y1 = v2ptr[1] - v1ptr[1];
+	float y2 = v3ptr[1] - v1ptr[1];
+	float z1 = v2ptr[2] - v1ptr[2];
+	float z2 = v3ptr[2] - v1ptr[2];
+
+	float s1 = w2.mV[0] - w1.mV[0];
+	float s2 = w3.mV[0] - w1.mV[0];
+	float t1 = w2.mV[1] - w1.mV[1];
+	float t2 = w3.mV[1] - w1.mV[1];
+
+	F32 rd = s1*t2-s2*t1;
+
+	float r = ((rd*rd) > FLT_EPSILON) ? 1.0F / rd : 1024.f; //some made up large ratio for division by zero
+
+	llassert(llfinite(r));
+	llassert(!llisnan(r));
+
+	LLVector4a sdir(
+		(t2 * x1 - t1 * x2) * r,
+		(t2 * y1 - t1 * y2) * r,
+		(t2 * z1 - t1 * z2) * r);
+
+	LLVector4a tdir(
+		(s1 * x2 - s2 * x1) * r,
+		(s1 * y2 - s2 * y1) * r,
+		(s1 * z2 - s2 * z1) * r);
+
+	LLVector4a	n = normal;
+	LLVector4a	t = sdir;
+
+	LLVector4a ncrosst;
+	ncrosst.setCross3(n,t);
+
+	// Gram-Schmidt orthogonalize
+	n.mul(n.dot3(t).getF32());
+
+	LLVector4a tsubn;
+	tsubn.setSub(t,n);
+
+	if (tsubn.dot3(tsubn).getF32() > F_APPROXIMATELY_ZERO)
+	{
+		tsubn.normalize3fast_checked();
+
+		// Calculate handedness
+		F32 handedness = ncrosst.dot3(tdir).getF32() < 0.f ? -1.f : 1.f;
+
+		tsubn.getF32ptr()[3] = handedness;
+
+		tangent_out = tsubn;
+	}
+	else
+	{
+		// degenerate, make up a value
+		//
+		tangent_out.set(0,0,1,1);
+	}
+
+}
 
 
 // intersect test between triangle vert0, vert1, vert2 and a ray from orig in direction dir.
@@ -5908,10 +5984,10 @@ void LLVolumeFace::cacheOptimize()
 		wght = (LLVector4a*) ll_aligned_malloc_16(sizeof(LLVector4a)*num_verts);
 	}
 
-	LLVector4a* binorm = NULL;
+	LLVector4a* tangent = NULL;
 	if (mTangents)
 	{
-		binorm = (LLVector4a*) ll_aligned_malloc_16(sizeof(LLVector4a)*num_verts);
+		tangent = (LLVector4a*) ll_aligned_malloc_16(sizeof(LLVector4a)*num_verts);
 	}
 
 	//allocate mapping of old indices to new indices
@@ -5936,7 +6012,7 @@ void LLVolumeFace::cacheOptimize()
 			}
 			if (mTangents)
 			{
-				binorm[cur_idx] = mTangents[idx];
+				tangent[cur_idx] = mTangents[idx];
 			}
 
 			cur_idx++;
@@ -5958,7 +6034,7 @@ void LLVolumeFace::cacheOptimize()
 	mNormals = norm;
 	mTexCoords = tc;
 	mWeights = wght;
-	mTangents = binorm;
+	mTangents = tangent;
 
 	//std::string result = llformat("ACMR pre/post: %.3f/%.3f  --  %d triangles %d breaks", pre_acmr, post_acmr, mNumIndices/3, breaks);
 	//llinfos << result << llendl;
@@ -6306,6 +6382,43 @@ BOOL LLVolumeFace::createCap(LLVolume* volume, BOOL partial_build)
 
 	cuv = (min_uv + max_uv)*0.5f;
 
+
+	LLVector4a tangent;
+	calc_tangent_from_triangle(
+			*norm,
+			tangent,
+			*mCenter, cuv,
+			pos[0], tc[0],
+			pos[1], tc[1]);
+
+	if (tangent.getLength3() < 0.01)
+	{
+		tangent.set(1,0,0,1);
+	}
+	else
+	{
+		LLVector4a default_tangent;
+		default_tangent.set(1,0,0,1);
+		tangent.normalize3fast_checked(&default_tangent);
+	}
+
+	LLVector4a normal;
+	LLVector4a d0, d1;
+
+	d0.setSub(*mCenter, pos[0]);
+	d1.setSub(*mCenter, pos[1]);
+	
+	if (mTypeMask & TOP_MASK)
+	{
+		normal.setCross3(d0, d1);
+	}
+	else
+	{
+		normal.setCross3(d1, d0);
+	}
+
+	normal.normalize3fast_checked();
+
 	VertexData vd;
 	vd.setPosition(*mCenter);
 	vd.mTexCoord = cuv;
@@ -6318,6 +6431,14 @@ BOOL LLVolumeFace::createCap(LLVolume* volume, BOOL partial_build)
 		num_vertices++;
 	}
 		
+	allocateTangents(num_vertices);		
+
+	for (S32 i = 0; i < num_vertices; i++)
+	{
+		mTangents[i].load4a(tangent.getF32ptr());
+		norm[i].load4a(normal.getF32ptr());
+	}	
+
 	if (partial_build)
 	{
 		return TRUE;
@@ -6553,36 +6674,6 @@ BOOL LLVolumeFace::createCap(LLVolume* volume, BOOL partial_build)
 
 	}
 
-	LLVector4a d0,d1;
-
-	d0.setSub(mPositions[mIndices[1]], mPositions[mIndices[0]]);
-	d1.setSub(mPositions[mIndices[2]], mPositions[mIndices[0]]);
-
-	LLVector4a normal;
-	normal.setCross3(d0,d1);
-
-	if (normal.dot3(normal).getF32() > F_APPROXIMATELY_ZERO)
-	{
-		normal.normalize3fast();
-	}
-	else
-	{ //degenerate, make up a value
-		normal.set(0,0,1);
-	}
-
-	llassert(llfinite(normal.getF32ptr()[0]));
-	llassert(llfinite(normal.getF32ptr()[1]));
-	llassert(llfinite(normal.getF32ptr()[2]));
-
-	llassert(!llisnan(normal.getF32ptr()[0]));
-	llassert(!llisnan(normal.getF32ptr()[1]));
-	llassert(!llisnan(normal.getF32ptr()[2]));
-	
-	for (S32 i = 0; i < num_vertices; i++)
-	{
-		norm[i].load4a(normal.getF32ptr());
-	}
-
 	return TRUE;
 }
 
@@ -6611,11 +6702,13 @@ void LLVolumeFace::createTangents()
 		CalculateTangentArray(mNumVertices, mPositions, mNormals, mTexCoords, mNumIndices/3, mIndices, mTangents);
 
 		//normalize tangents
+		LLVector4a default_norm;
+		default_norm.set(0,1,0,1);
 		for (U32 i = 0; i < mNumVertices; i++) 
 		{
-			//binorm[i].normalize3fast();
+			//tangent[i].normalize3fast();
 			//bump map/planar projection code requires normals to be normalized
-			mNormals[i].normalize3fast();
+			mNormals[i].normalize3fast_checked();
 		}
 	}
 }
@@ -6800,7 +6893,7 @@ void LLVolumeFace::appendFace(const LLVolumeFace& face, LLMatrix4& mat_in, LLMat
 
 		//transform appended face normal and store
 		norm_mat.rotate(src_norm[i], dst_norm[i]);
-		dst_norm[i].normalize3fast();
+		dst_norm[i].normalize3fast_checked();
 
 		//copy appended face texture coordinate
 		dst_tc[i] = src_tc[i];
@@ -7209,11 +7302,61 @@ BOOL LLVolumeFace::createSide(LLVolume* volume, BOOL partial_build)
 	return TRUE;
 }
 
+// Finds binormal based on three vertices with texture coordinates.
+// Fills in dummy values if the triangle has degenerate texture coordinates.
+void calc_binormal_from_triangle(LLVector4a& binormal,
+
+	const LLVector4a& pos0,
+	const LLVector2& tex0,
+	const LLVector4a& pos1,
+	const LLVector2& tex1,
+	const LLVector4a& pos2,
+	const LLVector2& tex2)
+{
+	LLVector4a rx0( pos0[VX], tex0.mV[VX], tex0.mV[VY] );
+	LLVector4a rx1( pos1[VX], tex1.mV[VX], tex1.mV[VY] );
+	LLVector4a rx2( pos2[VX], tex2.mV[VX], tex2.mV[VY] );
+	
+	LLVector4a ry0( pos0[VY], tex0.mV[VX], tex0.mV[VY] );
+	LLVector4a ry1( pos1[VY], tex1.mV[VX], tex1.mV[VY] );
+	LLVector4a ry2( pos2[VY], tex2.mV[VX], tex2.mV[VY] );
+
+	LLVector4a rz0( pos0[VZ], tex0.mV[VX], tex0.mV[VY] );
+	LLVector4a rz1( pos1[VZ], tex1.mV[VX], tex1.mV[VY] );
+	LLVector4a rz2( pos2[VZ], tex2.mV[VX], tex2.mV[VY] );
+	
+	LLVector4a lhs, rhs;
+
+	LLVector4a r0; 
+	lhs.setSub(rx0, rx1); rhs.setSub(rx0, rx2);
+	r0.setCross3(lhs, rhs);
+		
+	LLVector4a r1;
+	lhs.setSub(ry0, ry1); rhs.setSub(ry0, ry2);
+	r1.setCross3(lhs, rhs);
+
+	LLVector4a r2;
+	lhs.setSub(rz0, rz1); rhs.setSub(rz0, rz2);
+	r2.setCross3(lhs, rhs);
+
+	if( r0[VX] && r1[VX] && r2[VX] )
+	{
+		binormal.set(
+				-r0[VZ] / r0[VX],
+				-r1[VZ] / r1[VX],
+				-r2[VZ] / r2[VX]);
+		// binormal.normVec();
+	}
+	else
+	{
+		binormal.set( 0, 1 , 0 );
+	}
+}
+
 //adapted from Lengyel, Eric. “Computing Tangent Space Basis Vectors for an Arbitrary Mesh”. Terathon Software 3D Graphics Library, 2001. http://www.terathon.com/code/tangent.html
 void CalculateTangentArray(U32 vertexCount, const LLVector4a *vertex, const LLVector4a *normal,
         const LLVector2 *texcoord, U32 triangleCount, const U16* index_array, LLVector4a *tangent)
 {
-    //LLVector4a *tan1 = new LLVector4a[vertexCount * 2];
 	LLVector4a* tan1 = (LLVector4a*) ll_aligned_malloc_16(vertexCount*2*sizeof(LLVector4a));
 
     LLVector4a* tan2 = tan1 + vertexCount;