OpenSubdiv: Prepare majority of things to have proper subdivided UV

Mainly the changes are related on establishing API to feed UV islands
to OpenSubdiv, so it will know all the connectivity information and
will be able to do proper interpolation.

Island calculation is currently rather slow, not sure how to make it
fast and not use lots of allocations.

Shouldn't be THAT bad, since this code is only runs once when creating
OSD mesh, and it's probably still faster than our orientation code.

1 files changed, 49 insertions, 71 deletions

diff --git a/intern/opensubdiv/opensubdiv_converter.cc b/intern/opensubdiv/opensubdiv_converter.cc
index e6c8985e947..f637f514bf4 100644
--- a/intern/opensubdiv/opensubdiv_converter.cc
+++ b/intern/opensubdiv/opensubdiv_converter.cc
@@ -53,6 +53,11 @@ inline void reverse_face_verts(int *face_verts, int num_verts)
 	face_verts[0] = last_vert;
 }
 
+struct TopologyRefinerData {
+	const OpenSubdiv_Converter& conv;
+	std::vector<float> *uvs;
+};
+
 }  /* namespace */
 #endif /* OPENSUBDIV_ORIENT_TOPOLOGY */
 
@@ -141,10 +146,11 @@ inline void check_oriented_vert_connectivity(const int num_vert_edges,
 }  /* namespace */
 
 template <>
-inline bool TopologyRefinerFactory<OpenSubdiv_Converter>::resizeComponentTopology(
+inline bool TopologyRefinerFactory<TopologyRefinerData>::resizeComponentTopology(
         TopologyRefiner& refiner,
-        const OpenSubdiv_Converter& conv)
+        const TopologyRefinerData& cb_data)
 {
+	const OpenSubdiv_Converter& conv = cb_data.conv;
 	/* Faces and face-verts */
 	const int num_faces = conv.get_num_faces(&conv);
 	setNumBaseFaces(refiner, num_faces);
@@ -172,10 +178,11 @@ inline bool TopologyRefinerFactory<OpenSubdiv_Converter>::resizeComponentTopolog
 }
 
 template <>
-inline bool TopologyRefinerFactory<OpenSubdiv_Converter>::assignComponentTopology(
+inline bool TopologyRefinerFactory<TopologyRefinerData>::assignComponentTopology(
 	  TopologyRefiner& refiner,
-        const OpenSubdiv_Converter& conv)
+	  const TopologyRefinerData &cb_data)
 {
+	const OpenSubdiv_Converter& conv = cb_data.conv;
 	using Far::IndexArray;
 	/* Face relations. */
 	const int num_faces = conv.get_num_faces(&conv);
@@ -430,10 +437,11 @@ inline bool TopologyRefinerFactory<OpenSubdiv_Converter>::assignComponentTopolog
 };
 
 template <>
-inline bool TopologyRefinerFactory<OpenSubdiv_Converter>::assignComponentTags(
+inline bool TopologyRefinerFactory<TopologyRefinerData>::assignComponentTags(
         TopologyRefiner& refiner,
-        const OpenSubdiv_Converter& conv)
+        const TopologyRefinerData& cb_data)
 {
+	const OpenSubdiv_Converter& conv = cb_data.conv;
 	typedef OpenSubdiv::Sdc::Crease Crease;
 
 	int num_edges = conv.get_num_edges(&conv);
@@ -480,43 +488,48 @@ inline bool TopologyRefinerFactory<OpenSubdiv_Converter>::assignComponentTags(
 }
 
 template <>
-inline void TopologyRefinerFactory<OpenSubdiv_Converter>::reportInvalidTopology(
+inline void TopologyRefinerFactory<TopologyRefinerData>::reportInvalidTopology(
         TopologyError /*errCode*/,
         const char *msg,
-        const OpenSubdiv_Converter& /*mesh*/)
+        const TopologyRefinerData& /*mesh*/)
 {
 	printf("OpenSubdiv Error: %s\n", msg);
 }
 
 template <>
-inline bool TopologyRefinerFactory<OpenSubdiv_Converter>::assignFaceVaryingTopology(
+inline bool TopologyRefinerFactory<TopologyRefinerData>::assignFaceVaryingTopology(
         TopologyRefiner& refiner,
-        const OpenSubdiv_Converter& conv)
+        const TopologyRefinerData& cb_data)
 {
-	if (conv.get_num_uv_layers(&conv) <= 0) {
+	const OpenSubdiv_Converter& conv = cb_data.conv;
+	const int num_layers = conv.get_num_uv_layers(&conv);
+	if (num_layers <= 0) {
 		/* No UV maps, we can skip any face-varying data. */
 		return true;
 	}
-	/* Count overall number of UV data.
-	 * NOTE: We only do single UV layer here, and we don't "merge" loops
-	 * together as it is done in OpenSubdiv examples.x
-	 */
 	const int num_faces = getNumBaseFaces(refiner);
-	int num_uvs = 0;
-	for (int face = 0; face < num_faces; ++face) {
-		IndexArray face_verts = getBaseFaceVertices(refiner, face);
-		num_uvs += face_verts.size();
-	}
-	/* Fill in actual UV offsets. */
-	const int channel = createBaseFVarChannel(refiner, num_uvs);
-	for (int face = 0, offset = 0; face < num_faces; ++face) {
-		Far::IndexArray dst_face_uvs = getBaseFaceFVarValues(refiner,
-		                                                     face,
-		                                                     channel);
-		for (int corner = 0; corner < dst_face_uvs.size(); ++corner) {
-			dst_face_uvs[corner] = offset;
-			++offset;
+	for (int layer = 0; layer < num_layers; ++layer) {
+		conv.precalc_uv_layer(&conv, layer);
+		const int num_uvs = conv.get_num_uvs(&conv);
+		/* Fill in UV coordinates. */
+		cb_data.uvs->resize(num_uvs * 2);
+		conv.get_uvs(&conv, &cb_data.uvs->at(0));
+		/* Fill in per-corner index of the UV. */
+		const int channel = createBaseFVarChannel(refiner, num_uvs);
+		for (int face = 0; face < num_faces; ++face) {
+			Far::IndexArray dst_face_uvs = getBaseFaceFVarValues(refiner,
+			                                                     face,
+			                                                     channel);
+			for (int corner = 0; corner < dst_face_uvs.size(); ++corner) {
+				const int uv_index = conv.get_face_corner_uv_index(&conv,
+				                                                   face,
+				                                                   corner);
+				dst_face_uvs[corner] = uv_index;
+			}
 		}
+		conv.finish_uv_layer(&conv);
+		/* TODO(sergey): Single layer only for now. */
+		break;
 	}
 	return true;
 }
@@ -541,33 +554,6 @@ OpenSubdiv::Sdc::SchemeType get_capi_scheme_type(OpenSubdiv_SchemeType type)
 	return OpenSubdiv::Sdc::SCHEME_CATMARK;
 }
 
-static void import_fvar_data(OpenSubdiv_TopologyRefinerDescr *result,
-                             const OpenSubdiv_Converter& conv)
-{
-	const int num_layers = conv.get_num_uv_layers(&conv),
-	          num_faces = conv.get_num_faces(&conv);
-	/* Pre-allocate values in one go. */
-	int num_fvar_values = 0;
-	for (int layer = 0; layer < num_layers; ++layer) {
-		num_fvar_values = result->osd_refiner->GetNumFVarValuesTotal();
-	}
-	result->uvs.resize(num_fvar_values * 2);
-	/* Fill in all channels. */
-	for (int layer = 0, offset = 0; layer < num_layers; ++layer) {
-		for (int face = 0; face < num_faces; ++face) {
-			const int num_verts = conv.get_num_face_verts(&conv, face);
-			for (int vert = 0; vert < num_verts; ++vert) {
-				float uv[2];
-				conv.get_face_corner_uv(&conv, face, vert, uv);
-				result->uvs[offset++] = uv[0];
-				result->uvs[offset++] = uv[1];
-			}
-		}
-		/* TODO(sergey): Currently we only support first layer only. */
-		break;
-	}
-}
-
 }  /* namespace */
 
 struct OpenSubdiv_TopologyRefinerDescr *openSubdiv_createTopologyRefinerDescr(
@@ -581,33 +567,25 @@ struct OpenSubdiv_TopologyRefinerDescr *openSubdiv_createTopologyRefinerDescr(
 	Options options;
 	options.SetVtxBoundaryInterpolation(Options::VTX_BOUNDARY_EDGE_ONLY);
 	options.SetCreasingMethod(Options::CREASE_UNIFORM);
-	options.SetFVarLinearInterpolation(Options::FVAR_LINEAR_ALL);
+	/* TODO(sergey): Get proper UV subdivide flag. */
+	// options.SetFVarLinearInterpolation(Options::FVAR_LINEAR_ALL);
+	options.SetFVarLinearInterpolation(Options::FVAR_LINEAR_CORNERS_ONLY);
 
-	TopologyRefinerFactory<OpenSubdiv_Converter>::Options
+	TopologyRefinerFactory<TopologyRefinerData>::Options
 	        topology_options(scheme_type, options);
 #ifdef OPENSUBDIV_VALIDATE_TOPOLOGY
 	topology_options.validateFullTopology = true;
 #endif
 	OpenSubdiv_TopologyRefinerDescr *result = OBJECT_GUARDED_NEW(OpenSubdiv_TopologyRefinerDescr);
+	TopologyRefinerData cb_data = {*converter, &result->uvs};
 	/* We don't use guarded allocation here so we can re-use the refiner
 	 * for GL mesh creation directly.
 	 */
 	result->osd_refiner =
-	        TopologyRefinerFactory<OpenSubdiv_Converter>::Create(
-	                *converter,
+	        TopologyRefinerFactory<TopologyRefinerData>::Create(
+	                cb_data,
 	                topology_options);
 
-	if (result->osd_refiner->GetNumFVarChannels() > 0) {
-		/* Import face varrying data now since later we wouldn't have
-		 * access to the converter.
-		 *
-		 * TODO(sergey): This is so-called "for now", for until we'll
-		 * find better way to plug OSD to Blender or for until something
-		 * happens inside of OSD API.
-		 */
-		import_fvar_data(result, *converter);
-	}
-
 	return result;
 }