OpenSubdiv: Support for multiple materials in solid shading mode

Implementation is less optimal compared to non-opensubdiv drawing but
it is now as good as we can do it without affecting on how patches are
being created by OpenSubdiv.

4 files changed, 50 insertions, 47 deletions

diff --git a/intern/opensubdiv/opensubdiv_capi.h b/intern/opensubdiv/opensubdiv_capi.h
index c86e739f12b..c09d0326264 100644
--- a/intern/opensubdiv/opensubdiv_capi.h
+++ b/intern/opensubdiv/opensubdiv_capi.h
@@ -135,8 +135,8 @@ void openSubdiv_osdGLMeshDisplayPrepare(int use_osd_glsl,
 /* Draw patches which corresponds to a given partition. */
 void openSubdiv_osdGLMeshDisplay(OpenSubdiv_GLMesh *gl_mesh,
                                  int fill_quads,
-                                 int start_partition,
-                                 int num_partitions);
+                                 int start_patch,
+                                 int num_patches);
 
 /* ** Utility functions ** */
 int openSubdiv_supportGPUDisplay(void);
diff --git a/intern/opensubdiv/opensubdiv_converter.cc b/intern/opensubdiv/opensubdiv_converter.cc
index 09880742895..5d43cafd1f3 100644
--- a/intern/opensubdiv/opensubdiv_converter.cc
+++ b/intern/opensubdiv/opensubdiv_converter.cc
@@ -574,6 +574,17 @@ int openSubdiv_topologyRefinerGetNumFaces(
 	return base_level.GetNumFaces();
 }
 
+int openSubdiv_topologyRefinerGetNumFaceVerts(
+        const OpenSubdiv_TopologyRefinerDescr *topology_refiner,
+        int face)
+{
+	using OpenSubdiv::Far::TopologyLevel;
+	using OpenSubdiv::Far::TopologyRefiner;
+	const TopologyRefiner *refiner = (const TopologyRefiner *)topology_refiner;
+	const TopologyLevel &base_level = refiner->GetLevel(0);
+	return base_level.GetFaceVertices(face).size();
+}
+
 int openSubdiv_topologyRefnerCompareConverter(
         const OpenSubdiv_TopologyRefinerDescr *topology_refiner,
         OpenSubdiv_Converter *converter)
diff --git a/intern/opensubdiv/opensubdiv_converter_capi.h b/intern/opensubdiv/opensubdiv_converter_capi.h
index 7c96d3d8b96..ac1e8301a42 100644
--- a/intern/opensubdiv/opensubdiv_converter_capi.h
+++ b/intern/opensubdiv/opensubdiv_converter_capi.h
@@ -94,7 +94,7 @@ void openSubdiv_deleteTopologyRefinerDescr(
         OpenSubdiv_TopologyRefinerDescr *topology_refiner);
 
 /* TODO(sergey): Those calls are not strictly related on conversion.
- * needs some dedicated fiel perhaps.
+ * needs some dedicated file perhaps.
  */
 
 int openSubdiv_topologyRefinerGetSubdivLevel(
@@ -109,6 +109,10 @@ int openSubdiv_topologyRefinerGetNumEdges(
 int openSubdiv_topologyRefinerGetNumFaces(
         const OpenSubdiv_TopologyRefinerDescr *topology_refiner);
 
+int openSubdiv_topologyRefinerGetNumFaceVerts(
+        const OpenSubdiv_TopologyRefinerDescr *topology_refiner,
+        int face);
+
 int openSubdiv_topologyRefnerCompareConverter(
         const OpenSubdiv_TopologyRefinerDescr *topology_refiner,
         OpenSubdiv_Converter *converter);
diff --git a/intern/opensubdiv/opensubdiv_gpu_capi.cc b/intern/opensubdiv/opensubdiv_gpu_capi.cc
index 9498f936b6b..803265dbe28 100644
--- a/intern/opensubdiv/opensubdiv_gpu_capi.cc
+++ b/intern/opensubdiv/opensubdiv_gpu_capi.cc
@@ -575,46 +575,41 @@ static void finish_patchDraw(bool fill_quads)
 	}
 }
 
-#if 0
 static void draw_partition_patches_range(PartitionedGLMeshInterface *mesh,
                                          GLuint program,
-                                         int start_partition,
-                                         int num_partitions)
+                                         int start_patch,
+                                         int num_patches)
 {
-	/* Glue patches from all partitions in the range together. */
-	int patch_index = -1, start_element = -1, num_elements = 0;
-	for (int partition = start_partition;
-	     partition < start_partition + num_partitions;
-	     ++partition)
-	{
-		OsdDrawContext::PatchArrayVector const &patches =
-		        mesh->GetPatchArrays(partition);
-		for (int i = 0; i < (int)patches.size(); ++i) {
-			OsdDrawContext::PatchArray const &patch = patches[i];
-			OsdDrawContext::PatchDescriptor desc = patch.GetDescriptor();
-			OpenSubdiv::FarPatchTables::Type patchType = desc.GetType();
-			if (patchType == OpenSubdiv::FarPatchTables::QUADS) {
-				if (start_element == -1) {
-					patch_index = patch.GetPatchIndex();
-					start_element = patch.GetVertIndex();
-				}
+	int traversed_patches = 0, num_remained_patches = num_patches;
+	const OpenSubdiv::Osd::PatchArrayVector& patches =
+	        mesh->GetPatchTable()->GetPatchArrays();
+	for (int i = 0; i < (int)patches.size(); ++i) {
+		const OpenSubdiv::Osd::PatchArray& patch = patches[i];
+		OpenSubdiv::Far::PatchDescriptor desc = patch.GetDescriptor();
+		OpenSubdiv::Far::PatchDescriptor::Type patchType = desc.GetType();
 
-				assert(patch.GetVertIndex() == start_element + num_elements);
-				num_elements += patch.GetNumIndices();
+		if (patchType == OpenSubdiv::Far::PatchDescriptor::QUADS) {
+			const int num_block_patches = patch.GetNumPatches();
+			if (start_patch >= traversed_patches &&
+			    start_patch < traversed_patches + num_block_patches)
+			{
+				const int num_control_verts = desc.GetNumControlVertices();
+				const int start_draw_patch = start_patch - traversed_patches;
+				const int num_draw_patches = std::min(num_remained_patches,
+				                                      num_block_patches - start_draw_patch);
+				perform_drawElements(program,
+				                     i,
+				                     num_draw_patches * num_control_verts,
+				                     patch.GetIndexBase() + start_draw_patch * num_control_verts);
+				num_remained_patches -= num_draw_patches;
 			}
-			else {
-				assert(!"Discontinuitied are not supported yet.");
+			if (num_remained_patches == 0) {
+				break;
 			}
+			traversed_patches += num_block_patches;
 		}
-	}
-
-	/* Perform actual draw. */
-	perform_drawElements(program,
-	                     patch_index,
-	                     num_elements,
-	                     start_element);
+    }
 }
-#endif
 
 static void draw_all_patches(PartitionedGLMeshInterface *mesh,
                              GLuint program)
@@ -637,8 +632,8 @@ static void draw_all_patches(PartitionedGLMeshInterface *mesh,
 
 void openSubdiv_osdGLMeshDisplay(OpenSubdiv_GLMesh *gl_mesh,
                                  int fill_quads,
-                                 int start_partition,
-                                 int num_partitions)
+                                 int start_patch,
+                                 int num_patches)
 {
 	PartitionedGLMeshInterface *mesh =
 		(PartitionedGLMeshInterface *)(gl_mesh->descriptor);
@@ -649,18 +644,11 @@ void openSubdiv_osdGLMeshDisplay(OpenSubdiv_GLMesh *gl_mesh,
 	/* Setup GLSL/OpenGL to draw patches in current context. */
 	GLuint program = preapre_patchDraw(mesh, fill_quads != 0);
 
-	if (start_partition != -1) {
-#if 0
+	if (start_patch != -1) {
 		draw_partition_patches_range(mesh,
 		                             program,
-		                             start_partition,
-		                             num_partitions);
-#else
-		(void)num_partitions;
-		if(start_partition == 0) {
-			draw_all_patches(mesh, program);
-		}
-#endif
+		                             start_patch,
+		                             num_patches);
 	}
 	else {
 		draw_all_patches(mesh, program);