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.

7 files changed, 144 insertions, 63 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);
diff --git a/source/blender/blenkernel/intern/CCGSubSurf.h b/source/blender/blenkernel/intern/CCGSubSurf.h
index e9ad4c52531..a825cffe7a0 100644
--- a/source/blender/blenkernel/intern/CCGSubSurf.h
+++ b/source/blender/blenkernel/intern/CCGSubSurf.h
@@ -215,6 +215,12 @@ bool ccgSubSurf_prepareGLMesh(CCGSubSurf *ss, bool use_osd_glsl);
 void ccgSubSurf_drawGLMesh(CCGSubSurf *ss, bool fill_quads,
                            int start_partition, int num_partitions);
 
+/* Get number of base faces in a particular GL mesh. */
+int ccgSubSurf_getNumGLMeshBaseFaces(CCGSubSurf *ss);
+
+/* Get number of vertices in base faces in a particular GL mesh. */
+int ccgSubSurf_getNumGLMeshBaseFaceVerts(CCGSubSurf *ss, int face);
+
 /* Controls whether CCG are needed (Cmeaning CPU evaluation) or fully GPU compute
  * and draw is allowed.
  */
diff --git a/source/blender/blenkernel/intern/CCGSubSurf_opensubdiv.c b/source/blender/blenkernel/intern/CCGSubSurf_opensubdiv.c
index eb7c3bf6ffd..fcc46308efa 100644
--- a/source/blender/blenkernel/intern/CCGSubSurf_opensubdiv.c
+++ b/source/blender/blenkernel/intern/CCGSubSurf_opensubdiv.c
@@ -308,6 +308,31 @@ void ccgSubSurf_drawGLMesh(CCGSubSurf *ss, bool fill_quads,
 	}
 }
 
+int ccgSubSurf_getNumGLMeshBaseFaces(CCGSubSurf *ss)
+{
+	const OpenSubdiv_TopologyRefinerDescr *topology_refiner;
+	if (ss->osd_topology_refiner != NULL) {
+		topology_refiner = ss->osd_topology_refiner;
+	}
+	else {
+		topology_refiner = openSubdiv_getGLMeshTopologyRefiner(ss->osd_mesh);
+	}
+	return openSubdiv_topologyRefinerGetNumFaces(topology_refiner);
+}
+
+/* Get number of vertices in base faces in a particular GL mesh. */
+int ccgSubSurf_getNumGLMeshBaseFaceVerts(CCGSubSurf *ss, int face)
+{
+	const OpenSubdiv_TopologyRefinerDescr *topology_refiner;
+	if (ss->osd_topology_refiner != NULL) {
+		topology_refiner = ss->osd_topology_refiner;
+	}
+	else {
+		topology_refiner = openSubdiv_getGLMeshTopologyRefiner(ss->osd_mesh);
+	}
+	return openSubdiv_topologyRefinerGetNumFaceVerts(topology_refiner, face);
+}
+
 void ccgSubSurf_setSkipGrids(CCGSubSurf *ss, bool skip_grids)
 {
 	ss->skip_grids = skip_grids;
diff --git a/source/blender/blenkernel/intern/subsurf_ccg.c b/source/blender/blenkernel/intern/subsurf_ccg.c
index e38d62cd9bc..867065b060d 100644
--- a/source/blender/blenkernel/intern/subsurf_ccg.c
+++ b/source/blender/blenkernel/intern/subsurf_ccg.c
@@ -2622,24 +2622,72 @@ static void ccgDM_drawFacesSolid(DerivedMesh *dm, float (*partial_redraw_planes)
 #ifdef WITH_OPENSUBDIV
 	if (ccgdm->useGpuBackend) {
 		CCGSubSurf *ss = ccgdm->ss;
-		DMFlagMat *faceFlags = ccgdm->faceFlags;
-		int new_matnr;
-		bool draw_smooth;
+		const DMFlagMat *faceFlags = ccgdm->faceFlags;
+		const int level = ccgSubSurf_getSubdivisionLevels(ss);
+		const int face_side = 1 << level;
+		const int grid_side = 1 << (level - 1);
+		const int face_patches = face_side * face_side;
+		const int grid_patches = grid_side * grid_side;
+		const int num_base_faces = ccgSubSurf_getNumGLMeshBaseFaces(ss);
+		int i, current_patch = 0;
+		int mat_nr = -1;
+		bool draw_smooth = false;
+		int start_draw_patch = -1, num_draw_patches = 0;
 		if (UNLIKELY(ccgSubSurf_prepareGLMesh(ss, setMaterial != NULL) == false)) {
 			return;
 		}
-		/* TODO(sergey): Single matierial currently. */
-		if (faceFlags) {
-			draw_smooth = (faceFlags[0].flag & ME_SMOOTH);
-			new_matnr = (faceFlags[0].mat_nr + 1);
-		}
-		else {
-			draw_smooth = true;
-			new_matnr = 1;
+		if (setMaterial == NULL) {
+			ccgSubSurf_drawGLMesh(ss,
+			                      true,
+			                      -1,
+			                      -1);
+			return;
 		}
-		if (setMaterial && setMaterial(new_matnr, NULL)) {
-			glShadeModel(draw_smooth ? GL_SMOOTH : GL_FLAT);
-			ccgSubSurf_drawGLMesh(ss, true, -1, -1);
+		for (i = 0; i < num_base_faces; ++i) {
+			const int num_face_verts = ccgSubSurf_getNumGLMeshBaseFaceVerts(ss, i);
+			const int num_patches = (num_face_verts == 4) ? face_patches
+			                                              : num_face_verts * grid_patches;
+			int new_matnr;
+			bool new_draw_smooth;
+			if (faceFlags) {
+				new_draw_smooth = (faceFlags[i].flag & ME_SMOOTH);
+				new_matnr = (faceFlags[i].mat_nr + 1);
+			}
+			else {
+				new_draw_smooth = true;
+				new_matnr = 1;
+			}
+			if (new_draw_smooth != draw_smooth || new_matnr != mat_nr) {
+				if (num_draw_patches != 0) {
+					bool do_draw = setMaterial == NULL ||
+					               setMaterial(mat_nr, NULL);
+					if (do_draw) {
+						glShadeModel(draw_smooth ? GL_SMOOTH : GL_FLAT);
+						ccgSubSurf_drawGLMesh(ss,
+						                      true,
+						                      start_draw_patch,
+						                      num_draw_patches);
+					}
+				}
+				start_draw_patch = current_patch;
+				num_draw_patches = num_patches;
+				mat_nr = new_matnr;
+				draw_smooth = new_draw_smooth;
+			}
+			else {
+				num_draw_patches += num_patches;
+			}
+			current_patch += num_patches;
+		}
+		if (num_draw_patches != 0) {
+			bool do_draw = setMaterial(mat_nr, NULL);
+			if (do_draw) {
+				glShadeModel(draw_smooth ? GL_SMOOTH : GL_FLAT);
+				ccgSubSurf_drawGLMesh(ss,
+				                      true,
+				                      start_draw_patch,
+				                      num_draw_patches);
+			}
 		}
 		return;
 	}
@@ -4528,8 +4576,7 @@ static void set_ccgdm_gpu_geometry(CCGDerivedMesh *ccgdm, DerivedMesh *dm)
 
 	for (index = 0; index < totface; index++) {
 		faceFlags->flag = mpoly ?  mpoly[index].flag : 0;
-		/* faceFlags->mat_nr = mpoly ? mpoly[index].mat_nr : 0; */
-		faceFlags->mat_nr = 0;
+		faceFlags->mat_nr = mpoly ? mpoly[index].mat_nr : 0;
 		faceFlags++;
 	}