UI: Add Sculpt Session info to stats

This adds the vertex and face count info to the scene stats in sculpt
mode. These stats count the active vertices and faces in the
sculptsession for the active object. This has the following advantages:
- It is possible to know how many vertices the sculptsession has active
comparted to the vertex count of the entire scene from sculpt mode
- When sculpting with constructive modifiers, these stats will report the
number of vertices that you can actually sculpt with, instead of the
vertex count of the modified mesh and the entire scene.

Reviewed By: sergey, dbystedt

Differential Revision: https://developer.blender.org/D9623

3 files changed, 56 insertions, 15 deletions

diff --git a/source/blender/blenkernel/BKE_pbvh.h b/source/blender/blenkernel/BKE_pbvh.h
index cd213b49c5b..fd600a41796 100644
--- a/source/blender/blenkernel/BKE_pbvh.h
+++ b/source/blender/blenkernel/BKE_pbvh.h
@@ -235,6 +235,7 @@ const struct CCGKey *BKE_pbvh_get_grid_key(const PBVH *pbvh);
 struct CCGElem **BKE_pbvh_get_grids(const PBVH *pbvh);
 BLI_bitmap **BKE_pbvh_get_grid_visibility(const PBVH *pbvh);
 int BKE_pbvh_get_grid_num_vertices(const PBVH *pbvh);
+int BKE_pbvh_get_grid_num_faces(const PBVH *pbvh);
 
 /* Only valid for type == PBVH_BMESH */
 struct BMesh *BKE_pbvh_get_bmesh(PBVH *pbvh);
diff --git a/source/blender/blenkernel/intern/pbvh.c b/source/blender/blenkernel/intern/pbvh.c
index ab87772d844..47d2ae8e283 100644
--- a/source/blender/blenkernel/intern/pbvh.c
+++ b/source/blender/blenkernel/intern/pbvh.c
@@ -1707,6 +1707,12 @@ int BKE_pbvh_get_grid_num_vertices(const PBVH *pbvh)
   return pbvh->totgrid * pbvh->gridkey.grid_area;
 }
 
+int BKE_pbvh_get_grid_num_faces(const PBVH *pbvh)
+{
+  BLI_assert(pbvh->type == PBVH_GRIDS);
+  return pbvh->totgrid * (pbvh->gridkey.grid_size - 1) * (pbvh->gridkey.grid_size - 1);
+}
+
 BMesh *BKE_pbvh_get_bmesh(PBVH *pbvh)
 {
   BLI_assert(pbvh->type == PBVH_BMESH);
diff --git a/source/blender/editors/space_info/info_stats.c b/source/blender/editors/space_info/info_stats.c
index bf21b383ba6..43d0d4fc425 100644
--- a/source/blender/editors/space_info/info_stats.c
+++ b/source/blender/editors/space_info/info_stats.c
@@ -55,6 +55,7 @@
 #include "BKE_object.h"
 #include "BKE_paint.h"
 #include "BKE_particle.h"
+#include "BKE_pbvh.h"
 #include "BKE_scene.h"
 #include "BKE_subdiv_ccg.h"
 
@@ -69,9 +70,9 @@
 #define MAX_INFO_NUM_LEN 16
 
 typedef struct SceneStats {
-  uint64_t totvert, totvertsel;
+  uint64_t totvert, totvertsel, totvertsculpt;
   uint64_t totedge, totedgesel;
-  uint64_t totface, totfacesel;
+  uint64_t totface, totfacesel, totfacesculpt;
   uint64_t totbone, totbonesel;
   uint64_t totobj, totobjsel;
   uint64_t totlamp, totlampsel;
@@ -81,9 +82,9 @@ typedef struct SceneStats {
 
 typedef struct SceneStatsFmt {
   /* Totals */
-  char totvert[MAX_INFO_NUM_LEN], totvertsel[MAX_INFO_NUM_LEN];
+  char totvert[MAX_INFO_NUM_LEN], totvertsel[MAX_INFO_NUM_LEN], totvertsculpt[MAX_INFO_NUM_LEN];
   char totface[MAX_INFO_NUM_LEN], totfacesel[MAX_INFO_NUM_LEN];
-  char totedge[MAX_INFO_NUM_LEN], totedgesel[MAX_INFO_NUM_LEN];
+  char totedge[MAX_INFO_NUM_LEN], totedgesel[MAX_INFO_NUM_LEN], totfacesculpt[MAX_INFO_NUM_LEN];
   char totbone[MAX_INFO_NUM_LEN], totbonesel[MAX_INFO_NUM_LEN];
   char totobj[MAX_INFO_NUM_LEN], totobjsel[MAX_INFO_NUM_LEN];
   char totlamp[MAX_INFO_NUM_LEN], totlampsel[MAX_INFO_NUM_LEN];
@@ -350,15 +351,34 @@ static void stats_object_pose(Object *ob, SceneStats *stats)
   }
 }
 
-static void stats_object_sculpt_dynamic_topology(Object *ob, SceneStats *stats)
+static bool stats_is_object_dynamic_topology_sculpt(Object *ob, const eObjectMode object_mode)
 {
-  stats->totvert = ob->sculpt->bm->totvert;
-  stats->tottri = ob->sculpt->bm->totface;
+  return (ob && (object_mode & OB_MODE_SCULPT) && ob->sculpt && ob->sculpt->bm);
 }
 
-static bool stats_is_object_dynamic_topology_sculpt(Object *ob, const eObjectMode object_mode)
+static void stats_object_sculpt(Object *ob, SceneStats *stats)
 {
-  return (ob && (object_mode & OB_MODE_SCULPT) && ob->sculpt && ob->sculpt->bm);
+
+  SculptSession *ss = ob->sculpt;
+
+  if (!ss) {
+    return;
+  }
+
+  switch (BKE_pbvh_type(ss->pbvh)) {
+    case PBVH_FACES:
+      stats->totvertsculpt = ss->totvert;
+      stats->totfacesculpt = ss->totfaces;
+      break;
+    case PBVH_BMESH:
+      stats->totvertsculpt = ob->sculpt->bm->totvert;
+      stats->tottri = ob->sculpt->bm->totface;
+      break;
+    case PBVH_GRIDS:
+      stats->totvertsculpt = BKE_pbvh_get_grid_num_vertices(ss->pbvh);
+      stats->totfacesculpt = BKE_pbvh_get_grid_num_faces(ss->pbvh);
+      break;
+  }
 }
 
 /* Statistics displayed in info header. Called regularly on scene changes. */
@@ -385,9 +405,9 @@ static void stats_update(Depsgraph *depsgraph, ViewLayer *view_layer)
     /* Pose Mode */
     stats_object_pose(ob, &stats);
   }
-  else if (ob && stats_is_object_dynamic_topology_sculpt(ob, ob->mode)) {
-    /* Dynamic-topology sculpt mode */
-    stats_object_sculpt_dynamic_topology(ob, &stats);
+  else if (stats_is_object_dynamic_topology_sculpt(ob, ob->mode)) {
+    /* Dynamic topology. Do not count all vertices, dynamic topology stats are initialized later as
+     * part of sculpt stats. */
   }
   else {
     /* Objects */
@@ -399,6 +419,12 @@ static void stats_update(Depsgraph *depsgraph, ViewLayer *view_layer)
     BLI_gset_free(objects_gset, NULL);
   }
 
+  if (ob && (ob->mode & OB_MODE_SCULPT)) {
+    /* Sculpt Mode. When dynamic topology is not enabled both sculpt stats and scene stats are
+     * collected. */
+    stats_object_sculpt(ob, &stats);
+  }
+
   if (!view_layer->stats) {
     view_layer->stats = MEM_callocN(sizeof(SceneStats), "SceneStats");
   }
@@ -437,12 +463,14 @@ static bool format_stats(Main *bmain,
 
   SCENE_STATS_FMT_INT(totvert);
   SCENE_STATS_FMT_INT(totvertsel);
+  SCENE_STATS_FMT_INT(totvertsculpt);
 
   SCENE_STATS_FMT_INT(totedge);
   SCENE_STATS_FMT_INT(totedgesel);
 
   SCENE_STATS_FMT_INT(totface);
   SCENE_STATS_FMT_INT(totfacesel);
+  SCENE_STATS_FMT_INT(totfacesculpt);
 
   SCENE_STATS_FMT_INT(totbone);
   SCENE_STATS_FMT_INT(totbonesel);
@@ -727,9 +755,15 @@ void ED_info_draw_stats(
     stats_row(col1, labels[STROKES], col2, stats_fmt.totgpstroke, NULL, y, height);
     stats_row(col1, labels[POINTS], col2, stats_fmt.totgppoint, NULL, y, height);
   }
-  else if (stats_is_object_dynamic_topology_sculpt(ob, object_mode)) {
-    stats_row(col1, labels[VERTS], col2, stats_fmt.totvert, NULL, y, height);
-    stats_row(col1, labels[TRIS], col2, stats_fmt.tottri, NULL, y, height);
+  else if (ob && (object_mode & OB_MODE_SCULPT)) {
+    if (stats_is_object_dynamic_topology_sculpt(ob, object_mode)) {
+      stats_row(col1, labels[VERTS], col2, stats_fmt.totvertsculpt, NULL, y, height);
+      stats_row(col1, labels[TRIS], col2, stats_fmt.tottri, NULL, y, height);
+    }
+    else {
+      stats_row(col1, labels[VERTS], col2, stats_fmt.totvertsculpt, stats_fmt.totvert, y, height);
+      stats_row(col1, labels[FACES], col2, stats_fmt.totfacesculpt, stats_fmt.totface, y, height);
+    }
   }
   else {
     stats_row(col1, labels[VERTS], col2, stats_fmt.totvert, NULL, y, height);