Replace hardcoded DMGridData structure with CCGElem/CCGKey.

* Changes to DerivedMesh interface: DMGridData has been removed,
  getGridData() now returns an array of CCGElem pointers. Also added
  getGridKey() to initialize a CCGKey (implemented only by
  CCGDerivedMesh.)

* PBVH: added BLI_pbvh_get_grid_key().

* A lot of code is affected, but mainly is just replacing
  DMGridData.co, DMGridData.no, and sizeof(DMGridData) with the
  CCG_*_elem functions, removing the reliance on grid elements of
  exactly six floats.

3 files changed, 35 insertions, 22 deletions

diff --git a/source/blender/editors/sculpt_paint/paint_hide.c b/source/blender/editors/sculpt_paint/paint_hide.c
index a3c74b33f9e..ca70a81055c 100644
--- a/source/blender/editors/sculpt_paint/paint_hide.c
+++ b/source/blender/editors/sculpt_paint/paint_hide.c
@@ -45,6 +45,7 @@
 #include "DNA_object_types.h"
 #include "DNA_scene_types.h"
 
+#include "BKE_ccg.h"
 #include "BKE_context.h"
 #include "BKE_DerivedMesh.h"
 #include "BKE_mesh.h"
@@ -141,16 +142,18 @@ static void partialvis_update_grids(Object *ob,
                                     PartialVisArea area,
                                     float planes[4][4])
 {
-	DMGridData **grids;
+	CCGElem **grids;
+	CCGKey key;
 	BLI_bitmap *grid_hidden;
 	int any_visible = 0;
-	int *grid_indices, gridsize, totgrid, any_changed, i;
+	int *grid_indices, totgrid, any_changed, i;
 
 	/* get PBVH data */
 	BLI_pbvh_node_get_grids(pbvh, node,
-	                        &grid_indices, &totgrid, NULL, &gridsize,
-	                        &grids, NULL);
+							&grid_indices, &totgrid, NULL, NULL,
+							&grids, NULL);
 	grid_hidden = BLI_pbvh_grid_hidden(pbvh);
+	BLI_pbvh_get_grid_key(pbvh, &key);
 	
 	sculpt_undo_push_node(ob, node, SCULPT_UNDO_HIDDEN);
 	
@@ -164,8 +167,8 @@ static void partialvis_update_grids(Object *ob,
 			switch (action) {
 				case PARTIALVIS_HIDE:
 					/* create grid flags data */
-					gh = grid_hidden[g] = BLI_BITMAP_NEW(gridsize * gridsize,
-					                                     "partialvis_update_grids");
+					gh = grid_hidden[g] = BLI_BITMAP_NEW(key.grid_area,
+														 "partialvis_update_grids");
 					break;
 				case PARTIALVIS_SHOW:
 					/* entire grid is visible, nothing to show */
@@ -182,21 +185,21 @@ static void partialvis_update_grids(Object *ob,
 			continue;
 		}
 
-		for (y = 0; y < gridsize; y++) {
-			for (x = 0; x < gridsize; x++) {
-				const float *co = grids[g][y * gridsize + x].co;
+		for (y = 0; y < key.grid_size; y++) {
+			for (x = 0; x < key.grid_size; x++) {
+				const float *co = CCG_grid_elem_co(&key, grids[g], x, y);
 
 				/* skip grid element if not in the effected area */
 				if (is_effected(area, planes, co)) {
 					/* set or clear the hide flag */
-					BLI_BITMAP_MODIFY(gh, y * gridsize + x,
-					                  action == PARTIALVIS_HIDE);
+					BLI_BITMAP_MODIFY(gh, y * key.grid_size + x,
+									  action == PARTIALVIS_HIDE);
 
 					any_changed = 1;
 				}
 
 				/* keep track of whether any elements are still hidden */
-				if (BLI_BITMAP_GET(gh, y * gridsize + x))
+				if (BLI_BITMAP_GET(gh, y * key.grid_size + x))
 					any_hidden = 1;
 				else
 					any_visible = 1;
diff --git a/source/blender/editors/sculpt_paint/sculpt.c b/source/blender/editors/sculpt_paint/sculpt.c
index 3edda91e4e4..77f9a444153 100644
--- a/source/blender/editors/sculpt_paint/sculpt.c
+++ b/source/blender/editors/sculpt_paint/sculpt.c
@@ -52,6 +52,7 @@
 #include "DNA_brush_types.h"
 
 #include "BKE_brush.h"
+#include "BKE_ccg.h"
 #include "BKE_cdderivedmesh.h"
 #include "BKE_context.h"
 #include "BKE_depsgraph.h"
@@ -1049,7 +1050,8 @@ static void do_multires_smooth_brush(Sculpt *sd, SculptSession *ss, PBVHNode *no
 {
 	Brush *brush = paint_brush(&sd->paint);
 	SculptBrushTest test;
-	DMGridData **griddata, *data;
+	CCGElem **griddata, *data;
+	CCGKey key;
 	DMGridAdjacency *gridadj, *adj;
 	float (*tmpgrid)[3], (*tmprow)[3];
 	int v1, v2, v3, v4;
@@ -1060,7 +1062,8 @@ static void do_multires_smooth_brush(Sculpt *sd, SculptSession *ss, PBVHNode *no
 	CLAMP(bstrength, 0.0f, 1.0f);
 
 	BLI_pbvh_node_get_grids(ss->pbvh, node, &grid_indices, &totgrid,
-	                        NULL, &gridsize, &griddata, &gridadj);
+							NULL, &gridsize, &griddata, &gridadj);
+	BLI_pbvh_get_grid_key(ss->pbvh, &key);
 
 	#pragma omp critical
 	{
@@ -1078,7 +1081,9 @@ static void do_multires_smooth_brush(Sculpt *sd, SculptSession *ss, PBVHNode *no
 			float tmp[3];
 
 			v1 = y * gridsize;
-			add_v3_v3v3(tmprow[0], data[v1].co, data[v1 + gridsize].co);
+			add_v3_v3v3(tmprow[0],
+						CCG_elem_offset_co(&key, data, v1),
+						CCG_elem_offset_co(&key, data, v1 + gridsize));
 
 			for (x = 0; x < gridsize - 1; x++) {
 				v1 = x + y * gridsize;
@@ -1086,7 +1091,9 @@ static void do_multires_smooth_brush(Sculpt *sd, SculptSession *ss, PBVHNode *no
 				v3 = v1 + gridsize;
 				v4 = v3 + 1;
 
-				add_v3_v3v3(tmprow[x + 1], data[v2].co, data[v4].co);
+				add_v3_v3v3(tmprow[x + 1],
+							CCG_elem_offset_co(&key, data, v2),
+							CCG_elem_offset_co(&key, data, v4));
 				add_v3_v3v3(tmp, tmprow[x + 1], tmprow[x]);
 
 				add_v3_v3(tmpgrid[v1], tmp);
@@ -1115,9 +1122,9 @@ static void do_multires_smooth_brush(Sculpt *sd, SculptSession *ss, PBVHNode *no
 				if (y == gridsize - 1 && adj->index[1] == -1)
 					continue;
 
-				index = x + y * gridsize;
-				co =  data[index].co;
-				fno = data[index].no;
+				index = x + y*gridsize;
+				co = CCG_elem_offset_co(&key, data, index);
+				fno = CCG_elem_offset_no(&key, data, index);
 
 				if (sculpt_brush_test(&test, co)) {
 					const float fade = bstrength * tex_strength(ss, brush, co, test.dist,
diff --git a/source/blender/editors/sculpt_paint/sculpt_undo.c b/source/blender/editors/sculpt_paint/sculpt_undo.c
index 801bfabc748..ea5c173e410 100644
--- a/source/blender/editors/sculpt_paint/sculpt_undo.c
+++ b/source/blender/editors/sculpt_paint/sculpt_undo.c
@@ -47,6 +47,7 @@
 #include "DNA_scene_types.h"
 #include "DNA_mesh_types.h"
 
+#include "BKE_ccg.h"
 #include "BKE_cdderivedmesh.h"
 #include "BKE_context.h"
 #include "BKE_depsgraph.h"
@@ -157,19 +158,21 @@ static int sculpt_undo_restore_coords(bContext *C, DerivedMesh *dm, SculptUndoNo
 	}
 	else if (unode->maxgrid && dm->getGridData) {
 		/* multires restore */
-		DMGridData **grids, *grid;
+		CCGElem **grids, *grid;
+		CCGKey key;
 		float (*co)[3];
 		int gridsize;
 
 		grids = dm->getGridData(dm);
 		gridsize = dm->getGridSize(dm);
+		dm->getGridKey(dm, &key);
 
 		co = unode->co;
 		for (j = 0; j < unode->totgrid; j++) {
 			grid = grids[unode->grids[j]];
 
-			for (i = 0; i < gridsize * gridsize; i++, co++)
-				swap_v3_v3(grid[i].co, co[0]);
+			for (i = 0; i < gridsize*gridsize; i++, co++)
+				swap_v3_v3(CCG_elem_offset_co(&key, grid, i), co[0]);
 		}
 	}