Weight Paint: restore non-spray functionality

When painting with spray disabled - we need to re-apply
on top of the original each time.

Applying the soc-2016-pbvh-painting branch removed this.
While I'd added back a simple previous weight array,
this won't work when multiple groups are painted at once.

2 files changed, 10 insertions, 2 deletions

diff --git a/source/blender/blenkernel/BKE_paint.h b/source/blender/blenkernel/BKE_paint.h
index 6cae8d28947..fe7461c810d 100644
--- a/source/blender/blenkernel/BKE_paint.h
+++ b/source/blender/blenkernel/BKE_paint.h
@@ -228,9 +228,12 @@ typedef struct SculptSession {
 
 			/* Vertex aligned arrays of weights. */
 			float *previous_accum;
-			float *previous_weight;
 			/* Keep track of how much each vertex has been painted (non-airbrush only). */
 			float *alpha_weight;
+
+			/* Needed to continuously re-apply over the same weights (VP_SPRAY disabled).
+			 * Lazy initialize as needed (flag is set to 1 to tag it as uninitialized). */
+			struct MDeformVert *dvert_prev;
 		} wpaint;
 
 		//struct {
diff --git a/source/blender/blenkernel/intern/paint.c b/source/blender/blenkernel/intern/paint.c
index 849fb5c6b5a..c2f1d05dd89 100644
--- a/source/blender/blenkernel/intern/paint.c
+++ b/source/blender/blenkernel/intern/paint.c
@@ -49,6 +49,7 @@
 
 #include "BKE_brush.h"
 #include "BKE_colortools.h"
+#include "BKE_deform.h"
 #include "BKE_main.h"
 #include "BKE_context.h"
 #include "BKE_crazyspace.h"
@@ -686,8 +687,12 @@ void BKE_sculptsession_free_vwpaint_data(struct SculptSession *ss)
 		gmap = &ss->mode.wpaint.gmap;
 
 		MEM_SAFE_FREE(ss->mode.wpaint.alpha_weight);
-		MEM_SAFE_FREE(ss->mode.wpaint.previous_weight);
 		MEM_SAFE_FREE(ss->mode.wpaint.previous_accum);
+		if (ss->mode.wpaint.dvert_prev) {
+			BKE_defvert_array_free_elems(ss->mode.wpaint.dvert_prev, ss->totvert);
+			MEM_freeN(ss->mode.wpaint.dvert_prev);
+			ss->mode.wpaint.dvert_prev = NULL;
+		}
 	}
 	else {
 		return;