Undo the front-facing only commit for clay strips brushes, it adds an

attenuation that should really be optional. There's also a minor
performance penalty and all this only for one problematic case. In case
the tool flattens two surfaces, users can manually set the front face
only option. A better non-attenuating way to cull such vertices can be
added later.

Also flatten brush should calculate the flatten plane from the original
vertices or the flattening will not converge for planes offsets
different than zero.

Reported by Michalis Zissiou, thanks!

4 files changed, 8 insertions, 28 deletions

diff --git a/source/blender/blenkernel/BKE_brush.h b/source/blender/blenkernel/BKE_brush.h
index ea2aa9c8bd3..b4c5f47cf25 100644
--- a/source/blender/blenkernel/BKE_brush.h
+++ b/source/blender/blenkernel/BKE_brush.h
@@ -111,8 +111,5 @@ void BKE_brush_scale_size(int *BKE_brush_size_get,
 /* debugging only */
 void BKE_brush_debug_print_state(struct Brush *br);
 
-/* sculpt */
-bool BKE_sculpt_brush_frontface_only(struct Brush *);
-
 #endif
 
diff --git a/source/blender/blenkernel/intern/brush.c b/source/blender/blenkernel/intern/brush.c
index 7864216f39e..790c1f09ff0 100644
--- a/source/blender/blenkernel/intern/brush.c
+++ b/source/blender/blenkernel/intern/brush.c
@@ -1048,8 +1048,3 @@ struct ImBuf *BKE_brush_gen_radial_control_imbuf(Brush *br, bool secondary)
 
 	return im;
 }
-
-bool BKE_sculpt_brush_frontface_only(struct Brush *br)
-{
-	return br->sculpt_tool == SCULPT_TOOL_CLAY_STRIPS;
-}
diff --git a/source/blender/editors/sculpt_paint/sculpt.c b/source/blender/editors/sculpt_paint/sculpt.c
index a7d851d7a67..d07f447b2fa 100644
--- a/source/blender/editors/sculpt_paint/sculpt.c
+++ b/source/blender/editors/sculpt_paint/sculpt.c
@@ -318,8 +318,6 @@ typedef struct StrokeCache {
 	float plane_trim_squared;
 
 	rcti previous_r; /* previous redraw rectangle */
-
-	bool frontface; /* use front face */
 } StrokeCache;
 
 /************** Access to original unmodified vertex data *************/
@@ -671,10 +669,10 @@ static int sculpt_brush_test_cube(SculptBrushTest *test, float co[3], float loca
 	}
 }
 
-static float frontface(bool ff, const float sculpt_normal[3],
+static float frontface(Brush *br, const float sculpt_normal[3],
                        const short no[3], const float fno[3])
 {
-	if (ff) {
+	if (br->flag & BRUSH_FRONTFACE) {
 		float dot;
 
 		if (no) {
@@ -1011,7 +1009,7 @@ static float tex_strength(SculptSession *ss, Brush *br,
 	/* Falloff curve */
 	avg *= BKE_brush_curve_strength(br, len, cache->radius);
 
-	avg *= frontface(cache->frontface, sculpt_normal, vno, fno);
+	avg *= frontface(br, sculpt_normal, vno, fno);
 
 	/* Paint mask */
 	avg *= 1.0f - mask;
@@ -1289,13 +1287,13 @@ static void update_brush_local_mat(Sculpt *sd, Object *ob)
 
 /* Test whether the StrokeCache.sculpt_normal needs update in
  * do_brush_action() */
-static int brush_needs_sculpt_normal(const Brush *brush, SculptSession *ss)
+static int brush_needs_sculpt_normal(const Brush *brush)
 {
 	return ((ELEM(brush->sculpt_tool,
 	              SCULPT_TOOL_GRAB,
 	              SCULPT_TOOL_SNAKE_HOOK) &&
 	         ((brush->normal_weight > 0) ||
-	          ss->cache->frontface)) ||
+	          (brush->flag & BRUSH_FRONTFACE))) ||
 
 	        ELEM7(brush->sculpt_tool,
 	              SCULPT_TOOL_BLOB,
@@ -3139,7 +3137,7 @@ static void do_brush_action(Sculpt *sd, Object *ob, Brush *brush)
 			BKE_pbvh_node_mark_update(nodes[n]);
 		}
 
-		if (brush_needs_sculpt_normal(brush, ss))
+		if (brush_needs_sculpt_normal(brush))
 			update_sculpt_normal(sd, ob, nodes, totnode);
 
 		if (brush->mtex.brush_map_mode == MTEX_MAP_MODE_AREA)
@@ -3905,10 +3903,10 @@ static void sculpt_update_cache_invariants(bContext *C, Sculpt *sd, SculptSessio
 		cache->original = 1;
 	}
 
-	if (ELEM8(brush->sculpt_tool,
+	if (ELEM9(brush->sculpt_tool,
 	          SCULPT_TOOL_DRAW, SCULPT_TOOL_CREASE, SCULPT_TOOL_BLOB,
 	          SCULPT_TOOL_LAYER, SCULPT_TOOL_INFLATE, SCULPT_TOOL_CLAY,
-	          SCULPT_TOOL_CLAY_STRIPS, SCULPT_TOOL_ROTATE))
+	          SCULPT_TOOL_CLAY_STRIPS, SCULPT_TOOL_ROTATE, SCULPT_TOOL_FLATTEN))
 	{
 		if (!(brush->flag & BRUSH_ACCUMULATE)) {
 			cache->original = 1;
@@ -3922,9 +3920,6 @@ static void sculpt_update_cache_invariants(bContext *C, Sculpt *sd, SculptSessio
 	cache->previous_vertex_rotation = 0;
 	cache->init_dir_set = false;
 
-	cache->frontface = ((brush->flag & BRUSH_FRONTFACE) != 0) ||
-	                     BKE_sculpt_brush_frontface_only(brush);
-
 	sculpt_omp_start(sd, ss);
 }
 
diff --git a/source/blender/makesrna/intern/rna_brush.c b/source/blender/makesrna/intern/rna_brush.c
index 78a1e7aa368..405d38e9683 100644
--- a/source/blender/makesrna/intern/rna_brush.c
+++ b/source/blender/makesrna/intern/rna_brush.c
@@ -237,12 +237,6 @@ static int rna_SculptToolCapabilities_has_strength_get(PointerRNA *ptr)
 	return !ELEM(br->sculpt_tool, SCULPT_TOOL_GRAB, SCULPT_TOOL_SNAKE_HOOK);
 }
 
-static int rna_SculptToolCapabilities_has_frontface_get(PointerRNA *ptr)
-{
-	Brush *br = (Brush *)ptr->data;
-	return !BKE_sculpt_brush_frontface_only(br);
-}
-
 static int rna_BrushCapabilities_has_texture_angle_get(PointerRNA *ptr)
 {
 	Brush *br = (Brush *)ptr->data;
@@ -562,7 +556,6 @@ static void rna_def_sculpt_capabilities(BlenderRNA *brna)
 	SCULPT_TOOL_CAPABILITY(has_smooth_stroke, "Has Smooth Stroke");
 	SCULPT_TOOL_CAPABILITY(has_space_attenuation, "Has Space Attenuation");
 	SCULPT_TOOL_CAPABILITY(has_strength, "Has Strength");
-	SCULPT_TOOL_CAPABILITY(has_frontface, "Has Front Facing");
 
 #undef SCULPT_CAPABILITY
 }