[Bf-blender-cvs] [b708f459228] master: Fix T99248: GPencil Sculpt Grab/Push don't work with one point

[Antonio Vazquez]

Commit: b708f459228a589bb0a127c81f12af4f939dd15c
Author: Antonio Vazquez
Date:   Wed Jun 29 16:03:55 2022 +0200
Branches: master
https://developer.blender.org/rBb708f459228a589bb0a127c81f12af4f939dd15c

Fix T99248: GPencil Sculpt Grab/Push don't work with one point

There were two problems:

1) The checking of the collision was not working with one point only.
2) For one point, the masking was checked always and if the masking was not activated, the stroke was skipped.

===================================================================

M	source/blender/editors/gpencil/gpencil_sculpt_paint.c

===================================================================

diff --git a/source/blender/editors/gpencil/gpencil_sculpt_paint.c b/source/blender/editors/gpencil/gpencil_sculpt_paint.c
index 6d0848de36d..f25d5937ac4 100644
--- a/source/blender/editors/gpencil/gpencil_sculpt_paint.c
+++ b/source/blender/editors/gpencil/gpencil_sculpt_paint.c
@@ -1161,6 +1161,7 @@ static bool gpencil_sculpt_brush_init(bContext *C, wmOperator *op)
 
   gso->is_painting = false;
   gso->first = true;
+  gso->mval_prev[0] = -1.0f;
 
   gso->gpd = ED_gpencil_data_get_active(C);
   gso->cfra = INT_MAX; /* NOTE: So that first stroke will get handled in init_stroke() */
@@ -1442,6 +1443,7 @@ static bool gpencil_sculpt_brush_do_stroke(tGP_BrushEditData *gso,
   char tool = gso->brush->gpencil_sculpt_tool;
   const int radius = (brush->flag & GP_BRUSH_USE_PRESSURE) ? gso->brush->size * gso->pressure :
                                                              gso->brush->size;
+  const bool is_masking = GPENCIL_ANY_SCULPT_MASK(gso->mask);
 
   bGPDstroke *gps_active = (gps->runtime.gps_orig) ? gps->runtime.gps_orig : gps;
   bGPDspoint *pt_active = NULL;
@@ -1459,7 +1461,7 @@ static bool gpencil_sculpt_brush_do_stroke(tGP_BrushEditData *gso,
   if (gps->totpoints == 1) {
     bGPDspoint pt_temp;
     pt = &gps->points[0];
-    if (GPENCIL_ANY_SCULPT_MASK(gso->mask) && (pt->flag & GP_SPOINT_SELECT) != 0) {
+    if ((is_masking && (pt->flag & GP_SPOINT_SELECT) != 0) || (!is_masking)) {
       gpencil_point_to_parent_space(gps->points, diff_mat, &pt_temp);
       gpencil_point_to_xy(gsc, gps, &pt_temp, &pc1[0], &pc1[1]);
 
@@ -1618,7 +1620,8 @@ static bool gpencil_sculpt_brush_do_frame(bContext *C,
     }
 
     /* Check if the stroke collide with brush. */
-    if (!ED_gpencil_stroke_check_collision(gsc, gps, gso->mval, radius, bound_mat)) {
+    if ((gps->totpoints > 1) &&
+        (!ED_gpencil_stroke_check_collision(gsc, gps, gso->mval, radius, bound_mat))) {
       continue;
     }
 
@@ -1982,7 +1985,7 @@ static void gpencil_sculpt_brush_apply(bContext *C, wmOperator *op, PointerRNA *
   }
 
   /* Store coordinates as reference, if operator just started running */
-  if (gso->first) {
+  if (gso->mval_prev[0] == -1.0f) {
     gso->mval_prev[0] = gso->mval[0];
     gso->mval_prev[1] = gso->mval[1];
     gso->pressure_prev = gso->pressure;