GPencil: Changes in Fill and new 3D Cursor View Plane

This commit groups several options that were tested in grease pencil branch:

- Changes to fill algorithms and improves, specially in small areas and stroke corners.
  New options has been added in order to define how the fill is working and internally there are optimizations in detect the small areas in the extremes.

  Kudos to @charlie for coding this fill improvements.

- New 3D cursor view plane option.

  Now it's possible to lock the drawing plane to the 3D cursor and use the 3D cursor orientation. This allows more flexibility when you are drawing and reduce the need to create geometry to draw over surfaces.

- Canvas Grid now can be locked to 3D cursor.
- New option to reproject stroke using 3D cursor.
- Small tweaks and fixes.

Changes reviewed by @pepeland and @mendio

2 files changed, 13 insertions, 3 deletions

diff --git a/source/blender/makesrna/intern/rna_brush.c b/source/blender/makesrna/intern/rna_brush.c
index b14e97b8656..86ac8d3bae6 100644
--- a/source/blender/makesrna/intern/rna_brush.c
+++ b/source/blender/makesrna/intern/rna_brush.c
@@ -126,10 +126,10 @@ static EnumPropertyItem rna_enum_gpencil_brush_eraser_modes_items[] = {
 };
 
 static EnumPropertyItem rna_enum_gpencil_fill_draw_modes_items[] = {
+	{GP_FILL_DMODE_BOTH, "BOTH", 0, "Default", "Use both visible strokes and edit lines as fill boundary limits"},
 	{GP_FILL_DMODE_STROKE, "STROKE", 0, "Strokes", "Use visible strokes as fill boundary limits"},
-	{GP_FILL_DMODE_CONTROL, "CONTROL", 0, "Control", "Use internal control lines as fill boundary limits"},
-	{GP_FILL_DMODE_BOTH, "BOTH", 0, "Both", "Use visible strokes and control lines as fill boundary limits"},
-	{0, NULL, 0, NULL, NULL},
+	{GP_FILL_DMODE_CONTROL, "CONTROL", 0, "Edit Lines", "Use edit lines as fill boundary limits"},
+	{0, NULL, 0, NULL, NULL}
 };
 
 static EnumPropertyItem rna_enum_gpencil_brush_icons_items[] = {
@@ -1160,6 +1160,15 @@ static void rna_def_gpencil_options(BlenderRNA *brna)
 	RNA_def_parameter_clear_flags(prop, PROP_ANIMATABLE, 0);
 	RNA_def_property_update(prop, NC_GPENCIL | ND_DATA, NULL);
 
+	/* fill factor size */
+	prop = RNA_def_property(srna, "fill_factor", PROP_INT, PROP_NONE);
+	RNA_def_property_int_sdna(prop, NULL, "fill_factor");
+	RNA_def_property_range(prop, 1, 8);
+	RNA_def_property_ui_text(prop, "Resolution",
+		"Multiplier for fill resolution, higher resolution is more accurate but slower");
+	RNA_def_parameter_clear_flags(prop, PROP_ANIMATABLE, 0);
+	RNA_def_property_update(prop, NC_GPENCIL | ND_DATA, NULL);
+
 	/* fill simplify steps */
 	prop = RNA_def_property(srna, "fill_simplify_level", PROP_INT, PROP_NONE);
 	RNA_def_property_int_sdna(prop, NULL, "fill_simplylvl");
diff --git a/source/blender/makesrna/intern/rna_sculpt_paint.c b/source/blender/makesrna/intern/rna_sculpt_paint.c
index 1393a9d9888..b66363f45ae 100644
--- a/source/blender/makesrna/intern/rna_sculpt_paint.c
+++ b/source/blender/makesrna/intern/rna_sculpt_paint.c
@@ -82,6 +82,7 @@ static const EnumPropertyItem rna_enum_gpencil_lock_axis_items[] = {
 	{GP_LOCKAXIS_Y, "AXIS_Y", ICON_AXIS_FRONT, "Front (X-Z)", "Project strokes to plane locked to Y"},
 	{GP_LOCKAXIS_X, "AXIS_X", ICON_AXIS_SIDE, "Side (Y-Z)", "Project strokes to plane locked to X"},
 	{GP_LOCKAXIS_Z, "AXIS_Z", ICON_AXIS_TOP, "Top (X-Y)", "Project strokes to plane locked to Z"},
+	{GP_LOCKAXIS_CURSOR, "CURSOR", ICON_PIVOT_CURSOR, "Cursor", "Align strokes to current 3D cursor orientation"},
 	{0, NULL, 0, NULL, NULL},
 };
 #endif