UI: Tweak labels, descriptions, and panel layout for line art

Changes include:
 - Use `IFACE_` for UI labels set in the modifier panels
 - Use a sub-sub-panel for transparency
 - Fix grammar and spelling mistakes
 - Use more natural user-friendly wording
 - Make descriptions more specific and more useful
 - Don't capitalize "line art" in descriptions (tooltips)

These changes are aimed at making the UI strings more consistent with
the rest of the UI and being more helpful to someone trying to understand
how to use the modifier.

Differential Revision: https://developer.blender.org/D10750

2 files changed, 64 insertions, 43 deletions

diff --git a/source/blender/gpencil_modifiers/intern/MOD_gpencillineart.c b/source/blender/gpencil_modifiers/intern/MOD_gpencillineart.c
index 7fed771dabe..67563c5679f 100644
--- a/source/blender/gpencil_modifiers/intern/MOD_gpencillineart.c
+++ b/source/blender/gpencil_modifiers/intern/MOD_gpencillineart.c
@@ -267,29 +267,28 @@ static void panel_draw(const bContext *UNUSED(C), Panel *panel)
 
   uiLayout *col = uiLayoutColumnWithHeading(layout, true, IFACE_("Edge Types"));
 
-  uiItemR(col, ptr, "use_contour", 0, "Contour", ICON_NONE);
-  uiItemR(col, ptr, "use_material", 0, "Material", ICON_NONE);
-  uiItemR(col, ptr, "use_edge_mark", 0, "Edge Marks", ICON_NONE);
-  uiItemR(col, ptr, "use_intersection", 0, "Intersection", ICON_NONE);
+  uiItemR(col, ptr, "use_contour", 0, IFACE_("Contour"), ICON_NONE);
+  uiItemR(col, ptr, "use_material", 0, IFACE_("Material Borders"), ICON_NONE);
+  uiItemR(col, ptr, "use_edge_mark", 0, IFACE_("Edge Marks"), ICON_NONE);
+  uiItemR(col, ptr, "use_intersection", 0, IFACE_("Intersections"), ICON_NONE);
+  uiItemR(col, ptr, "use_crease", 0, IFACE_("Crease"), ICON_NONE);
+  uiLayout *sub = uiLayoutRow(col, true);
+  uiLayoutSetActive(sub, RNA_boolean_get(ptr, "use_crease"));
+  uiLayoutSetPropSep(sub, true);
 
-  uiLayout *row = uiLayoutRow(col, true);
-  /* Don't automatically add the "animate property" button. */
-  uiLayoutSetPropDecorate(row, false);
-
-  const bool use_crease = RNA_boolean_get(ptr, "use_crease");
-  uiLayout *sub = uiLayoutRow(row, true);
-  uiItemR(sub, ptr, "use_crease", 0, "Crease", ICON_NONE);
-  sub = uiLayoutRow(sub, true);
-  uiLayoutSetEnabled(sub, use_crease);
-  uiItemR(sub, ptr, "crease_threshold", UI_ITEM_R_SLIDER, "", ICON_NONE);
-  uiItemDecoratorR(row, ptr, "crease_threshold", 0);
+  uiItemR(sub, ptr, "crease_threshold", UI_ITEM_R_SLIDER, " ", ICON_NONE);
 
   uiItemPointerR(layout, ptr, "target_layer", &obj_data_ptr, "layers", NULL, ICON_GREASEPENCIL);
   uiItemPointerR(
       layout, ptr, "target_material", &obj_data_ptr, "materials", NULL, ICON_SHADING_TEXTURE);
 
   uiItemR(layout, ptr, "remove_doubles", 0, NULL, ICON_NONE);
-  uiItemR(layout, ptr, "allow_overlapping_edges", 0, "Overlapping Edges As Contour", ICON_NONE);
+  uiItemR(layout,
+          ptr,
+          "allow_overlapping_edges",
+          0,
+          IFACE_("Overlapping Edges As Contour"),
+          ICON_NONE);
 
   gpencil_modifier_panel_end(layout, ptr);
 }
@@ -322,9 +321,8 @@ static void occlusion_panel_draw(const bContext *UNUSED(C), Panel *panel)
   uiLayoutSetEnabled(layout, !is_baked);
 
   const bool use_multiple_levels = RNA_boolean_get(ptr, "use_multiple_levels");
-  const bool use_transparency = RNA_boolean_get(ptr, "use_transparency");
 
-  uiItemR(layout, ptr, "use_multiple_levels", 0, "Multiple Levels", ICON_NONE);
+  uiItemR(layout, ptr, "use_multiple_levels", 0, IFACE_("Range"), ICON_NONE);
 
   if (use_multiple_levels) {
     uiLayout *col = uiLayoutColumn(layout, true);
@@ -332,28 +330,43 @@ static void occlusion_panel_draw(const bContext *UNUSED(C), Panel *panel)
     uiItemR(col, ptr, "level_end", 0, NULL, ICON_NONE);
   }
   else {
-    uiItemR(layout, ptr, "level_start", 0, "Level", ICON_NONE);
+    uiItemR(layout, ptr, "level_start", 0, IFACE_("Level"), ICON_NONE);
   }
+}
 
-  uiItemR(layout, ptr, "use_transparency", 0, "Transparency", ICON_NONE);
+static void transparency_panel_draw_header(const bContext *UNUSED(C), Panel *panel)
+{
+  uiLayout *layout = panel->layout;
+  PointerRNA *ptr = gpencil_modifier_panel_get_property_pointers(panel, NULL);
 
-  uiLayout *col = uiLayoutColumn(layout, true);
+  uiItemR(layout, ptr, "use_transparency", 0, IFACE_("Transparency"), ICON_NONE);
+}
 
-  if (use_transparency) {
-    uiItemR(col, ptr, "transparency_match", 0, "Match", ICON_NONE);
-  }
+static void transparency_panel_draw(const bContext *UNUSED(C), Panel *panel)
+{
+  uiLayout *layout = panel->layout;
+  PointerRNA *ptr = gpencil_modifier_panel_get_property_pointers(panel, NULL);
 
-  if (use_transparency) {
-    uiLayout *row = uiLayoutRow(col, true);
-    uiItemR(row, ptr, "transparency_mask_0", UI_ITEM_R_TOGGLE, "0", ICON_NONE);
-    uiItemR(row, ptr, "transparency_mask_1", UI_ITEM_R_TOGGLE, "1", ICON_NONE);
-    uiItemR(row, ptr, "transparency_mask_2", UI_ITEM_R_TOGGLE, "2", ICON_NONE);
-    uiItemR(row, ptr, "transparency_mask_3", UI_ITEM_R_TOGGLE, "3", ICON_NONE);
-    uiItemR(row, ptr, "transparency_mask_4", UI_ITEM_R_TOGGLE, "4", ICON_NONE);
-    uiItemR(row, ptr, "transparency_mask_5", UI_ITEM_R_TOGGLE, "5", ICON_NONE);
-    uiItemR(row, ptr, "transparency_mask_6", UI_ITEM_R_TOGGLE, "6", ICON_NONE);
-    uiItemR(row, ptr, "transparency_mask_7", UI_ITEM_R_TOGGLE, "7", ICON_NONE);
-  }
+  uiLayoutSetPropSep(layout, true);
+
+  uiLayoutSetActive(layout, RNA_boolean_get(ptr, "use_transparency"));
+
+  uiLayout *row = uiLayoutRow(layout, true);
+  uiLayoutSetPropDecorate(row, false);
+  uiLayout *sub = uiLayoutRow(row, true);
+  uiItemR(sub, ptr, "transparency_mask_0", UI_ITEM_R_TOGGLE, IFACE_("0"), ICON_NONE);
+  uiItemR(sub, ptr, "transparency_mask_1", UI_ITEM_R_TOGGLE, IFACE_("1"), ICON_NONE);
+  uiItemR(sub, ptr, "transparency_mask_2", UI_ITEM_R_TOGGLE, IFACE_("2"), ICON_NONE);
+  uiItemR(sub, ptr, "transparency_mask_3", UI_ITEM_R_TOGGLE, IFACE_("3"), ICON_NONE);
+  uiItemR(sub, ptr, "transparency_mask_4", UI_ITEM_R_TOGGLE, IFACE_("4"), ICON_NONE);
+  uiItemR(sub, ptr, "transparency_mask_5", UI_ITEM_R_TOGGLE, IFACE_("5"), ICON_NONE);
+  uiItemR(sub, ptr, "transparency_mask_6", UI_ITEM_R_TOGGLE, IFACE_("6"), ICON_NONE);
+  uiItemR(sub, ptr, "transparency_mask_7", UI_ITEM_R_TOGGLE, IFACE_("7"), ICON_NONE);
+  uiItemL(row, "", ICON_BLANK1); /* Space for decorator. */
+
+  uiLayout *col = uiLayoutColumn(layout, true);
+  // uiLayoutSetPropDecorate(col, true);
+  uiItemR(col, ptr, "transparency_match", 0, IFACE_("Match All Masks"), ICON_NONE);
 }
 
 static void chaining_panel_draw(const bContext *UNUSED(C), Panel *panel)
@@ -395,17 +408,18 @@ static void vgroup_panel_draw(const bContext *UNUSED(C), Panel *panel)
   uiLayout *col = uiLayoutColumn(layout, true);
 
   uiLayout *row = uiLayoutRow(col, true);
-  uiItemR(row, ptr, "source_vertex_group", 0, "Filter Source", ICON_GROUP_VERTEX);
+  uiItemR(row, ptr, "source_vertex_group", 0, IFACE_("Filter Source"), ICON_GROUP_VERTEX);
   uiItemR(row, ptr, "invert_source_vertex_group", UI_ITEM_R_TOGGLE, "", ICON_ARROW_LEFTRIGHT);
 
   uiItemR(col, ptr, "match_output_vertex_group", 0, NULL, ICON_NONE);
 
   bool match_output = RNA_boolean_get(ptr, "match_output_vertex_group");
   if (!match_output) {
-    uiItemPointerR(col, ptr, "vertex_group", &ob_ptr, "vertex_groups", "Target", ICON_NONE);
+    uiItemPointerR(
+        col, ptr, "vertex_group", &ob_ptr, "vertex_groups", IFACE_("Target"), ICON_NONE);
   }
 
-  uiItemR(layout, ptr, "soft_selection", 0, NULL, ICON_NONE);
+  uiItemR(col, ptr, "soft_selection", 0, NULL, ICON_NONE);
 }
 
 static void baking_panel_draw(const bContext *UNUSED(C), Panel *panel)
@@ -421,8 +435,9 @@ static void baking_panel_draw(const bContext *UNUSED(C), Panel *panel)
   if (is_baked) {
     uiLayout *col = uiLayoutColumn(layout, false);
     uiLayoutSetPropSep(col, false);
-    uiItemL(col, "Modifier has baked data.", ICON_NONE);
-    uiItemR(col, ptr, "is_baked", UI_ITEM_R_TOGGLE, "Continue Without Clearing", ICON_NONE);
+    uiItemL(col, IFACE_("Modifier has baked data."), ICON_NONE);
+    uiItemR(
+        col, ptr, "is_baked", UI_ITEM_R_TOGGLE, IFACE_("Continue Without Clearing"), ICON_NONE);
   }
 
   uiLayout *col = uiLayoutColumn(layout, false);
@@ -442,8 +457,14 @@ static void panelRegister(ARegionType *region_type)
 
   gpencil_modifier_subpanel_register(
       region_type, "style", "Style", NULL, style_panel_draw, panel_type);
-  gpencil_modifier_subpanel_register(
+  PanelType *occlusion_panel = gpencil_modifier_subpanel_register(
       region_type, "occlusion", "Occlusion", NULL, occlusion_panel_draw, panel_type);
+  gpencil_modifier_subpanel_register(region_type,
+                                     "transparency",
+                                     "",
+                                     transparency_panel_draw_header,
+                                     transparency_panel_draw,
+                                     occlusion_panel);
   gpencil_modifier_subpanel_register(
       region_type, "chaining", "Chaining", NULL, chaining_panel_draw, panel_type);
   gpencil_modifier_subpanel_register(
diff --git a/source/blender/gpencil_modifiers/intern/lineart/lineart_ops.c b/source/blender/gpencil_modifiers/intern/lineart/lineart_ops.c
index d5bd232cc9c..56490a84279 100644
--- a/source/blender/gpencil_modifiers/intern/lineart/lineart_ops.c
+++ b/source/blender/gpencil_modifiers/intern/lineart/lineart_ops.c
@@ -402,7 +402,7 @@ void OBJECT_OT_lineart_bake_strokes(wmOperatorType *ot)
 void OBJECT_OT_lineart_bake_strokes_all(wmOperatorType *ot)
 {
   ot->name = "Bake Line Art (All)";
-  ot->description = "Bake all GPencil objects who has at least one Line Art modifier";
+  ot->description = "Bake all Grease Pencil objects that have a line art modifier";
   ot->idname = "OBJECT_OT_lineart_bake_strokes_all";
 
   ot->invoke = lineart_gpencil_bake_strokes_all_invoke;
@@ -424,7 +424,7 @@ void OBJECT_OT_lineart_clear(wmOperatorType *ot)
 void OBJECT_OT_lineart_clear_all(wmOperatorType *ot)
 {
   ot->name = "Clear Baked Line Art (All)";
-  ot->description = "Clear all strokes in all GPencil obejcts who has a Line Art modifier";
+  ot->description = "Clear all strokes in all Grease Pencil objects that have a line art modifier";
   ot->idname = "OBJECT_OT_lineart_clear_all";
 
   ot->exec = lineart_gpencil_clear_strokes_all_exec;