GPencil: New Outline modifier

This modifier converts any stroke (no fill strokes) into perimeter
from camera view.  Also, it's possible to define an alternative 
material for the outline.

There is an option to include a target object to manipulate the start 
point of the strokes. The start point will be the nearest point 
to the target object.

Reviewed By: mendio, frogstomp

Maniphest Tasks: T100826

Differential Revision: https://developer.blender.org/D15882

Note: Icon will be updated in T101155

1 files changed, 141 insertions, 0 deletions

diff --git a/source/blender/makesrna/intern/rna_gpencil_modifier.c b/source/blender/makesrna/intern/rna_gpencil_modifier.c
index 2dfd9d46665..0a400d3bcef 100644
--- a/source/blender/makesrna/intern/rna_gpencil_modifier.c
+++ b/source/blender/makesrna/intern/rna_gpencil_modifier.c
@@ -105,6 +105,11 @@ const EnumPropertyItem rna_enum_object_greasepencil_modifier_type_items[] = {
      ICON_GP_MULTIFRAME_EDITING,
      "Multiple Strokes",
      "Produce multiple strokes along one stroke"},
+    {eGpencilModifierType_Outline,
+     "GP_OUTLINE",
+     ICON_MOD_SKIN,
+     "Outline",
+     "Convert stroke to perimeter"},
     {eGpencilModifierType_Simplify,
      "GP_SIMPLIFY",
      ICON_MOD_SIMPLIFY,
@@ -286,6 +291,8 @@ static StructRNA *rna_GpencilModifier_refine(struct PointerRNA *ptr)
       return &RNA_BuildGpencilModifier;
     case eGpencilModifierType_Opacity:
       return &RNA_OpacityGpencilModifier;
+    case eGpencilModifierType_Outline:
+      return &RNA_OutlineGpencilModifier;
     case eGpencilModifierType_Lattice:
       return &RNA_LatticeGpencilModifier;
     case eGpencilModifierType_Length:
@@ -668,6 +675,37 @@ static void rna_OpacityGpencilModifier_material_set(PointerRNA *ptr,
   rna_GpencilModifier_material_set(ptr, value, ma_target, reports);
 }
 
+static void rna_OutlineGpencilModifier_object_set(PointerRNA *ptr,
+                                                  PointerRNA value,
+                                                  struct ReportList *UNUSED(reports))
+{
+  OutlineGpencilModifierData *omd = ptr->data;
+  Object *ob = (Object *)value.data;
+
+  omd->object = ob;
+  id_lib_extern((ID *)ob);
+}
+
+static void rna_OutlineGpencilModifier_material_set(PointerRNA *ptr,
+                                                    PointerRNA value,
+                                                    struct ReportList *reports)
+{
+  OutlineGpencilModifierData *omd = (OutlineGpencilModifierData *)ptr->data;
+  Material **ma_target = &omd->material;
+
+  rna_GpencilModifier_material_set(ptr, value, ma_target, reports);
+}
+
+static void rna_OutlineStrokeGpencilModifier_material_set(PointerRNA *ptr,
+                                                          PointerRNA value,
+                                                          struct ReportList *reports)
+{
+  OutlineGpencilModifierData *omd = (OutlineGpencilModifierData *)ptr->data;
+  Material **ma_target = &omd->outline_material;
+
+  rna_GpencilModifier_material_set(ptr, value, ma_target, reports);
+}
+
 static void rna_LatticeGpencilModifier_material_set(PointerRNA *ptr,
                                                     PointerRNA value,
                                                     struct ReportList *reports)
@@ -1972,6 +2010,108 @@ static void rna_def_modifier_gpencilopacity(BlenderRNA *brna)
   RNA_define_lib_overridable(false);
 }
 
+static void rna_def_modifier_gpenciloutline(BlenderRNA *brna)
+{
+  StructRNA *srna;
+  PropertyRNA *prop;
+
+  srna = RNA_def_struct(brna, "OutlineGpencilModifier", "GpencilModifier");
+  RNA_def_struct_ui_text(srna, "Outline Modifier", "Outline of Strokes modifier from camera view");
+  RNA_def_struct_sdna(srna, "OutlineGpencilModifierData");
+  // TODO: add new icon
+  RNA_def_struct_ui_icon(srna, ICON_MOD_SKIN);
+
+  RNA_define_lib_overridable(true);
+
+  prop = RNA_def_property(srna, "layer", PROP_STRING, PROP_NONE);
+  RNA_def_property_string_sdna(prop, NULL, "layername");
+  RNA_def_property_ui_text(prop, "Layer", "Layer name");
+  RNA_def_property_update(prop, 0, "rna_GpencilModifier_update");
+
+  prop = RNA_def_property(srna, "material", PROP_POINTER, PROP_NONE);
+  RNA_def_property_flag(prop, PROP_EDITABLE);
+  RNA_def_property_pointer_funcs(prop,
+                                 NULL,
+                                 "rna_OutlineGpencilModifier_material_set",
+                                 NULL,
+                                 "rna_GpencilModifier_material_poll");
+  RNA_def_property_ui_text(prop, "Material", "Material used for filtering effect");
+  RNA_def_property_update(prop, 0, "rna_GpencilModifier_update");
+
+  prop = RNA_def_property(srna, "pass_index", PROP_INT, PROP_NONE);
+  RNA_def_property_int_sdna(prop, NULL, "pass_index");
+  RNA_def_property_range(prop, 0, 100);
+  RNA_def_property_ui_text(prop, "Pass", "Pass index");
+  RNA_def_property_update(prop, 0, "rna_GpencilModifier_update");
+
+  prop = RNA_def_property(srna, "invert_layers", PROP_BOOLEAN, PROP_NONE);
+  RNA_def_property_boolean_sdna(prop, NULL, "flag", GP_OUTLINE_INVERT_LAYER);
+  RNA_def_property_ui_text(prop, "Inverse Layers", "Inverse filter");
+  RNA_def_property_update(prop, 0, "rna_GpencilModifier_update");
+
+  prop = RNA_def_property(srna, "invert_materials", PROP_BOOLEAN, PROP_NONE);
+  RNA_def_property_boolean_sdna(prop, NULL, "flag", GP_OUTLINE_INVERT_MATERIAL);
+  RNA_def_property_ui_text(prop, "Inverse Materials", "Inverse filter");
+  RNA_def_property_update(prop, 0, "rna_GpencilModifier_update");
+
+  prop = RNA_def_property(srna, "invert_material_pass", PROP_BOOLEAN, PROP_NONE);
+  RNA_def_property_boolean_sdna(prop, NULL, "flag", GP_OUTLINE_INVERT_PASS);
+  RNA_def_property_ui_text(prop, "Inverse Pass", "Inverse filter");
+  RNA_def_property_update(prop, 0, "rna_GpencilModifier_update");
+
+  prop = RNA_def_property(srna, "layer_pass", PROP_INT, PROP_NONE);
+  RNA_def_property_int_sdna(prop, NULL, "layer_pass");
+  RNA_def_property_range(prop, 0, 100);
+  RNA_def_property_ui_text(prop, "Pass", "Layer pass index");
+  RNA_def_property_update(prop, 0, "rna_GpencilModifier_update");
+
+  prop = RNA_def_property(srna, "invert_layer_pass", PROP_BOOLEAN, PROP_NONE);
+  RNA_def_property_boolean_sdna(prop, NULL, "flag", GP_OUTLINE_INVERT_LAYERPASS);
+  RNA_def_property_ui_text(prop, "Inverse Pass", "Inverse filter");
+  RNA_def_property_update(prop, 0, "rna_GpencilModifier_update");
+
+  prop = RNA_def_property(srna, "thickness", PROP_INT, PROP_NONE);
+  RNA_def_property_int_sdna(prop, NULL, "thickness");
+  RNA_def_property_range(prop, 1, 1000);
+  RNA_def_property_ui_text(prop, "Thickness", "Thickness of the perimeter stroke");
+  RNA_def_property_update(prop, 0, "rna_GpencilModifier_update");
+
+  prop = RNA_def_property(srna, "sample_length", PROP_FLOAT, PROP_NONE);
+  RNA_def_property_float_sdna(prop, NULL, "sample_length");
+  RNA_def_property_ui_range(prop, 0.0f, 100.0f, 0.1f, 2);
+  RNA_def_property_ui_text(prop, "Sample Length", "");
+  RNA_def_property_update(prop, 0, "rna_GpencilModifier_update");
+
+  prop = RNA_def_property(srna, "subdivision", PROP_INT, PROP_NONE);
+  RNA_def_property_int_sdna(prop, NULL, "subdiv");
+  RNA_def_property_range(prop, 0, 10);
+  RNA_def_property_ui_text(prop, "Subdivisions", "Number of subdivisions");
+  RNA_def_property_update(prop, 0, "rna_GpencilModifier_update");
+
+  prop = RNA_def_property(srna, "use_keep_shape", PROP_BOOLEAN, PROP_NONE);
+  RNA_def_property_boolean_sdna(prop, NULL, "flag", GP_OUTLINE_KEEP_SHAPE);
+  RNA_def_property_ui_text(prop, "Keep Shape", "Try to keep global shape");
+  RNA_def_property_update(prop, 0, "rna_GpencilModifier_update");
+
+  prop = RNA_def_property(srna, "outline_material", PROP_POINTER, PROP_NONE);
+  RNA_def_property_flag(prop, PROP_EDITABLE);
+  RNA_def_property_pointer_funcs(prop,
+                                 NULL,
+                                 "rna_OutlineStrokeGpencilModifier_material_set",
+                                 NULL,
+                                 "rna_GpencilModifier_material_poll");
+  RNA_def_property_ui_text(prop, "Outline Material", "Material used for outline strokes");
+  RNA_def_property_update(prop, 0, "rna_GpencilModifier_update");
+
+  prop = RNA_def_property(srna, "object", PROP_POINTER, PROP_NONE);
+  RNA_def_property_ui_text(prop, "Target Object", "Target object to define stroke start");
+  RNA_def_property_flag(prop, PROP_EDITABLE | PROP_ID_SELF_CHECK);
+  RNA_def_property_pointer_funcs(prop, NULL, "rna_OutlineGpencilModifier_object_set", NULL, NULL);
+  RNA_def_property_update(prop, 0, "rna_GpencilModifier_dependency_update");
+
+  RNA_define_lib_overridable(false);
+}
+
 static void rna_def_modifier_gpencilarray(BlenderRNA *brna)
 {
   StructRNA *srna;
@@ -4353,6 +4493,7 @@ void RNA_def_greasepencil_modifier(BlenderRNA *brna)
   rna_def_modifier_gpencilarray(brna);
   rna_def_modifier_gpencilbuild(brna);
   rna_def_modifier_gpencilopacity(brna);
+  rna_def_modifier_gpenciloutline(brna);
   rna_def_modifier_gpencillattice(brna);
   rna_def_modifier_gpencilmirror(brna);
   rna_def_modifier_gpencilhook(brna);