scripts/startup/bl_ui/properties_data_modifier.py

@@ -46,6 +46,7 @@ class DATA_PT_modifiers(ModifierButtonsPanel, Panel):
 
     def draw(self, _context):
         layout = self.layout
+        ob_type = _context.object.type
         layout.operator("wm.call_menu", text="Add Modifier", icon='ADD').name = "OBJECT_MT_modifier_add"
         layout.template_modifiers()
 
@@ -71,7 +72,7 @@ class OBJECT_MT_modifier_add(ModifierAddMenu, Menu):
         if geometry_nodes_supported:
             self.operator_modifier_add(layout, 'NODES')
             layout.separator()
-        if ob_type in {'MESH', 'CURVE', 'FONT', 'SURFACE', 'LATTICE'}:
+        if ob_type in {'MESH', 'CURVE', 'FONT', 'SURFACE', 'LATTICE', 'GREASEPENCIL'}:
             layout.menu("OBJECT_MT_modifier_add_edit")
         if ob_type in {'MESH', 'CURVE', 'FONT', 'SURFACE', 'VOLUME'}:
             layout.menu("OBJECT_MT_modifier_add_generate")
@@ -105,6 +106,8 @@ class OBJECT_MT_modifier_add_edit(ModifierAddMenu, Menu):
             self.operator_modifier_add(layout, 'VERTEX_WEIGHT_EDIT')
             self.operator_modifier_add(layout, 'VERTEX_WEIGHT_MIX')
             self.operator_modifier_add(layout, 'VERTEX_WEIGHT_PROXIMITY')
+        if ob_type == 'GREASEPENCIL':
+            self.operator_modifier_add(layout, 'GREASE_PENCIL_OPACITY')
         layout.template_modifier_asset_menu_items(catalog_path=self.bl_label)
 
 

source/blender/makesdna/DNA_modifier_types.h

@@ -93,6 +93,7 @@ typedef enum ModifierType {
   eModifierType_MeshToVolume = 58,
   eModifierType_VolumeDisplace = 59,
   eModifierType_VolumeToMesh = 60,
+  eModifierType_GreasePencilOpacity = 61,
   NUM_MODIFIER_TYPES,
 } ModifierType;
 
@@ -2484,3 +2485,8 @@ typedef enum VolumeToMeshResolutionMode {
 typedef enum VolumeToMeshFlag {
   VOLUME_TO_MESH_USE_SMOOTH_SHADE = 1 << 0,
 } VolumeToMeshFlag;
+
+typedef struct GreasePencilOpacityModifierData {
+  ModifierData modifier;
+
+} GreasePencilOpacityModifierData;

source/blender/makesrna/intern/rna_modifier.cc

@@ -100,6 +100,11 @@ const EnumPropertyItem rna_enum_object_modifier_type_items[] = {
      ICON_MOD_VERTEX_WEIGHT,
      "Vertex Weight Proximity",
      "Set the vertex group weights based on the distance to another target object"},
+    {eModifierType_GreasePencilOpacity,
+     "GREASE_PENCIL_OPACITY",
+     ICON_MOD_OPACITY,
+     "Opacity",
+     "Opacity of the strokes"},
 
     RNA_ENUM_ITEM_HEADING(N_("Generate"), nullptr),
     {eModifierType_Array,
@@ -7423,6 +7428,22 @@ static void rna_def_modifier_volume_to_mesh(BlenderRNA *brna)
   RNA_define_lib_overridable(false);
 }
 
+static void rna_def_modifier_grease_pencil_opacity(BlenderRNA *brna)
+{
+  StructRNA *srna;
+
+  srna = RNA_def_struct(brna, "GreasePencilOpacityModifier", "Modifier");
+  RNA_def_struct_ui_text(srna, "Grease Pencil Opacity Modifier", "");
+  RNA_def_struct_sdna(srna, "GreasePencilOpacityModifierData");
+  RNA_def_struct_ui_icon(srna, ICON_MOD_OPACITY);
+
+  RNA_define_lib_overridable(true);
+
+  // TODO
+
+  RNA_define_lib_overridable(false);
+}
+
 void RNA_def_modifier(BlenderRNA *brna)
 {
   StructRNA *srna;
@@ -7583,6 +7604,7 @@ void RNA_def_modifier(BlenderRNA *brna)
   rna_def_modifier_mesh_to_volume(brna);
   rna_def_modifier_volume_displace(brna);
   rna_def_modifier_volume_to_mesh(brna);
+  rna_def_modifier_grease_pencil_opacity(brna);
 }
 
 #endif

source/blender/modifiers/CMakeLists.txt

@@ -44,6 +44,7 @@ set(SRC
   intern/MOD_edgesplit.cc
   intern/MOD_explode.cc
   intern/MOD_fluid.cc
+  intern/MOD_grease_pencil_opacity.cc
   intern/MOD_hook.cc
   intern/MOD_laplaciandeform.cc
   intern/MOD_laplaciansmooth.cc

source/blender/modifiers/MOD_modifiertypes.hh

@@ -73,6 +73,7 @@ extern ModifierTypeInfo modifierType_Nodes;
 extern ModifierTypeInfo modifierType_MeshToVolume;
 extern ModifierTypeInfo modifierType_VolumeDisplace;
 extern ModifierTypeInfo modifierType_VolumeToMesh;
+extern ModifierTypeInfo modifierType_GreasePencilOpacity;
 
 /* MOD_util.cc */
 

source/blender/modifiers/intern/MOD_grease_pencil_opacity.cc

@@ -0,0 +1,151 @@
+/* SPDX-FileCopyrightText: 2005 Blender Authors
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later */
+
+/** \file
+ * \ingroup modifiers
+ */
+
+#include "MEM_guardedalloc.h"
+
+#include "DNA_defaults.h"
+#include "DNA_modifier_types.h"
+
+#include "BKE_modifier.hh"
+
+#include "BLO_read_write.hh"
+
+#include "UI_interface.hh"
+#include "UI_resources.hh"
+
+#include "BLT_translation.h"
+
+#include "WM_types.hh"
+
+#include "RNA_access.hh"
+#include "RNA_enum_types.hh"
+#include "RNA_prototypes.h"
+
+#include "MOD_modifiertypes.hh"
+#include "MOD_ui_common.hh"
+
+namespace blender {
+
+static void init_data(ModifierData *md)
+{
+  GreasePencilOpacityModifierData *omd = (GreasePencilOpacityModifierData *)md;
+
+  BLI_assert(MEMCMP_STRUCT_AFTER_IS_ZERO(omd, modifier));
+
+  MEMCPY_STRUCT_AFTER(omd, DNA_struct_default_get(GreasePencilOpacityModifierData), modifier);
+
+  // TODO
+}
+
+static void copy_data(const ModifierData *md, ModifierData *target, const int flag)
+{
+  const GreasePencilOpacityModifierData *omd = (const GreasePencilOpacityModifierData *)md;
+  GreasePencilOpacityModifierData *tomd = (GreasePencilOpacityModifierData *)target;
+
+  BKE_modifier_copydata_generic(md, target, flag);
+
+  // TODO
+  UNUSED_VARS(omd, tomd);
+}
+
+static void required_data_mask(ModifierData *md, CustomData_MeshMasks *r_cddata_masks)
+{
+  GreasePencilOpacityModifierData *omd = (GreasePencilOpacityModifierData *)md;
+
+  // TODO
+  UNUSED_VARS(omd, r_cddata_masks);
+}
+
+static void free_data(ModifierData *md)
+{
+  GreasePencilOpacityModifierData *omd = (GreasePencilOpacityModifierData *)md;
+
+  // TODO
+  UNUSED_VARS(omd);
+}
+
+static void modify_geometry_set(ModifierData *md,
+                                const ModifierEvalContext *ctx,
+                                bke::GeometrySet *geometry_set)
+{
+  GreasePencilOpacityModifierData *omd = (GreasePencilOpacityModifierData *)md;
+
+  // TODO
+  UNUSED_VARS(omd, ctx, geometry_set);
+}
+
+static void panel_draw(const bContext * /*C*/, Panel *panel)
+{
+  uiLayout *layout = panel->layout;
+
+  PointerRNA ob_ptr;
+  PointerRNA *ptr = modifier_panel_get_property_pointers(panel, &ob_ptr);
+
+  uiLayoutSetPropSep(layout, true);
+
+  // TODO
+
+  modifier_panel_end(layout, ptr);
+}
+
+static void panel_register(ARegionType *region_type)
+{
+  modifier_panel_register(region_type, eModifierType_GreasePencilOpacity, panel_draw);
+}
+
+static void blend_write(BlendWriter *writer, const ID * /*id_owner*/, const ModifierData *md)
+{
+  const GreasePencilOpacityModifierData *omd = (const GreasePencilOpacityModifierData *)md;
+
+  BLO_write_struct(writer, GreasePencilOpacityModifierData, omd);
+}
+
+static void blend_read(BlendDataReader *reader, ModifierData *md)
+{
+  GreasePencilOpacityModifierData *omd = (GreasePencilOpacityModifierData *)md;
+  UNUSED_VARS(reader, omd);
+}
+
+}  // namespace blender
+
+ModifierTypeInfo modifierType_GreasePencilOpacity = {
+    /*idname*/ "GreasePencilOpacity",
+    /*name*/ N_("GreasePencilOpacity"),
+    /*struct_name*/ "GreasePencilOpacityModifierData",
+    /*struct_size*/ sizeof(GreasePencilOpacityModifierData),
+    /*srna*/ &RNA_GreasePencilOpacityModifier,
+    /*type*/ ModifierTypeType::NonGeometrical,
+    /*flags*/
+    static_cast<ModifierTypeFlag>(
+        eModifierTypeFlag_AcceptsGreasePencil | eModifierTypeFlag_SupportsEditmode |
+        eModifierTypeFlag_EnableInEditmode | eModifierTypeFlag_SupportsMapping),
+    /*icon*/ ICON_MOD_OPACITY,
+
+    /*copy_data*/ blender::copy_data,
+
+    /*deform_verts*/ nullptr,
+    /*deform_matrices*/ nullptr,
+    /*deform_verts_EM*/ nullptr,
+    /*deform_matrices_EM*/ nullptr,
+    /*modify_mesh*/ nullptr,
+    /*modify_geometry_set*/ blender::modify_geometry_set,
+
+    /*init_data*/ blender::init_data,
+    /*required_data_mask*/ blender::required_data_mask,
+    /*free_data*/ blender::free_data,
+    /*is_disabled*/ nullptr,
+    /*update_depsgraph*/ nullptr,
+    /*depends_on_time*/ nullptr,
+    /*depends_on_normals*/ nullptr,
+    /*foreach_ID_link*/ nullptr,
+    /*foreach_tex_link*/ nullptr,
+    /*free_runtime_data*/ nullptr,
+    /*panel_register*/ blender::panel_register,
+    /*blend_write*/ blender::blend_write,
+    /*blend_read*/ blender::blend_read,
+};

source/blender/modifiers/intern/MOD_util.cc

@@ -270,5 +270,6 @@ void modifier_type_init(ModifierTypeInfo *types[])
   INIT_TYPE(VolumeDisplace);
   INIT_TYPE(VolumeToMesh);
   INIT_TYPE(Nodes);
+  INIT_TYPE(GreasePencilOpacity);
 #undef INIT_TYPE
 }