Ondine: add Weight Gradient tool for GPv3

scripts/presets/keyconfig/keymap_data/blender_default.py

@@ -4792,6 +4792,34 @@ def km_grease_pencil_weight_paint(params):
     return keymap
 
 
+def km_grease_pencil_weight_gradient(params):
+    items = []
+    keymap = (
+        "Grease Pencil Weight Gradient",
+        {"space_type": 'EMPTY', "region_type": 'WINDOW'},
+        {"items": items},
+    )
+
+    items.extend([
+        ("grease_pencil.weight_gradient",
+            {"type": params.tool_mouse, "value": params.tool_maybe_tweak_value},
+            {"properties": [("mode", 'NORMAL')]}),
+        ("grease_pencil.weight_gradient",
+            {"type": params.tool_mouse, "value": params.tool_maybe_tweak_value, "ctrl": True},
+            {"properties": [("mode", 'INVERT')]}),
+        # Radial controls
+        *_template_paint_radial_control("gpencil_weight_paint"),
+        ("wm.radial_control", {"type": 'F', "value": 'PRESS', "ctrl": True},
+         radial_control_properties("gpencil_weight_paint", 'weight', 'use_unified_weight')),
+        # Toggle Add/Subtract for weight draw tool
+        ("grease_pencil.weight_toggle_direction", {"type": 'D', "value": 'PRESS'}, None),
+        # Context menu
+        *_template_items_context_panel("VIEW3D_PT_gpencil_weight_context_menu", params.context_menu_event),
+    ])
+
+    return keymap
+
+
 # Grease Pencil v3 Fill Tool.
 def km_grease_pencil_fill_tool(_params):
     items = []
@@ -9108,6 +9136,7 @@ def generate_keymaps(params=None):
         km_grease_pencil_edit_mode(params),
         km_grease_pencil_sculpt_mode(params),
         km_grease_pencil_weight_paint(params),
+        km_grease_pencil_weight_gradient(params),
         km_grease_pencil_brush_stroke(params),
         km_grease_pencil_fill_tool(params),
         # Object mode.

scripts/startup/bl_ui/properties_paint_common.py

@@ -2,7 +2,7 @@
 #
 # SPDX-License-Identifier: GPL-2.0-or-later
 
-from bpy.types import Menu
+from bpy.types import Menu, WindowManager
 
 
 class BrushAssetShelf:
@@ -1625,18 +1625,21 @@ def brush_basic_gpencil_vertex_settings(layout, _context, brush, *, compact=Fals
 
 
 def brush_basic_grease_pencil_weight_settings(layout, context, brush, *, compact=False):
-    UnifiedPaintPanel.prop_unified(
-        layout,
-        context,
-        brush,
-        "size",
-        pressure_name="use_pressure_size",
-        unified_name="use_unified_size",
-        text="Radius",
-        slider=True,
-        header=compact,
-    )
+    # Brush radius
+    if brush.gpencil_weight_tool != 'GRADIENT':
+        UnifiedPaintPanel.prop_unified(
+            layout,
+            context,
+            brush,
+            "size",
+            pressure_name="use_pressure_size",
+            unified_name="use_unified_size",
+            text="Radius",
+            slider=True,
+            header=compact,
+        )
 
+    # Strength
     capabilities = brush.sculpt_capabilities
     pressure_name = "use_pressure_strength" if capabilities.has_strength_pressure else None
     UnifiedPaintPanel.prop_unified(
@@ -1650,7 +1653,8 @@ def brush_basic_grease_pencil_weight_settings(layout, context, brush, *, compact
         header=compact,
     )
 
-    if brush.gpencil_weight_tool in {'WEIGHT'}:
+    # Weight
+    if brush.gpencil_weight_tool in {'WEIGHT', 'GRADIENT'}:
         UnifiedPaintPanel.prop_unified(
             layout,
             context,
@@ -1661,8 +1665,15 @@ def brush_basic_grease_pencil_weight_settings(layout, context, brush, *, compact
             slider=True,
             header=compact,
         )
+
+        # Direction: add/subtract
         layout.prop(brush, "direction", expand=True, text="" if compact else "Direction")
 
+        # Gradient type: linear/radial
+        if brush.gpencil_weight_tool == 'GRADIENT':
+            # Bit of a trick, but the only working way to expose the operator property `type`
+            layout.prop(WindowManager.operator_properties_last("grease_pencil.weight_gradient"), "type", expand=True)
+
 
 classes = (
     VIEW3D_MT_tools_projectpaint_clone,

scripts/startup/bl_ui/space_toolsystem_toolbar.py

@@ -2861,9 +2861,6 @@ def generate_from_brushes(context):
             type=bpy.types.Brush,
             # Uses GPv2 tool settings
             attr="gpencil_weight_tool",
-            tooldef_keywords=dict(
-                operator="grease_pencil.weight_brush_stroke",
-            ),
         )
 
 

source/blender/blenkernel/intern/brush.cc

@@ -1435,6 +1435,7 @@ void BKE_gpencil_brush_preset_set(Main *bmain, Brush *brush, const short type)
     }
     case GP_BRUSH_PRESET_WEIGHT_GRADIENT: {
       brush->gpencil_settings->icon_id = GP_BRUSH_ICON_VERTEX_BLUR;
+      brush->gpencil_weight_tool = GPWEIGHT_TOOL_GRADIENT;
 
       brush->alpha = 1.0f;
       brush->weight = 1.0f;

source/blender/editors/datafiles/CMakeLists.txt

@@ -826,6 +826,7 @@ set_property(GLOBAL PROPERTY ICON_GEOM_NAMES
   ops.gpencil.sculpt_blur
   ops.gpencil.sculpt_clone
   ops.gpencil.sculpt_grab
+  ops.gpencil.sculpt_gradient
   ops.gpencil.sculpt_pinch
   ops.gpencil.sculpt_push
   ops.gpencil.sculpt_randomize

source/blender/editors/gpencil_legacy/gpencil_data.cc

@@ -2107,7 +2107,7 @@ static void gpencil_brush_delete_mode_brushes(Main *bmain,
       }
 
       if (mode == CTX_MODE_WEIGHT_GPENCIL_LEGACY) {
-        if ((preset < GP_BRUSH_PRESET_WEIGHT_DRAW) || (preset > GP_BRUSH_PRESET_WEIGHT_SMEAR)) {
+        if ((preset < GP_BRUSH_PRESET_WEIGHT_DRAW) || (preset > GP_BRUSH_PRESET_WEIGHT_GRADIENT)) {
           continue;
         }
         if ((brush_active) && (brush_active->gpencil_weight_tool != brush->gpencil_weight_tool)) {

source/blender/editors/grease_pencil/intern/grease_pencil_ops.cc

@@ -114,7 +114,25 @@ bool grease_pencil_weight_painting_poll(bContext *C)
   if (!ts || !ts->gp_weightpaint) {
     return false;
   }
-  return true;
+  Brush *brush = BKE_paint_brush(&ts->gp_weightpaint->paint);
+  return brush && brush->gpencil_settings && brush->gpencil_weight_tool != GPWEIGHT_TOOL_GRADIENT;
+}
+
+bool grease_pencil_weight_gradient_poll(bContext *C)
+{
+  if (!active_grease_pencil_poll(C)) {
+    return false;
+  }
+  Object *object = CTX_data_active_object(C);
+  if ((object->mode & OB_MODE_WEIGHT_GPENCIL_LEGACY) == 0) {
+    return false;
+  }
+  ToolSettings *ts = CTX_data_tool_settings(C);
+  if (!ts || !ts->gp_weightpaint) {
+    return false;
+  }
+  Brush *brush = BKE_paint_brush(&ts->gp_weightpaint->paint);
+  return brush && brush->gpencil_settings && brush->gpencil_weight_tool == GPWEIGHT_TOOL_GRADIENT;
 }
 
 static void keymap_grease_pencil_edit_mode(wmKeyConfig *keyconf)
@@ -143,6 +161,9 @@ static void keymap_grease_pencil_weight_paint_mode(wmKeyConfig *keyconf)
   wmKeyMap *keymap = WM_keymap_ensure(
       keyconf, "Grease Pencil Weight Paint", SPACE_EMPTY, RGN_TYPE_WINDOW);
   keymap->poll = grease_pencil_weight_painting_poll;
+  keymap = WM_keymap_ensure(
+      keyconf, "Grease Pencil Weight Gradient", SPACE_EMPTY, RGN_TYPE_WINDOW);
+  keymap->poll = grease_pencil_weight_gradient_poll;
 }
 
 /* Enabled for all tools except the fill tool. */