Weight Paint: implement a red shade for bones with locked weights.

Blender supports locking vertex groups to prevent changes to the
weights. However, as mentioned in comments for D3837, it is hard
to use this because there is no interface for locking in 3D View.

This adds a red shade to bones that are associated with a locked
weight group during weight paint mode, as the first step to adding
such interface. The next step is adding a pie menu for lock/unlock.

Differential Revision: https://developer.blender.org/D6533

release/datafiles/userdef/userdef_default_theme.c

@@ -339,6 +339,7 @@ const bTheme U_theme_default = {
     .bone_solid = RGBA(0xb2b2b2ff),
     .bone_pose = RGBA(0x50c8ff50),
     .bone_pose_active = RGBA(0x8cffff50),
+    .bone_locked_weight = RGBA(0xff000080),
     .cframe = RGBA(0x60c040ff),
     .time_keyframe = RGBA(0xddd700ff),
     .time_gp_keyframe = RGBA(0xb5e61dff),

release/scripts/startup/bl_ui/space_userpref.py

@@ -997,6 +997,7 @@ class PreferenceThemeSpacePanel:
             "freestyle_face_mark",
             "split_normal",
             "bone_solid",
+            "bone_locked_weight",
             "paint_curve_pivot",
         },
         'GRAPH_EDITOR': {

source/blender/blenkernel/BKE_blender_version.h

@@ -27,7 +27,7 @@
  * \note Use #STRINGIFY() rather than defining with quotes.
  */
 #define BLENDER_VERSION 283
-#define BLENDER_SUBVERSION 0
+#define BLENDER_SUBVERSION 1
 /** Several breakages with 280, e.g. collections vs layers. */
 #define BLENDER_MINVERSION 280
 #define BLENDER_MINSUBVERSION 0

source/blender/blenloader/intern/readfile.c

@@ -3874,7 +3874,7 @@ static void direct_link_bones(FileData *fd, Bone *bone)
   bone->bbone_next = newdataadr(fd, bone->bbone_next);
   bone->bbone_prev = newdataadr(fd, bone->bbone_prev);
 
-  bone->flag &= ~BONE_DRAW_ACTIVE;
+  bone->flag &= ~(BONE_DRAW_ACTIVE | BONE_DRAW_LOCKED_WEIGHT);
 
   link_list(fd, &bone->childbase);
 

source/blender/blenloader/intern/versioning_userdef.c

@@ -164,6 +164,10 @@ static void do_versions_theme(const UserDef *userdef, bTheme *btheme)
     FROM_DEFAULT_V4_UCHAR(space_view3d.face_front);
   }
 
+  if (!USER_VERSION_ATLEAST(283, 1)) {
+    FROM_DEFAULT_V4_UCHAR(space_view3d.bone_locked_weight);
+  }
+
   /**
    * Versioning code until next subversion bump goes here.
    *

source/blender/draw/engines/overlay/overlay_armature.c

@@ -35,6 +35,7 @@
 #include "BLI_math.h"
 #include "BLI_utildefines.h"
 
+#include "BKE_action.h"
 #include "BKE_armature.h"
 #include "BKE_modifier.h"
 
@@ -974,6 +975,15 @@ static bool set_pchan_color(const ArmatureDrawContext *ctx,
 /** \name Drawing Color Helpers
  * \{ */
 
+static void bone_locked_color_shade(float color[4])
+{
+  float locked_color[4];
+
+  UI_GetThemeColor4fv(TH_BONE_LOCKED_WEIGHT, locked_color);
+
+  interp_v3_v3v3(color, color, locked_color, locked_color[3]);
+}
+
 static const float *get_bone_solid_color(const ArmatureDrawContext *ctx,
                                          const EditBone *UNUSED(eBone),
                                          const bPoseChannel *pchan,
@@ -989,6 +999,11 @@ static const float *get_bone_solid_color(const ArmatureDrawContext *ctx,
     static float disp_color[4];
     copy_v4_v4(disp_color, pchan->draw_data->solid_color);
     set_pchan_color(ctx, PCHAN_COLOR_SOLID, boneflag, constflag, disp_color);
+
+    if (boneflag & BONE_DRAW_LOCKED_WEIGHT) {
+      bone_locked_color_shade(disp_color);
+    }
+
     return disp_color;
   }
 
@@ -1009,7 +1024,7 @@ static const float *get_bone_solid_with_consts_color(const ArmatureDrawContext *
   const float *col = get_bone_solid_color(ctx, eBone, pchan, arm, boneflag, constflag);
 
   static float consts_color[4];
-  if ((arm->flag & ARM_POSEMODE) &&
+  if ((arm->flag & ARM_POSEMODE) && !(boneflag & BONE_DRAW_LOCKED_WEIGHT) &&
       set_pchan_color(ctx, PCHAN_COLOR_CONSTS, boneflag, constflag, consts_color)) {
     interp_v3_v3v3(consts_color, col, consts_color, 0.5f);
   }
@@ -1065,6 +1080,10 @@ static const float *get_bone_wire_color(const ArmatureDrawContext *ctx,
   else if (arm->flag & ARM_POSEMODE) {
     copy_v4_v4(disp_color, pchan->draw_data->wire_color);
     set_pchan_color(ctx, PCHAN_COLOR_NORMAL, boneflag, constflag, disp_color);
+
+    if (boneflag & BONE_DRAW_LOCKED_WEIGHT) {
+      bone_locked_color_shade(disp_color);
+    }
   }
   else {
     copy_v3_v3(disp_color, ctx->color.vertex);
@@ -1518,7 +1537,7 @@ static void draw_bone_custom_shape(ArmatureDrawContext *ctx,
       drw_shgroup_bone_custom_empty(ctx, disp_mat, col_wire, pchan->custom);
     }
   }
-  if ((boneflag & BONE_DRAWWIRE) == 0) {
+  if ((boneflag & BONE_DRAWWIRE) == 0 && (boneflag & BONE_DRAW_LOCKED_WEIGHT) == 0) {
     drw_shgroup_bone_custom_solid(ctx, disp_mat, col_solid, col_hint, col_wire, pchan->custom);
   }
   else {
@@ -2010,6 +2029,8 @@ static void draw_armature_edit(ArmatureDrawContext *ctx)
           boneflag |= BONE_DRAW_ACTIVE;
         }
 
+        boneflag &= ~BONE_DRAW_LOCKED_WEIGHT;
+
         draw_bone_relations(ctx, eBone, NULL, arm, boneflag, constflag);
 
         if (arm->drawtype == ARM_ENVELOPE) {
@@ -2054,6 +2075,7 @@ static void draw_armature_pose(ArmatureDrawContext *ctx)
   bPoseChannel *pchan;
   int index = -1;
   const bool show_text = DRW_state_show_text();
+  bool draw_locked_weights = false;
 
   /* We can't safely draw non-updated pose, might contain NULL bone pointers... */
   if (ob->pose->flag & POSE_RECALC) {
@@ -2089,6 +2111,28 @@ static void draw_armature_pose(ArmatureDrawContext *ctx)
     }
   }
 
+  /* In weight paint mode retrieve the vertex group lock status. */
+  if ((draw_ctx->object_mode == OB_MODE_WEIGHT_PAINT) && (draw_ctx->object_pose == ob) &&
+      (draw_ctx->obact != NULL)) {
+    draw_locked_weights = true;
+
+    for (pchan = ob->pose->chanbase.first; pchan; pchan = pchan->next) {
+      pchan->bone->flag &= ~BONE_DRAW_LOCKED_WEIGHT;
+    }
+
+    const Object *obact_orig = DEG_get_original_object(draw_ctx->obact);
+
+    LISTBASE_FOREACH (bDeformGroup *, dg, &obact_orig->defbase) {
+      if (dg->flag & DG_LOCK_WEIGHT) {
+        pchan = BKE_pose_channel_find_name(ob->pose, dg->name);
+
+        if (pchan) {
+          pchan->bone->flag |= BONE_DRAW_LOCKED_WEIGHT;
+        }
+      }
+    }
+  }
+
   for (pchan = ob->pose->chanbase.first; pchan; pchan = pchan->next, index += 0x10000) {
     Bone *bone = pchan->bone;
     const bool bone_visible = (bone->flag & (BONE_HIDDEN_P | BONE_HIDDEN_PG)) == 0;
@@ -2120,6 +2164,10 @@ static void draw_armature_pose(ArmatureDrawContext *ctx)
           boneflag |= BONE_DRAW_ACTIVE;
         }
 
+        if (!draw_locked_weights) {
+          boneflag &= ~BONE_DRAW_LOCKED_WEIGHT;
+        }
+
         draw_bone_relations(ctx, NULL, pchan, arm, boneflag, constflag);
 
         if ((pchan->custom) && !(arm->flag & ARM_NO_CUSTOM)) {

source/blender/editors/include/UI_resources.h

@@ -143,6 +143,7 @@ typedef enum ThemeColorID {
   TH_BONE_SOLID,
   TH_BONE_POSE,
   TH_BONE_POSE_ACTIVE,
+  TH_BONE_LOCKED_WEIGHT,
 
   TH_STRIP,
   TH_STRIP_SELECT,

source/blender/editors/interface/resources.c

@@ -443,6 +443,9 @@ const uchar *UI_ThemeGetColorPtr(bTheme *btheme, int spacetype, int colorid)
         case TH_BONE_POSE_ACTIVE:
           cp = ts->bone_pose_active;
           break;
+        case TH_BONE_LOCKED_WEIGHT:
+          cp = ts->bone_locked_weight;
+          break;
         case TH_STRIP:
           cp = ts->strip;
           break;

source/blender/editors/object/object_vgroup.c

@@ -3179,6 +3179,8 @@ static int vertex_group_lock_exec(bContext *C, wmOperator *op)
 
   vgroup_lock_all(ob, action);
 
+  WM_event_add_notifier(C, NC_OBJECT | ND_DRAW, ob);
+
   return OPERATOR_FINISHED;
 }
 

source/blender/makesdna/DNA_armature_types.h

@@ -252,7 +252,8 @@ typedef enum eBone_Flag {
   BONE_ADD_PARENT_END_ROLL = (1 << 24),
   /** this bone was transformed by the mirror function */
   BONE_TRANSFORM_MIRROR = (1 << 25),
-
+  /** this bone is associated with a locked vertex group, ONLY USE FOR DRAWING */
+  BONE_DRAW_LOCKED_WEIGHT = (1 << 26),
 } eBone_Flag;
 
 /* bone->inherit_scale_mode */

source/blender/makesdna/DNA_userdef_types.h

@@ -283,13 +283,12 @@ typedef struct ThemeSpace {
   unsigned char normal[4];
   unsigned char vertex_normal[4];
   unsigned char loop_normal[4];
-  unsigned char bone_solid[4], bone_pose[4], bone_pose_active[4];
+  unsigned char bone_solid[4], bone_pose[4], bone_pose_active[4], bone_locked_weight[4];
   unsigned char strip[4], strip_select[4];
   unsigned char cframe[4];
   unsigned char time_keyframe[4], time_gp_keyframe[4];
   unsigned char freestyle_edge_mark[4], freestyle_face_mark[4];
   unsigned char time_scrub_background[4];
-  char _pad5[4];
 
   unsigned char nurb_uline[4], nurb_vline[4];
   unsigned char act_spline[4], nurb_sel_uline[4], nurb_sel_vline[4], lastsel_point[4];

source/blender/makesrna/intern/rna_userdef.c

@@ -2231,6 +2231,14 @@ static void rna_def_userdef_theme_space_view3d(BlenderRNA *brna)
   RNA_def_property_ui_text(prop, "Bone Solid", "");
   RNA_def_property_update(prop, 0, "rna_userdef_theme_update");
 
+  prop = RNA_def_property(srna, "bone_locked_weight", PROP_FLOAT, PROP_COLOR_GAMMA);
+  RNA_def_property_array(prop, 4);
+  RNA_def_property_ui_text(
+      prop,
+      "Bone Locked Weight",
+      "Shade for bones corresponding to a locked weight group during painting");
+  RNA_def_property_update(prop, 0, "rna_userdef_theme_update");
+
   /* misc */
 
   prop = RNA_def_property(srna, "bundle_solid", PROP_FLOAT, PROP_COLOR_GAMMA);