3D View: add opacity for sculpt mask display

This matches vertex/texture paint opacity options.

Useful because 0.75 is sometimes too dark to see the surface shading.

Resolves T63746

release/scripts/startup/bl_ui/space_view3d.py

@@ -5572,8 +5572,14 @@ class VIEW3D_PT_overlay_sculpt(Panel):
         tool_settings = context.tool_settings
         sculpt = tool_settings.sculpt
 
+        view = context.space_data
+        overlay = view.overlay
+
         layout.prop(sculpt, "show_diffuse_color")
         layout.prop(sculpt, "show_mask")
+        row = layout.row()
+        row.active = sculpt.show_mask
+        row.prop(overlay, "sculpt_mode_mask_opacity", text="Opacity")
 
 
 class VIEW3D_PT_overlay_pose(Panel):

source/blender/blenloader/intern/versioning_280.c

@@ -3177,6 +3177,20 @@ void blo_do_versions_280(FileData *fd, Library *UNUSED(lib), Main *bmain)
       }
     }
 
+    if (!DNA_struct_elem_find(
+            fd->filesdna, "View3DOverlay", "float", "sculpt_mode_mask_opacity")) {
+      for (bScreen *screen = bmain->screens.first; screen; screen = screen->id.next) {
+        for (ScrArea *sa = screen->areabase.first; sa; sa = sa->next) {
+          for (SpaceLink *sl = sa->spacedata.first; sl; sl = sl->next) {
+            if (sl->spacetype == SPACE_VIEW3D) {
+              View3D *v3d = (View3D *)sl;
+              v3d->overlay.sculpt_mode_mask_opacity = 0.75f;
+            }
+          }
+        }
+      }
+    }
+
     /* Versioning code until next subversion bump goes here. */
   }
 }

source/blender/draw/modes/sculpt_mode.c

@@ -135,9 +135,15 @@ static void SCULPT_cache_init(void *vedata)
   }
 
   {
+    const DRWContextState *draw_ctx = DRW_context_state_get();
+    View3D *v3d = draw_ctx->v3d;
+
     DRWState state = DRW_STATE_WRITE_COLOR | DRW_STATE_DEPTH_EQUAL | DRW_STATE_MULTIPLY;
     psl->pass = DRW_pass_create("Sculpt Pass", state);
-    stl->g_data->group_smooth = DRW_shgroup_create(e_data.shader_smooth, psl->pass);
+
+    DRWShadingGroup *shgrp = DRW_shgroup_create(e_data.shader_smooth, psl->pass);
+    DRW_shgroup_uniform_float(shgrp, "maskOpacity", &v3d->overlay.sculpt_mode_mask_opacity, 1);
+    stl->g_data->group_smooth = shgrp;
   }
 }
 

source/blender/draw/modes/shaders/sculpt_mask_vert.glsl

@@ -1,5 +1,6 @@
 
 uniform mat4 ModelViewProjectionMatrix;
+uniform float maskOpacity;
 
 in vec3 pos;
 in float msk;
@@ -10,6 +11,6 @@ void main()
 {
   gl_Position = ModelViewProjectionMatrix * vec4(pos, 1.0);
 
-  float mask = 1.0 - msk * 0.75;
+  float mask = 1.0 - (msk * maskOpacity);
   finalColor = vec4(mask, mask, mask, 1.0);
 }

source/blender/editors/space_view3d/space_view3d.c

@@ -262,6 +262,10 @@ static SpaceLink *view3d_new(const ScrArea *UNUSED(sa), const Scene *scene)
   v3d->overlay.texture_paint_mode_opacity = 1.0f;
   v3d->overlay.weight_paint_mode_opacity = 1.0f;
   v3d->overlay.vertex_paint_mode_opacity = 1.0f;
+  /* Intentionally different to vertex/paint mode,
+   * we typically want to see shading too. */
+  v3d->overlay.sculpt_mode_mask_opacity = 0.75f;
+
   v3d->overlay.edit_flag = V3D_OVERLAY_EDIT_FACES | V3D_OVERLAY_EDIT_SEAMS |
                            V3D_OVERLAY_EDIT_SHARP | V3D_OVERLAY_EDIT_FREESTYLE_EDGE |
                            V3D_OVERLAY_EDIT_FREESTYLE_FACE | V3D_OVERLAY_EDIT_EDGES |

source/blender/makesdna/DNA_view3d_types.h

@@ -200,12 +200,12 @@ typedef struct View3DOverlay {
 
   /** Weight paint mode settings. */
   int wpaint_flag;
-  char _pad2[4];
 
   /** Alpha for texture, weight, vertex paint overlay. */
   float texture_paint_mode_opacity;
   float vertex_paint_mode_opacity;
   float weight_paint_mode_opacity;
+  float sculpt_mode_mask_opacity;
 
   /** Armature edit/pose mode settings. */
   int _pad3;

source/blender/makesrna/intern/rna_space.c

@@ -3468,6 +3468,13 @@ static void rna_def_space_view3d_overlay(BlenderRNA *brna)
   RNA_def_property_range(prop, 0.0f, 1.0f);
   RNA_def_property_update(prop, NC_SPACE | ND_SPACE_VIEW3D, NULL);
 
+  prop = RNA_def_property(srna, "sculpt_mode_mask_opacity", PROP_FLOAT, PROP_FACTOR);
+  RNA_def_property_float_sdna(prop, NULL, "overlay.sculpt_mode_mask_opacity");
+  RNA_def_property_float_default(prop, 1.0f);
+  RNA_def_property_ui_text(prop, "Sculpt Mask Opacity", "");
+  RNA_def_property_range(prop, 0.0f, 1.0f);
+  RNA_def_property_update(prop, NC_SPACE | ND_SPACE_VIEW3D, NULL);
+
   /* grease pencil paper settings */
   prop = RNA_def_property(srna, "show_annotation", PROP_BOOLEAN, PROP_NONE);
   RNA_def_property_boolean_sdna(prop, NULL, "flag2", V3D_SHOW_ANNOTATION);