From ed5b077f929a14528df0b5fb1c5a8407fe4eebe7 Mon Sep 17 00:00:00 2001
From: Jeroen Bakker <jeroen@blender.org>
Date: Mon, 17 Feb 2025 14:14:12 +0100
Subject: [PATCH] Fix #134634: Overlay: Mask not drawing on top of render
 result/viewer

Logical error in the overlay engine. Moved mask drawing before the early
exit for viewer/render results.

Pull Request: https://projects.blender.org/blender/blender/pulls/134660
---
 .../draw/engines/overlay/overlay_next_mesh.hh | 47 ++++++++++---------
 1 file changed, 25 insertions(+), 22 deletions(-)

diff --git a/source/blender/draw/engines/overlay/overlay_next_mesh.hh b/source/blender/draw/engines/overlay/overlay_next_mesh.hh
index d31edc27730..56b63483d52 100644
--- a/source/blender/draw/engines/overlay/overlay_next_mesh.hh
+++ b/source/blender/draw/engines/overlay/overlay_next_mesh.hh
@@ -528,16 +528,6 @@ class MeshUVs : Overlay {
     const ToolSettings *tool_setting = state.scene->toolsettings;
     const SpaceImage *space_image = reinterpret_cast<const SpaceImage *>(state.space_data);
     ::Image *image = space_image->image;
-    const bool is_tiled_image = image && (image->source == IMA_SRC_TILED);
-    const bool is_viewer = image && ELEM(image->type, IMA_TYPE_R_RESULT, IMA_TYPE_COMPOSITE);
-    /* Only disable UV drawing on top of render results.
-     * Otherwise, show UVs even in the absence of active image. */
-    enabled_ = !is_viewer;
-
-    if (!enabled_) {
-      return;
-    }
-
     const bool space_mode_is_paint = space_image->mode == SI_MODE_PAINT;
     const bool space_mode_is_view = space_image->mode == SI_MODE_VIEW;
     const bool space_mode_is_mask = space_image->mode == SI_MODE_MASK;
@@ -546,6 +536,31 @@ class MeshUVs : Overlay {
     const bool object_mode_is_edit = state.object_mode & OB_MODE_EDIT;
     const bool object_mode_is_paint = state.object_mode & OB_MODE_TEXTURE_PAINT;
 
+    const bool is_viewer = image && ELEM(image->type, IMA_TYPE_R_RESULT, IMA_TYPE_COMPOSITE);
+    const bool is_tiled_image = image && (image->source == IMA_SRC_TILED);
+
+    /* The mask overlay is always drawn when enabled, even on top of viewers. */
+    {
+      /* Mask Overlay. */
+      show_mask_ = space_mode_is_mask && space_image->mask_info.mask &&
+                   space_image->mask_info.draw_flag & MASK_DRAWFLAG_OVERLAY;
+      if (show_mask_) {
+        mask_mode_ = eMaskOverlayMode(space_image->mask_info.overlay_mode);
+        mask_id_ = (Mask *)DEG_get_evaluated_id(state.depsgraph, &space_image->mask_info.mask->id);
+      }
+      else {
+        mask_id_ = nullptr;
+      }
+    }
+
+    /* Only disable UV drawing on top of render results.
+     * Otherwise, show UVs even in the absence of active image. */
+    enabled_ = !is_viewer || show_mask_;
+
+    if (!enabled_) {
+      return;
+    }
+
     {
       /* Edit UV Overlay. */
       show_uv_edit = space_mode_is_uv && object_mode_is_edit;
@@ -605,18 +620,6 @@ class MeshUVs : Overlay {
                       (brush->image_brush_type == IMAGE_PAINT_BRUSH_TYPE_CLONE) &&
                       brush->clone.image;
     }
-    {
-      /* Mask Overlay. */
-      show_mask_ = space_mode_is_mask && space_image->mask_info.mask &&
-                   space_image->mask_info.draw_flag & MASK_DRAWFLAG_OVERLAY;
-      if (show_mask_) {
-        mask_mode_ = eMaskOverlayMode(space_image->mask_info.overlay_mode);
-        mask_id_ = (Mask *)DEG_get_evaluated_id(state.depsgraph, &space_image->mask_info.mask->id);
-      }
-      else {
-        mask_id_ = nullptr;
-      }
-    }
     {
       /* UDIM Overlay. */
       /* TODO: Always enable this overlay even if overlays are disabled. */