Add option to enable the Snap to Grid option for the brush preview (fix #4137)

data/pref.xml

@@ -212,6 +212,7 @@
       <option id="cursor_color" type="app::Color" default="app::Color::fromMask()" />
       <option id="painting_cursor_type" type="PaintingCursorType" default="PaintingCursorType::CROSSHAIR_ON_SPRITE" />
       <option id="brush_preview" type="BrushPreview" default="BrushPreview::FULL" />
+      <option id="snap_to_grid" type="bool" default="false" />
     </section>
     <section id="preview" text="Preview">
       <option id="play_once" type="bool" default="false" />

data/strings/en.ini

@@ -1701,6 +1701,7 @@ brush_preview_fullnedges = Full Preview and Edges
 cursor_color_type = Crosshair && Brush Edges Color:
 cursor_neg_bw = Negative Black and White
 cursor_specific_color = Specific Color
+snap_cursor_to_grid = Snap To Grid when the option is enabled
 bg_checkered = Checkered Background
 bg_size = Size:
 bg_custom_size = Custom

data/widgets/options.xml

@@ -346,6 +346,9 @@
 
 	    <boxfiller />
 	    <colorpicker id="cursor_color" rgba="true" />
+
+            <check text="@.snap_cursor_to_grid"
+                   pref="cursor.snap_to_grid" cell_hspan="2" />
 	  </grid>
         </vbox>
 

src/app/ui/editor/brush_preview.cpp

@@ -176,7 +176,8 @@ void BrushPreview::show(const gfx::Point& screenPos)
 
   // Get cursor position in the editor
   gfx::Point spritePos = m_editor->screenToEditor(screenPos);
-  if (m_editor->docPref().grid.snap()) {
+  if (pref.cursor.snapToGrid() &&
+      m_editor->docPref().grid.snap()) {
     spritePos = snap_to_grid(m_editor->docPref().grid.bounds(),
                              spritePos,
                              PreferSnapTo::ClosestGridVertex) +