dim-inactive-windows: Do not dim the tab bar and active window padding

The builtin pipeline dimmed everything outside the cell area of the
active window, which produced a dark frame around the active window
(whose thickness varied with the size mismatch padding) and a dimmed tab
bar. Enable DIM_CENTRAL_AREA_ONLY and INCLUDE_WINDOW_PADDING.

Fixes #10524

docs/changelog.rst

@@ -208,6 +208,9 @@ Detailed list of changes
 - Fix a memory leak when loading a corrupt PNG image that has an embedded ICC
   color profile
 
+- Custom shaders: The builtin :code:`dim-inactive-windows` shader no longer dims
+  the tab bar and the padding around the active window (:iss:`10524`)
+
 0.49.1 [2026-09-24]
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 

kitty/shaders/custom/dim-inactive-windows.pipeline

@@ -3,5 +3,9 @@ startgroup
     animation_step 0
     var float HIGHLIGHT_INTENSITY = 0
     var float BORDER_WIDTH = 0
+    # do not dim the tab bar and treat the padding/title bar of the active
+    # window as part of it, so it is not surrounded by a dimmed frame
+    var bool DIM_CENTRAL_AREA_ONLY = true
+    var bool INCLUDE_WINDOW_PADDING = true
     shaders focus-highlight
 endgroup