M src/config.c → src/config.c

@@ -244,7 +244,9 @@ {
     char *value1 = 0, *value2 = 0, *value3 = 0;
 
     /* Background and border */
-    if (strcmp(key, "rounded") == 0) {
+    if (strcmp(key, "scale_relative_to_dpi") == 0) {
+        ui_scale_dpi_ref = atof(value);
+    } else if (strcmp(key, "rounded") == 0) {
         // 'rounded' is the first parameter => alloc a new background
         if (backgrounds->len > 0) {
             Background *bg = &g_array_index(backgrounds, Background, backgrounds->len - 1);

M src/panel.c → src/panel.c

@@ -79,11 +79,14 @@ 
 GArray *backgrounds;
 GArray *gradients;
 
+double ui_scale_dpi_ref;
+
 Imlib_Image default_icon;
 char *default_font = NULL;
 
 void default_panel()
 {
+    ui_scale_dpi_ref = 0;
     panels = NULL;
     num_panels = 0;
     default_icon = NULL;

M src/panel.h → src/panel.h

@@ -95,6 +95,7 @@ extern gboolean debug_fps;
 extern double tracing_fps_threshold;
 extern gboolean debug_frames;
 extern gboolean debug_thumbnails;
+extern double ui_scale_dpi_ref;
 
 typedef struct Panel {
     Area area;