Merge branch 'non-dpi-aware-if-any-output-uses-scaling'

CHANGELOG.md

@@ -56,6 +56,9 @@
   still exported, like before.
 * The default install location for the terminfo definitions have been
   changed back to `${datadir}/terminfo`.
+* `dpi-aware=auto`: fonts are now scaled using the monitor’s DPI only
+  when **all** monitors have a scaling factor of one
+  (https://codeberg.org/dnkl/foot/issues/714).
 
 
 ### Deprecated

README.md

@@ -347,9 +347,9 @@ This is not how it is meant to be. Fonts are measured in _point sizes_
 all mediums, be it printers or monitors, regardless of their DPI.
 
 Foot’s default behavior is to use the monitor’s DPI to size fonts when
-output scaling has been disabled. On monitors where output scaling has
-been enabled, fonts will instead be sized using the scaling
-factor.
+output scaling has been disabled on **all** monitors. If at least one
+monitor has output scaling enabled, fonts will instead by sized using
+the scaling factor.
 
 This can be changed to either **always** use the monitor’s DPI
 (regardless of scaling factor), or to **never** use it, with the

box-drawing.c

@@ -2837,8 +2837,8 @@ box_drawing(const struct terminal *term, wchar_t wc)
         abort();
     }
 
-    double dpi = term_font_sized_by_dpi(term, term->scale) ? term->font_dpi : 96.;
-    double scale = term_font_sized_by_scale(term, term->scale) ? term->scale : 1.;
+    double dpi = term->font_is_sized_by_dpi ? term->font_dpi : 96.;
+    double scale = term->font_is_sized_by_dpi ? 1. : term->scale;
     double cell_size = sqrt(pow(term->cell_width, 2) + pow(term->cell_height, 2));
 
     int base_thickness =

doc/foot.ini.5.scd

@@ -161,8 +161,10 @@ in this order:
 	scaling factor *does* double the font size.
 	
 	Finally, if set to *auto*, fonts will be sized using the monitor's
-	DPI on monitors with a scaling factor of 1, but otherwise using
-	the scaling factor.
+	DPI if _all_ monitors have a scaling factor of 1. If at least one
+	monitor as a scaling factor larger than 1 (regardless of whether
+	the foot window is mapped on that monitor or not), fonts will be
+	scaled using the scaling factor.
 	
 	Note that this option typically does not work with bitmap fonts,
 	which only contains a pre-defined set of sizes, and cannot be

terminal.c

@@ -813,25 +813,48 @@ get_font_subpixel(const struct terminal *term)
     return FCFT_SUBPIXEL_DEFAULT;
 }
 
-bool
-term_font_sized_by_dpi(const struct terminal *term, int scale)
+static bool
+term_font_size_by_dpi(const struct terminal *term)
 {
-    return term->conf->dpi_aware == DPI_AWARE_YES ||
-        (term->conf->dpi_aware == DPI_AWARE_AUTO && scale <= 1);
-}
+    switch (term->conf->dpi_aware) {
+    case DPI_AWARE_YES:  return true;
+    case DPI_AWARE_NO:   return false;
 
-bool
-term_font_sized_by_scale(const struct terminal *term, int scale)
-{
-    return !term_font_sized_by_dpi(term, scale);
+    case DPI_AWARE_AUTO:
+        /*
+         * Scale using DPI if all monitors have a scaling factor or 1.
+         *
+         * The idea is this: if a user, with multiple monitors, have
+         * enabled scaling on at least one monitor, then he/she has
+         * most likely done so to match the size of his/hers other
+         * monitors.
+         *
+         * I.e. if the user has one monitor with a scaling factor of
+         * one, and another with a scaling factor of two, he/she
+         * expects things to be twice as large on the second
+         * monitor.
+         *
+         * If we (foot) scale using DPI on the first monitor, and
+         * using the scaling factor on the second monitor, foot will
+         * *not* look twice as big on the second monitor.
+         */
+        tll_foreach(term->wl->monitors, it) {
+            const struct monitor *mon = &it->item;
+            if (mon->scale > 1)
+                return false;
+        }
+        return true;
+    }
+
+    BUG("unhandled DPI awareness value");
 }
 
 int
 term_pt_or_px_as_pixels(const struct terminal *term,
                         const struct pt_or_px *pt_or_px)
 {
-    double scale = term_font_sized_by_scale(term, term->scale) ? term->scale : 1.;
-    double dpi = term_font_sized_by_dpi(term, term->scale) ? term->font_dpi : 96.;
+    double scale = !term->font_is_sized_by_dpi ? term->scale : 1.;
+    double dpi = term->font_is_sized_by_dpi  ? term->font_dpi : 96.;
 
     return pt_or_px->px == 0
         ? round(pt_or_px->pt * scale * dpi / 72)
@@ -878,8 +901,7 @@ reload_fonts(struct terminal *term)
             bool use_px_size = term->font_sizes[i][j].px_size > 0;
             char size[64];
 
-            const int scale =
-                term_font_sized_by_scale(term, term->scale) ? term->scale : 1;
+            const int scale = term->font_is_sized_by_dpi ? 1 : term->scale;
 
             if (use_px_size)
                 snprintf(size, sizeof(size), ":pixelsize=%d",
@@ -914,7 +936,7 @@ reload_fonts(struct terminal *term)
     const size_t count_bold_italic = custom_bold_italic ? counts[3] : counts[0];
     const char **names_bold_italic = (const char **)(custom_bold_italic ? names[3] : names[0]);
 
-    const bool use_dpi = term_font_sized_by_dpi(term, term->scale);
+    const bool use_dpi = term->font_is_sized_by_dpi;
 
     char *attrs[4] = {NULL};
     int attr_len[4] = {-1, -1, -1, -1};  /* -1, so that +1 (below) results in 0 */
@@ -2008,8 +2030,8 @@ term_font_dpi_changed(struct terminal *term, int old_scale)
     float dpi = get_font_dpi(term);
     xassert(term->scale > 0);
 
-    bool was_scaled_using_dpi = term_font_sized_by_dpi(term, old_scale);
-    bool will_scale_using_dpi = term_font_sized_by_dpi(term, term->scale);
+    bool was_scaled_using_dpi = term->font_is_sized_by_dpi;
+    bool will_scale_using_dpi = term_font_size_by_dpi(term);
 
     bool need_font_reload =
         was_scaled_using_dpi != will_scale_using_dpi ||
@@ -2019,15 +2041,16 @@ term_font_dpi_changed(struct terminal *term, int old_scale)
 
     if (need_font_reload) {
         LOG_DBG("DPI/scale change: DPI-awareness=%s, "
-                "DPI: %.2f -> %.2f, scale: %d, "
+                "DPI: %.2f -> %.2f, scale: %d -> %d, "
                 "sizing font based on monitor's %s",
                 term->conf->dpi_aware == DPI_AWARE_AUTO ? "auto" :
                 term->conf->dpi_aware == DPI_AWARE_YES ? "yes" : "no",
-                term->font_dpi, dpi, term->scale,
+                term->font_dpi, dpi, old_scale, term->scale,
                 will_scale_using_dpi ? "DPI" : "scaling factor");
     }
 
     term->font_dpi = dpi;
+    term->font_is_sized_by_dpi = will_scale_using_dpi;
 
     if (!need_font_reload)
         return true;

terminal.h

@@ -329,6 +329,7 @@ struct terminal {
     struct config_font *font_sizes[4];
     struct pt_or_px font_line_height;
     float font_dpi;
+    bool font_is_sized_by_dpi;
     int16_t font_x_ofs;
     int16_t font_y_ofs;
     enum fcft_subpixel font_subpixel;
@@ -660,8 +661,6 @@ bool term_font_size_reset(struct terminal *term);
 bool term_font_dpi_changed(struct terminal *term, int old_scale);
 void term_font_subpixel_changed(struct terminal *term);
 
-bool term_font_sized_by_dpi(const struct terminal *term, int scale);
-bool term_font_sized_by_scale(const struct terminal *term, int scale);
 int term_pt_or_px_as_pixels(
     const struct terminal *term, const struct pt_or_px *pt_or_px);
 

wayland.c

@@ -340,6 +340,11 @@ update_terms_on_monitor(struct monitor *mon)
     tll_foreach(wayl->terms, it) {
         struct terminal *term = it->item;
 
+        if (term->conf->dpi_aware == DPI_AWARE_AUTO) {
+            update_term_for_output_change(term);
+            continue;
+        }
+
         tll_foreach(term->window->on_outputs, it2) {
             if (it2->item == mon) {
                 update_term_for_output_change(term);