From 09354286955a6a7eb05e0e336ce7fc9cc43cb5f3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20Ekl=C3=B6f?= <daniel@ekloef.se>
Date: Thu, 13 May 2021 00:15:00 +0200
Subject: [PATCH] term: remove get_font_scale()
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get_font_scale() was used to get the new scaling factor when loading
fonts. This was then compared to the last seen font scaling factor. If
there was no difference, the fonts were not reloaded.

The problem was, the initial term->scale was set differently. This
sometimes led to term->scale=2, while get_font_scale() return 1. That
meant, fonts were initially scaled by 2 (when dpi-aware=no). Later,
when mapped on an output (and thus term->scale being set to 1), the
fonts weren’t reloaded with the correct scaling factor since the
cached term->font_scale value was already 1.

Since term->scale always reflects the *new* scaling factor when
term_font_dpi_changed() is called, use that directly, and remove
get_font_scale().

Also rename the following functions:

* font_should_size_by_dpi() -> font_size_by_dpi_for_scale()
* font_size_by_dpi() -> font_sized_by_dpi()
* font_size_by_scale() -> font_sized_by_scale()
---
 terminal.c | 51 +++++++++++++--------------------------------------
 terminal.h |  2 +-
 2 files changed, 14 insertions(+), 39 deletions(-)

diff --git a/terminal.c b/terminal.c
index b4abbb0f..7fd6f551 100644
--- a/terminal.c
+++ b/terminal.c
@@ -724,31 +724,6 @@ get_font_dpi(const struct terminal *term)
     return dpi;
 }
 
-static int
-get_font_scale(const struct terminal *term)
-{
-    /* Same as get_font_dpi(), but returns output scale factor instead */
-    int scale = 0;
-
-    xassert(term->window != NULL);
-    tll_foreach(term->window->on_outputs, it) {
-        if (it->item->scale > scale)
-            scale = it->item->scale;
-    }
-
-    if (scale == 0) {
-        tll_foreach(term->wl->monitors, it) {
-            scale = it->item.scale;
-            break;
-        }
-    }
-
-    if (scale == 0)
-        scale = 1;
-
-    return scale;
-}
-
 static enum fcft_subpixel
 get_font_subpixel(const struct terminal *term)
 {
@@ -794,22 +769,22 @@ get_font_subpixel(const struct terminal *term)
 }
 
 static bool
-font_should_size_by_dpi(const struct terminal *term, int new_scale)
+font_size_by_dpi_for_scale(const struct terminal *term, int new_scale)
 {
     return term->conf->dpi_aware == DPI_AWARE_YES ||
         (term->conf->dpi_aware == DPI_AWARE_AUTO && new_scale <= 1);
 }
 
 static bool
-font_size_by_dpi(const struct terminal *term)
+font_sized_by_dpi(const struct terminal *term)
 {
-    return font_should_size_by_dpi(term, term->font_scale);
+    return font_size_by_dpi_for_scale(term, term->font_scale);
 }
 
 static bool
-font_size_by_scale(const struct terminal *term)
+font_sized_by_scale(const struct terminal *term)
 {
-    return !font_size_by_dpi(term);
+    return !font_sized_by_dpi(term);
 }
 
 
@@ -849,7 +824,7 @@ reload_fonts(struct terminal *term)
             bool use_px_size = term->font_sizes[i][j].px_size > 0;
             char size[64];
 
-            const int scale = font_size_by_scale(term) ? term->scale : 1;
+            const int scale = font_sized_by_scale(term) ? term->scale : 1;
 
             if (use_px_size)
                 snprintf(size, sizeof(size), ":pixelsize=%d",
@@ -885,7 +860,7 @@ 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 = font_size_by_dpi(term);
+    const bool use_dpi = font_sized_by_dpi(term);
 
     char *attrs[4] = {NULL};
     int attr_len[4] = {-1, -1, -1, -1};  /* -1, so that +1 (below) results in 0 */
@@ -1798,16 +1773,16 @@ bool
 term_font_dpi_changed(struct terminal *term)
 {
     float dpi = get_font_dpi(term);
-    int scale = get_font_scale(term);
+    xassert(term->scale > 0);
 
-    bool was_scaled_using_dpi = font_size_by_dpi(term);
-    bool will_scale_using_dpi = font_should_size_by_dpi(term, scale);
+    bool was_scaled_using_dpi = font_sized_by_dpi(term);
+    bool will_scale_using_dpi = font_size_by_dpi_for_scale(term, term->scale);
 
     bool need_font_reload =
         was_scaled_using_dpi != will_scale_using_dpi ||
         (will_scale_using_dpi
          ? term->font_dpi != dpi
-         : term->font_scale != scale);
+         : term->font_scale != term->scale);
 
     if (need_font_reload) {
         LOG_DBG("DPI/scale change: DPI-awareness=%s, "
@@ -1815,12 +1790,12 @@ term_font_dpi_changed(struct terminal *term)
                 "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->font_scale, scale,
+                term->font_dpi, dpi, term->font_scale, term->scale,
                 will_scale_using_dpi ? "DPI" : "scaling factor");
     }
 
     term->font_dpi = dpi;
-    term->font_scale = scale;
+    term->font_scale = term->scale;
 
     if (!need_font_reload)
         return true;
diff --git a/terminal.h b/terminal.h
index 85ba90eb..42e2fd2a 100644
--- a/terminal.h
+++ b/terminal.h
@@ -320,7 +320,7 @@ struct terminal {
     struct config_font *font_sizes[4];
     struct pt_or_px font_line_height;
     float font_dpi;
-    int font_scale;
+    int font_scale;  /* scaling factor last time we loaded fonts */
     int16_t font_x_ofs;
     int16_t font_y_ofs;
     enum fcft_subpixel font_subpixel;