From 886160ba891e2ebe7b654ec29a359a1bf3a5ba7b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20Ekl=C3=B6f?= <daniel@ekloef.se>
Date: Fri, 23 Apr 2021 21:30:47 +0200
Subject: [PATCH] render: modify background color for highlighted text when fg
 == bg

When rendering a selected/highlighted cell where the foreground and
background colors are the same, invert the background color to make
the selected text legible.

Closes #455
---
 CHANGELOG.md | 4 ++++
 render.c     | 5 +++++
 2 files changed, 9 insertions(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index c329882f..74d29d3a 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -33,6 +33,10 @@
 * `generate-alt-random-writes.py --sixel`: width and height of emitted
   sixels has been adjusted.
 * _Concealed_ text (`\E[8m`) is now revealed when highlighted.
+* The background color of highlighted text is now adjusted, when the
+  foreground and background colors are the same, making the
+  highlighted text legible
+  (https://codeberg.org/dnkl/foot/issues/455).
 
 
 ### Deprecated
diff --git a/render.c b/render.c
index bee7108f..faa04183 100644
--- a/render.c
+++ b/render.c
@@ -443,6 +443,11 @@ render_cell(struct terminal *term, pixman_image_t *pix,
         }
     }
 
+    if (unlikely(is_selected && _fg == _bg)) {
+        /* Invert bg when selected/highlighted text has same fg/bg */
+        _bg = ~_bg;
+    }
+
     if (cell->attrs.dim)
         _fg = color_dim(_fg);
     if (term->conf->bold_in_bright.enabled && cell->attrs.bold)