From e426e77b1d3640868b521b65617525f76ab3b35c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20Ekl=C3=B6f?= <daniel@ekloef.se>
Date: Tue, 14 Sep 2021 10:20:07 +0200
Subject: [PATCH] box-drawing: braille: prefer increasing spacing over dot
 width

Too large dots make them harder to distinguish, when the spacing
between them is small.

Prefer increasing the spacing, instead of increasing the dot
size. This looks better at small font sizes in particular.
---
 box-drawing.c | 37 ++++++++++++++++++++-----------------
 1 file changed, 20 insertions(+), 17 deletions(-)

diff --git a/box-drawing.c b/box-drawing.c
index 1c694627..f1789f64 100644
--- a/box-drawing.c
+++ b/box-drawing.c
@@ -1962,8 +1962,8 @@ draw_braille(struct buf *buf, wchar_t wc)
     int x_margin = x_spacing / 2;
     int y_margin = y_spacing / 2;
 
-    int x_pix_left = buf->width - 2 * x_margin - x_spacing - 2 * w;
-    int y_pix_left = buf->height - 2 * y_margin - 3 * y_spacing - 4 * w;
+    int x_px_left = buf->width - 2 * x_margin - x_spacing - 2 * w;
+    int y_px_left = buf->height - 2 * y_margin - 3 * y_spacing - 4 * w;
 
     LOG_DBG(
         "braille: before adjusting: "
@@ -1972,35 +1972,38 @@ draw_braille(struct buf *buf, wchar_t wc)
         w, x_pix_left, y_pix_left);
 
     /* First, try hard to ensure the DOT width is non-zero */
-    if (x_pix_left >= 2 && y_pix_left >= 4 && w == 0) {
+    if (x_px_left >= 2 && y_px_left >= 4 && w == 0) {
         w++;
-        x_pix_left -= 2;
-        y_pix_left -= 4;
+        x_px_left -= 2;
+        y_px_left -= 4;
     }
 
     /* Second, prefer a non-zero margin */
-    if (x_pix_left >= 2 && x_margin == 0) { x_margin = 1; x_pix_left -= 2; }
-    if (y_pix_left >= 2 && y_margin == 0) { y_margin = 1; y_pix_left -= 2; }
+    if (x_px_left >= 2 && x_margin == 0) { x_margin = 1; x_px_left -= 2; }
+    if (y_px_left >= 2 && y_margin == 0) { y_margin = 1; y_px_left -= 2; }
 
-    if (x_pix_left >= 2 && y_pix_left >= 4) {
+    /* Third, increase spacing */
+    if (x_px_left >= 1) { x_spacing++; x_px_left--; }
+    if (y_px_left >= 3) { y_spacing++; y_px_left -= 3; }
+
+    /* Fourth, margins (“spacing”, but on the sides) */
+    if (x_px_left >= 2) { x_margin++; x_px_left -= 2; }
+    if (y_px_left >= 2) { y_margin++; y_px_left -= 2; }
+
+    /* Last - increase dot width */
+    if (x_px_left >= 2 && y_px_left >= 4) {
         w++;
-        x_pix_left -= 2;
-        y_pix_left -= 4;
+        x_px_left -= 2;
+        y_px_left -= 4;
     }
 
-    if (x_pix_left >= 1) { x_spacing++; x_pix_left--; }
-    if (y_pix_left >= 3) { y_spacing++; y_pix_left -= 3; }
-
-    if (x_pix_left >= 2) { x_margin++; x_pix_left -= 2; }
-    if (y_pix_left >= 2) { y_margin++; y_pix_left -= 2; }
-
     LOG_DBG(
         "braille: after adjusting: "
         "cell: %dx%d, margin=%dx%d, spacing=%dx%d, width=%d, left=%dx%d",
         buf->width, buf->height, x_margin, y_margin, x_spacing, y_spacing,
         w, x_pix_left, y_pix_left);
 
-    xassert(x_pix_left <= 1 || y_pix_left <= 1);
+    xassert(x_px_left <= 1 || y_px_left <= 1);
     xassert(2 * x_margin + 2 * w + x_spacing <= buf->width);
     xassert(2 * y_margin + 4 * w + 3 * y_spacing <= buf->height);