From: Ben Harris <bjh21@bjh21.me.uk>
Date: Sat, 16 Oct 2021 14:13:52 +0000 (+0100)
Subject: Fix outline adjustment for Bedstead Bold
X-Git-Tag: bedstead-002.003~9
X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~bjharris/git?a=commitdiff_plain;h=4592cdfb22ff50df0bfcf719cd255d4e03af9e6c;p=bedstead.git

Fix outline adjustment for Bedstead Bold

A couple of special cases handle the inside corners of glyphs like
"asterisk".  They're very ad-hoc, but also reasonably simple so I'll
forgive them.
---

diff --git a/bedstead.c b/bedstead.c
index 59dfd89..c2b89d4 100644
--- a/bedstead.c
+++ b/bedstead.c
@@ -2747,9 +2747,10 @@ emit_path()
  * vertical strokes.  More precisely, we pretend that the weight
  * variation is achieved by moving the rising edges of the output
  * waveform of the SAA5050.  This is implemented by moving all left
- * edges left and right.  The code below only handles cases where we
- * don't run out of slack in horizontal lines, which limits weight to
- * the range (-0.5 * XPIX) < weight < (0.25 * XPIX).
+ * edges left and right.  The code below is not fully general: it can
+ * handle cases where the slack in horizontal lines doesn't run out,
+ * and one special case where it does.  This means it should work
+ * correctly for the range (2 * XQTR_S - 1) < weight < (2 * XQTR_S).
  */
 static void
 adjust_weight()
@@ -2767,8 +2768,26 @@ adjust_weight()
 		PX = p->prev->v.x; PY = p->prev->v.y;
 		NX = p->next->v.x; NY = p->next->v.y;
 		/* Move left-edge points horizontally */
-		if (PY <= Y && Y <= NY)
+		if (PY <= Y && Y <= NY) {
 			moves[i].x -= W;
+			/*
+			 * These two clauses deal in an ad-hoc way
+			 * with the special cases (all four seen on
+			 * the "asterisk" glyph) where the bevel of an
+			 * inside corner gets completely consumed by
+			 * boldening.
+			 */
+			if (W > XQTR_S && PY == Y && PX == X - XQTR_S) {
+				moves[i].y += W - XQTR_S;
+				if (NX != X) moves[i].x += W - XQTR_S;
+				killpoint(p->prev);
+			}
+			if (W > XQTR_S && NY == Y && NX == X - XQTR_S) {
+				moves[i].y -= W - XQTR_S;
+				if (PX != X) moves[i].x += W - XQTR_S;
+				killpoint(p->next);
+			}
+		}
 		/* Move top inner corner points along NE/SW diagonal */
 		if (PY < Y && Y > NY && PX > X && X > NX) {
 			moves[i].x -= W/2;