From d165afec1d301167754c4152f868a0110b3144a6 Mon Sep 17 00:00:00 2001
From: Behdad Esfahbod <behdad@behdad.org>
Date: Sat, 4 Mar 2023 21:09:26 -0700
Subject: [PATCH] [justify-demo] Create new fonts all the time

The hb.shape_justify() call modifies the font. This was messing
up justification. Create new fonts all the time.
---
 src/justify.py | 18 ++++++++++--------
 1 file changed, 10 insertions(+), 8 deletions(-)

diff --git a/src/justify.py b/src/justify.py
index f36da8633..af48fd990 100644
--- a/src/justify.py
+++ b/src/justify.py
@@ -114,7 +114,8 @@ def makebuffer(words):
     return buf
 
 
-def justify(font, words, advance, target_advance):
+def justify(face, words, advance, target_advance):
+    font = hb.font_create(face)
     buf = makebuffer(words)
 
     wiggle = 5
@@ -149,7 +150,8 @@ def justify(font, words, advance, target_advance):
     return True, buf, variation
 
 
-def shape(font, words):
+def shape(face, words):
+    font = hb.font_create(face)
     buf = makebuffer(words)
     hb.shape(font, buf)
     positions = hb.buffer_get_glyph_positions(buf)
@@ -157,15 +159,15 @@ def shape(font, words):
     return buf, advance
 
 
-def typeset(font, text, target_advance):
+def typeset(face, text, target_advance):
     lines = []
     words = []
     for word in text.split():
         words.append(word)
-        buf, advance = shape(font, words)
+        buf, advance = shape(face, words)
         if advance > target_advance:
             # Shrink
-            ret, buf, variation = justify(font, words, advance, target_advance)
+            ret, buf, variation = justify(face, words, advance, target_advance)
             if ret:
                 lines.append((buf, variation))
                 words = []
@@ -173,7 +175,7 @@ def typeset(font, text, target_advance):
             # A too short line is better than too long.
             elif len(words) > 1:
                 words.pop()
-                _, buf, variation = justify(font, words, advance, target_advance)
+                _, buf, variation = justify(face, words, advance, target_advance)
                 lines.append((buf, variation))
                 words = [word]
             # But if it is one word, meh.
@@ -183,7 +185,7 @@ def typeset(font, text, target_advance):
 
     # Justify last line
     if words:
-        _, buf, variation = justify(font, words, advance, target_advance)
+        _, buf, variation = justify(face, words, advance, target_advance)
         lines.append((buf, variation))
 
     return lines
@@ -196,7 +198,7 @@ def render(face, text, context, width, height, fontsize):
     scale = fontsize / hb.face_get_upem(face)
     target_advance = (width - (margin * 2)) / scale
 
-    lines = typeset(font, text, target_advance)
+    lines = typeset(face, text, target_advance)
 
     _, extents = hb.font_get_h_extents(font)
     lineheight = extents.ascender - extents.descender + extents.line_gap