Add a test for glyph extents

This verifies a recent fix for COLRv1 returning
0,0,-1,1 for extents of non-painting glyphs.

test/api/Makefile.am

@@ -42,6 +42,7 @@ TEST_PROGS = \
 	test-cplusplus \
 	test-common \
 	test-draw \
+	test-extents \
 	test-font \
 	test-font-scale \
 	test-instance-cff2 \

test/api/meson.build

@@ -15,6 +15,7 @@ tests = [
   'test-cplusplus.cc',
   'test-common.c',
   'test-draw.c',
+  'test-extents.c',
   'test-font.c',
   'test-font-scale.c',
   'test-instance-cff2.c',

test/api/test-extents.c

@@ -0,0 +1,104 @@
+/*
+ * Copyright © 2023 Red Hat, Inc.
+ *
+ *  This is part of HarfBuzz, a text shaping library.
+ *
+ * Permission is hereby granted, without written agreement and without
+ * license or royalty fees, to use, copy, modify, and distribute this
+ * software and its documentation for any purpose, provided that the
+ * above copyright notice and the following two paragraphs appear in
+ * all copies of this software.
+ *
+ * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
+ * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
+ * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
+ * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
+ * DAMAGE.
+ *
+ * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
+ * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
+ * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
+ * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
+ * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
+ *
+ * Author(s): Matthias Clasen
+ */
+
+#include "hb-test.h"
+
+
+static void
+test_glyph_extents (void)
+{
+  hb_face_t *face;
+  hb_font_t *font;
+  hb_glyph_extents_t extents;
+  hb_bool_t ret;
+
+  /* This font contains a COLRv1 glyph with a ClipBox,
+   * and various components without. The main thing
+   * we test here is that glyphs with no paint return
+   * 0,0,0,0 and not meaningless numbers.
+   */
+
+  face = hb_test_open_font_file ("fonts/adwaita.ttf");
+  font = hb_font_create (face);
+
+  ret = hb_font_get_glyph_extents (font, 0, &extents);
+  g_assert_true (ret);
+  g_assert_true (extents.x_bearing == 0 &&
+                 extents.y_bearing == 0 &&
+                 extents.width     == 0 &&
+                 extents.height    == 0);
+
+  ret = hb_font_get_glyph_extents (font, 1, &extents);
+  g_assert_true (ret);
+  g_assert_true (extents.x_bearing == 0 &&
+                 extents.y_bearing == 0 &&
+                 extents.width     == 0 &&
+                 extents.height    == 0);
+
+  ret = hb_font_get_glyph_extents (font, 2, &extents);
+  g_assert_true (ret);
+  g_assert_true (extents.x_bearing ==   180 &&
+                 extents.y_bearing ==   960 &&
+                 extents.width     ==  1060 &&
+                 extents.height    == -1220);
+
+  ret = hb_font_get_glyph_extents (font, 3, &extents);
+  g_assert_true (ret);
+  g_assert_true (extents.x_bearing ==   188 &&
+                 extents.y_bearing ==   950 &&
+                 extents.width     ==   900 &&
+                 extents.height    == -1200);
+
+  ret = hb_font_get_glyph_extents (font, 4, &extents);
+  g_assert_true (ret);
+  g_assert_true (extents.x_bearing ==   413 &&
+                 extents.y_bearing ==    50 &&
+                 extents.width     ==   150 &&
+                 extents.height    ==   -75);
+
+  ret = hb_font_get_glyph_extents (font, 5, &extents);
+  g_assert_true (ret);
+  g_assert_true (extents.x_bearing ==   638 &&
+                 extents.y_bearing ==   350 &&
+                 extents.width     ==   600 &&
+                 extents.height    ==  -600);
+
+  ret = hb_font_get_glyph_extents (font, 1000, &extents);
+  g_assert_false (ret);
+
+  hb_font_destroy (font);
+  hb_face_destroy (face);
+}
+
+int
+main (int argc, char **argv)
+{
+  hb_test_init (&argc, &argv);
+
+  hb_test_add (test_glyph_extents);
+
+  return hb_test_run();
+}