altos/draw: Add ao_text_width

[fw/altos] / src / draw / ao_text_width.c

diff --git a/src/draw/ao_text_width.c b/src/draw/ao_text_width.c
new file mode 100644 (file)
index 0000000..9f08bd0
--- /dev/null
+++ b/src/draw/ao_text_width.c
@@ -0,0 +1,40 @@
+/*
+ * Copyright © 2024 Keith Packard <keithp@keithp.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
+ */
+
+#include <ao_draw.h>
+#include <ao_draw_int.h>
+#include "ao_font.h"
+#include <string.h>
+#include <stdio.h>
+
+int16_t
+ao_text_width(const struct ao_font     *font,
+             const char                *string)
+{
+       char            c;
+       int16_t         x = 0;
+
+       while ((c = *string++)) {
+               if (font->metrics) {
+                       x += font->metrics[(uint8_t) c].advance;
+               } else {
+                       x += font->max_width;
+               }
+       }
+       return x;
+}