From 889860377b6c46d0c46d15a2f0250fa7bd5ba4c7 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Franti=C5=A1ek=20Boh=C3=A1=C4=8Dek?=
 <fandabohacek@gmail.com>
Date: Mon, 28 Jun 2021 22:18:46 +0200
Subject: [PATCH] refactor: mark font char functions constant

---
 lib-gui/include/font.h               | 10 +++++-----
 lib-gui/include/gui_component_text.h |  2 +-
 lib-gui/src/font.c                   | 18 +++++++++++-------
 3 files changed, 17 insertions(+), 13 deletions(-)

diff --git a/lib-gui/include/font.h b/lib-gui/include/font.h
index c5e85a6..ca8e8e3 100644
--- a/lib-gui/include/font.h
+++ b/lib-gui/include/font.h
@@ -66,7 +66,7 @@ font_t font_create(font_descriptor_t descriptor);
 font_t font_family_create(font_descriptor_t def, font_family_t *family);
 font_descriptor_t *font_family_get_descriptor(font_t *font);
 
-uint32_t font_get_real_char(char *text, uint16_t *bytes);
+uint32_t font_get_real_char(const char *text, uint16_t *bytes);
 
 /**
  * @brief Get text dimensions for given font
@@ -75,7 +75,7 @@ uint32_t font_get_real_char(char *text, uint16_t *bytes);
  * @param text
  * @return size2d_t
  */
-size2d_t font_measure_text(font_t *font, char *text);
+size2d_t font_measure_text(font_t *font, const char *text);
 
 /**
  * @brief Get font character for font from char
@@ -105,8 +105,8 @@ bool font_contains_character(font_t *font, uint32_t c);
  * @param ellipsis
  * @return uint16_t number of characters that can be fit
  */
-uint16_t font_fit_ellipsis(font_t *font, size2d_t size, char *text,
-                           char *ellipsis);
+uint16_t font_fit_ellipsis(font_t *font, size2d_t size, const char *text,
+                           const char *ellipsis);
 
 /**
  * @brief Fit cut text without any ellipsis to get how many characters can be
@@ -117,7 +117,7 @@ uint16_t font_fit_ellipsis(font_t *font, size2d_t size, char *text,
  * @param text
  * @return uint16_t
  */
-uint16_t font_fit_cut(font_t *font, size2d_t size, char *text);
+uint16_t font_fit_cut(font_t *font, size2d_t size, const char *text);
 
 extern font_descriptor_t font_rom8x16;
 extern font_descriptor_t font_winFreeSystem14x16;
diff --git a/lib-gui/include/gui_component_text.h b/lib-gui/include/gui_component_text.h
index 12db55b..6a57ddb 100644
--- a/lib-gui/include/gui_component_text.h
+++ b/lib-gui/include/gui_component_text.h
@@ -5,7 +5,7 @@
 #include "gui.h"
 
 typedef struct {
-  char *line;
+  const char *line;
   font_t *font;
   display_pixel_t color;
 } text_t;
diff --git a/lib-gui/src/font.c b/lib-gui/src/font.c
index e3c2043..363b7f7 100644
--- a/lib-gui/src/font.c
+++ b/lib-gui/src/font.c
@@ -32,7 +32,7 @@ font_descriptor_t *font_family_get_descriptor(font_t *font) {
   return font->family->descriptors[nearest_index];
 }
 
-uint32_t font_get_real_char(char *text, uint16_t *bytes) {
+uint32_t font_get_real_char(const char *text, uint16_t *bytes) {
   *bytes = 1;
   uint8_t first_byte_offset = 0;
 
@@ -105,7 +105,7 @@ font_t font_family_create(font_descriptor_t def, font_family_t *family) {
   return font;
 }
 
-size2d_t font_measure_text(font_t *font, char *text) {
+size2d_t font_measure_text(font_t *font, const char *text) {
   size2d_t size = {.x = 0, .y = font->size};
 
   double scale = (double)font->size / font_family_get_descriptor(font)->height;
@@ -170,21 +170,25 @@ bool font_contains_character(font_t *font, uint32_t c){
 }
 
 uint16_t
-    font_fit_ellipsis(font_t *font, size2d_t size, char *text, char *ellipsis) {
+    font_fit_ellipsis(font_t *font, size2d_t size, const char *text, const char *ellipsis) {
   uint16_t ellipsis_width = font_measure_text(font, ellipsis).x;
   size.x -= ellipsis_width;
 
   return font_fit_cut(font, size, text);
 }
 
-uint16_t font_fit_cut(font_t *font, size2d_t size, char *text) {
+uint16_t font_fit_cut(font_t *font, size2d_t size, const char *text) {
   size_t len = strlen(text);
 
   uint16_t x_size = 0;
-  double scale = (double)font->size / font->font.height;
+  double scale = (double)font->size / font_family_get_descriptor(font)->height;
   for (int i = 0; i < len; i++) {
-    font_character_t character = font_get_character(font, text[i]);
-    x_size += character.width * scale;
+    uint16_t bytes = 0;
+    uint32_t c = font_get_real_char(&text[i], &bytes);
+    i += bytes - 1;
+
+    font_character_t character = font_get_character(font, c);
+    x_size += character.width * scale + font->char_spacing;
 
     if (x_size > size.x) {
       return i;
-- 
2.48.1