From 913458f721e98844eaf57138b09894da4e629c81 Mon Sep 17 00:00:00 2001
From: Stephen Molloy <stephen.molloy@maxiv.lu.se>
Date: Thu, 28 Dec 2023 00:16:25 +0100
Subject: [PATCH] Added the new function

---
 src/raylib.h |  1 +
 src/rtext.c  | 27 +++++++++++++++++++++++++++
 2 files changed, 28 insertions(+)

diff --git a/src/raylib.h b/src/raylib.h
index 2ab3f3041..35e22274e 100644
--- a/src/raylib.h
+++ b/src/raylib.h
@@ -1427,6 +1427,7 @@ RLAPI int GetPixelDataSize(int width, int height, int format);              // G
 RLAPI Font GetFontDefault(void);                                                            // Get the default Font
 RLAPI Font LoadFont(const char *fileName);                                                  // Load font from file into GPU memory (VRAM)
 RLAPI Font LoadFontEx(const char *fileName, int fontSize, int *codepoints, int codepointCount);  // Load font from file with extended parameters, use NULL for codepoints and 0 for codepointCount to load the default character set
+RLAPI void AddNewCharsToFontEx(Font *font, const char *fileName, int fontSize, char *newChars);  // Reload the font after adding the new characters to the list of desired characters
 RLAPI Font LoadFontFromImage(Image image, Color key, int firstChar);                        // Load font from Image (XNA style)
 RLAPI Font LoadFontFromMemory(const char *fileType, const unsigned char *fileData, int dataSize, int fontSize, int *codepoints, int codepointCount); // Load font from memory buffer, fileType refers to extension: i.e. '.ttf'
 RLAPI bool IsFontReady(Font font);                                                          // Check if a font is ready
diff --git a/src/rtext.c b/src/rtext.c
index 2a6aa1273..8012b2a0d 100644
--- a/src/rtext.c
+++ b/src/rtext.c
@@ -378,6 +378,33 @@ Font LoadFontEx(const char *fileName, int fontSize, int *codepoints, int codepoi
     return font;
 }
 
+// Reload the font after adding the new characters to the list of desired characters
+// Passing NULL to the newChars variable results in a reset to the default of LoadFontEx
+void AddNewCharsToFontEx(Font *font, const char *fileName, int fontSize, char *newChars)
+{
+  if (newChars == NULL) {
+    *font = LoadFontEx(fileName, fontSize, NULL, 0);
+    return;
+  }
+
+  int codepointCount = 0;
+  int *codepoints = LoadCodepoints(newChars, &codepointCount);
+
+  int newCount = font->glyphCount + codepointCount;
+
+  int *newCodepoints = MemAlloc(newCount * sizeof(int));
+  for (int i=0; i<font->glyphCount; i++) {
+    newCodepoints[i] = font->glyphs[i].value;
+  }
+  for (int i=font->glyphCount; i<newCount; i++) {
+    newCodepoints[i] = codepoints[i-font->glyphCount];
+  }
+
+  *font = LoadFontEx(fileName, fontSize, newCodepoints, newCount);
+
+  MemFree(newCodepoints);
+}
+
 // Load an Image font file (XNA style)
 Font LoadFontFromImage(Image image, Color key, int firstChar)
 {