From 319147449f80f9d20729395e6fada6bc0c021e30 Mon Sep 17 00:00:00 2001
From: shy <18635772+shyraptor@users.noreply.github.com>
Date: Sun, 12 Apr 2026 18:03:54 +0200
Subject: [PATCH] Fix GuiGetTextWidth() to measure multi-line text correctly

Resolves #415.

GuiGetTextWidth() stopped at the first '\n', so auto-sized widgets
(GuiLabel, GuiMessageBox, ...) clipped multi-line text.

Factor the existing single-line measurement into a new static
GetLineWidth() helper and turn GuiGetTextWidth() into a wrapper that
iterates '\n'-separated lines and returns the maximum line width.

GuiDrawText() now calls GetLineWidth() directly for per-line text
positioning, so its existing per-line alignment behavior is preserved
byte-for-byte (the icon is already stripped by GetTextIcon() before
measurement, so GetLineWidth() takes no icon path there).

Incidental corrections in GetLineWidth() vs. the old GuiGetTextWidth()
body, to bring it into agreement with GetTextIcon():

- The icon-marker skip now uses text += (pos + 1) to land past the
  closing '#', matching GetTextIcon(). Previously it was
  text += textIconOffset where textIconOffset was the index OF the
  closing '#', leaving that '#' in the measured string and
  over-measuring icon-prefixed labels by ~1 glyph.

- The icon marker is recognised only as '#' + 1..3 digits + '#',
  matching GetTextIcon(). The old detector accepted any character
  between the hashes, so e.g. "#abc#Text" was misclassified as an
  icon and the label width was computed incorrectly.
---
 src/raygui.h | 55 ++++++++++++++++++++++++++++++++++++++--------------
 1 file changed, 40 insertions(+), 15 deletions(-)

diff --git a/src/raygui.h b/src/raygui.h
index 72f7108e..0e5a58b7 100644
--- a/src/raygui.h
+++ b/src/raygui.h
@@ -4772,8 +4772,11 @@ void GuiSetIconScale(int scale)
     if (scale >= 1) guiIconScale = scale;
 }
 
-// Get text width considering gui style and icon size (if required)
-int GuiGetTextWidth(const char *text)
+// Get the width of a single line of gui text (stops at '\n' or '\0'),
+// considering the gui font/style and an optional icon marker '#NNN#' at
+// the start. Icon detection matches GetTextIcon(): 1..3 digits, skip past
+// the closing '#'.
+static int GetLineWidth(const char *text)
 {
     #if !defined(ICON_TEXT_PADDING)
         #define ICON_TEXT_PADDING   4
@@ -4784,16 +4787,12 @@ int GuiGetTextWidth(const char *text)
 
     if ((text != NULL) && (text[0] != '\0'))
     {
+        // Icon marker: '#' + 1..3 digits + '#' (matches GetTextIcon())
         if (text[0] == '#')
         {
-            for (int i = 1; (i < 5) && (text[i] != '\0'); i++)
-            {
-                if (text[i] == '#')
-                {
-                    textIconOffset = i;
-                    break;
-                }
-            }
+            int pos = 1;
+            while ((pos < 4) && (text[pos] >= '0') && (text[pos] <= '9')) pos++;
+            if (text[pos] == '#') textIconOffset = pos + 1;
         }
 
         text += textIconOffset;
@@ -4801,10 +4800,10 @@ int GuiGetTextWidth(const char *text)
         // Make sure guiFont is set, GuiGetStyle() initializes it lazynessly
         float fontSize = (float)GuiGetStyle(DEFAULT, TEXT_SIZE);
 
-        // Custom MeasureText() implementation
+        // Custom MeasureText() implementation -- single line only
         if ((guiFont.texture.id > 0) && (text != NULL))
         {
-            // Get size in bytes of text, considering end of line and line break
+            // Get size in bytes of the line, considering end of line and line break
             int size = 0;
             for (int i = 0; i < MAX_LINE_BUFFER_SIZE; i++)
             {
@@ -4834,6 +4833,32 @@ int GuiGetTextWidth(const char *text)
     return (int)textSize.x;
 }
 
+// Get text width considering gui style and icon size (if required).
+// For multi-line text (containing '\n'), returns the width of the widest line.
+int GuiGetTextWidth(const char *text)
+{
+    if (text == NULL) return 0;
+
+    int maxWidth = 0;
+    const char *linePtr = text;
+
+    while ((linePtr[0] != '\0') && ((linePtr - text) < MAX_LINE_BUFFER_SIZE))
+    {
+        int lineWidth = GetLineWidth(linePtr);
+        if (lineWidth > maxWidth) maxWidth = lineWidth;
+
+        // Skip to the next '\n' (or end of string/buffer)
+        while ((linePtr[0] != '\0') && (linePtr[0] != '\n') && ((linePtr - text) < MAX_LINE_BUFFER_SIZE))
+        {
+            linePtr++;
+        }
+        // Advance past the '\n' delimiter to the start of the next line
+        if (linePtr[0] == '\n') linePtr++;
+    }
+
+    return maxWidth;
+}
+
 #endif      // !RAYGUI_NO_ICONS
 
 //----------------------------------------------------------------------------------
@@ -5223,9 +5248,9 @@ static void GuiDrawText(const char *text, Rectangle textBounds, int alignment, C
         Vector2 textBoundsPosition = { textBounds.x, textBounds.y };
         float textBoundsWidthOffset = 0.0f;
 
-        // NOTE: Get text size after icon has been processed
-        // WARNING: GuiGetTextWidth() also processes text icon to get width! -> Really needed?
-        int textSizeX = GuiGetTextWidth(lines[i]);
+        // NOTE: Icon was already stripped above by GetTextIcon(); GetLineWidth()
+        // takes no icon path here and returns only the glyph width of this line.
+        int textSizeX = GetLineWidth(lines[i]);
 
         // If text requires an icon, add size to measure
         if (iconId >= 0)