From e55bdd5d8af913016b74776d0878b30eb830f138 Mon Sep 17 00:00:00 2001
From: Hanaxar <87268284+hanaxar@users.noreply.github.com>
Date: Wed, 22 Mar 2023 13:00:13 +0300
Subject: [PATCH] Fix packing logic error in ```GenImageFontAtlas``` (#2979)

Basic packing algorithm currently follows this order: Copy pixel data -> Move offsetX for current glyph -> Check remaining space for current glyph...
Since X offset already moved according current glyph, remaining space should be checked for next glyph. Because of this, occasionally, current logic causes glyphs wrapping around texture.
Proposed fix accomplishes that by moving offsetX check to the beginning of the loop.
---
 src/rtext.c | 37 +++++++++++++++++++------------------
 1 file changed, 19 insertions(+), 18 deletions(-)

diff --git a/src/rtext.c b/src/rtext.c
index da93af7e3..e8493778e 100644
--- a/src/rtext.c
+++ b/src/rtext.c
@@ -725,24 +725,7 @@ Image GenImageFontAtlas(const GlyphInfo *chars, Rectangle **charRecs, int glyphC
         // NOTE: Using simple packaging, one char after another
         for (int i = 0; i < glyphCount; i++)
         {
-            // Copy pixel data from fc.data to atlas
-            for (int y = 0; y < chars[i].image.height; y++)
-            {
-                for (int x = 0; x < chars[i].image.width; x++)
-                {
-                    ((unsigned char *)atlas.data)[(offsetY + y)*atlas.width + (offsetX + x)] = ((unsigned char *)chars[i].image.data)[y*chars[i].image.width + x];
-                }
-            }
-
-            // Fill chars rectangles in atlas info
-            recs[i].x = (float)offsetX;
-            recs[i].y = (float)offsetY;
-            recs[i].width = (float)chars[i].image.width;
-            recs[i].height = (float)chars[i].image.height;
-
-            // Move atlas position X for next character drawing
-            offsetX += (chars[i].image.width + 2*padding);
-
+            // Check remaining space for glyph
             if (offsetX >= (atlas.width - chars[i].image.width - 2*padding))
             {
                 offsetX = padding;
@@ -766,6 +749,24 @@ Image GenImageFontAtlas(const GlyphInfo *chars, Rectangle **charRecs, int glyphC
                     break;
                 }
             }
+
+            // Copy pixel data from fc.data to atlas
+            for (int y = 0; y < chars[i].image.height; y++)
+            {
+                for (int x = 0; x < chars[i].image.width; x++)
+                {
+                    ((unsigned char *)atlas.data)[(offsetY + y)*atlas.width + (offsetX + x)] = ((unsigned char *)chars[i].image.data)[y*chars[i].image.width + x];
+                }
+            }
+
+            // Fill chars rectangles in atlas info
+            recs[i].x = (float)offsetX;
+            recs[i].y = (float)offsetY;
+            recs[i].width = (float)chars[i].image.width;
+            recs[i].height = (float)chars[i].image.height;
+
+            // Move atlas position X for next character drawing
+            offsetX += (chars[i].image.width + 2*padding);
         }
     }
     else if (packMethod == 1)  // Use Skyline rect packing algorithm (stb_pack_rect)