implement dynamic font atlas resizing in GenImageFontAtlas()

src/rtext.c

@@ -690,6 +690,10 @@ Image GenImageFontAtlas(const GlyphInfo *chars, Rectangle **charRecs, int glyphC
     float guessSize = sqrtf(requiredArea)*1.4f;
     int imageSize = (int)powf(2, ceilf(logf((float)guessSize)/logf(2)));  // Calculate next POT
 
+    int currentRepeatCount = 0;
+    const int maxRepeatCount = 2;
+    bool undersizedAtlasFlag = false;
+
     atlas.width = imageSize;   // Atlas bitmap width
     atlas.height = imageSize;  // Atlas bitmap height
     atlas.data = (unsigned char *)RL_CALLOC(1, atlas.width*atlas.height);      // Create a bitmap to store characters (8 bpp)
@@ -701,6 +705,25 @@ Image GenImageFontAtlas(const GlyphInfo *chars, Rectangle **charRecs, int glyphC
 
     if (packMethod == 0)   // Use basic packing algorithm
     {
+        // When the guesstimate of the atlas size is determined to be undersized,
+        // repeat the atlas generation process with an atlas data texture of a size
+        // that is double the previous size, up to a limit of `maxRepeatCount` times
+        while (currentRepeatCount < maxRepeatCount)
+        {
+            if (currentRepeatCount > 0) 
+            {
+                // Recreate the atlas for the new, doubled size when all glyphs don't fit on the previous-sized atlas
+                // (but not on the first pass)
+                RL_FREE(atlas.data);
+                
+                atlas.width = atlas.width*2;   // Atlas bitmap width
+                atlas.height = atlas.height*2;  // Atlas bitmap height
+                atlas.data = (unsigned char *)RL_CALLOC(1, atlas.width*atlas.height);      // Create a bitmap to store characters (8 bpp)
+                TRACELOG(LOG_INFO, "FONT: Font atlas undersized, expanding atlas to %ix%i", atlas.width, atlas.height);
+                
+                undersizedAtlasFlag = false;
+            }
+
             int offsetX = padding;
             int offsetY = padding;
 
@@ -736,9 +759,20 @@ Image GenImageFontAtlas(const GlyphInfo *chars, Rectangle **charRecs, int glyphC
 
                     if (offsetY > (atlas.height - fontSize - padding))
                     {
+                        // The current atlas is too small to hold all glyphs, so move to the next atlas size
+                        
+
+
+                        currentRepeatCount++;
+                        undersizedAtlasFlag = true;
+                       
+                        // If the process repeats more times than the defined limit, abort and log the unpackaged characters
                         for(int j = i + 1; j < glyphCount; j++)
+                        {
+                            if (currentRepeatCount > maxRepeatCount)
                             {
                                 TRACELOG(LOG_WARNING, "FONT: Failed to package character (%i)", j);
+                            }
                             // make sure remaining recs contain valid data
                             recs[j].x = 0;
                             recs[j].y = 0;
@@ -749,6 +783,12 @@ Image GenImageFontAtlas(const GlyphInfo *chars, Rectangle **charRecs, int glyphC
                     }
                 }
             }
+            // After any pass, if all the glyphs fit, immediately end the packing process
+            if (!undersizedAtlasFlag)
+            {
+                break;
+            }
+        }
     }
     else if (packMethod == 1)  // Use Skyline rect packing algorithm (stb_pack_rect)
     {