[rtext] `GenImageFontAtlas()` default package method is very strict for atlas height

[vitassuper]

Issue description

I’m trying to load the NotoSans-Regular.ttf font with the default codepoints plus a few additional Cyrillic codepoints. The font size is 96. Interestingly, if I use another size (e.g., 100), the issue disappears.

This problem occurs randomly—it seems to depend on the font size and the number of codepoints being loaded. When adding more codepoints or changing the font size, the issue sometimes goes away.

In the terminal, I also see:
WARNING: FONT: Failed to package character (103)

After investigating, I noticed that the code which checks the atlas height is quite strict:

rtext.c:844

if (totalArea < ((imageSize*imageSize)/2))

I have some draft improvements to make this check slightly more flexible, which could reduce edge cases like this. If you’re open to improving this algorithm, I’d be happy to submit a PR.

Environment

MacOS 12.7.6
Raylib 5.5
OpenGL 4.1 INTEL-18.8.16

Issue Screenshot

Code Example

FontWrapper *load_font(const char *font_path, int font_size) {
  FontWrapper *wrapper = malloc(sizeof(FontWrapper));
  wrapper->font_path = font_path;
  wrapper->font_size = font_size;
  int default_codepoints[95 + 9];

  for (int i = 0; i < 95; i++) {
    default_codepoints[i] = 32 + i;
  }

  int size = 0;
  int * codepoints = LoadCodepoints("йцукенгшщ", &size);
  for (int i = 0; i < 9; i++) {
    default_codepoints[95+i] = codepoints[i];
  } 
  wrapper->raylib_font = LoadFontEx(font_path, font_size, default_codepoints, 95+9);

  return wrapper;
}

FontWrapper *font = load_font("NotoSans-Regular.ttf", 96);

[raysan5]

@vitassuper there have been already multiple reviews of that code, the atlas size is estimated so there could be some side cases where it does not fit the texture. Did you try with latest raylib master branch? (In the report you specific 5.5 but I think it was reviewed lately).

Another option is defining SUPPORT_FONT_ATLAS_SIZE_CONSERVATIVE for a more conservative size estimation.

[vitassuper]

@vitassuper there have been already multiple reviews of that code, the atlas size is estimated so there could be some side cases where it does not fit the texture. Did you try with latest raylib master branch? (In the report you specific 5.5 but I think it was reviewed lately).

Another option is defining SUPPORT_FONT_ATLAS_SIZE_CONSERVATIVE for a more conservative size estimation.

I also tested this with the latest master, and I see the same issue. I can use the SUPPORT_FONT_ATLAS_SIZE_CONSERVATIVE flag to get better sizing, but in my opinion the default behavior is a bit unpredictable. You never know whether the atlas will contain all characters or not.

One possible solution would be: if a new row does not fit, resize the atlas and use a larger height instead of just printing a warning message like here:
rtext.c