Wrong character width with BitmapFontTexture

[TMTH]

Character width calculation is wrong for not mono-spaced fonts. Error is here (BMFontLoaderTxt._buildCharInfo):

if (xadv) {
   width = xadv;
}

Character width is not always equal to xadv. Try to export Arial from BMFont and look to number characters  (48-57)

When rendering, wrong part of texture is taken for character.

@Nockawa

[Nockawa]

Hello,

Thanks for reporting, I've created this Trello Card. I'm really focused right now to revamp the positioning engine, that's why I don't fix the other things right away. 

But once I'm done with the current task, I'll work on them immediately.

[Nockawa]

@TMTH so I should not set width = xadv; right? but just feed width with the width property from the file and discard xadv?

[TMTH]

@Nockawa, Yes, width is the width of the character, but you can't discard xadv because it defines position increment when moving from one character to the another. And yes, that increment is not equal to character width.

Example is here https://www.gamedev.net/topic/330742-quick-tutorial-variable-width-bitmap-fonts/

[Nockawa]

Ok, I apparently I didn't look my code closer enough, let's go again then!

[Nockawa]

I just recheck my code, thing is: I don't need to compute the position of the next char, right? I can just use the x and y position for this, right? I mean they are absolute values, right? If that's so, then I don't need xadvance

[TMTH]

I'm not sure that I understand your question.

There are two kinds of positions - position of glyph in the source texture, and position of glyph in the target texture (or on screen). rectangle(x, y, x + width, y + height ) gives you rectangle in source texture, in absolute, not normalized coordinates - the glyph, that has to be rendered.  On the other side, xoffset, yoffset, xadvance gives you directions on how to render that glyph in target. You need all of them  - xoffset and yoffset to render current glyph, and xadvance to find base position for the next glyph.

They've got a picture here http://www.angelcode.com/products/bmfont/doc/render_text.html

[Nockawa]

Ok, now I'm reading the doc (RTFM rules...) I understand that it's actually way more complicated than what I did. But I did dead simple, it's not that complicate in absolute, I would even said that it makes more sense to me, the guys did that to pack as tight as possible the chars but still storing values to place them correctly during rendering! (which is btw something I have trouble with when using font converted from HTML because I don't have all these informations).

So it's great, now I know what to do and how to improve the rendering thanks to your information, it shouldn't be that hard to code, it's 4 additional properties to store and use.

[Nockawa]

Hello @TMTH

I've made the changes, I've built a BMFont map with the Arial font and the text is now displayed correctly. There's a new preview build reflecting these changes.

If you have feedback, they are welcomed!