tigregalis
commented
3 years ago So, I've done a bit of research.
It looks like it's trying to access an index (i.e. write to a pixel) outside the bounding box, so there's an index out of bounds error.
I cloned ab_glyph, downloaded your font, and was able to reproduce the panic, taking bevy out of the equation.
The issue itself probably needs to be handled upstream by ab_glyph (ab_glyph_rasterizer to be exact).
I've found the following issues which are similar to your bevy-0.4.0 and bevy-master respectively. https://github.com/alexheretic/ab-glyph/issues/21 https://github.com/alexheretic/ab-glyph/issues/26
The reason it's outside the bounding box is that the bounding box for the 'v' glyph appears to have dimensions of 0 width and 0 height.
I've traced it back to ttf_parser::glyf::outline_impl which is ultimately just reading binary data.
I cloned ttf_parser and put some dbg!()s in there. Below is for the character 'v' (glyph id = 89):
glyf_table
[src\tables\glyf.rs:560] &range = 7060..7128
[src\tables\glyf.rs:562] &glyph_data = [
0, # ->
1, # -> number of contours = 1
0, # --->
0, # ---> x_min = 0
0, # ----->
0, # -----> y_min = 0
0, # ------->
0, # -------> x_max = 0
0, # --------->
0, # ---------> y_max = 0
0,
15,
0,
0,
# ...
]
[src\tables\glyf.rs:606] rect = Rect {
x_min: 0,
y_min: 0,
x_max: 0,
y_max: 0,
}By contrast, this is 'w' (glyph id = 90)
glyf_table
[src\tables\glyf.rs:560] &range = 7128..7212
[src\tables\glyf.rs:562] &glyph_data = [
0, # ->
1, # -> number of contours = 1
0, # --->
0, # ---> x_min = 0
255, # ----->
254, # -----> y_min = -2
6, # ------->
164, # -------> x_max = 1700
5, # --------->
20, # ---------> y_max = 1300
0,
28,
0,
0,
# ...
]
[src\tables\glyf.rs:606] rect = Rect {
x_min: 0,
y_min: -2,
x_max: 1700,
y_max: 1300,
}
[examples\outline-glyph.rs:34] bbox = Rect {
x_min: 0,
y_min: -2,
x_max: 1700,
y_max: 1300,
}So, it could be that the font itself is corrupt, as it's showing a zero sized bounding box for 'v'. Other text rendering engines handle it fine, so perhaps they have a fallback, or don't use the encoded bounding box, or something like that.
The subpixel work (the biggest/only? difference between bevy 0.4.0 and master) seems to hide this panic for some reason (but still renders nothing). I think it's because it now produces a non-zero-sized bounding box (0 width, 1 high).
The curves themselves seem to be fine, as I tested it with Lyon and successfully rendered a 'v'.
luke-biel
alice-i-cecile
Bevy version
0.4 and master
Operating system & version
Mac OS Big Sur 11.1
What you did
Copied
ui/buttonexample, changed font toairstrip four(http://www.vicfieger.com/~font/techno.html). Ran example.What you expected to happen
Example displayed button that changes text on hover and press.
What actually happened
On
0.4game crashed when hovered a button.On
mastergame did not crash, just lettervin wordhoverwas not displayed.Additional information
Seems like there's issue in displaying letter
vin this particular font. Some work must've been done since release of0.4, becausemasteris at least not panicking, but desired goal is to have font render properly. UppercaseVis being displayed.