thanks Igor.

I’m trying to look at the font reloading bug.

On 28 Mar 2014, at 17:19, Igor Stasenko <siguctua@gmail.com> wrote:

https://pharo.fogbugz.com/f/cases/13150/Different-memory-alignment-on-different-platforms

On 28 March 2014 16:42, Igor Stasenko <siguctua@gmail.com> wrote:

so, the quick and dirty fix is to put:

CairoGlyph class>>byteAlignment

    NativeBoost platformId = NativeBoostConstants win32PlatformId ifTrue: [  ^ 8 ].
    ^ super byteAlignment

and then:

CairoGlyph rebuildFieldAccessors
CairoGlyphsArray initialize

(note you must run this snippet each time your image changes platform)..

and i need more time to fix it for real, because it is NB issue, to automatically recalculate the structs size

if it changes platform.. (which also means you cannot store instances of struct in image which survive the session)

... damn.. that's going to be complicated.

---

On 28 March 2014 16:27, Igor Stasenko <siguctua@gmail.com> wrote:

On 28 March 2014 16:01, Igor Stasenko <siguctua@gmail.com> wrote:

Ookkayy..

so, current status:

 - finally we got an agreement that big red square because of font loading issues and font rendering artifacts is two separate issues.

Thanks!

- i am not going to address font-loading issue here and now.. (because we spent time on it earlier today with Stef already and you should have the report on it in separate mail).

- we seem to be agreed that it is best to use same (up-to-date version) of software when reporting issues to work on them. Thanks again. :)

- while on linux and mac things seem to be working fine, i can confirm that there is rendering artifacts (same as reported by Vincent) on Windows.

so i going to explore what causing this problem..

... and found the cause:

On windows, for unknown reason, the structure (cairo_glyph_t) uses different memory space alignment than on mac and linux

fieldsDesc
    ^ #(
    ulong        index;
    double               x;
    double               y;
    )

on mac and linux , the size of this structure in memory = 4 + 8 + 8 = 20 bytes,
on windows, however, due to 8-byte alignment, it is  4 + 8 + 8 + (4 alignment) bytes...

 

this causing the effect that if you copy array of glyphs in memory,
it does not copying whole array by slightly less  (because it uses wrong struct size which is smaller than it is)..

and because of that, you got weird artefacts at the tail of string, replaced by misplaced/invalid characters etc..
because it is basically read from uninitialized part of memory with random data.

i going to fix structure alignment for windows from default 4 bytes to 8 bytes..

but this is not very good news.. because this affecting many things... (as you can imagine, not only cairo/athens working with external structures, which need to be properly aligned).

--
Best regards,
Igor Stasenko.

--
Best regards,
Igor Stasenko.

--
Best regards,
Igor Stasenko.