math: ± and ∓ are shifted

math: ± and ∓ are shifted

[Xenia]

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Hi context list,

I noticed that the ∓ sign is a little higher than the ± sign, so that
the + signs are at the same height. But this looks strange and should be
changed.

$ context --version
mtx-context     | ConTeXt Process Management 0.60
mtx-context     | current version: 2013.03.24 15:11

Thanks,
Xenia

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\starttext
\startformula
A = a ± b ∓ c = a \pm b \mp c
\stopformula
\stoptext

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Re: math: ± and ∓ are shifted

[Aditya Mahajan]

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On Thu, 4 Apr 2013, Xenia wrote:

> Hi context list,
>
> I noticed that the ∓ sign is a little higher than the ± sign, so that
> the + signs are at the same height. But this looks strange and should be
> changed.

Indeed. These look very odd. I tested this with cambria and the outcome is 
similar, so this is not a font bug, but something wrong in ConTeXt's math 
handling.

Aditya

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Re: math: ± and ∓ are shifted

[Hans Hagen]

On 4/4/2013 11:44 PM, Aditya Mahajan wrote:
> On Thu, 4 Apr 2013, Xenia wrote:
>
>> Hi context list,
>>
>> I noticed that the ∓ sign is a little higher than the ± sign, so that
>> the + signs are at the same height. But this looks strange and should be
>> changed.
>
> Indeed. These look very odd. I tested this with cambria and the outcome
> is similar, so this is not a font bug, but something wrong in ConTeXt's
> math handling.

I'm not sure if I understand the issue

- lm has + and - touching with the + in the same position as the regular +

- cambria has a gap between + and - and moves the + up and down

Afaik context isn't doing any magic here as these are precomposed glyphs 
that directly map.

$a \ruledhbox{$+$} b \ruledhbox{$-$} c$

$a \ruledhbox{$±$} b \ruledhbox{$∓$} c$

they are 'binary' in math mode, just like + and -

Hans

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               Ridderstraat 27 | 8061 GH Hasselt | The Netherlands
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                                              | www.pragma-pod.nl
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Re: math: ± and ∓ are shifted

[Aditya Mahajan]

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On Fri, 5 Apr 2013, Hans Hagen wrote:

> On 4/4/2013 11:44 PM, Aditya Mahajan wrote:
>> On Thu, 4 Apr 2013, Xenia wrote:
>> 
>>> Hi context list,
>>> 
>>> I noticed that the ∓ sign is a little higher than the ± sign, so that
>>> the + signs are at the same height. But this looks strange and should be
>>> changed.
>> 
>> Indeed. These look very odd. I tested this with cambria and the outcome
>> is similar, so this is not a font bug, but something wrong in ConTeXt's
>> math handling.
>
> I'm not sure if I understand the issue
>
> - lm has + and - touching with the + in the same position as the regular +
>
> - cambria has a gap between + and - and moves the + up and down
>
> Afaik context isn't doing any magic here as these are precomposed glyphs that 
> directly map.
>
> $a \ruledhbox{$+$} b \ruledhbox{$-$} c$
>
> $a \ruledhbox{$±$} b \ruledhbox{$∓$} c$
>
> they are 'binary' in math mode, just like + and -

The question is not about the shape of the glyph, but their location. 
But after looking at the output of latex for CM and Cambria, I am no 
longer sure what the correct output should be. For Cambria, ConTeXt and 
LaTeX give similar outputs. For CM/LM they give different outputs.

Aditya

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___________________________________________________________________________________

Re: math: ± and ∓ are shifted

[Hans Hagen]

On 4/5/2013 12:13 AM, Aditya Mahajan wrote:
> On Fri, 5 Apr 2013, Hans Hagen wrote:
>
>> On 4/4/2013 11:44 PM, Aditya Mahajan wrote:
>>> On Thu, 4 Apr 2013, Xenia wrote:
>>>
>>>> Hi context list,
>>>>
>>>> I noticed that the ∓ sign is a little higher than the ± sign, so that
>>>> the + signs are at the same height. But this looks strange and
>>>> should be
>>>> changed.
>>>
>>> Indeed. These look very odd. I tested this with cambria and the outcome
>>> is similar, so this is not a font bug, but something wrong in ConTeXt's
>>> math handling.
>>
>> I'm not sure if I understand the issue
>>
>> - lm has + and - touching with the + in the same position as the
>> regular +
>>
>> - cambria has a gap between + and - and moves the + up and down
>>
>> Afaik context isn't doing any magic here as these are precomposed
>> glyphs that directly map.
>>
>> $a \ruledhbox{$+$} b \ruledhbox{$-$} c$
>>
>> $a \ruledhbox{$±$} b \ruledhbox{$∓$} c$
>>
>> they are 'binary' in math mode, just like + and -
>
> The question is not about the shape of the glyph, but their location.
> But after looking at the output of latex for CM and Cambria, I am no
> longer sure what the correct output should be. For Cambria, ConTeXt and
> LaTeX give similar outputs. For CM/LM they give different outputs.

it looks like the open type version has a fitting boundingbox while the 
type 1 variants have a bit of the + sticking out:

\starttext

     $x \ruledhbox{$\pm$} x \ruledhbox{$\mp$} x$

\stoptext

Hans

-----------------------------------------------------------------
                                           Hans Hagen | PRAGMA ADE
               Ridderstraat 27 | 8061 GH Hasselt | The Netherlands
     tel: 038 477 53 69 | voip: 087 875 68 74 | www.pragma-ade.com
                                              | www.pragma-pod.nl
-----------------------------------------------------------------
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___________________________________________________________________________________

Re: math: ± and ∓ are shifted

[Khaled Hosny]

On Fri, Apr 05, 2013 at 12:55:40AM +0200, Hans Hagen wrote:
> On 4/5/2013 12:13 AM, Aditya Mahajan wrote:
> >On Fri, 5 Apr 2013, Hans Hagen wrote:
> >
> >>On 4/4/2013 11:44 PM, Aditya Mahajan wrote:
> >>>On Thu, 4 Apr 2013, Xenia wrote:
> >>>
> >>>>Hi context list,
> >>>>
> >>>>I noticed that the ∓ sign is a little higher than the ± sign, so that
> >>>>the + signs are at the same height. But this looks strange and
> >>>>should be
> >>>>changed.
> >>>
> >>>Indeed. These look very odd. I tested this with cambria and the outcome
> >>>is similar, so this is not a font bug, but something wrong in ConTeXt's
> >>>math handling.
> >>
> >>I'm not sure if I understand the issue
> >>
> >>- lm has + and - touching with the + in the same position as the
> >>regular +
> >>
> >>- cambria has a gap between + and - and moves the + up and down
> >>
> >>Afaik context isn't doing any magic here as these are precomposed
> >>glyphs that directly map.
> >>
> >>$a \ruledhbox{$+$} b \ruledhbox{$-$} c$
> >>
> >>$a \ruledhbox{$±$} b \ruledhbox{$∓$} c$
> >>
> >>they are 'binary' in math mode, just like + and -
> >
> >The question is not about the shape of the glyph, but their location.
> >But after looking at the output of latex for CM and Cambria, I am no
> >longer sure what the correct output should be. For Cambria, ConTeXt and
> >LaTeX give similar outputs. For CM/LM they give different outputs.
> 
> it looks like the open type version has a fitting boundingbox while
> the type 1 variants have a bit of the + sticking out:

CFF fonts do not store bounding box info anywhere, the engine just
calculates it based on glyph outlines. For TFM fonts the metrics can be
adjusted to achieve specific alignment.

Regards,
Khaled
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___________________________________________________________________________________

Re: math: ± and ∓ are shifted

[Hans Hagen]

On 4/5/2013 2:16 AM, Khaled Hosny wrote:
> On Fri, Apr 05, 2013 at 12:55:40AM +0200, Hans Hagen wrote:
>> On 4/5/2013 12:13 AM, Aditya Mahajan wrote:
>>> On Fri, 5 Apr 2013, Hans Hagen wrote:
>>>
>>>> On 4/4/2013 11:44 PM, Aditya Mahajan wrote:
>>>>> On Thu, 4 Apr 2013, Xenia wrote:
>>>>>
>>>>>> Hi context list,
>>>>>>
>>>>>> I noticed that the ∓ sign is a little higher than the ± sign, so that
>>>>>> the + signs are at the same height. But this looks strange and
>>>>>> should be
>>>>>> changed.
>>>>>
>>>>> Indeed. These look very odd. I tested this with cambria and the outcome
>>>>> is similar, so this is not a font bug, but something wrong in ConTeXt's
>>>>> math handling.
>>>>
>>>> I'm not sure if I understand the issue
>>>>
>>>> - lm has + and - touching with the + in the same position as the
>>>> regular +
>>>>
>>>> - cambria has a gap between + and - and moves the + up and down
>>>>
>>>> Afaik context isn't doing any magic here as these are precomposed
>>>> glyphs that directly map.
>>>>
>>>> $a \ruledhbox{$+$} b \ruledhbox{$-$} c$
>>>>
>>>> $a \ruledhbox{$±$} b \ruledhbox{$∓$} c$
>>>>
>>>> they are 'binary' in math mode, just like + and -
>>>
>>> The question is not about the shape of the glyph, but their location.
>>> But after looking at the output of latex for CM and Cambria, I am no
>>> longer sure what the correct output should be. For Cambria, ConTeXt and
>>> LaTeX give similar outputs. For CM/LM they give different outputs.
>>
>> it looks like the open type version has a fitting boundingbox while
>> the type 1 variants have a bit of the + sticking out:
>
> CFF fonts do not store bounding box info anywhere, the engine just
> calculates it based on glyph outlines. For TFM fonts the metrics can be
> adjusted to achieve specific alignment.

Sure, but one can 'cheat' with the boundingboxes as they're not cropboxes.

It's no big deal to adapt some metrics in mkiv, but best have the font 
do the job.

Hans


-- 

-----------------------------------------------------------------
                                           Hans Hagen | PRAGMA ADE
               Ridderstraat 27 | 8061 GH Hasselt | The Netherlands
     tel: 038 477 53 69 | voip: 087 875 68 74 | www.pragma-ade.com
                                              | www.pragma-pod.nl
-----------------------------------------------------------------
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If your question is of interest to others as well, please add an entry to the Wiki!

maillist : ntg-context@ntg.nl / http://www.ntg.nl/mailman/listinfo/ntg-context
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___________________________________________________________________________________

Re: math: ± and ∓ are shifted

[Hans Hagen]

On 4/5/2013 9:32 AM, Hans Hagen wrote:
> On 4/5/2013 2:16 AM, Khaled Hosny wrote:
>> On Fri, Apr 05, 2013 at 12:55:40AM +0200, Hans Hagen wrote:
>>> On 4/5/2013 12:13 AM, Aditya Mahajan wrote:
>>>> On Fri, 5 Apr 2013, Hans Hagen wrote:
>>>>
>>>>> On 4/4/2013 11:44 PM, Aditya Mahajan wrote:
>>>>>> On Thu, 4 Apr 2013, Xenia wrote:
>>>>>>
>>>>>>> Hi context list,
>>>>>>>
>>>>>>> I noticed that the ∓ sign is a little higher than the ± sign, so
>>>>>>> that
>>>>>>> the + signs are at the same height. But this looks strange and
>>>>>>> should be
>>>>>>> changed.
>>>>>>
>>>>>> Indeed. These look very odd. I tested this with cambria and the
>>>>>> outcome
>>>>>> is similar, so this is not a font bug, but something wrong in
>>>>>> ConTeXt's
>>>>>> math handling.
>>>>>
>>>>> I'm not sure if I understand the issue
>>>>>
>>>>> - lm has + and - touching with the + in the same position as the
>>>>> regular +
>>>>>
>>>>> - cambria has a gap between + and - and moves the + up and down
>>>>>
>>>>> Afaik context isn't doing any magic here as these are precomposed
>>>>> glyphs that directly map.
>>>>>
>>>>> $a \ruledhbox{$+$} b \ruledhbox{$-$} c$
>>>>>
>>>>> $a \ruledhbox{$±$} b \ruledhbox{$∓$} c$
>>>>>
>>>>> they are 'binary' in math mode, just like + and -
>>>>
>>>> The question is not about the shape of the glyph, but their location.
>>>> But after looking at the output of latex for CM and Cambria, I am no
>>>> longer sure what the correct output should be. For Cambria, ConTeXt and
>>>> LaTeX give similar outputs. For CM/LM they give different outputs.
>>>
>>> it looks like the open type version has a fitting boundingbox while
>>> the type 1 variants have a bit of the + sticking out:
>>
>> CFF fonts do not store bounding box info anywhere, the engine just
>> calculates it based on glyph outlines. For TFM fonts the metrics can be
>> adjusted to achieve specific alignment.
>
> Sure, but one can 'cheat' with the boundingboxes as they're not cropboxes.
>
> It's no big deal to adapt some metrics in mkiv, but best have the font
> do the job.

Experimental in beta:

\definefontfeature [lm-math] [mathdimensions=signs]

\starttext

\startTEXpage[offset=10pt]
     $x \ruledhbox{$\pm$} x \ruledhbox{$\mp$} x$
\stopTEXpage

\stoptext

(explanation in font manual, not yet uploaded)

Hans

-----------------------------------------------------------------
                                           Hans Hagen | PRAGMA ADE
               Ridderstraat 27 | 8061 GH Hasselt | The Netherlands
     tel: 038 477 53 69 | voip: 087 875 68 74 | www.pragma-ade.com
                                              | www.pragma-pod.nl
-----------------------------------------------------------------
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___________________________________________________________________________________