kicad-developers team mailing list archive

[Maciej Sumiński <maciej.suminski@xxxxxxx>]

On 04/15/2016 02:01 PM, Mário Luzeiro wrote:
> Here is the result of my test (attached)
> 
> Question: Is the text rendered every draw frame?
> 
> If yes:
> My suggestion was to clamp to a max size (in order to render the text 1:1 on relation to the font pixel size in the texture) and to a minimum (or not display it.. )
> See the too_big.png issue.
> I think as this is informative text it can be render dynamically and doesn't not matter the exactly position / scale.

Maybe it would be enough just to double the font atlas texture size? I
suppose people do not spend much time staring at pads at such zoom
level, so it should not be a major problem.

I like when KiCad looks nice, but it is not the main objective here, so
we have to decide when it looks good enough.

> mipmap_spacing_issue.png:
> I notice for some zoom levels that there are "blur margin" effects issues.
> I believe it may be fixed if you increase the spacing of the chars in the texture. (So you may need to decrease the font size to keep the same texture size)

Good point, I have not noticed them before. From what I see, it is a
byproduct of OpenGL way of mipmapping. I will have a look at it.

Regards,
Orson

> Mario
> 
> ________________________________________
> From: Kicad-developers [kicad-developers-bounces+mrluzeiro=ua.pt@xxxxxxxxxxxxxxxxxxx] on behalf of jp charras [jp.charras@xxxxxxxxxx]
> Sent: 15 April 2016 11:39
> To: kicad-developers@xxxxxxxxxxxxxxxxxxx
> Subject: Re: [Kicad-developers] Bitmap fonts
> 
> Le 15/04/2016 11:21, Maciej Sumiński a écrit :
>> On 04/14/2016 06:39 PM, Simon Richter wrote:
>>> Hi,
>>>
>>> On 14.04.2016 11:33, Maciej Sumiński wrote:
>>>
>>>> Currently, the most expensive thing to draw is stroked text, as there
>>>> are lots of labels on tracks and pads. To reduce the drawing cost (and
>>>> memory requirements), texts that are not targeted to Gerber files (i.e.
>>>> pad & track labels) might be displayed using bitmap fonts. This way, a
>>>> single letter cost is reduced from tens of triangles to just two.
>>>
>>> Do these actually need to be stored, or can they be generated on the fly
>>> from some simpler representation?
>>>
>>>    Simon
>>
>> Previously they were generated on the fly for every frame. Storing them
>> occupied a lot of memory, so I decided to generate them only when
>> appropriate (i.e. they are in the current view area and the zoom level
>> is high enough).
>>
>> Another solution that comes to my mind is some kind of
>> pseudo-instancing, where the stroked font lines are stored once and the
>> video card receives only a range of indexes to draw and a transformation
>> matrix to apply. That should be not that hard to introduce.
>>
>> Still, it is hard to beat 2 triangles per character. I am willing to
>> increase the font texture atlas resolution if people are not satisfied
>> with the outcome.
>>
>> Regards,
>> Orson
> 
> Orson,
> 
> I just tested your last version, and I find the result rather good.
> 
> Only one thing: I have some trouble to understand the criteria used to decide if pad numbers and net
> names are shown or not:
> For a given pad (i.e. font size), it depends not only on the zoom level (this is what I was
> expecting), but also on other things like the fact you are zooming from high level to low level or
> the opposite, and the board area shown on screen.
> 
> Thanks.
> 
> 
> --
> Jean-Pierre CHARRAS
> 
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