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Author Topic: Eve3 built-in fontset  (Read 15678 times)

darkjezter

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Eve3 built-in fontset
« on: September 08, 2020, 10:53:05 PM »

Greetings all,

I've been looking to see if there are any details available on the font sets which are built into the Eve3 series of chips, but haven't found anything specific.

I'm interested in knowing what the different fonts are, and what licenses apply to their use.  It would also be helpful to know for each of the built in fonts, what the sizes are.  (Regarding size: is there a corresponding point size assuming a given dpi, or some other similar metric)

This information will be helpful to us both for updating our user-manual to reflect the new graphic layouts, and for the purposes of duplicating the appearance of our UI on other platforms.

Many thanks!
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BRT Community

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Re: Eve3 built-in fontset
« Reply #1 on: September 09, 2020, 04:00:00 PM »

Hello

Here are details of which fonts are used. The fonts are in three groups:

•             Non-proportionate and non-anti-aliased - Fixed-width CP437 fonts are taken from the FreeBSD distribution's console driver. Please see CP437 8x8 and 8x16 (handles 16,17,18,19).
•             Proportionate non-anti-aliased - Variable width fonts are helvR08, etc. from X11 (handles 20 to 25)
•             Proportionate anti-aliased fonts were taken from the roboto regular file and converted into bitmap and into L4 format.

Best Regards,
BRT Community
« Last Edit: September 09, 2020, 04:06:25 PM by BRT Community »
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Rudolph

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Re: Eve3 built-in fontset
« Reply #2 on: April 27, 2024, 09:57:44 PM »

I need to use Roboto and compared what I converted to builtin font 31, looked really similar.
Now I remembered this post and it turns out that fonts 26 to 34 *are* Roboto. :-)
I need more than "Basic Latin" though, at very least some from "Latin-1 Supplement" as well.

Ok, I have a couple more questions now.
I am using a BT817 and the datasheet says that the four largest fonts are encoded in ASTC 8x8 format.
And using both ROM fonts and custom fonts would mean that I could reduce the usage of custom fonts.

What are the font sizes the internal fonts are converted to?
To match font number 31 I had to convert to a font size of 43, at least when viewed in ESE side by side.

But when I zoom in it does not look exactly the same although I used ASTC 8x8 and I have to move my converted font one pixel down.
The anti-aliasing is not the same.
See, the attachments, I used the Roboto-Regular.ttf from the archive you attached and converted it with EAB 2.11.0.
This Roboto-Regular.ttf is version 1.000 from 2011.

Generated Folder: Roboto-Regular_43_Extend
Format:           ASTC 8x8
Compressed:       exhaustive
Layout Width:     96
Layout Height:    6
Pixel Width:      48
Pixel Height:     48
Number of characters provided by the user: 119
Number of characters in xfont file: 256
Number of characters eligible for conversion: 119
   Success: 119
   Fail:    0

The Roboto-Regular_43_ASTC.glyph has a size of 103104 bytes.

When I convert Roboto-Regular.ttf version 2.137 from 2017 though I get a much different result:

Generated Folder: Roboto-Regular_43_Extend
Format:           ASTC 8x8
Compressed:       exhaustive
Layout Width:     128
Layout Height:    7
Pixel Width:      64
Pixel Height:     56
Number of characters provided by the user: 119
Number of characters in xfont file: 256
Number of characters eligible for conversion: 119
   Success: 119
   Fail:    0

The Roboto-Regular_43_ASTC.glyph has a size of 160384 bytes.

But a font size of 42 comes out like this:
Generated Folder: Roboto-Regular_42_Extend
Format:           ASTC 8x8
Compressed:       exhaustive
Layout Width:     96
Layout Height:    6
Pixel Width:      48
Pixel Height:     48
Number of characters provided by the user: 119
Number of characters in xfont file: 256
Number of characters eligible for conversion: 119
   Success: 119
   Fail:    0

The Roboto-Regular_43_ASTC.glyph has a size of 103104 bytes.

So the V2 font changed something which requires to use a font size of one less.

I also converted the font to L4 and L8 which results in the same "wrong" anti-aliasing.
But now I need to move the converted font two pixels down to match the ROM font.

The shift and the change in anti-aliasing is odd, is that due to EAB using different parameters now compared to when the fonts for the BT817 got converted?
The ROM fonts do look more sharp, again, at least in ESE.
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BRT Community

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Re: Eve3 built-in fontset
« Reply #3 on: May 01, 2024, 02:49:22 PM »

Hello,

I'm just double checking what the exact font size conversions are for the inbuilt fonts with the development team.

But the difference between the fonts relates to when the conversion was done, as you have alluded too. The ROM fonts in all versions of EVE are the same, and the same data is used to render these fonts from EVE to EVE4, as such this conversion was performed during the initial EVE release with an older version of the font converter. Since this time there have been several updates to the font conversion utility and its aliasing settings which accounts for the changes you have noted between these versions of the font in ESE.

Best Regards,
BRT Community
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Rudolph

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Re: Eve3 built-in fontset
« Reply #4 on: May 01, 2024, 08:43:02 PM »

I played some more with ESE and these might be the font sizes:

#26 -> 15
#27 -> 17
#28 -> 21
#29 -> 24
#30 -> 31
#31 -> 42
#32 -> 55
#33 -> 70
#34 -> 94

Quote
The ROM fonts in all versions of EVE are the same, and the same data is used to render these fonts from EVE to EVE4,"

The BT817/8 datasheet states though:
"Fonts 31-34 are large ROM fonts encoded in ASTC 8x8 format."

And:
"Using ASTC for the large ROM fonts can save considerable space. Encoding the four largest fonts in
ASTC 8x8 formats gives no noticeable loss in quality and reduces the ROM size from 1 Mbytes to
about 640 Kbytes."

So at least these four should have been converted later for the BT817, like 2019?

Knowing the original settings for the font conversion probably is not enough?
At least I am not seeing a dithering option with "eab_tools.exe font -h" in EAB 2.11.0



« Last Edit: May 08, 2024, 06:57:44 PM by Rudolph »
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brtchip.truongly

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Re: Eve3 built-in fontset
« Reply #5 on: May 08, 2024, 07:59:37 AM »



The image has been magnified to 200% and captured from the ESE.
The upper text is ROM font 34.
The lower text is EAB converted font: Roboto, 94 points, ASTC 8x8 exhaustive.

It is difficult to find any different from these two converted character. The parts encircled in red indicate that the EAB conversion appears slightly better, although this might not be noticeable to the naked eye without zooming in.

*** Extended Font conversion is intended to be versatile and adaptable for various use cases. It may not necessarily align perfectly with the built-in font.
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Rudolph

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Re: Eve3 built-in fontset
« Reply #6 on: May 08, 2024, 07:56:08 PM »

Ok. fine, I guess I have to check what it actually looks like on the display. :-)
Unfortunately I have no idea so far what I need to display, I only have a very vague project description.
It is even possible that font 34 is not big enough.
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