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

I am using a RVT101HVBNWC00-B from Riverdi which is a BT817 with a 1280x800 panel.
And to rotate the screen does not work properly, just flipping it with either REG_ROTATE set to 1 or using CMD_SETROTATE(1) causes major distortion.

When I use CMD_SETROTATE(5) it curiously works fine though, I have no use for a mirrored image though.

0 - image is fine, just for reference
1 - image is distorted
2 - image is fine
3 - image is distorted
4 - image is distorted
5 - image is fine
6 - image is fine
7 - image is distorted

And right now it does not have to display much at all, it looks like this with more empty pixels:
https://github.com/RudolphRiedel/FT800-FT813/blob/5.x/example_pics/CFAF800480E0_050SC_Arduino_Uno.jpg

Pixelclock is 72MHz with REG_PCLK_2X set to 1.

Hmm, I dropped the pixel clock to 51MHz with REG_PCLK_2X set to 0 and now the flipped image is fine.
But this dropped the frames/s as well and the pixel-clock is now well below the minimum of 66.3MHz that is listed in the datasheet.

I set REG_PCLK_2X to 1 while still using 51Mhz -> image is distorted when flipped.
I set REG_PCLK_2X to 0 while using 72MHz -> image is fine.
I set REG_PCLK_2X to 0 while using 66MHz -> image is fine.

Any more advice on this why REG_PCLK_2X = 1 with REG_ROTATE = 1 leads to a distorted image?

At 72MHz pixel-clock with 72Mhz system clock the datasheet says that REG_PCLK_2X needs to be set to 1.
And 66MHz is out of spec for the panel, although barely, it is not possible though to set PLL2 to anything between 66MHz and 72MHz.

I reduced the pixel clock to 38MHz and it still works, here at my desk.
But there is no way to tell what will happen out in the field with -20°C....+60°C.

Hi,

No problem, we'll post an MCU to RAM_G example first and then provide a flash one too,

Best Regards, BRT Community

Hi,
firstly I go directly from the CPU to the RAM G. but you can also show another example by having the method of going from the CPU to the flash then to the RAM G

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.

Hi,
Yes we can post an example,
Are we correct that you want 2 or more ASTC images in Flash which are then copied to RAM_G and displayed simultaneously on the screen?
Best Regards, BRT Community

Another solution that I am considering is to generate an image directly via the CPU with the generated text and then send it to the GPU and display it.
But currently I have a problem with my graphics library because I cannot send uncompressed images via it.
If I send the data to the bt815 memory with uncompressed data it systematically crashes and I can't figure out why. 

I use the Gameduino 3 Dazler library. 

With compressed data it works but I don't know how to compress them directly via the CPU of the teensy 4. So I always have to go through a PC to compress the images and send them to the Teensy which will send it to the graphics chip.  but this prevents me from generating images directly at the heart of teensy

Thank you for your response but I can't.  the text is dynamic.
we can't use the 8m of external ram?

Hi,

In addition to a few instructions for the actual setup of the font bitmap properties, each character will require at least a Vertex command.

For characters which are beyond the reach of VERTEX2II (e.g. more than 511) there is also a CELL() instruction since EVE needs to use VERTEX2F and that needs a preceding command to set which cell/character.

Therefore, you should budget at least 4 bytes per character and 8 bytes in some cases.

if the text is fixed, you may be able to write it to a bitmap or display it and take a snapshot after start-up and that would save some DL space by displaying the sentence as a bitmap.

Best Regards, BRT Community

Thank you for your reply. 
It can be long text of more than 2000 characters