How to add the Euro sign

[PaulskPt]

Hi Peter,
For a project using the following hardware:
A Pimoroni Pico Breakout Garden base, onto which stacked: a Raspberry Pi Pico; a Pimoroni BG RV3028 rtc module; an Adafruit TMP117 sensor via STEMMA/Qwiic connection wired to a Pimoroni BG adapter; a Pimoroni BG 1.12in OLED SPI 128x128px monochrome display.

I successfully created a font file using your font-to-py repo.
Using the -k parameter I added the extended characters (python3 ./font_to_py.py -x -k extended NotoSansDispCondMed.ttf 18 my_extended18hor.py).

For a future expansion of my project I want to be able to print the Euro sign. I saw that the Euro sign does not exist in the file: extended.

I tried to study the created font file. I see that the last part, a bytearray, with the name _sparse contains a certain pattern, consisting of 4 bytes starting with a value that appears to me to be a value into the Extended ascii chart (e.g. published on: https://www.ascii-code.com). In the file 'extended' I replaced the Pound Sterling sign, the last character in that file, with the Euro sign. Now the contents of the file 'extended' is:
¬!"#£$%&'()*+,-./0123456789:;<=>?@ABCDEFGHIJKLMNOPQRSTUVWXYZ[\]^_`abcdefghijklmnopqrstuvwxyz{|}~�°Ωαβγδθλμπωϕ€

Then I built a new version of the font file using the -k parameter. However, in the test, when using a string value of chr(128) which is the ordinal value for the Euro sign in the Extended ascii chart (on ascii-code.com at least), still a question mark ('?') is printed in the REPL.

In the file: font_to_py.py, Class Font, I added the following line:
289 print("len(cs): {}, ultimate char: {}, ord ultimate char: {}".format(len(cs), cs[len(cs)-1], ord(cs[len(cs)-1])),end='\n')
The result of this addition in the output was:
len(cs): 8333, ultimate char: €, ord ultimate char: 8364 (see also the image below of a font building run output).

Analyzing the creation of the font file by inserting another line 289 (printing the value of cs) to the function __init__() of the Class Font in file: font_to_py.py, revealed that the Pound Sterling sign still was present in the created font file.

When I changed the contents of the file extended in such a way that I put the Euro sign at it's ascii ordinal place,
that is: between DEL and the degrees sign, as shown here:

then the result of building the font file is that the Euro sign (again) is moved to the end of the string, as showed in the build output:

I copied various functions from the file font_test.py into my main.py script.
In the definition of the function test_font(), when I changed the default value for parameter string into:

def test_font(fontfile, string=''+'abg'+chr(176)+chr(163)+chr(8364)+chr(98)+chr(110)+chr(120)+chr(131)+chr(181)):
                                          |          |         |
                                        degs (°)     £         €

while, for the Euro sign, using the ord() value of 8364 as indicated by the font_to_py.py script,
the result in REPL is that the degrees sign and the pound sterling sign are printed however a '?' was printed for the Euro sign.

I guess that the Euro sign is not defined inside the created font file: my_extended18hor.py.

Question:
How can I get the wanted output for the Euro sign being printed in REPL and on the OLED display?

Paulus Schulinck

Attachments: 1) REPL output during run of my script; 2) image of the hardware.

[peterhinch]

Have you checked that your source otf or ttf font includes a Euro glyph?

[PaulskPt]

I used a ttf font that I created from Google fonts service. Font family: Noto, type filtered: NotoSansDisplayCondensedMedium (file size 352kB).

How I can see which glyphs are actually in a .ttf file? In MS Windows 10, when right-clicking on a .ttf file and select 'Visualize' then it shows only the standard alphabet in the available corps sizes as shown in the image below.

I checked with Google Fonts for the font family I choose before: Noto. It contains the following currency symbols:

[PaulskPt]

I just created a glyphs test function. In the (partly) print of the run result it shows that there are no glyphs for in the range: 128 - 160. It starts with 161 (and later on a lot of other glyphs among them arabic. I guess I have to create another .ttf. I come back when I have done that.

[PaulskPt]

I downloaded from Google Fonts: Noto Sans - Regular. Ran it with font-to-py. Imported the file my_notosansregluar18.
Ran the test_glyphs() in range 8300-8365 and the Euro symbol was printed.

Then (just for test/fun) added the Euro symbol instead of 'C' (Celsius). See the result below. The Euro symbol was also displayed on the OLED.

Thank you for your answer / 'trigger'. Issue can be closed.