I want to make my own font file, but Error encountered

[lixy123]

I want to make my own font file, but even with your example practice, the font Successfully generated，but can't run in esp32. I'll revise it according to the guide you gave "fontconvert.py" The exercise generated a custom font file, The firmware generated by compilation will report an error when running .can you give us some suggestions?

This is my generation step:

1. modify fontconvert.py here:
   intervals= [
   # arrows
   (0x2190, 0x21FF),
   # math
   (0x2200, 0x22FF),
   # symbols
   (0x2300, 0x23FF),
   ]
2. run command in Raspberry where can run python:
   python3 fontconvert.py msyh 10 FiraCode-Regular.ttf Symbola.ttf >hz500.h

FiraCode-Regular.ttf Symbola.ttf   the same as your example.

hz500.zip

3. esp32 run error：

rst:0xc (SW_CPU_RESET),boot:0x13 (SPI_FAST_FLASH_BOOT)
configsip: 0, SPIWP:0xee
clk_drv:0x00,q_drv:0x00,d_drv:0x00,cs0_drv:0x00,hd_drv:0x00,wp_drv:0x00
mode:DIO, clock div:1
load:0x3fff0018,len:4
load:0x3fff001c,len:1216
ho 0 tail 12 room 4
load:0x40078000,len:9720
ho 0 tail 12 room 4
load:0x40080400,len:6352
entry 0x400806b8
Guru Meditation Error: Core 1 panic'ed (StoreProhibited). Exception was unhandled.
Core 1 register dump:
PC : 0x4000c46c PS : 0x00060130 A0 : 0x800d0e74 A1 : 0x3ffb1f70
A2 : 0x00000000 A3 : 0xffffffff A4 : 0x0003f480 A5 : 0x00000000
A6 : 0x00000001 A7 : 0x00003f48 A8 : 0x00000000 A9 : 0x3ffb1f40
A10 : 0x4008ed10 A11 : 0x000001e0 A12 : 0x00000000 A13 : 0x3ffd1efc
A14 : 0x00060120 A15 : 0x00000000 SAR : 0x0000001d EXCCAUSE: 0x0000001d
EXCVADDR: 0x00000000 LBEG : 0x4000c46c LEND : 0x4000c477 LCOUNT : 0x00003f47

Backtrace: 0x4000c46c:0x3ffb1f70 0x400d0e71:0x3ffb1f80 0x400d4617:0x3ffb1fb0 0x40088d2d:0x3ffb1fd0

[vroland]

It's hard to make anything of the backtrace with only the addresses, but I would guess that the problem occurs because the ASCII characters are missing.
E.g. if a glyph is not found, "?" is used by default, which is not present in that font. Could you try again with the ASCII range included? (32, 126)

[lixy123]

oh, you are right! I success, thanks you!

According to your instructions, alphanumeric characters can now be displayed, but “Guru Meditation Error: Core 1 panic'ed (LoadProhibited). Exception was unhandled.
" will still appear when characters not in the font are displayed

[vroland]

Hm, that's strange. I'll mark it as a bug and have a look in the next days.
But the non-alphanumeric characters that are present in the font work?

[lixy123]

Hm, that's strange. I'll mark it as a bug and have a look in the next days.
But the non-alphanumeric characters that are present in the font work?

The exact description of the bug is: “Guru Meditation Error: Core 1 panic'ed (LoadProhibited). Exception was unhandled." bug is triggered ,when all the characters are not in the font library. Although it's not very elegant, in the end, my temporary method is to add a space before all the displayed characters.

[vroland]

Could you give me an example string? Right now I have some trouble reproducing this.

[lixy123]

Could you give me an example string? Right now I have some trouble reproducing this.

for example
writeln((GFXfont *)&msyh36, (char *)now_string.c_str(), &cursor_x, &cursor_y, NULL);

1.when now_string be equal to 'abc', which 'abc' exist in the font library, No mistakes
2.when now_string be equal to '嗯', which '嗯' no exist in the font library, run error.
3.when now_string be equal to 'abc嗯', which 'abc' exist in the font library and '嗯' no exist in the font library, No mistakes

so, Finally, I skipped the bug in the following way:
now_string=">"+now_string;
writeln((GFXfont *)&msyh36, (char *)now_string.c_str(), &cursor_x, &cursor_y, NULL);

[vroland]

Thanks, looks like the code still wanted to allocate a buffer with negative height. This should be fixed now.

[lixy123]

Thanks, looks like the code still wanted to allocate a buffer with negative height. This should be fixed now.

by the way, function writeln string wrap is not supported now, whether there are plans to support string wrap in the future, or provides the function of auxiliary judgment

[vroland]

You mean breaking the string into multiple lines based on some line width?
I'm not sure if the display library is the right place for that, since the rules for breaking strings into lines vary from language to language and can be quite complex.

[lixy123]

You mean breaking the string into multiple lines based on some line width?
I'm not sure if the display library is the right place for that, since the rules for breaking strings into lines vary from language to language and can be quite complex.

That's what I asked, You can do the simplest case first, for example, like office word software, when a line of text cannot be displayed in the line, you can wrap it normally