Problem with some fonts conversion - glyph data IndexError

[amirotin]

Hi. I'm trying to convert some fonts, but when i use Pixel Writer class i got error

  File "D:\Work\Micropython\tt.py", line 16, in <module>
    data = glyph[srow * gbytes + gbyte]
IndexError: index out of bounds on dimension 1

Here is my code

import font

COLOR_BLACK   = 0x0000
COLOR_RED     = 0x07E0

glyph, char_height, char_width = font.get_ch('1')

div, mod = divmod(char_width, 8)
gbytes = div + 1 if mod else div

char_image = bytearray()
for srow in range(char_height):
    for scol in range(char_width):
        gbyte, gbit = divmod(scol, 8)
        if gbit == 0: 
            data = glyph[srow * gbytes + gbyte]
        pixel = COLOR_RED if data & (1 << (7 - gbit)) else COLOR_BLACK
        char_image.append(pixel>>8)
        char_image.append(pixel & 0xff)

for testing, I'm trying to get an image of the number 1. This does not work with any of the fonts if I use the Cyrillic character set. On some fonts, the standard set does not work either. Error is same in all cases. I attached some fonts that i'm trying to use pixel_sans_serif 8.zip free_pixel 16.zip minecraftia 8.zip

[peterhinch]

The error message looks odd. On current MicroPython an out of range error appears as "IndexError: memoryview index out of range". What version of MicroPython are you using, and on what platform? Rather than the source fonts, your converted Python font files would be more informative.

[amirotin]

Sorry, I was checking the script on a regular python 3.6.6 and copied the error from there. On MicroPython error is IndexError: memoryview index out of range. Here is one of converted fonts with command font_to_py.py -k cyrillic FreePixel.ttf 16 freepixel.py

MicroPython v1.11-8-g48dcbbe60 on 2019-05-29; ESP module with ESP8266 freepixel.zip

[peterhinch]

I can replicate your error, but I can find no fault with the font file: the glyph "1" can be rendered correctly:

>>> import font_test
>>> font_test.test_font('freepixel', '123')
Vertical map
Normal bit order
Proportional spacing
Dimensions height*max_width 17 * 9
Start char "!" (ord 33) end char "ё" (ord 1105)
...........................
...........................
...........................
....#......####.....####...
...##.....#....#...#....#..
..#.#.....#....#........#..
....#..........#.......#...
....#.........#......##....
....#........#.........#...
....#.......#..........#...
....#......#............#..
....#......#............#..
....#.....#........#...#...
..#####...######....###....
...........................
...........................
...........................
>>> 

I suspect something is wrong with the way you are rendering it, but I haven't yet managed to spot the problem. I'll study your code later today.

Note that font_test.py must be run under Python 3.

[amirotin]

font_test.py works for me too. As for my code - i just took your writer.py _printchar function and it works fine with your fonts in writer folder (courier20.py, font10.py, ...)

[peterhinch]

I think the problem is that you have created a vertically mapped font but are rendering it using the algorithm for horizontal mapping. Unless you need vertical mapping you might like to simply re-create the Python font file with horizontal mapping using the -x option. If you need vertical mapping you'll need to adapt your code.

Most of my example fonts are horizontally mapped as this is the best fit for most display hardware.

[amirotin]

Yep, that it is. My fault, didn't check this moment. Thanks for help!