character width issue

[akizuha]

CudaText 1.100

Lazarus (synedit)

1. when a line becomes too long (>= 501 Chinese character exactly), full width characters will be compressed to half width. (pic 1)
2. because of 1, normal selecting of compressed characters is deviantly. (pic 2)
3. vertical selecting mixed width character is not aligned. (pic 1) which Lazarus can (pic 3)

[Alexey-T]

1. can be solved by new option - max_line_len_for_accurate_width

2/3. it is documented (i cannot find where) - column block always makes selection from the same col-1..col-2 on all lines. picture may look weird with it.

[akizuha]

Why need a "max_line_len_for_accurate_width" other than unlimited accurate width length?

2/3 Maybe count full width characters as 2 cols?

↑THIS is really strange.

[Alexey-T]

Option is needed- on renreding LONG Unicode lines, rendering is too slow.

Picture. you started at column 7 (line 1) and ended at column 20 (line 6). picture is weird. but text block is columns 7 to 20.

[Alexey-T]

added this to Wiki, https://wiki.freepascal.org/CudaText#Why_column_selection_looks_weird_with_CJK_characters

[akizuha]

Long line rendering can be FAST, even with word wrap.

[Alexey-T]

maybe. current ATSynEdit code calcs TextWidth for all chars in a line. so max len=500 makes sense

[Alexey-T]

maybe EmEditor calcs CharWidth fast. w/o calling Win32 API. not sure.

[akizuha]

IIRC LCL has built-in platform independent freetype support. Also, why not just calculate two width: one for half-width character, one for full-wdith. (Assume nobody use proportional fonts in such editor?)

this is awkward

[Alexey-T]

Made a fix, detect now char-width by char 'N' (was used wide char 'M'- it gave too wide cells for Colibri)

[Alexey-T]

full-width size: engine already uses some fixed width - "unicode_full_width":190 but problem is another one, sometimes code needs that "limit" of 500 chars.

[Alexey-T]

IIRC code needs the "limit" to optimize caret jumps over HUGE (len=4M) lines