Characters cannot be displayed when use SimSun ttf font

[J-F-Liu]

Used simsunb.ttf, 宋体, 新宋体, both fonts display square boxes.

[packetmonkey]

Can you please provide links to both fonts you are having a problem with and a script to reproduce the issue?

[J-F-Liu]

The font file in the Windows\Fonts folder, created a script as below:

require 'prawn'

Prawn::Document.generate("test.pdf") do
  font("c:/Windows/Fonts/simsunb.ttf") do
    text "宋体，是为适应印刷术而出现的一种汉字字体。常用于书籍、杂志、报纸印刷的正文排版。
    中国书法和雕版印刷的结合产生了宋体字，因此，宋体字不但有中国书法的魅力，还具有雕版印刷及木版刀刻的韵味。"
    text "Windows系统的中易宋体（宋体、新宋体，非简体环境下显示为SimSun、NSimSun）
    是由北京中易中标电子信息技术有限公司制作的简体字字体；
    繁体的宋体字体则是华康科技制作的细明体（细明体、新细明体，非繁体环境下显示为MingLiU、PMingLiU）。
    Mac中的衬线字体有俪宋 Pro （LiSongPro）及苹果俪细宋（LiSungLight）。
    Linux发行版中使用较多的有AR PL 上海宋（AR PL Uming）和完全民间开发的文泉驿点阵宋体。
    此外网络上还有民间开发的“华秀月明”字体。"
  end
end

[packetmonkey]

I don't have access to a windows machine to get a copy of the fonts so I can try to reproduce the problem.

I suspect we will find the problem is rooted in ttfunk which is the library prawn uses to deal with ttf fonts. Can you either help me find where I can get a copy of the fonts or confirm that ttfunk is able/unable to work with these specific fonts?

[J-F-Liu]

The file size of simsunb.ttf is 16.1MB, I confirmed the issue is in ttfunk when comparing the result of simhei.ttf and simsunb.ttf by running ttfunk/examples/metrics.rb

postscript: SimHei
-- FONT METRICS ----------------------------
units/em  : 256
ascent    : 220
descent   : -36
line gap  : 36
bbox      : (-3,-40)-(255,220)
-- SIMPLE CHARACTER -> GLYPH LOOKUP --------
character     : 我
character code: 25105
glyph id      : 6215
glyph type    : simple
glyph size    : 272b
glyph bbox    : (14,-28)-(247,206)
-- COMPOUND CHARACTER -> GLYPH LOOKUP ------
character     : 们
character code: 20204
glyph id      : 1314
glyph type    : simple
glyph size    : 168b
glyph bbox    : (9,-27)-(232,210)

postscript: SimSun-ExtB
-- FONT METRICS ----------------------------
units/em  : 256
ascent    : 220
descent   : -36
line gap  : 36
bbox      : (0,-41)-(470,220)
-- SIMPLE CHARACTER -> GLYPH LOOKUP --------
character     : 我
character code: 25105
glyph id      : 0
glyph type    : simple
glyph size    : 34b
glyph bbox    : (28,-13)-(224,193)
-- COMPOUND CHARACTER -> GLYPH LOOKUP ------
character     : 们
character code: 20204
glyph id      : 0
glyph type    : simple
glyph size    : 34b
glyph bbox    : (28,-13)-(224,193)

With simsunb.ttf glyph id is 0 for all Chinese characters.

[J-F-Liu]

Well, this issue is not urgent now. I found a tool called AiFont and converted c:/Windows/Fonts/simsun.ttc to simsun.ttf, then this ttf file can be used to render PDF correctly.

[packetmonkey]

Glad to hear you came up with a solution!

I'll close this issue as it wasn't a prawn bug but ttfunk related. I would be happy to look at a PR to implement that functionality on the ttfunk side so the original font worked out of the box. Without the actual font file and spending some time in the TrueType spec, I won't be able to patch ttfunk myself.

Thanks for the update!