hoffstadt/DearPyGui

Error loading font for Chinese path

monkeycc opened this issue · 3 comments

monkeycc commented

ttf_path E:\中文\config\ttf\MiSans-Regular.ttf

ttf_path = r"E:\中文\config\ttf\MiSans-Regular.ttf"
with dpg.font_registry():
    with dpg.font(
            ttf_path, 40, default_font=True
    ) as default_font:
        dpg.add_font_range_hint(dpg.mvFontRangeHint_Chinese_Full)

dpg.bind_font(default_font)
Exception: Error: [1000] Message:       Font file could not be found

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "E:\anaconda3\envs\gui\lib\site-packages\dearpygui\dearpygui.py", line 1905, in font_registry
    yield widget
  File "e:\code\main.py", line 440, in run
    ttf_path, 40, default_font=True
  File "E:\anaconda3\envs\gui\lib\contextlib.py", line 112, in __enter__
    return next(self.gen)
  File "E:\anaconda3\envs\gui\lib\site-packages\dearpygui\dearpygui.py", line 1878, in font
    widget = internal_dpg.add_font(file, size, label=label, user_data=user_data, use_internal_label=use_internal_label, tag=tag, pixel_snapH=pixel_snapH, parent=parent, **kwargs)
SystemError: <built-in function add_font> returned a result with an error set

During handling of the above exception, another exception occurred:

Exception: Error: [1009] Message:       No container to pop.

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "e:/code/main.py", line 15, in <module>
    main(parent)
  File "e:/code/main.py", line 11, in main
    dbok.run(dizhi)
  File "e:\code\main.py", line 445, in run
    dpg.add_font_range_hint(dpg.mvFontRangeHint_Chinese_Full)
  File "E:\anaconda3\envs\gui\lib\contextlib.py", line 130, in __exit__
    self.gen.throw(type, value, traceback)
  File "E:\anaconda3\envs\gui\lib\site-packages\dearpygui\dearpygui.py", line 1907, in font_registry
    internal_dpg.pop_container_stack()
SystemError: <built-in function pop_container_stack> returned a result with an error set

How to solve it ?

v-ein commented

This error occurs because DPG tries to interpret a UTF-8 string as an ANSI string. Unfortunately there's no workaround because further in the code, the same string is treated as UTF-8.

Here's what happens:

  • The path to the font file is passed to mvFont as a Python object;
  • That object gets converted to a UTF-8 string, which is pointed to by a char* pointer (see mvFont::handleSpecificRequiredArgs -> ToString -> _PyUnicode_AsString -> PyUnicode_AsUTF8).
  • mvFont then attempts to check whether the font file exists. It does so by opening the file with std::ifstream::open, which receives a char* - and on Windows, treats that pointer as ANSI encoded string (correct me if I'm wrong).
    • This call fails for non-ASCII strings.
  • If the ifstream::open check succeeded, the path would further be passed to ImFontAtlas::AddFontFromFileTTF -> ImFileLoadToMemory -> ImFileOpen. On Windows, ImFileOpen explicitly converts the file name from UTF-8 to UTF-16 (wchar_t*), thus treating making the entire call chain (and ImFontAtlas::AddFontFromFileTTF) UTF-8 aware.
  • 👍1