one errors on windows for font

[vastyao]

I set a font have chinese with draw.font, then when i use draw.get_font_metrics(), it would be errors with valueError? what can I do for this?

[emcconville]

Can you share an example of the code that produced the ValueError? OR perhaps what the ValueError message was?

[vastyao]

ValueError: NULL pointer access. the errors is location in wand/drawing.py.
the code is
args = [result[i] for i in xrange(13)]
If transform chinese in the name of fontchinese to english , it can work well.

[emcconville]

I'm not able to reproduce (yet), but I would suspect that font library can not load the typeface. Usually the font-resolver will fallback to system fault if there's an issue, so we need to know what the actual error is. The following patch should at least emit ImageMagick's internal exception.

index 43f35eb..7f39dd3 100644
--- a/wand/drawing.py
+++ b/wand/drawing.py
@@ -1151,6 +1151,13 @@ class Drawing(Resource):
             else:
                 text = binary(text)
         result = font_metrics_f(image.wand, self.resource, text)
+        if not result:
+            # Possible error on drawing context
+            self.raise_exception()
+            # Or error on image canvas
+            image.raise_exception()
+            # Generate a generic error if ImageMagick couldn't emit one.
+            raise ValueError('Unable to render text with current font.')
         args = [result[i] for i in xrange(13)]
         library.MagickRelinquishMemory(result)
         return FontMetrics(*args)

Don't know if you're able to patch & test, but I would like a minimum test case. Both Simplified & Traditional Chinese fonts work for me.

with Image(filename='wizard:') as img:
    with Drawing() as traditional_chinese:
        traditional_chinese.font = '/path/to/Apple LiSung Light.ttf'
        traditional_chinese.font_size = 64
        metrics = traditional_chinese.get_font_metrics(img, u'你好，世界')
        print('Traditional Chinese', metrics)
    with Drawing() as simplified_chinese:
        simplified_chinese.font = '/path/to/FandolHei-Bold.otf'
        simplified_chinese.font_size = 64
        metrics = simplified_chinese.get_font_metrics(img, u'你好，世界')
        print('Simplified Chinese', metrics)

[emcconville]

Okay, this method will now raise the correct error. Should be a TypeError along the lines as...

wand.exceptions.TypeError: unable to read font `[INSERT BAD FONT VALUE HERE]' @ error/annotate.c/RenderFreetype/1362

As far as why it would fail, that's usually just a typo. Also ensure that freetype can read the font file.

[vastyao]

such as the font's name is '方正兰亭黑.TTF', it would be error.when I change it to 'a.TTF',it will work well.