When a textbox, browser or other program can't display a character, or the character is not valid unicode, a white-box character is drawn instead to represent the missing glyph.
I assume that this box-glyph is a Unicode character itself, thus I am looking for its codepoint so I can use it. Does anyone know which codepoint is used, or perhaps if my assumption is wrong and it is not necessarily a member of the font?
At first I thought it might be the White Square (U+25A1), but, after I compared this glyph with an example, I found white square was smaller. There is a larger variant of it (medium and large), but these do not appear in the font under consideration, so these can not be the ones I am seeing.
I managed to find my answer, here on stackoverflow: https://stackoverflow.com/a/22636426/2718186
Particularly, the part that talks about .notdef glyph. It seems that fonts reserve a special glyph, that is not mapped to by any Unicode point, to indicate that a character has no glyph in the current font.
Related
In a unicode string, each grapheme consists of one or more code points. However, there are some code points, such as the Zero-width joiner (ZWJ), which are never a part of a grapheme. The ZWJ is, in itself, invisible. Are all of those "non-grapheme" code points always invisible?
The Unicode representation of the Ogham script is notable for containing a non-invisible whitespace character. (U+1680: OGHAM SPACE MARK)
Tom Scott made an excellent YouTube video on the subject: link
There are many joining characters which are intended to modify a base character. Whether they provide a grapheme on their own is partially an implementation detail, I expect.
Example: o followed by U+0308 COMBINING DIAERESIS produces ö (the glyph in isolation is rendered by your browser as ̈)
List of all code points in this category: https://codepoints.net/search?lb=CM
Recent Unicode versions also have invisible characters which modify how a previous emoji is being rendered, famously to add e.g. a skin color trait to emojis with human figures or faces. These by definition are not graphemes in their own right, though again, rendering engines are probably free to figure out a way to represent them if they are encountered in isolation.
Example: 👋 U+1F44B WAVING HAND SIGN followed by U+1F3FB EMOJI MODIFIER FITZPATRICK TYPE-1-2 (which in isolation renders as 🏻) produces 👋🏻
Full catalog: https://www.unicode.org/emoji/charts/full-emoji-modifiers.html
I am trying to minimize the vertical distance between controls on a programmatically constructed Windows Form (using C#). This involves setting the Height property appropriately.
I have found that if the text of the control does not contain any letters with descenders in them (i.e. does not have any of the characters j, g, p, q or y) then the control Height can be smaller than when it does contain such letters (if it does contain letters with descenders then the descenders are chopped off if the Height isn't enough).
It will work fine to test for any of the above 5 characters as long as the language is English, or English - like, but I need to be able to cater for (just about) any language.
Is there a way, given some arbitrary Unicode character (and perhaps a font) to determine if that Unicode character has a descender or not?
There is no property defined for Unicode characters to indicate the presence of a descender, and it’s really a feature of glyph design rather than characters. For example, “Q” has a descenders in many fonts, and “J” has one in some. Besides, given the context, you should also consider diacritic marks placed below a letter, not just descenders of base letters. And probably diacritics above letters, too.
So you would need to read the font information (when available) about character dimensions, or tentatively draw characters in your software and measure their dimensions.
As a rule of thumb, any line height below 1.1 times the font size will cause problems with some characters and fonts. Using 1 (“setting solid”) is not enough, because characters may in fact extend outside the font size.
In Windows, you call GetPath() to get an array containing the X/Y coordinates of every point making up the perimeter or outline of the string of glyphs. Search the array for min/max, which will get you the rectangle exactly enclosing the string. Right to the edge of the letters.
I'm looking for a font which contains a graphic character which is (essentially), the space character, inverted. I'm looking for a graphic character equivalent to the largest-possible solid-black box. The closest I have been able to find is Wingings 2 character 162, but that doesn't fill the entire available character space. When I insert two consecutive Wingdings 2 162 characters, there is still appreciable whitespace between them when displayed or printed. Does anyone know of a black-box font/character which would fill all available character space?
All characters are going to have whitespace between them, or they would be unreadable. This is called "kerning". You can adjust the kerning and line-height in whatever program you are using to send the malicious fax, if you want to be sure to use the maximum amount of toner per page.
Have you considered creating your own font using a software package like this or like this? You could edit the space character to be a solid black square. But as Chris McCall mentioned, you may still have space between characters of any size due to kerning applied by the layout engine that draws the fonts.
You other option is to owner draw your own text and programmatically replacing spaces with black boxes. You would have complete control over kerning and everything else.
I don't know if this is exactly what you were looking for, but...
I was looking for the same thing, since I wanted to create a "textbox" when I wanted to write text using the spritefont, but I never knew how long the total string was going to be, so I wanted something that I could "write" in the same location right before the string with a contrasting color which could be expected to be as long as the string it needed to encompass. That being the case, try:
Webdings - character 103.
I tried lining them up and there wasn't even any space in between. Perfect.
Sorry if this isn't the right overflow for this question. I need a unicode character that is as long as ⎢ (23A2, LEFT SQUARE BRACKET EXTENSION) but lines up horizontally with ⎮ (23AE, INTEGRAL EXTENSION). Is there such a character?
Take a look at shapecatcher. If you draw a straight line, it shows plenty of different codepoints resembling |.
As already pointed out, exact placement and size may depend on the font, but if you know that the font is going to be a specific one (because you supply it), you could still find the character you're looking for.
It turns out this does depend on the font. If I use DejaVu Sans Mono, INTEGRAL EXTENSION is as long as I want it to be. This font appears to be almost exactly the same as the font I was using, Menlo, except for some small differences with some characters (including this one).
Characters included in BMP as specified by 4 digits,
and those characters outside of BMP contains 5 or 6 digits.
But my doubt is:
how is the finanal character drawed from value of code point?
Are the pictures of each character restored in each computer and when displaying just show the matching picture?
Or the final glyph is a computed result of code point itself?
Each Unicode character has a code. The software displaying the character obtains a glyph for that character code - usually from a font installed onto the hosting computer. It then uses the obtained glyph to display the character.
If it can't find a glyph for that character (many fonts for Latin characters completely omit the glyphs used for East Asian languages characters) it formally can't display it. It will then either indicate error or use a supplement glyph meaning that the actual glyph can't be displayed (it can be a question mark or a square or whatever).