Pim Blokland schreef: > Frank da Cruz schreef > > > (e.g. VT220) or PC code page (e.g. CP437) can reveal such things. > > I really was speaking about the geometric shape range (U+25A0 > through U+25FF), not about the box drawing characters > (U+2500..U+257F) and block elements (U+2580..U+259F), which I do > understand better. > It's the same problem. The many and varied "shapes" in the Unicode standard do not come with specs. Many of the boxes and other geometric shapes are also terminal and/or code page glyphs. Some of them should extend to the edges and/or corners of the cell (in a monospace font); others shouldn't. In the latter case, what are the relative sizes, and where in the cell should the glyph be placed? What should line up or join with what? What are the different line thicknesses and which lines have which thickness? Exactly where do lines intersect cell boundaries? When a line is slanted, what is the angle? This is all left implicit in the standard. (You'll also find that monospace fonts vary widely in their ability to handle character-cell graphics made from line- and box-drawing and geometric shape characters.)
As Mark said, somebody should write a Techical Note :-) Make that "-bodies" -- I don't think any single person has all the pieces of the puzzle. STIX, terminals, code pages... Different terminals have different glyphs for different uses, and different people know about them. And as I said previously, the original character sets were not documented. To illustrate, I didn't understand some of the VT terminal technical glyphs. A character that looked like a NOT or CEILING sign, which was in my original proposal, was unified with the characters it looked like during the review process. But later I found out it was a RADICAL SYMBOL TOP expressly intended to join with the RADICAL SYMBOL BOTTOM that was also proposed (and accepted), and the NOT and CEILING characters didn't work for this purpose. ISO and the Unicode Consortium are to be commended for documenting character sets not only by showing a picture of each character, but also giving it a name. The next step is to write a little story about each character: history, etymology, applications, specs, anecdotes, controversies, ... For some characters, this could be a book in itself. - Frank
