XFont and Font Manager Support
------------------------------
You can now use the font commands built into BASIC for
accessing the font manager. Text printed with the PLOT TEXT command will
be in the user-specified font while text printed with the PRINT statement
will still be in the default font.
The BASIC commands for font handling are:
def setfont(fontname$)
sub askfont(fontname$)
def setfontsize(pointsize)
sub askfontsize(pointsize)
def setfontstyle(style$)
sub askfontstyle(style$)
The "set" statements return TRUE or FALSE depending on whether or not the font
could be loaded.
To get an idea of the different formats for font specification, run the
program "glsfonts.tru" in this directory to list the GL fonts and the
program "xlsfonts" to list the X fonts. (see note below on how to use the
output from these programs to set the associated font.)
***
FONT SIZE
---------
For portability, you should always set the font size. The font size is a
point size NOT a pixel size so that 75 dpi (dots per inch) and 100 dpi
displays can be supported by the same setfontsize statement.
Using the output from the "*lsfonts" programs:
The only time when the fontsize should not be set is when you are using the
entire font name for X windows in the form that it is returned by "xlsfonts".
In this case, the fontsize should be set to zero (the default for X) where
it will be treated as a wildcard value. The style should be set to null.
***
FONT STYLE
----------
The font managers are case sensitive. The SG font manager accepts styles
such as "BoldItalic" while the X font manager handles the same style in
the format "bold-i".
For portability, the style may be set in the form "<weight>,<slant>".
Roman, Italic, and Oblique slants will be converted to the eqivalent r,i,o for
the X manager. For the SG manager, they will simply be combined.
For example, the statement "call setfontstyle("Bold,Italic")" will be
translated to "BoldItalic" for the SG and "bold-i" for X. However, the
statement "call setfontstyle("bold,italic")" will have the same effect for
X, but for the SG the resulting "bolditalic" will be different from "BoldItalic"
and may not be found.
***
SETTING THE FONT
----------------
Asking the font, size, or style after setting them will return the null string
if the font could not be loaded.
You can pass an entire font name consisting of family name, size, and style
to the "setfont" subroutine. In this way, you can access the other font fields
supported by X.
***
DEFAULTS
--------
The default font size for the GL is 12 while the X default size is set to 0
(which is translated to be a wildcarded size).
The GL loads the font with a single pixel size that is scaled to the font
point size by True BASIC (using fmscale).
For the GL, unset fields will be left blank. For X, unset fields will be
wildcarded.
***
To see a list of the availiable X fonts, type: "xlsfonts".
The program "glsfonts" in this directory lists the GL fonts.
***
WARNING
-------
IMPORTANT NOTE: some fonts names which are listed by "glsfonts" (fmenumerate)
cause core dumps when loaded and set by the font manager. Using the following
if/then statement will avoid this problem. See the example "fontdemo.tru".
! skip fonts we don't want
! these fonts cause memory-faults and core dumps
if f$<>"vxms" and f$<>"xif" and f$<>"vsgn" and f$<>"vsg" and f$<>"stan" and f$<>"mit" and f$<>"chp" and f$<>"Cursor" and f$<>"Icon" and f$<>"arrow" and f$<>"chess" then
call setfont(f$)
end if
11/10/91
Documentation
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