xref: /plan9/sys/lib/troff/font/devutf/charlib/LH.example (revision 3e12c5d1bb89fc02707907988834ef147769ddaf)
1%
2% An example logo character. Building the PostScript program that prints
3% your company logo is not addressed here; we assume you already have
4% such a program, that it's relatively simple, and that it prints the
5% logo by itself on a page. What you'll find here are instructions for
6% converting that logo program into a character that can be accessed by
7% troff and dpost.
8%
9% Building a new charlib character involves some PostScript programming.
10% We've tried to isolate parameters that you'll need to change (Xoffset,
11% Yoffset, and Scaling), but we can't guarantee things will work properly
12% with every logo program. PostScript is a complex language and subtle
13% interactions between your logo program and what we've done here can
14% cause problems.
15%
16% Tuning the new character is an iterative process. You may want to adjust
17% the size of the logo (via Scaling), it's position relative to adjacent
18% characters and the baseline (Xoffset and Yoffset), and the distance troff
19% moves after printing the character (width field in file ../S1). The steps
20% to follow are:
21%
22%	1: Create a simple troff test file for the new character. Something
23%	   like,
24%
25%		.sp 1i
26%		.ps 10
27%		size 10: \(LH
28%		.sp 1i
29%		.ps 18
30%		size 18: \(LH
31%		.sp 1i
32%		.ps 36
33%		size 36: \(LH
34%		.sp 1i
35%		.ps 10
36%		four logo characters: \(LH\(LH\(LH\(LH
37%
38%	   is sufficient. The test file can go anywhere.
39%
40%	2: Change into directory /usr/lib/font/devpost/charlib. All file
41%	   pathnames will be relative to that directory.
42%
43%	3: Save a copy of the working LH logo file. Then replace LH with
44%	   this file (i.e. LH.example). Changes described below should be
45%	   be made in the new LH file (not in LH.example).
46%
47%	4: Your PostScript logo program will eventually replace whatever
48%	   you find between the <<StartLogo>> and <<EndLogo>> comment lines
49%	   in the PostScript build_LH procedure (below). What's there now
50%	   prints an example logo that you can use until you understand the
51%	   remaining steps.
52%
53%	5: Print your troff test file using (assuming your making changes
54%	   in the devpost charlib directory),
55%
56%		troff -Tpost testfile | dpost | lp ...
57%
58%	6: Adjust the logo positioning by changing the numbers assigned to
59%	   Xoffset and Yoffset (below). Both are in units of 72 per inch.
60%	   Positive offsets should move the logo to the right and up the
61%	   page.
62%
63%	7: Adjust the logo size by changing the the number assigned to
64%	   Scaling. Unitsize also controls scaling, but there's no good
65%	   reason to change both Scaling and Unitsize.
66%
67%	8: Control the horizontal distance troff moves after printing the
68%	   new LH character by changing the width (i.e. the number in the
69%	   second column) assigned to LH in file ../S1. Character width
70%	   adjustments should probably wait until you're satisfied with
71%	   the Scaling set in step 7.
72%
73%	9: Back to step 5 until your satisfied with the output.
74%
75% The remaining steps are suggested but not required:
76%
77%      10: Delete PostScript comments in your new LH charlib file - comments
78%	   start with % and go to the end of the line.
79%
80%      11: Update the width field assigned to LH in file ../shell.lib. The
81%	   new width should reflect what's currently in your S1 font file.
82%
83%      12: Make a similiar set of changes in /usr/lib/font/devLatin1/charlib.
84%	   You can use the devpost version of LH to devLatin1/charlib/LH,
85%	   but changes to files devLatin1/S1 and devLatin1/shell.lib must be
86%	   entered by hand.
87%
88
89/Logo_Dict 100 dict dup begin
90	/Xoffset 0 def			% 72 dpi with positive to the right
91	/Yoffset 0 def			% 72 dpi with positive up the page
92	/Scaling 1.0 def		% adjust this number to change the size
93	/Unitsize 36 def		% for point size scaling - leave it be
94	/showpage {} def
95end def
96
97/build_LH {				% don't bind this procedure
98	Logo_Dict begin
99		gsave
100		/charwidth exch def
101		currentpoint translate
102		resolution 72 div dup scale
103		Xoffset Yoffset translate
104		Scaling Scaling scale
105		ptsize Unitsize div dup scale
106
107		%% Replace everything between the <<StartLogo>> and <<EndLogo>>
108		%% comment lines by the PostScript program that prints your
109		%% logo.
110
111		%% <<StartLogo>>
112			newpath
113			.5 .5 scale
114			0 0 moveto
115			100 0 lineto
116			100 100 lineto
117			closepath
118			.5 setgray
119			fill
120			0 setgray
121			10 10 translate
122			45 rotate
123			0 5 moveto
124			/Helvetica findfont 18 scalefont setfont
125			(Example Logo) show
126		%% <<EndLogo>>
127
128		grestore
129	end
130} def
131
132