File: z17.c

package info (click to toggle)
lout 3.25-1
  • links: PTS
  • area: main
  • in suites: woody
  • size: 9,252 kB
  • ctags: 3,152
  • sloc: ansic: 31,182; makefile: 254; awk: 83
file content (407 lines) | stat: -rw-r--r-- 15,919 bytes parent folder | download
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
/*@z17.c:Gap Widths:GetGap()@*************************************************/
/*                                                                           */
/*  THE LOUT DOCUMENT FORMATTING SYSTEM (VERSION 3.25)                       */
/*  COPYRIGHT (C) 1991, 2001 Jeffrey H. Kingston                             */
/*                                                                           */
/*  Jeffrey H. Kingston (jeff@cs.usyd.edu.au)                                */
/*  Basser Department of Computer Science                                    */
/*  The University of Sydney 2006                                            */
/*  AUSTRALIA                                                                */
/*                                                                           */
/*  This program is free software; you can redistribute it and/or modify     */
/*  it under the terms of the GNU General Public License as published by     */
/*  the Free Software Foundation; either Version 2, or (at your option)      */
/*  any later version.                                                       */
/*                                                                           */
/*  This program is distributed in the hope that it will be useful,          */
/*  but WITHOUT ANY WARRANTY; without even the implied warranty of           */
/*  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the            */
/*  GNU General Public License for more details.                             */
/*                                                                           */
/*  You should have received a copy of the GNU General Public License        */
/*  along with this program; if not, write to the Free Software              */
/*  Foundation, Inc., 59 Temple Place, Suite 330, Boston MA 02111-1307 USA   */
/*                                                                           */
/*  FILE:         z17.c                                                      */
/*  MODULE:       Gap Widths                                                 */
/*  EXTERNS:      GetGap(), MinGap(), ExtraGap(), ActualGap(), EchoGap()     */
/*                                                                           */
/*****************************************************************************/
#include "externs.h"


/*****************************************************************************/
/*                                                                           */
/*  GetGap(x, style, res_gap, res_inc)                                       */
/*                                                                           */
/*  Object x is expected to be a WORD or QWORD containing a gap:             */
/*                                                                           */
/*      <gap>        ::=  [ <increment> ] <width> [ <mode> ] [ <nobreak> ]   */
/*                   ::=                                                     */
/*                                                                           */
/*      <nobreak>    ::=  u                                                  */
/*      <increment>  ::=  +  |  -                                            */
/*      <width>      ::=  <unsigned number> <units>                          */
/*      <units>      ::=  c  |  i  |  p  |  m  |  f  |  s                    */
/*                   ::=  v  |  w  |  b  |  r  |  d  |  y  |  z              */
/*      <mode>       ::=  e  |  h  |  x  |  o  |  k  |  t  |  n              */
/*                                                                           */
/*  Set *res_gap to the gap in the strings of x; *res_inc is the increment.  */
/*  The gap is calculated using the given style.                             */
/*  If the gap is empty, this is a synonym for 0ie.                          */
/*  If there is an error, GetGap prints a message and returns 0ie.           */
/*                                                                           */
/*****************************************************************************/
#define setwidths(x, y) w = x; units(*res_gap) = y;  break;

void GetGap(OBJECT x, STYLE *style, GAP *res_gap, unsigned *res_inc)
{ int w;  float num; 
  FULL_CHAR *str;

  debug2(DGW, D, "GetGap( %s, %s, res_gap, res_inc )",
	EchoObject(x), EchoStyle(style));

  nobreak(*res_gap) = FALSE;
  width(*res_gap) = 0;  units(*res_gap) = FIXED_UNIT;
  mode(*res_gap)  = EDGE_MODE;  *res_inc = GAP_ABS;

  /* make sure we have a WORD or QWORD argument */
  if( !is_word(type(x)) )
  { Error(17, 1, "gap is not a simple word", WARN, &fpos(x));
    debug1(DGW, D, "GetGap failing (x = %s)", EchoObject(x));
    return;
  }
  str = string(x);

  /* if word is empty, return 0ie */
  if( *str == '\0' )
  { debug0(DGW, D, "GetGap returning (null word)");
    return;
  }

  /* read the optional gap increment */
  if( *str == CH_INCGAP )       *res_inc = GAP_INC, str++;
  else if( *str == CH_DECGAP )  *res_inc = GAP_DEC, str++;

  /* read the gap width */
  if( sscanf((char *) str, "%f", &num) != 1 )
  { Error(17, 2, "width missing from %s", WARN, &fpos(x), string(x));
    Error(17, 3, "%s, %s and %s must be enclosed in double quotes",
      WARN, &fpos(x), KW_VCAT_NJ, KW_HCAT_NJ, KW_ACAT_NJ);
    debug0(DGW, D, "GetGap failing (width missing)");
    return;
  }
  while( numericchar(*str) )  str++;

  /* read the compulsory units, calculate length, and check reasonableness */
  switch( *str++ )
  {
    case CH_UNIT_CM:	setwidths( num*CM,                        FIXED_UNIT );
    case CH_UNIT_IN:	setwidths( num*IN,                        FIXED_UNIT );
    case CH_UNIT_PT:	setwidths( num*PT,                        FIXED_UNIT );
    case CH_UNIT_EM:	setwidths( num*EM,                        FIXED_UNIT );
    case CH_UNIT_FT:	setwidths( num*FontSize(font(*style), x), FIXED_UNIT );
    case CH_UNIT_SP:	setwidths( num*width(space_gap(*style)),  FIXED_UNIT );
    case CH_UNIT_VS:	setwidths( num*width(line_gap(*style)),   FIXED_UNIT );
    case CH_UNIT_YU:	setwidths( num*yunit(*style),             FIXED_UNIT );
    case CH_UNIT_ZU:	setwidths( num*zunit(*style),             FIXED_UNIT );
    case CH_UNIT_WD:	setwidths( num*FR,                        NEXT_UNIT  );
    case CH_UNIT_BD:	setwidths( num*FR,                        FRAME_UNIT );
    case CH_UNIT_RL:	setwidths( num*FR,                        AVAIL_UNIT );

    case CH_UNIT_DG:	if( *res_inc == GAP_DEC ) num = - num;
			*res_inc = GAP_ABS;
			while( num >  180.0 ) num -= 360.0;
			while( num < -180.0 ) num += 360.0;
			assert((num>=-180.0) && (num<=180.0), "GetGap: dg!");
			setwidths( num*DG,                        DEG_UNIT   );

    default:	Error(17, 4, "units letter missing from %s",
		  WARN, &fpos(x), string(x));
		debug0(DGW, D, "GetGap failing (units letter missing)");
		return;
  }

  if( units(*res_gap) == AVAIL_UNIT && w > FR )
  { Error(17, 5, "%.1fr too large (1.0r substituted)", WARN, &fpos(x), num);
    w = FR;
  }
  width(*res_gap) = w;

  /* read the optional gap mode */
  switch( *str )
  {
    case CH_NOBREAK:
    case '\0':		mode(*res_gap) = EDGE_MODE;          break;
    case CH_MODE_EDGE:	mode(*res_gap) = EDGE_MODE;  str++;  break;
    case CH_MODE_HYPH:	mode(*res_gap) = HYPH_MODE;  str++;  break;
    case CH_MODE_MARK:	mode(*res_gap) = MARK_MODE;  str++;  break;
    case CH_MODE_OVER:	mode(*res_gap) = OVER_MODE;  str++;  break;
    case CH_MODE_KERN:	mode(*res_gap) = KERN_MODE;  str++;  break;
    case CH_MODE_TABL:	mode(*res_gap) = TAB_MODE;   str++;  break;

    default:	Error(17, 7, "unknown gap mode in %s",
		  WARN, &fpos(x), string(x));
		debug0(DGW, D, "GetGap failing (spacing mode)");
		return;
  }

  /* read the optional nobreak */
  if( *str == CH_NOBREAK )
  {
    if( mode(*res_gap) == HYPH_MODE )
      Error(17, 9, "replacing self-contradictory gap %s by breakable version",
	WARN, &fpos(x), string(x));
    else nobreak(*res_gap) = TRUE;
    str++;
  }

  /* if string has not terminated, error */
  if( *str != '\0' )
    Error(17, 8, "invalid width or gap %s", WARN, &fpos(x), string(x));

  debug2(DGW, D, "GetGap returning (res_gap = %s, res_inc = %s)",
    EchoGap(res_gap), Image( (int) *res_inc) );
} /* end GetGap */


/*@::MinGap()@****************************************************************/
/*                                                                           */
/*  FULL_LENGTH MinGap(a, b, c, xgap)                                        */
/*                                                                           */
/*  Returns the minimum possible separation between the marks of two         */
/*  objects with the given intervening gap.                                  */
/*  The first object has fwd value a, the second has back value b and fwd c. */
/*                                                                           */
/*****************************************************************************/

FULL_LENGTH MinGap(FULL_LENGTH a, FULL_LENGTH b, FULL_LENGTH c, GAP *xgap)
{ FULL_LENGTH res;  int w;
  switch( units(*xgap) )
  {
    case FIXED_UNIT:	w = width(*xgap);
			break;

    case FRAME_UNIT:	w = 0;
			break;

    case AVAIL_UNIT:	w = 0;
			break;

    case NEXT_UNIT:	w = width(*xgap) * (b + c) / FR;
			break;

    default:		assert(FALSE, "MinGap: units");
			break;
  }
  switch( mode(*xgap) )
  {
    case NO_MODE:	assert(FALSE, "MinGap: NO_MODE");
			res = 0;
			break;

    case ADD_HYPH:
    case HYPH_MODE:
    case EDGE_MODE:	res = find_min(MAX_FULL_LENGTH, a + w + b);
			break;

    case MARK_MODE:	if( BackEnd->fractional_spacing_avail )
			  res = find_max(w, a + b + (FULL_LENGTH) (0.1 * w) );
			else
			  res = find_max(w, a + b);
			break;

    case OVER_MODE:	res = w;
			break;

    case KERN_MODE:	res = find_max(find_max(a, b), w);
			break;

    case TAB_MODE:	res = a + b;
			break;

    default:		assert(FALSE, "MinGap: mode");
			res = 0;
			break;

  }
  debug5(DGW, DD, "MinGap( _,%s  %s  %s,%s ) = %s", EchoLength(a),
	EchoGap(xgap), EchoLength(b), EchoLength(c), EchoLength(res) );
  return res;
} /* end MinGap */


/*@::ExtraGap()@**************************************************************/
/*                                                                           */
/*  FULL_LENGTH ExtraGap(a, b, xgap, dir)                                    */
/*                                                                           */
/*  Consider two objects, the first with forward length a, the second with   */
/*  back length b.  The objects are separated by the given gap.              */
/*  If dir == FWD, ExtraGap returns the maximum amount that a could be       */
/*  increased without increasing MinGap(a, b, c, xgap).                      */
/*  If dir == BACK, similarly for b.                                         */
/*                                                                           */
/*****************************************************************************/

FULL_LENGTH ExtraGap(FULL_LENGTH a, FULL_LENGTH b, GAP *xgap, int dir)
{ FULL_LENGTH tmp, res;
  FULL_LENGTH w = units(*xgap) == FIXED_UNIT ? width(*xgap) : 0;
  switch( mode(*xgap) )
  {
    case NO_MODE:	assert(FALSE, "ExtraGap: NO_MODE");
			res = 0;
			break;

    case ADD_HYPH:
    case HYPH_MODE:
    case EDGE_MODE:	res = 0;
			break;

    case MARK_MODE:	if( BackEnd->fractional_spacing_avail )
			  res = find_max(0, (FULL_LENGTH) (0.9 * w) - a - b);
			else
			  res = find_max(0, w - a - b);
			break;

    case OVER_MODE:	res = MAX_FULL_LENGTH;
			break;

    case KERN_MODE:	tmp = find_max(a, find_max(b, w));
			res = dir == BACK ? tmp - b : tmp - a;
			break;

    case TAB_MODE:	res = 0;
			break;

    default:		assert(FALSE, "ExtraGap: mode");
			res = 0;
			break;

  }
  debug5(DGW, DD, "ExtraGap( %s, %s, %s, %s ) = %s", EchoLength(a),
		EchoLength(b), EchoGap(xgap), Image(dir), EchoLength(res));
  return res;
} /* end ExtraGap */


/*@::ActualGap()@*************************************************************/
/*                                                                           */
/*  FULL_LENGTH ActualGap(prevf, b, f, xgap, frame_size, mk)                 */
/*                                                                           */
/*  Returns the actual separation between the marks of an object of size     */
/*  (?, prevf) and an object of size (b, f) separated by gap *xgap in a      */
/*  frame of size frame_size; the first object lies at mk in the frame,      */
/*  where 0 <= mk <= frame_size.                                             */
/*                                                                           */
/*****************************************************************************/

FULL_LENGTH ActualGap(FULL_LENGTH prevf, FULL_LENGTH b, FULL_LENGTH f,
  GAP *xgap, FULL_LENGTH frame_size, FULL_LENGTH mk)
{ FULL_LENGTH res;  int w, w2;
  switch( units(*xgap) )
  {
    case FIXED_UNIT:	w = width(*xgap);
			break;

    case FRAME_UNIT:	if( width(*xgap) > FR )
			  w = MAX_FULL_LENGTH;
			else
			  w = (width(*xgap) * frame_size) / FR;
			break;

    case AVAIL_UNIT:	w = (width(*xgap) * (frame_size - b - f)) / FR;
			w = find_max(w, 0);
			break;

    case NEXT_UNIT:	w = width(*xgap) * (b + f) / FR;
			break;

    default:		assert(FALSE, "ActualGap: units");
			break;
  }
  switch( mode(*xgap) )
  {
    case NO_MODE:	Error(17, 10, "cannot continue after previous error(s)", FATAL, no_fpos);
			assert(FALSE, "ActualGap: NO_MODE");
			w2 = 0;
			break;

    case ADD_HYPH:
    case HYPH_MODE:
    case EDGE_MODE:	w2 = prevf + w + b;
			break;

    case MARK_MODE:	if( BackEnd->fractional_spacing_avail )
			  w2 = find_max(w, prevf + b + (FULL_LENGTH) (0.1 * w) );
			else
			  w2 = find_max(w, prevf + b);
			break;

    case OVER_MODE:	w2 = w;
			break;

    case KERN_MODE:	w2 = find_max( find_max(prevf, b), w);
			break;

    case TAB_MODE:	w2 = w + b - mk;
			w2 = find_max(w2, prevf + b );
			break;

    default:		assert(FALSE, "ActualGap: mode");
			w2 = 0;
			break;
  }
  res = find_min(MAX_FULL_LENGTH, w2);
  debug7(DGW, DD, "ActualGap( _,%s %s %s,%s; frame_size %s, mk %s ) = %s",
	EchoLength(prevf), EchoGap(xgap), EchoLength(b), EchoLength(f),
	EchoLength(frame_size), EchoLength(mk), EchoLength(res));
  return res;
} /* end ActualGap */


/*@::EchoGap()@***************************************************************/
/*                                                                           */
/*  FULL_CHAR *EchoGap(xgap)                                                 */
/*                                                                           */
/*  Returns a static string showing the indicated xgap.                      */
/*                                                                           */
/*****************************************************************************/
#if DEBUG_ON

FULL_CHAR *EchoGap(GAP *xgap)
{ char *letter = "?ehxoktH";  char c;  FULL_CHAR *res;
  char *u;
  static int i = 0;
  static char buff[3][20];
  c = mode(*xgap) <= 7 ? letter[mode(*xgap)] : '?';
  c = letter[mode(*xgap)];
  u = nobreak(*xgap) ? "u" : "";
  switch( units(*xgap) )
  {
    case 0:	     sprintf(buff[i], "(none)%c", c);
		     break;

    case FIXED_UNIT: sprintf(buff[i], "%.1fc%c%s", (float) width(*xgap)/CM, c,u);
		     break;

    case NEXT_UNIT:  sprintf(buff[i], "%.1fw%c%s", (float) width(*xgap)/FR, c,u);
		     break;

    case FRAME_UNIT: sprintf(buff[i], "%.1fb%c%s", (float) width(*xgap)/FR, c,u);
		     break;

    case AVAIL_UNIT: sprintf(buff[i], "%.1fr%c%s", (float) width(*xgap)/FR, c,u);
		     break;

    case DEG_UNIT:   sprintf(buff[i], "%.1fd", (float) width(*xgap) / DG);
		     break;

    default:	     assert(FALSE, "EchoGap: units");
		     break;

  }
  res = AsciiToFull(buff[i]);
  i = (i + 1) % 3;
  return res;
} /* end EchoGap */
#endif