about summary refs log tree commit diff
path: root/editor/pamperspective.c
blob: 543f72c33a2f2b544685f75f84349b56560e3acc (plain) (blame)
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
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
/*
    pamperspective -- a reverse scanline renderer

    Copyright (C) 2004 by Mark Weyer

    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 of the License, 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
*/

#define _BSD_SOURCE   /* Make sure strdup is int string.h */

#include <math.h>
#include <string.h>

#include "pam.h"
#include "shhopt.h"
#include "mallocvar.h"

typedef double number;

/* There was no reason for exactly this value of eps.
   For compatibility it should only be decreased in future versions.
*/

#define eps 0.0001


/* Multiple choice types for the command line */

typedef enum {image, pixel_u} unit;
const char *const unit_token[3] = {"image", "pixel", NULL};

typedef enum {lattice, pixel_s} coord_system;
const char *const system_token[3] = {"lattice", "pixel", NULL};

/* Note that 'nearest' is a function in AIX's math.h.  So don't use
   that as a symbol.
*/
typedef enum {interp_nearest, interp_linear} interpolation;
const char *const interpolation_token[3] = {"nearest", "linear", NULL};

typedef enum {free_, fixed} proportion;
const char *const proportion_token[3] = {"free", "fixed", NULL};

const char *const bool_token[7] = {"yes", "true", "on",
                                    "no", "false", "off", NULL};
#define first_false_bool_token 3

/* All command line options that have float (actually number) values.
   We use our own parsing technique for these, to handle width/height
   ratios like 4/3
*/

#define num_float_options 15
const char *const float_option_name[num_float_options][3] = {
  {"upper left x", "upper_left_x", "ulx"},
  {"upper left y", "upper_left_y", "uly"},
  {"upper right x", "upper_right_x", "urx"},
  {"upper right y", "upper_right_y", "ury"},
  {"lower left x", "lower_left_x", "llx"},
  {"lower left y", "lower_left_y", "lly"},
  {"lower right x", "lower_right_x", "lrx"},
  {"lower right y", "lower_right_y", "lry"},
  {NULL, "detail", NULL},
  {NULL, "ratio", NULL},
  {NULL, "margin", NULL},
  {NULL, "top_margin", "tmargin"},
  {NULL, "bottom_margin", "bmargin"},
  {NULL, "left_margin", "lmargin"},
  {NULL, "right_margin", "rmargin"}
};

/* All command line options that have multiple choice values (except bools). */

#define num_enum_options 5
const char *const enum_option_name[num_enum_options] = {
  "input_system", "output_system", "input_unit", "interpolation", "proportion"
};
const char *const *const enum_option_type[num_enum_options] = {
  system_token, system_token, unit_token, interpolation_token, proportion_token
};

/* All command line options that have bool values */

#define num_bool_options 1
const char *const bool_option_name[num_bool_options] = {
  "frame_include"
};


/* A linked list node for --include points */

typedef struct include_point_tag {

  /* How the point is given on the command line (for error messages) */

  const char* specification;

  /* coordinates */

  number xi,yi;

  /* link */

  struct include_point_tag* next;

} include_point;


/* The collection of command line options */

typedef struct {

  /* float options */

  number floats[num_float_options];

  /* enum options */

  int enums[num_enum_options];

  /* bool options */

  bool bools[num_bool_options];

  /* flags */

  unsigned int width_spec, height_spec,
    top_margin_spec, left_margin_spec, right_margin_spec, bottom_margin_spec;

  /* Other stuff */

  int width, height;
  const char* infilename;
  include_point* include_points;

} option;


/* The collection of properties that correspond to the four specified
   vertices 
*/

typedef struct {

  /* 2d (image) coordinates of the 4 vertices */

  number xi_ul, yi_ul,  xi_ur, yi_ur,  xi_ll, yi_ll,  xi_lr, yi_lr;

  /* 3d (world) coordinates of the 4 vertices */

  number xw_ul, yw_ul, zw_ul,  xw_ur, yw_ur, zw_ur,
         xw_ll, yw_ll, zw_ll,  xw_lr, yw_lr, zw_lr;

  /* Originally I planned to include the possibility to move the
     center of projection, that is the pixel the camera "looks at".  It
     turned out, maybe surprisingly, that this does not have any
     effect. So now this center is moved to (0,0).
     
     Another original plan was to correct the output parameters
     depending on the lengths of the paralellograms sides or its
     angles.  This is, however, not possible without knowing something
     like the camera angle or focal length (in pixels).
  */
  
  /* The coefficients for the map from output to world coordinates.

     The actual mapping is
     u,v -> (ax+bx*u+cx*v, ay+by*u+cy*v, az+bz*u+cz*v)
  */     
  number ax,bx,cx, ay,by,cy, az,bz,cz;

} world_data;


/*
  Internal infile buffer

  This is a cyclic in random access out buffer, just large enough
  to store all input lines that are still in use.
*/

typedef struct {

    unsigned int num_rows;
    unsigned int last_physical;
    unsigned int last_logical;
        /* Row number of the input row most recently read from input
           file into buffer (i.e. one less than the number of rows we
           have read from the input)
        */
    tuple ** rows;
    const struct pam * inpamP;

} buffer;



typedef void interpolateFn(tuple, number, number);

/*
  The following are like MALLOCARRAY_NOFAIL and MALLOCVAR_NOFAIL,
  but abort (fail) the program instead of killing the process with an
  abort signal.
*/

#define MALLOCARRAY_SAFE(handle,length) \
{ \
  MALLOCARRAY(handle,length); \
  if (handle==NULL) \
    pm_error ("Out of memory."); \
}

#define MALLOCVAR_SAFE(handle) \
{ \
  MALLOCVAR(handle); \
  if (handle==NULL) \
    pm_error ("Out of memory."); \
}



static void set_command_line_defaults (option *const options)
{
  options->infilename = "-";
  options->include_points = NULL;
  options->floats[8] = 1.0;             /* --detail               */
  options->floats[9] = 1.0;             /* --ratio                */
  options->floats[10] = 0.0;            /* --margin               */
  options->floats[11] = 0.0;            /* --top_margin           */
  options->floats[12] = 0.0;            /* --bottom_margin        */
  options->floats[13] = 0.0;            /* --left_margin          */
  options->floats[14] = 0.0;            /* --right_margin         */
  options->enums[0] = lattice;          /* --input_system         */
  options->enums[1] = lattice;          /* --output_system        */
  options->enums[2] = pixel_u;          /* --input_unit           */
  options->enums[3] = interp_nearest;   /* --interpolation        */
  options->enums[4] = free_;            /* --proportion           */
  options->bools[0] = TRUE;             /* --frame_include        */
}



static int parse_enum (const char *const text,
                       const char *const *const tokens, const char *const name)
/*----------------------------------------------------------------------------
  Parse an argument given to a multiple choice command line option
-----------------------------------------------------------------------------*/
{
  bool found;
  const char *const * cur_token;
  char* tokenlist;
  int tokenlistlen;
  int value;
  int num_spaces;
  int i;

  /* We find out, whether ^text occurs in ^tokens */

  found = FALSE;
  value = 0;
  while (tokens[value] && !found) {
    if (strcmp (text, tokens[value]))
      value++;
    else
      found = TRUE;
  };

  /* otherwise issue an error */

  if (!found) {
    /* For the error message we want to list the allowed tokens.
       First we have to determine, how much memory we need for that.
    */
    num_spaces = 2;

    tokenlistlen = 0;
    cur_token = tokens;
    while (*cur_token) {
      tokenlistlen += (strlen(*cur_token) + num_spaces);
      cur_token++;
    };
    /* Then we create that list */
    MALLOCARRAY_SAFE(tokenlist, tokenlistlen);
    *tokenlist = 0;
    cur_token = tokens;
    while (*cur_token) {
      for (i=0; i<num_spaces; i++)
    strcat (tokenlist, " ");
      strcat (tokenlist, *cur_token);
      cur_token++;
    };
    /* Finally we issue the error */
    pm_error ("'%s' is not a valid value for --%s.  "
              "Valid values are:  %s", text, name, tokenlist);
    /* pm_error() aborts the program, so there is no memory freeing here. */
  };

  /* If all went well, we return the value associated with the token,
     which happens to be the index where we found the token
  */
  return value;
}



static number parse_float (char *const text)
/*----------------------------------------------------------------------------
  Parse an argument given to a float command line option.  We cannot
  just call strtod, because we want to parse fractions like "5/3"
-----------------------------------------------------------------------------*/
{
  bool error;
  char* end;
  char* denstart;
  number num,den;

  error = FALSE;
  num = strtod (text, &end);    /* try strtod anyway */
  switch (*end) {
  case 0:           /* It is a plain number */
    break;
  case '/':         /* It might be a fraction */
    /* (Try to) parse the numerator */
    *end = 0;
    num = strtod (text, &end);
    error = (*end) != 0;
    if (!error) {
      /* Undo the above change */
      *end = '/';
      /* (Try to) parse the denominator */
      denstart = end+1;
      den = strtod (denstart, &end);
      error = (fabs(den)<eps) || ((*end) != 0);
      if (!error)
    num /= den;
    };
    break;
  default:          /* It is no number format we know */
    error = TRUE;
  };
  if (error)
    pm_error ("Invalid number format: %s", text);

  return num;
}



static void parse_include_point(char * specification,
                                include_point ** const include_pointsP)
/*----------------------------------------------------------------------------
  Add one point to the front of the linked list of include points
  headed by include_pointsP.

  The point is described by the asciiz string at 'specification'.
----------------------------------------------------------------------------*/
{
  include_point* new_point;
  char* comma_seek;

  MALLOCVAR_SAFE(new_point);
  new_point->specification = specification;
  new_point->next = *include_pointsP;
  *include_pointsP = new_point;

  /* Now we parse the specification */

  for (comma_seek = specification; (*comma_seek != ',') && (*comma_seek != 0);
       comma_seek++);
  if (*comma_seek == 0)
    pm_error ("Invalid format for --include point: '%s'", specification);
  *comma_seek = 0;      /* separate the two parts for parsing purposes */
  new_point->xi = (number) parse_float(specification);
  new_point->yi = (number) parse_float(comma_seek+1);
  *comma_seek = ',';
}


static void parse_include_points(const char * const include_opt,
                                 include_point ** const include_pointsP)
/*----------------------------------------------------------------------------
  Process the --include option value include_opt by making a linked list
  of the points it describes (in reverse order).

  Return a pointer to the first element of that linked list as
  *include_pointsP.
----------------------------------------------------------------------------*/
{
    char * cursor;
    char * optWork;
        /* Same as include_opt, except we replace delimiters with nulls
           as we work.
        */

    optWork = strdup(include_opt);
    if (optWork == NULL)
        pm_error("out of memory");

    cursor = &optWork[0];
    while (*cursor != '\0') {
        bool hit_end;
        char * sem_seek;

        for (sem_seek = cursor;
             (*sem_seek != ';') && (*sem_seek != 0);
             sem_seek++);

        hit_end = (*sem_seek == '\0');
            
        *sem_seek = '\0';
        parse_include_point(cursor, include_pointsP);

        if (hit_end)
            cursor = sem_seek;
        else
            cursor = sem_seek+1;
    }
    free(optWork);
}


static void parse_command_line (int argc, char* argv[], option *const options)
{
  char* float_text[num_float_options];
  unsigned int float_spec[num_float_options];
  char* enum_text[num_enum_options];
  unsigned int enum_spec[num_enum_options];
  char* bool_text[num_bool_options];
  unsigned int bool_spec[num_bool_options];
  char * include_opt;
  unsigned int include_spec;
  int i,j;
  optStruct3 opt;
  unsigned int option_def_index;
  optEntry* option_def;

  /* Let shhopt try its best */

  option_def_index = 0;
  MALLOCARRAY_SAFE(option_def,
    (2*num_float_options + num_enum_options + num_bool_options + 3));
  for (i=0; i<num_float_options; i++)
    for (j=1; j<3; j++)
      if (float_option_name[i][j])
        OPTENT3(0, float_option_name[i][j], OPT_STRING,
                &(float_text[i]), &(float_spec[i]), 0);
  for (i=0; i<num_enum_options; i++)
    OPTENT3(0, enum_option_name[i], OPT_STRING,
            &(enum_text[i]), &(enum_spec[i]), 0);
  for (i=0; i<num_bool_options; i++)
    OPTENT3(0, bool_option_name[i], OPT_STRING,
            &(bool_text[i]), &(bool_spec[i]), 0);
  OPTENT3(0, "width", OPT_INT, &(options->width), &(options->width_spec), 0);
  OPTENT3(0, "height", OPT_INT, &(options->height), &(options->height_spec),
          0);
  OPTENT3(0, "include", OPT_STRING, &include_opt, &include_spec, 0);
  opt.opt_table = option_def;
  opt.short_allowed = FALSE;
  opt.allowNegNum = TRUE;
  optParseOptions3 (&argc, argv, opt, sizeof(opt), 0);

  /* The non-option arguments are optionally all eight coordinates
     and optionally the input filename
  */

  switch (argc-1) {
  case 1:
    options->infilename = argv[1];
  case 0:
    for (i=0; i<8; i++)
      if (!float_spec[i])
        pm_error ("The %s-coordinate was not specified",
                  float_option_name[i][0]);
    break;
  case 9:
    options->infilename = argv[9];
  case 8:
    for (i=0; i<8; i++) {
      float_text[i] = argv[i+1];
      float_spec[i] = 1;
    };
    break;
  default: pm_error ("Wrong (number of) command line arguments");
  };

  if (include_spec)
      parse_include_points(include_opt, &options->include_points);

  /* Parse float options -- shhopt retrieved them as strings */

  for (i=0; i<num_float_options; i++)
    if (float_spec[i])
      options->floats[i] = parse_float (float_text[i]);

  /* Parse enum options -- shhopt retrieved them as strings */

  for (i=0; i<num_enum_options; i++)
    if (enum_spec[i])
      options->enums[i] = parse_enum (enum_text[i],enum_option_type[i],
                                      enum_option_name[i]);

  /* Parse bool options -- shhopt retrieved them as strings */

  for (i=0; i<num_bool_options; i++)
    if (bool_spec[i])
      options->bools[i] = (first_false_bool_token >
                           parse_enum (bool_text[i], bool_token,
                                       bool_option_name[i]));

  /* Propagate values where neccessary */

  if (float_spec[10])           /* --margin */
    for (i=11; i<15; i++)       /* --top_margin through --right_margin */
      if (!(float_spec[i])) {
        options->floats[i] = options->floats[10];
        float_spec[i]=1;
      };
  options->top_margin_spec = float_spec[11];
  options->bottom_margin_spec = float_spec[12];
  options->left_margin_spec = float_spec[13];
  options->right_margin_spec = float_spec[14];

  /* Clean up */

  free(option_def);
}



static void free_option (option *const options)
{
  include_point* current;
  include_point* dispose;

  current = options->include_points;
  while (current != NULL) {
    dispose = current;
    current = current->next;
    free(dispose);
  };
}



static void init_world (option *const options,
                        const struct pam *const inpam, world_data *const world)
{
  /* constructs xi_ul,...,yi_lr

     Internally we use a pixel coordinate system with pixel units

     This also translates the --include points' coordinates
     into the internal system
  */

  number mult_x, mult_y, add_after;
  int add_before;
  include_point* current_include;

  switch (options->enums[0]) {  /* --input_system */
  case lattice:
    add_after = -0.5;
    add_before = 0;
    break;
  case pixel_s:
    add_after = 0.0;
    add_before = -1;
    break;
  };
  switch (options->enums[2]) {  /* --input_unit */
  case image:
    mult_x = (number)((inpam->width) + add_before);
    mult_y = (number)((inpam->height) + add_before);
    break;
  case pixel_u:
    mult_x = 1.0;
    mult_y = 1.0;
    break;
  };

  world->xi_ul = ((number) options->floats[0]) * mult_x + add_after;
  world->yi_ul = ((number) options->floats[1]) * mult_y + add_after;
  world->xi_ur = ((number) options->floats[2]) * mult_x + add_after;
  world->yi_ur = ((number) options->floats[3]) * mult_y + add_after;
  world->xi_ll = ((number) options->floats[4]) * mult_x + add_after;
  world->yi_ll = ((number) options->floats[5]) * mult_y + add_after;
  world->xi_lr = ((number) options->floats[6]) * mult_x + add_after;
  world->yi_lr = ((number) options->floats[7]) * mult_y + add_after;

  for (current_include = options->include_points; current_include != NULL;
       current_include = current_include->next) {
    current_include->xi = current_include->xi * mult_x + add_after;
    current_include->yi = current_include->yi * mult_y + add_after;
  };
}



static bool solve_3_linear_equations (number* x1, number* x2, number* x3,
                                      number const a11, number const a12,
                                      number const a13, number const b1,
                                      number const a21, number const a22,
                                      number const a23, number const b2,
                                      number const a31, number const a32,
                                      number const a33, number const b3)
/*----------------------------------------------------------------------------
  The three equations are
    a11*x1 + a12*x2 + a13*x3 = b1
    a21*x1 + a22*x2 + a23*x3 = b2
    a31*x1 + a32*x2 + a33*x3 = b3
  The return value is wether the system is solvable
----------------------------------------------------------------------------*/
{
  number c11,c12,d1,c21,c22,d2,e,f;
  int pivot;

  /* We do Gaussian elimination.
     Whenever we find the system to be unsolvable, we just return FALSE.
     In this specific case it makes the code clearer.
  */

  if (fabs(a11)<fabs(a21))
    if (fabs(a21)<fabs(a31))
      pivot=3;
    else
      pivot=2;
  else
    if (fabs(a11)<fabs(a31))
      pivot=3;
    else
      pivot=1;

  switch (pivot) {
  case 1:
    if (fabs(a11)<eps) return FALSE;
    c11 = a22-a12*a21/a11;
    c12 = a23-a13*a21/a11;
    d1 =   b2- b1*a21/a11;
    c21 = a32-a12*a31/a11;
    c22 = a33-a13*a31/a11;
    d2 =   b3- b1*a31/a11;
    break;
  case 2:
    if (fabs(a21)<eps) return FALSE;
    c11 = a12-a22*a11/a21;
    c12 = a13-a23*a11/a21;
    d1 =   b1- b2*a11/a21;
    c21 = a32-a22*a31/a21;
    c22 = a33-a23*a31/a21;
    d2 =   b3- b2*a31/a21;
    break;
  case 3:
    if (fabs(a31)<eps) return FALSE;
    c11 = a12-a32*a11/a31;
    c12 = a13-a33*a11/a31;
    d1 =   b1- b3*a11/a31;
    c21 = a22-a32*a21/a31;
    c22 = a23-a33*a21/a31;
    d2 =   b2- b3*a21/a31;
    break;
  }

  /* Now we have a subsystem:
       c11*x2 + c12*x3 = d1
       c21*x2 + c22*x3 = d2
  */

  if (fabs(c11)>fabs(c21)) {
    if (fabs(c11)<eps) return FALSE;
    e = c22-c12*c21/c11;
    f =  d2- d1*c21/c11;
    /* Now we have a single equation e*x3=f */
    if (fabs(e)<eps) return FALSE;
    *x3 = f/e;
    *x2 = (d1-c12*(*x3))/c11;
  }
  else {
    if (fabs(c21)<eps) return FALSE;
    e = c12-c22*c11/c21;
    f =  d1- d2*c11/c21;
    /* Now we have a single equation e*x3=f */
    if (fabs(e)<eps) return FALSE;
    *x3 = f/e;
    *x2 = (d2-c22*(*x3))/c21;
  };

  switch (pivot) {
  case 1:
    *x1 = (b1-a13*(*x3)-a12*(*x2))/a11;
    break;
  case 2:
    *x1 = (b2-a23*(*x3)-a22*(*x2))/a21;
    break;
  case 3:
    *x1 = (b3-a33*(*x3)-a32*(*x2))/a31;
    break;
  };

  return TRUE;
}


static void determine_world_parallelogram (world_data *const world,
                                           const option *const options)
/*----------------------------------------------------------------------------
  constructs xw_ul,...,zw_lr from xi_ul,...,yi_lr
     
  Actually this is a solution of a linear equation system.
  
  We first solve 4 variables (the 4 z-coordinates) against 4
  equations: Each z-coordinate determines the corresponding x- and
  y-coordinates in a linear fashion, where the coefficients are taken
  from the image coordinates. This corresponds to the fact that a
  point of an image determines a line in the world.
  
  3 equations state that the 4 points form a parallelogram.  The 4th
  equation is for normalization and states, that the center of the
  parallelogram has a z-coordinate of 1.
-----------------------------------------------------------------------------*/
{
  number dx1,dx2,dx3,dx4,dx5, dy1,dy2,dy3,dy4,dy5;
  number det;
  number xw_ul,yw_ul,zw_ul, xw_ur,yw_ur,zw_ur,
         xw_ll,yw_ll,zw_ll, xw_lr,yw_lr,zw_lr;
  number top_margin, left_margin, right_margin, bottom_margin;
  include_point* current_include;
  number include_xo, include_yo, include_zw;
  bool solvable, margin_spec;

  dx1 = world->xi_lr - world->xi_ul;  /* d1 is the image diagonal ul -> lr */
  dy1 = world->yi_lr - world->yi_ul;
  dx2 = world->xi_ur - world->xi_ll;  /* d2 is the image diagonal ll -> ur */
  dy2 = world->yi_ur - world->yi_ll;
  dx3 = world->xi_ur - world->xi_ul;  /* d3 is the image side ul -> ur */
  dy3 = world->yi_ur - world->yi_ul;
  dx4 = world->xi_ul - world->xi_ll;  /* d4 is the image side ll -> ul */
  dy4 = world->yi_ul - world->yi_ll;
  dx5 = world->xi_ur - world->xi_lr;  /* d5 is the image side lr -> ur */
  dy5 = world->yi_ur - world->yi_lr;

  det = dx2*dy1 - dx1*dy2;

  /* A determinant of 0 is really bad: It means that that diagonals in the
     image are parallel (or of zero length)
  */

  if ((-eps<det) && (det<eps))
    pm_error ("The specified vertices are degenerated.  "
              "Maybe they were given in the wrong order?");

  zw_ul = 2.0*(dx5*dy2-dx2*dy5)/det;
  zw_ur = 2.0*(dx4*dy1-dx1*dy4)/det;
  zw_ll = 2.0*(dx3*dy1-dx1*dy3)/det;
  zw_lr = 2.0*(dx2*dy3-dx3*dy2)/det;

  /* A zero or negative value for some z means that three of the points
     lie on a line in the image or that the four points do not define
     a convex shape.  We have to forbid this in order to prevent divisions
     by zero later on
  */

  if ((zw_ul<eps) || (zw_ur<eps) || (zw_ll<eps) || (zw_lr<eps))
    pm_error ("The specified vertices are degenerated.  "
              "Maybe they were given in the wrong order?");

  xw_ul = world->xi_ul * zw_ul;
  yw_ul = world->yi_ul * zw_ul;
  xw_ur = world->xi_ur * zw_ur;
  yw_ur = world->yi_ur * zw_ur;
  xw_ll = world->xi_ll * zw_ll;
  yw_ll = world->yi_ll * zw_ll;
  xw_lr = world->xi_lr * zw_lr;
  yw_lr = world->yi_lr * zw_lr;

  /* Now we introduce the margin. There are several ways the margin can be
     defined. margin_spec keeps track of wether one of them has yet been
     used. As long as margin_spec==FALSE, the variables top_margin to
     bottom_margin are not initialized! */

  if (options->bools[0]) {      /* --frame_include */
    top_margin = 0.0;
    left_margin = 0.0;
    right_margin = 0.0;
    bottom_margin = 0.0;
    margin_spec = TRUE;
  } else
    margin_spec = FALSE;

  for (current_include = options->include_points; current_include != NULL;
       current_include = current_include->next) {
    solvable = solve_3_linear_equations(&include_xo, &include_yo, &include_zw,
      xw_ul-xw_ur, xw_ul-xw_ll, current_include->xi, xw_ul,
      yw_ul-yw_ur, yw_ul-yw_ll, current_include->yi, yw_ul,
      zw_ul-zw_ur, zw_ul-zw_ll, 1.0, zw_ul);
    if (!solvable)
      pm_error ("The --include point %s lies on the horizon.",
                current_include->specification);
    if (include_zw<0.0)
      pm_error ("The --include point %s lies beyond the horizon.",
                current_include->specification);
    if (margin_spec) {
      top_margin = MAX(top_margin, -include_yo);
      left_margin = MAX(left_margin, -include_xo);
      right_margin = MAX(right_margin, include_xo-1.0);
      bottom_margin = MAX(bottom_margin, include_yo-1.0);
    } else {
      top_margin = -include_yo;
      left_margin = -include_xo;
      right_margin = include_xo-1.0;
      bottom_margin = include_yo-1.0;
      margin_spec = TRUE;
    };
  }

  if (margin_spec) {    /* the margin is there. --top_margin and such can
                           still enlarge it */
    if (options->top_margin_spec)
      top_margin = MAX(top_margin, options->floats[11]);
    if (options->left_margin_spec)
      left_margin = MAX(left_margin, options->floats[13]);
    if (options->right_margin_spec)
      right_margin = MAX(right_margin, options->floats[14]);
    if (options->bottom_margin_spec)
      bottom_margin = MAX(bottom_margin, options->floats[12]);
  } else                /* the margin is not yet there. --top_margin and
                           such can remedy this only if all of them are
                           given */
    if ((options->top_margin_spec) && (options->left_margin_spec) &&
        (options->right_margin_spec) && (options->bottom_margin_spec)) {
      top_margin = options->floats[11];
      left_margin = options->floats[13];
      right_margin = options->floats[14];
      bottom_margin = options->floats[12];
    } else              /* the margin finally is not there */
      pm_error ("No frame specified. "
                "Use --frame_include=yes or --include or --margin.");

  world->xw_ul = xw_ul
    - top_margin * (xw_ll-xw_ul)
    - left_margin * (xw_ur-xw_ul);
  world->yw_ul = yw_ul
    - top_margin * (yw_ll-yw_ul)
    - left_margin * (yw_ur-yw_ul);
  world->zw_ul = zw_ul
    - top_margin * (zw_ll-zw_ul)
    - left_margin * (zw_ur-zw_ul);
  world->xw_ur = xw_ur
    - top_margin * (xw_lr-xw_ur)
    - right_margin * (xw_ul-xw_ur);
  world->yw_ur = yw_ur
    - top_margin * (yw_lr-yw_ur)
    - right_margin * (yw_ul-yw_ur);
  world->zw_ur = zw_ur
    - top_margin * (zw_lr-zw_ur)
    - right_margin * (zw_ul-zw_ur);
  world->xw_ll = xw_ll
    - bottom_margin * (xw_ul-xw_ll)
    - left_margin * (xw_lr-xw_ll);
  world->yw_ll = yw_ll
    - bottom_margin * (yw_ul-yw_ll)
    - left_margin * (yw_lr-yw_ll);
  world->zw_ll = zw_ll
    - bottom_margin * (zw_ul-zw_ll)
    - left_margin * (zw_lr-zw_ll);
  world->xw_lr = xw_lr
    - bottom_margin * (xw_ur-xw_lr)
    - right_margin * (xw_ll-xw_lr);
  world->yw_lr = yw_lr
    - bottom_margin * (yw_ur-yw_lr)
    - right_margin * (yw_ll-yw_lr);
  world->zw_lr = zw_lr
    - bottom_margin * (zw_ur-zw_lr)
    - right_margin * (zw_ll-zw_lr);

  /* Again we have to forbid nonpositive z */

  if ((world->zw_ul<eps) || (world->zw_ur<eps) ||
       (world->zw_ll<eps) || (world->zw_lr<eps))
    pm_error ("The specified margin is too large.");

}



static int diff (int const a, int const b)
{
  return MAX (b-a, a-b);
}



static number norm_vector (number const x1, number const y1, number const z1,
                           number const x2, number const y2, number const z2)
/*----------------------------------------------------------------------------
  Two 3D vertices p1 and p2 are given by their coordinates.
  A linear movement from p1 to p2, parameterized by the interval [0,1],
  is projected to the input image. The function returns the norm of
  the derivative of this overall movement at time 0, that is at p1.
  The norm uses the max metric.
-----------------------------------------------------------------------------*/
{
  number dx,dy;

  dx = (x2-x1)/z1 - (z2-z1)*x1/(z1*z1);
  dy = (y2-y1)/z1 - (z2-z1)*y1/(z1*z1);

  return MAX (fabs(dx), fabs(dy));
}



static number norm_side (number const x1, number const y1, number const z1,
                         number const x2, number const y2, number const z2)
/*----------------------------------------------------------------------------
  This is similar to norm_vector. But now the norm of the derivative
  is computed at both endpoints of the movement and the maximum is
  returned.
  
  Why do we do this? The return value n is in fact the maximum of the
  norm of the derivative ALONG the movement. So we know that if we
  divide the movement into at least n steps, we will encounter every
  x- and every y-coordinate of the input image between the two points.
  This is our notion of losslessness with --detail=1.
-----------------------------------------------------------------------------*/
{
  return MAX (norm_vector(x1,y1,z1,x2,y2,z2),
              norm_vector(x2,y2,z2,x1,y1,z1));
}



static void determine_output_width_and_height (const world_data *const world,
                                               option *const options)
{
  number du,dv;
  int xsteps,ysteps,width,height;

  /* Determine the number of steps for losslessness */

  du = MAX (norm_side(world->xw_ul, world->yw_ul, world->zw_ul,
                      world->xw_ur, world->yw_ur, world->zw_ur),
            norm_side(world->xw_ll, world->yw_ll, world->zw_ll,
                      world->xw_lr, world->yw_lr, world->zw_lr));
  dv = MAX (norm_side(world->xw_ul, world->yw_ul, world->zw_ul,
                      world->xw_ll, world->yw_ll, world->zw_ll),
            norm_side(world->xw_ur, world->yw_ur, world->zw_ur,
                      world->xw_lr, world->yw_lr, world->zw_lr));
  xsteps = ceil(du*options->floats[8]);  /* option->floats[8] is --detail */
  ysteps = ceil(dv*options->floats[8]);

  /* Turn the numbers of steps into width and height */

  switch (options->enums[1]) {  /* --output_system */
  case lattice:
    width = xsteps;
    height = ysteps;
    break;
  case pixel_s:
    width = xsteps+1;
    height = ysteps+1;
    break;
  };

  /* Correct the proportion of width and height by increasing one of them */

  switch (options->enums[4]) {  /* --proportion */
  case free_:   /* no correction at all */
    break;
  case fixed:   /* correction now */
    /* options->floats[9] is --ratio */
    width = MAX (floor(0.5 + ((number)height) * options->floats[9]),
                 width);
    height = MAX (floor(0.5 + ((number)width) / options->floats[9]),
                  height);
    break;
  };

  /* Override anything we have by the specified width and height */

  if (!(options->width_spec))
    options->width=width;
  if (!(options->height_spec))
    options->height=height;
}



static void determine_coefficients_lattice (world_data *const world,
                                            const option *const options)
/*----------------------------------------------------------------------------
  Constructs ax,...,cz from xw_ul,...,zw_lr
     
  The calculations assume lattice coordinates, that is the point ul
  corresponds to the upper left corner of the pixel (0,0) and the
  point lr corresponds to the lower left corner of the pixel
  (width-1,height-1)
-----------------------------------------------------------------------------*/
{
  number width,height;

  width = (number) options->width;
  height = (number) options->height;

  world->bx = (world->xw_ur - world->xw_ul)/width;
  world->cx = (world->xw_ll - world->xw_ul)/height;
  world->by = (world->yw_ur - world->yw_ul)/width;
  world->cy = (world->yw_ll - world->yw_ul)/height;
  world->bz = (world->zw_ur - world->zw_ul)/width;
  world->cz = (world->zw_ll - world->zw_ul)/height;

  world->ax = world->xw_ul + world->bx/2.0 + world->cx/2.0;
  world->ay = world->yw_ul + world->by/2.0 + world->cy/2.0;
  world->az = world->zw_ul + world->bz/2.0 + world->cz/2.0;
}



static void determine_coefficients_pixel (world_data *const world,
                                          const option *const options)
/*----------------------------------------------------------------------------
  Constructs ax,...,cz from xw_ul,...,zw_lr
     
  The calculations assume pixel coordinates, that is the point ul
  corresponds to the center of the pixel (0,0) and the point lr
  corresponds to the center of the pixel (width-1,height-1)
-----------------------------------------------------------------------------*/
{
  number width,height;

  if (options->width == 1)
    pm_error ("You specified 'pixel' as output coordinate model "
              "and a width of 1.  These things don't mix.");
  if (options->height == 1)
    pm_error ("You specified 'pixel' as output coordinate model "
              "and a height of 1.  These things don't mix.");

  width = (number) (options->width-1);
  height = (number) (options->height-1);

  world->bx = (world->xw_ur - world->xw_ul)/width;
  world->cx = (world->xw_ll - world->xw_ul)/height;
  world->by = (world->yw_ur - world->yw_ul)/width;
  world->cy = (world->yw_ll - world->yw_ul)/height;
  world->bz = (world->zw_ur - world->zw_ul)/width;
  world->cz = (world->zw_ll - world->zw_ul)/height;

  world->ax = world->xw_ul;
  world->ay = world->yw_ul;
  world->az = world->zw_ul;
}



static void outpixel_to_inpixel (int const xo, int const yo, 
                                 number* const xi, number* const yi,
                                 const world_data *const world)
{
  number xof,yof,xw,yw,zw;

  xof = (number) xo;
  yof = (number) yo;
  xw = world->ax + world->bx*xof + world->cx*yof;
  yw = world->ay + world->by*xof + world->cy*yof;
  zw = world->az + world->bz*xof + world->cz*yof;
  *xi = xw/zw;
  *yi = yw/zw;
}

static int outpixel_to_iny (int xo, int yo, const world_data *const world)
{
  number xi,yi;

  outpixel_to_inpixel (xo,yo,&xi,&yi,world);

  return (int) yi;
}

static int clean_y (int const y,  const struct pam *const outpam)
{
  return MIN(MAX(0, y), outpam->height-1);
}

static void
init_buffer(buffer *           const bufferP,
            const world_data * const worldP,
            const option *     const optionsP,
            const struct pam * const inpamP,
            const struct pam * const outpamP) {

    unsigned int yul, yur, yll, ylr, y_min;
    unsigned int num_rows;

    yul = outpixel_to_iny(0, 0, worldP);
    yur = outpixel_to_iny(outpamP->width-1, 0, worldP);
    yll = outpixel_to_iny(0, outpamP->height-1, worldP);
    ylr = outpixel_to_iny(outpamP->width-1, outpamP->height-1, worldP);
    
    y_min = MIN(MIN(yul, yur), MIN(yll, ylr));
    num_rows = MAX(MAX(diff(yul, yur),
                       diff(yll, ylr)),
                   MAX(diff(clean_y(yul, outpamP), clean_y(y_min, outpamP)),
                       diff(clean_y(yur, outpamP), clean_y(y_min, outpamP))))
        + 2;
    switch (optionsP->enums[3]) {  /* --interpolation */
    case interp_nearest:
        break;
    case interp_linear:
        num_rows += 1;
        break;
    }
    if (num_rows > inpamP->height)
        num_rows = inpamP->height;

    MALLOCARRAY_SAFE(bufferP->rows, num_rows);
    bufferP->num_rows = num_rows;
    bufferP->last_logical = 0;
    bufferP->last_physical = 0;
    {
        unsigned int row;
        for (row = 0; row < num_rows; ++row) {
            bufferP->rows[row] = pnm_allocpamrow(inpamP);
            pnm_readpamrow(inpamP, bufferP->rows[row]);
            ++bufferP->last_logical;
            ++bufferP->last_physical;
        }
    }
    bufferP->inpamP = inpamP;
}



static tuple *
read_buffer(buffer *     const bufferP,
            unsigned int const logical_y) {

    unsigned int y;
    
    while (logical_y > bufferP->last_logical) {
        ++bufferP->last_physical;
        if (bufferP->last_physical == bufferP->num_rows)
            bufferP->last_physical = 0;
        pnm_readpamrow(bufferP->inpamP, bufferP->rows[bufferP->last_physical]);
        ++bufferP->last_logical;
    }
    
    y = logical_y - bufferP->last_logical + bufferP->last_physical;
    if (y < 0)
        y += bufferP->num_rows;

    return bufferP->rows[y];
}



static void
term_buffer(buffer * const bufferP) {

    unsigned int i;

    /* We have to read through the end of the input image even if we
       didn't use all the rows, because if the input is a pipe, the
       guy writing into the pipe may require all the data to go
       through.
    */

    while (bufferP->last_logical < bufferP->inpamP->height-1) {
        pnm_readpamrow(bufferP->inpamP, bufferP->rows[0]);
        ++bufferP->last_logical;
    }

    for (i = 0; i < bufferP->num_rows; ++i)
        pnm_freepamrow(bufferP->rows[i]);
    
    free(bufferP->rows);
}




/* The following variables are global for speed reasons.
   In this way they do not have to be passed to each call of the
   interpolation functions

   Think of this as Sch&ouml;nfinkeling (aka Currying).
*/

static tuple background;
static buffer* indata;
static int width,height,depth;

static void init_interpolation_global_vars (buffer* const inbuffer,
                                            const struct pam *const inpam,
                                            const struct pam *const outpam)
{
  pnm_createBlackTuple (outpam, &background);
  indata = inbuffer;
  width = inpam->width;
  height = inpam->height;
  depth = outpam->depth;
}



static void clean_interpolation_global_vars (void)
{
  free (background);
}



/* These functions perform the interpolation */

static tuple attempt_read (int const x, int const y)
{
  if ((x<0) || (x>=width) || (y<0) || (y>=height))
    return background;
  else
    return read_buffer(indata, y)[x];
}



static void take_nearest (tuple const dest, number const x, number const y)
{
  int xx,yy,entry;
  tuple p;

  xx = (int)floor(x+0.5);
  yy = (int)floor(y+0.5);
  p = attempt_read (xx, yy);
  for (entry=0; entry<depth; entry++) {
    dest[entry]=p[entry];
  }
}



static void linear_interpolation (tuple const dest, 
                                  number const x, number const y)
{
  int xx,yy,entry;
  number xf,yf,a,b,c,d;
  tuple p1,p2,p3,p4;

  xx = (int)floor(x);
  yy = (int)floor(y);
  xf = x-(number)xx;
  yf = y-(number)yy;
  p1 = attempt_read (xx, yy);
  p2 = attempt_read (xx+1, yy);
  p3 = attempt_read (xx, yy+1);
  p4 = attempt_read (xx+1, yy+1);
  a = (1.0-xf)*(1.0-yf);
  b = xf*(1.0-yf);
  c = (1.0-xf)*yf;
  d = xf*yf;
  for (entry=0; entry<depth; entry++) {
    dest[entry]=(sample) floor(
      a*((number) p1[entry]) +
      b*((number) p2[entry]) +
      c*((number) p3[entry]) +
      d*((number) p4[entry]) +
      0.5);
  }
}



static void
perspective(struct pam * const outpamP,
            world_data * const worldP,
            interpolateFn *    interpolater) {

    tuple * outrow;
    unsigned int row;

    outrow = pnm_allocpamrow(outpamP);

    for (row = 0; row < outpamP->height; ++row) {
        unsigned int col;

        for (col = 0; col < outpamP->width; ++col) {
            number xi,yi;
            outpixel_to_inpixel(col, row, &xi, &yi, worldP);
            interpolater(outrow[col], xi, yi);
        }
        pnm_writepamrow(outpamP, outrow);
    }
    pnm_freepamrow(outrow);
}



int
main(int argc, char* argv[]) {

    FILE * ifP;
    struct pam inpam;
    buffer inbuffer;
    struct pam outpam;
    option options;
    world_data world;
    interpolateFn * interpolater;

    pnm_init(&argc, argv);

    set_command_line_defaults(&options);

    parse_command_line(argc, argv, &options);

    ifP = pm_openr(options.infilename);

    pnm_readpaminit(ifP, &inpam, PAM_STRUCT_SIZE(tuple_type));

    /* Our own initializations */

    init_world(&options, &inpam, &world);
    determine_world_parallelogram(&world, &options);
    determine_output_width_and_height(&world, &options);
    switch (options.enums[1]) {   /* --output_system */
    case lattice:
        determine_coefficients_lattice(&world, &options);
        break;
    case pixel_s:
        determine_coefficients_pixel(&world, &options);
        break;
    };

    outpam.size             = sizeof(outpam);
    outpam.len              = PAM_STRUCT_SIZE(bytes_per_sample);
    outpam.file             = stdout;
    outpam.format           = inpam.format;
    outpam.plainformat      = FALSE;
    outpam.height           = options.height;
    outpam.width            = options.width;
    outpam.depth            = inpam.depth;
    outpam.maxval           = inpam.maxval;
    outpam.bytes_per_sample = inpam.bytes_per_sample;
    pnm_writepaminit(&outpam);

    /* Initialize the actual calculation */

    init_buffer(&inbuffer, &world, &options, &inpam, &outpam);
    init_interpolation_global_vars(&inbuffer, &inpam, &outpam);
    switch (options.enums[3]) {   /* --interpolation */
    case interp_nearest:
        interpolater = take_nearest;
        break;
    case interp_linear:
        interpolater = linear_interpolation;
        break;
    };

    perspective(&outpam, &world, interpolater);

    clean_interpolation_global_vars();
    term_buffer(&inbuffer);
    free_option(&options);
    pm_close(ifP);
    pm_close(stdout);

    return 0;
}