summaryrefslogtreecommitdiff
blob: ee2c69b42e17e4d73161d22f5d267ce2513f49ee (plain)
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
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
/* Copyright (C) 2001-2019 Artifex Software, Inc.
   All Rights Reserved.

   This software is provided AS-IS with no warranty, either express or
   implied.

   This software is distributed under license and may not be copied,
   modified or distributed except as expressly authorized under the terms
   of the license contained in the file LICENSE in this distribution.

   Refer to licensing information at http://www.artifex.com or contact
   Artifex Software, Inc.,  1305 Grant Avenue - Suite 200, Novato,
   CA 94945, U.S.A., +1(415)492-9861, for further information.
*/


/* General mono-component image rendering */
#include "gx.h"
#include "memory_.h"
#include "gpcheck.h"
#include "gserrors.h"
#include "gxfixed.h"
#include "gxarith.h"
#include "gxmatrix.h"
#include "gsccolor.h"
#include "gspaint.h"
#include "gsutil.h"
#include "gxdevice.h"
#include "gxcmap.h"
#include "gxdcolor.h"
#include "gxgstate.h"
#include "gxdevmem.h"
#include "gdevmem.h"            /* for mem_mono_device */
#include "gxcpath.h"
#include "gximage.h"
#include "gzht.h"
#include "gsicc.h"
#include "gsicc_cache.h"
#include "gsicc_cms.h"
#include "gxcie.h"
#include "gscie.h"
#include "gxht_thresh.h"
#include "gxdda.h"
#include "gxdevsop.h"
#ifdef WITH_CAL
#include "cal.h"
#endif

#define fastfloor(x) (((int)(x)) - (((x)<0) && ((x) != (float)(int)(x))))

/* Enable the following define to perform a little extra work to stop
 * spurious valgrind errors. The code should perform perfectly even without
 * this enabled, but enabling it makes debugging much easier.
 */
/* #define PACIFY_VALGRIND */

/* ------ Strategy procedure ------ */

/* Check the prototype. */
iclass_proc(gs_image_class_3_mono);

static irender_proc(image_render_mono);
#ifndef WITH_CAL
static irender_proc(image_render_mono_ht);
#else
static irender_proc(image_render_mono_ht_cal);
static int image_render_mono_ht_cal_skip_line(gx_image_enum *penum,
					      gx_device *dev);

static void
halftone_callback(cal_halftone_data_t *ht, void *arg)
{
    gx_device *dev = arg;
    gx_color_index dev_white = gx_device_white(dev);
    gx_color_index dev_black = gx_device_black(dev);

    if (dev->is_planar) {
        (*dev_proc(dev, copy_planes)) (dev, ht->data, ht->x + (ht->offset_x<<3), ht->raster,
            gx_no_bitmap_id, ht->x, ht->y, ht->w, ht->h,
            ht->plane_raster);
    } else {
        (*dev_proc(dev, copy_mono)) (dev, ht->data, ht->x + (ht->offset_x<<3), ht->raster,
            gx_no_bitmap_id, ht->x, ht->y, ht->w, ht->h, dev_white,
            dev_black);
    }
}

static cal_halftone*
halftone_init(gx_image_enum *penum)
{
    cal_halftone *cal_ht = NULL;
    gx_dda_fixed dda_ht;
    int k;
    gx_ht_order *d_order;
    int code;
    byte *cache = (penum->color_cache != NULL ? penum->color_cache->device_contone : NULL);
    cal_matrix matrix;
    int clip_x, clip_y;

    if (!gx_device_must_halftone(penum->dev))
        return NULL;

    if (penum->pgs == NULL || penum->pgs->dev_ht == NULL)
        return NULL;
    dda_ht = penum->dda.pixel0.x;
    if (penum->dxx > 0)
        dda_translate(dda_ht, -fixed_epsilon);
    matrix.xx = penum->matrix.xx;
    matrix.xy = penum->matrix.xy;
    matrix.yx = penum->matrix.yx;
    matrix.yy = penum->matrix.yy;
    matrix.tx = penum->matrix.tx + matrix.xx * penum->rect.x + matrix.yx * penum->rect.y;
    matrix.ty = penum->matrix.ty + matrix.xy * penum->rect.x + matrix.yy * penum->rect.y;

    clip_x = fixed2int(penum->clip_outer.p.x);
    clip_y = fixed2int(penum->clip_outer.p.y);
    cal_ht = cal_halftone_init(penum->memory->gs_lib_ctx->core->cal_ctx,
                               penum->memory->non_gc_memory,
                               penum->rect.w,
                               penum->rect.h,
                               &matrix,
                               penum->dev->color_info.num_components,
                               cache,
                               clip_x,
                               clip_y,
                               fixed2int_ceiling(penum->clip_outer.q.x) - clip_x,
                               fixed2int_ceiling(penum->clip_outer.q.y) - clip_y,
                               penum->adjust);
    if (cal_ht == NULL)
        goto fail;

    for (k = 0; k < penum->pgs->dev_ht->num_comp; k++) {
        d_order = &(penum->pgs->dev_ht->components[k].corder);
        code = gx_ht_construct_threshold(d_order, penum->dev, penum->pgs, k);
        if (code < 0)
            goto fail;
        if (cal_halftone_add_screen(penum->memory->gs_lib_ctx->core->cal_ctx,
                                    penum->memory->non_gc_memory,
                                    cal_ht,
                                    penum->pgs->dev_ht->components[k].corder.threshold_inverted,
                                    penum->pgs->dev_ht->components[k].corder.width,
                                    penum->pgs->dev_ht->components[k].corder.full_height,
                                    -penum->pgs->screen_phase[k].x,
                                    -penum->pgs->screen_phase[k].y,
                                    penum->pgs->dev_ht->components[k].corder.threshold) < 0)
            goto fail;
    }

    return cal_ht;

fail:
    cal_halftone_fin(cal_ht, penum->memory->non_gc_memory);
    return NULL;
}
#endif

int
gs_image_class_3_mono(gx_image_enum * penum, irender_proc_t *render_fn)
{
#if USE_FAST_HT_CODE
    bool use_fast_code = true;
#else
    bool use_fast_code = false;
#endif
    int code = 0;
    /* Set up the link now */
    const gs_color_space *pcs;
    gsicc_rendering_param_t rendering_params;
    cmm_dev_profile_t *dev_profile;
    bool dev_color_ok = false;
    bool is_planar_dev = penum->dev->is_planar;

    if (penum->spp == 1) {
        /* At this point in time, only use the ht approach if our device
           uses halftoning, and our source image is a reasonable size.  We
           probably don't want to do this if we have a bunch of tiny little
           images.  Then the rect fill approach is probably not all that bad.
           Also for now avoid images that include a type3 image mask.  Due
           to the limited precision and mismatch of the stepping space in which
           the interpolations occur this can cause a minor mismatch at large
           scalings */

        /* Allow this for CMYK planar and mono binary halftoned devices */
        dev_color_ok = ((penum->dev->color_info.num_components == 1 &&
                         penum->dev->color_info.depth == 1) ||
#if 0
                         /* Don't allow CMYK Planar devices just yet */
                         0);
#else
                        (penum->dev->color_info.num_components == 4 &&
                         penum->dev->color_info.depth == 4 && is_planar_dev));
#endif

        if (use_fast_code && penum->pcs != NULL && dev_color_ok &&
            penum->bps == 8 && (penum->posture == image_portrait
            || penum->posture == image_landscape) &&
            penum->image_parent_type == gs_image_type1 &&
            gx_transfer_is_monotonic(penum->pgs, 0)) {
            penum->icc_setup.need_decode = false;
            /* Check if we need to do any decoding.  */
            if ( penum->map[0].decoding != sd_none ) {
                if (!(penum->map[0].decoding == sd_compute
                     && penum->map[0].decode_factor == 1.0 &&
                        penum->map[0].decode_lookup[0] == 0.0)) {
                    penum->icc_setup.need_decode = true;
                }
            }
            code = dev_proc(penum->dev, get_profile)(penum->dev, &dev_profile);
            if (code < 0)
                return code;

            /* Define the rendering intents */
            rendering_params.black_point_comp = penum->pgs->blackptcomp;
            rendering_params.graphics_type_tag = GS_IMAGE_TAG;
            rendering_params.override_icc = false;
            rendering_params.preserve_black = gsBKPRESNOTSPECIFIED;
            rendering_params.rendering_intent = penum->pgs->renderingintent;
            rendering_params.cmm = gsCMM_DEFAULT;
            if (gs_color_space_get_index(penum->pcs) ==
                gs_color_space_index_Indexed) {
                pcs = penum->pcs->base_space;
            } else {
                pcs = penum->pcs;
            }
            if (gs_color_space_is_PSCIE(pcs) && pcs->icc_equivalent != NULL) {
                pcs = pcs->icc_equivalent;
            }

            /* The code below falls over if cmm->icc_profile_data is NULL.
             * For now, just drop out. Michael can review this when he
             * returns. */
            if (pcs->cmm_icc_profile_data == NULL)
                goto not_fast_halftoning;

            penum->icc_setup.is_lab = pcs->cmm_icc_profile_data->islab;
            penum->icc_setup.must_halftone = gx_device_must_halftone(penum->dev);
            /* The effective transfer is built into the threshold array */
            penum->icc_setup.has_transfer = false;
            if (penum->icc_setup.is_lab)
                penum->icc_setup.need_decode = false;
            if (penum->icc_link == NULL) {
                penum->icc_link = gsicc_get_link(penum->pgs, penum->dev, pcs, NULL,
                    &rendering_params, penum->memory);
            }
            /* PS CIE color spaces may have addition decoding that needs to
               be performed to ensure that the range of 0 to 1 is provided
               to the CMM since ICC profiles are restricted to that range
               but the PS color spaces are not. */
            penum->use_cie_range = false;
            if (gs_color_space_is_PSCIE(penum->pcs) &&
                penum->pcs->icc_equivalent != NULL) {
                /* We have a PS CIE space.  Check the range */
                if ( !check_cie_range(penum->pcs) ) {
                    /* It is not 0 to 1.  We will be doing decode
                       plus an additional linear adjustment */
                    penum->use_cie_range = (get_cie_range(penum->pcs) != NULL);
                }
            }
            /* If the image has more than 256 pixels then go ahead and
               precompute the contone device colors for all of our 256 source
               values.  We should not be taking this path for cases where
               we have lots of tiny little images.  Mark those that are
               transparent or masked also at this time.  Since halftoning will
               be done via thresholding we will keep clues in continuous tone */
            code = image_init_color_cache(penum, penum->bps, penum->spp);
            if (code >= 0) {
#ifdef WITH_CAL
                penum->cal_ht = halftone_init(penum);
                if (penum->cal_ht != NULL)
                {
                    penum->skip_next_line = image_render_mono_ht_cal_skip_line;
                    *render_fn = &image_render_mono_ht_cal;
                    return code;
                }
#else
                code = gxht_thresh_image_init(penum);
                if (code >= 0) {
                    *render_fn = &image_render_mono_ht;
                    return code;
                }
#endif
            }
        }
not_fast_halftoning:
        /*
         * Use the slow loop for imagemask with a halftone or a non-default
         * logical operation.
         */
        penum->slow_loop =
            (penum->masked && !color_is_pure(penum->icolor0)) ||
            penum->use_rop;
        /* We can bypass X clipping for portrait mono-component images. */
        if (!(penum->slow_loop || penum->posture != image_portrait))
            penum->clip_image &= ~(image_clip_xmin | image_clip_xmax);
        if_debug0m('b', penum->memory, "[b]render=mono\n");
        /* Precompute values needed for rasterizing. */
        penum->dxx =
            float2fixed(penum->matrix.xx + fixed2float(fixed_epsilon) / 2);
        /*
         * Scale the mask colors to match the scaling of each sample to a
         * full byte.  Also, if black or white is transparent, reset icolor0
         * or icolor1, which are used directly in the fast case loop.
         */
        if (penum->use_mask_color) {
            gx_image_scale_mask_colors(penum, 0);
            if (penum->mask_color.values[0] <= 0)
                color_set_null(penum->icolor0);
            if (penum->mask_color.values[1] >= 255)
                color_set_null(penum->icolor1);
        }
        /* Reset the clues here, rather than in image_render_mono as
         * previously. Even doing so this often may be overzealous. */
        image_init_clues(penum, penum->bps, penum->spp);
        *render_fn = &image_render_mono;
    }
    return 0;
}

#define USE_SET_GRAY_FUNCTION 0
#if USE_SET_GRAY_FUNCTION
/* Temporary function to make it easier to debug the uber-macro below */
static inline int
image_set_gray(byte sample_value, const bool masked, uint mask_base,
                uint mask_limit, gx_device_color **ppdevc, gs_client_color *cc,
                const gs_color_space *pcs, const gs_gstate *pgs,
                gx_device * dev, gs_color_select_t gs_color_select_source,
                gx_image_enum * penum)
{
   cs_proc_remap_color((*remap_color));
   int code;
   gx_device_color *pdevc;
   pdevc = *ppdevc = &penum->clues[sample_value].dev_color;

   if (!color_is_set(pdevc)) {
       if ((uint)(sample_value - mask_base) < mask_limit) {
           color_set_null(pdevc);
       } else {
            switch ( penum->map[0].decoding )
            {
            case sd_none:
            cc->paint.values[0] = (sample_value) * (1.0f / 255.0f);  /* faster than / */
            break;
            case sd_lookup:     /* <= 4 significant bits */
            cc->paint.values[0] =
              penum->map[0].decode_lookup[(sample_value) >> 4];
            break;
            case sd_compute:
            cc->paint.values[0] =
              penum->map[0].decode_base + (sample_value) * penum->map[0].decode_factor;
            }
            remap_color = pcs->type->remap_color;
            code = (*remap_color)(cc, pcs, pdevc, pgs, dev, gs_color_select_source);
            return(code);
        }
    } else if (!color_is_pure(pdevc)) {
        code = gx_color_load_select(pdevc, pgs, dev, gs_color_select_source);
        if (code < 0)
            return(code);
    }
    return(0);
}
#endif

/*
 * Rendering procedure for general mono-component images, dealing with
 * multiple bit-per-sample images, general transformations, arbitrary
 * single-component color spaces (DeviceGray, DevicePixel, CIEBasedA,
 * Separation, Indexed), and color masking. This procedure handles a
 * single scan line.
 */
static int
image_render_mono(gx_image_enum * penum, const byte * buffer, int data_x,
                  uint w, int h, gx_device * dev)
{
    const gs_gstate *pgs = penum->pgs;
    gs_logical_operation_t lop = penum->log_op;
    const bool masked = penum->masked;
    const gs_color_space *pcs = NULL;   /* only set for non-masks */
    cs_proc_remap_color((*remap_color)) = NULL; /* ditto */
    gs_client_color cc;
    gx_device_color *pdevc = penum->icolor1;    /* color for masking */
    uint mask_base =            /* : 0 to pacify Valgrind */
        (penum->use_mask_color ? penum->mask_color.values[0] : 0);
    uint mask_limit =
        (penum->use_mask_color ?
         penum->mask_color.values[1] - mask_base + 1 : 0);
/*
 * Free variables of IMAGE_SET_GRAY:
 *   Read: penum, pgs, dev, mask_base, mask_limit
 *   Set: pdevc, code, cc
 */
#define IMAGE_SET_GRAY(sample_value)\
  BEGIN\
    pdevc = &penum->clues[sample_value].dev_color;\
    if (!color_is_set(pdevc)) {\
        if ((uint)(sample_value - mask_base) < mask_limit)\
            color_set_null(pdevc);\
        else {\
            decode_sample(sample_value, cc, 0);\
            code = (*remap_color)(&cc, pcs, pdevc, pgs, dev, gs_color_select_source);\
            if (code < 0)\
                goto err;\
        }\
    } else if (!color_is_pure(pdevc)) {\
        code = gx_color_load_select(pdevc, pgs, dev, gs_color_select_source);\
        if (code < 0)\
            goto err;\
    }\
  END
    gx_dda_fixed_point next;    /* (y not used in fast loop) */
    gx_dda_step_fixed dxx2, dxx3, dxx4;         /* (not used in all loops) */
    const byte *psrc_initial = buffer + data_x;
    const byte *psrc = psrc_initial;
    const byte *rsrc = psrc;    /* psrc at start of run */
    const byte *endp = psrc + w;
    const byte *stop = endp;
    fixed xrun;                 /* x at start of run */
    byte run;           /* run value */
    int htrun = (masked ? 255 : -2);            /* halftone run value */
    int code = 0;

    if (h == 0)
        return 0;
    /*
     * Make sure the cache setup matches the graphics state.  Also determine
     * whether all tiles fit in the cache.  We may bypass the latter check
     * for masked images with a pure color.
     */

    next = penum->dda.pixel0;
    xrun = dda_current(next.x);
    if (!masked) {
        pcs = penum->pcs;       /* (may not be set for masks) */
        remap_color = pcs->type->remap_color;
    }
    run = *psrc;
    /* Find the last transition in the input. */
    if (masked &&
        (penum->posture != image_portrait) &&
        (penum->posture != image_landscape)) {
        /* No need to calculate stop */
    } else {
        byte last = stop[-1];

        while (stop > psrc && stop[-1] == last)
            --stop;
    }
    if (penum->slow_loop || penum->posture != image_portrait) {

        /**************************************************************
         * Slow case (skewed, rotated, or imagemask with a halftone). *
         **************************************************************/

        fixed yrun;
        const fixed pdyx = dda_current(penum->dda.row.x) - penum->cur.x;
        const fixed pdyy = dda_current(penum->dda.row.y) - penum->cur.y;
        dev_proc_fill_parallelogram((*fill_pgram)) =
            dev_proc(dev, fill_parallelogram);

#define xl dda_current(next.x)
#define ytf dda_current(next.y)
        yrun = ytf;
        if (masked) {

            /**********************
             * Slow case, masked. *
             **********************/

            pdevc = penum->icolor1;
            code = gx_color_load(pdevc, pgs, dev);
            if (code < 0)
                return code;
            if ((stop <= psrc) && (penum->adjust == 0) &&
                ((penum->posture == image_portrait) ||
                 (penum->posture == image_landscape)))
                goto last;
            if (penum->posture == image_portrait) {

                /********************************
                 * Slow case, masked, portrait. *
                 ********************************/

                /*
                 * We don't have to worry about the Y DDA, and the fill
                 * regions are rectangles.  Calculate multiples of the DDA
                 * step.
                 */
                fixed ax =
                    (penum->matrix.xx < 0 ? -penum->adjust : penum->adjust);
                fixed ay =
                    (pdyy < 0 ? -penum->adjust : penum->adjust);
                fixed dyy = pdyy + (ay << 1);

                yrun -= ay;
                dda_translate(next.x, -ax);
                ax <<= 1;
                dxx2 = next.x.step;
                dda_step_add(dxx2, next.x.step);
                dxx3 = dxx2;
                dda_step_add(dxx3, next.x.step);
                dxx4 = dxx3;
                dda_step_add(dxx4, next.x.step);
                for (;;) {      /* Skip a run of zeros. */
                    while (!psrc[0])
                        if (psrc + 4 <= endp) {
                            /* We can use fast skipping */
                            if (!psrc[1]) {
                                if (!psrc[2]) {
                                    if (!psrc[3]) {
                                        psrc += 4;
                                        dda_state_next(next.x.state, dxx4);
                                        if (psrc >= endp)
                                            break;
                                        continue;
                                    }
                                    psrc += 3;
                                    dda_state_next(next.x.state, dxx3);
                                    break;
                                }
                                psrc += 2;
                                dda_state_next(next.x.state, dxx2);
                                break;
                            } else {
                                ++psrc;
                                dda_next(next.x);
                                break;
                            }
                        } else {
                            /* We're too close to the end - skip 1 at a time */
                            while (!psrc[0]) {
                                ++psrc;
                                dda_next(next.x);
                                if (psrc >= endp)
                                    break;
                            }
                            if (psrc >= endp)
                                break;
                        }
                    xrun = xl;
                    if (psrc >= stop)
                        break;
                    for (; psrc < endp && *psrc; ++psrc)
                        dda_next(next.x);
                    code = (*fill_pgram)(dev, xrun, yrun,
                                         xl - xrun + ax, fixed_0, fixed_0, dyy,
                                         pdevc, lop);
                    if (code < 0)
                        goto err;
                    rsrc = psrc;
                    if (psrc >= stop)
                        break;
                }

            } else if (penum->posture == image_landscape) {

                /*********************************
                 * Slow case, masked, landscape. *
                 *********************************/

                /*
                 * We don't have to worry about the X DDA.  However, we do
                 * have to take adjustment into account.  We don't bother to
                 * optimize this as heavily as the portrait case.
                 */
                fixed ax =
                    (pdyx < 0 ? -penum->adjust : penum->adjust);
                fixed dyx = pdyx + (ax << 1);
                fixed ay =
                    (penum->matrix.xy < 0 ? -penum->adjust : penum->adjust);

                xrun -= ax;
                dda_translate(next.y, -ay);
                ay <<= 1;
                for (;;) {
                    for (; psrc < endp && !*psrc; ++psrc)
                        dda_next(next.y);
                    yrun = ytf;
                    if (psrc >= stop)
                        break;
                    for (; psrc < endp && *psrc; ++psrc)
                        dda_next(next.y);
                    code = (*fill_pgram)(dev, xrun, yrun, fixed_0,
                                         ytf - yrun + ay, dyx, fixed_0,
                                         pdevc, lop);
                    if (code < 0)
                        goto err;
                    rsrc = psrc;
                    if (psrc >= stop)
                        break;
                }

            } else {

                /**************************************
                 * Slow case, masked, not orthogonal. *
                 **************************************/
                /* FIXME: RJW: This code doesn't do adjustment. Should it?
                 * In the grand scheme of things it almost certainly doesn't
                 * matter (as adjust should only be used when plotting chars,
                 * and we use freetype now), but we record the fact that this
                 * may be a defect here. */
                /* Previous code here used to skip blocks of matching pixels
                 * and plot them all in one go. We can't do that, as it can
                 * cause rounding errors and mismatches with the image pixels
                 * that will be plotted after us. */
                stop = endp;
                for (;;) {
                    /* skip forward until we find a 1 bit */
                    for (; psrc < stop && !*psrc; ++psrc) {
                        dda_next(next.x);
                        dda_next(next.y);
                    }
                    if (psrc >= endp) /* Note, endp NOT stop! */
                        break;
                    /* Then draw the pgram and step forward until we find a
                     * 0 bit. */
                    do {
                        yrun = ytf;
                        xrun = xl;
                        dda_next(next.x);
                        dda_next(next.y);
                        code = (*fill_pgram)(dev, xrun, yrun, xl - xrun,
                                             ytf - yrun, pdyx, pdyy, pdevc, lop);
                        if (code < 0)
                            goto err;
                        psrc++;
                        rsrc = psrc;
                        if (psrc >= stop)
                            break;
                    } while (*psrc);
                }

            }

        } else if (penum->posture == image_portrait) {
            /**************************************
             * Slow case, not masked, portrait. *
             **************************************/
            dev_proc_fill_rectangle((*fill_proc)) =
                dev_proc(dev, fill_rectangle);
            int iy = fixed2int_pixround(yrun);
            int ih = fixed2int_pixround(yrun + pdyy) - iy;
            if (ih < 0)
                iy += ih, ih = -ih;

            /* In this case, we can fill runs quickly. */
            /****** DOESN'T DO ADJUSTMENT ******/
            if (stop <= psrc)
                goto last;
            for (;;) {
                byte c = *psrc++;
                if (c != run) {
                    int ix = fixed2int_pixround(xrun);
                    int iw = fixed2int_pixround(xl) - ix;
                    if (iw < 0)
                        ix += iw, iw = -iw;
                    switch (run)
                    {
                    case 0:
                        if (!color_is_pure(penum->icolor0))
                            goto ht_port;
                        code = (*fill_proc) (dev, ix, iy, iw, ih,
                                             penum->icolor0->colors.pure);
                        break;
                    case 0xff:
                        if (!color_is_pure(penum->icolor1))
                            goto ht_port;
                        code = (*fill_proc) (dev, ix, iy, iw, ih,
                                             penum->icolor1->colors.pure);
                        break;
                    default:
                        ht_port:
                        if (run != htrun) {
                            htrun = run;
#if USE_SET_GRAY_FUNCTION
                            code = image_set_gray(run,masked,mask_base,mask_limit,&pdevc,
                                    &cc,pcs,pgs,dev,gs_color_select_source,penum);
                            if (code < 0)
                                goto err;
#else
                            IMAGE_SET_GRAY(run);
#endif
                        }
                        code = gx_fill_rectangle_device_rop(ix, iy, iw, ih,
                                                            pdevc, dev, lop);
                    }
                    if (code < 0)
                        goto err;
                    xrun = xl;
                    rsrc = psrc;
                    if (psrc > stop)
                        break;
                    run = c;
                }
                dda_next(next.x);
                if (psrc >= endp)
                    break;
            }
        } else if (penum->posture == image_landscape) {

            /**************************************
             * Slow case, not masked, landscape. *
             **************************************/
            dev_proc_fill_rectangle((*fill_proc)) =
                dev_proc(dev, fill_rectangle);
            int ix = fixed2int_pixround(xrun);
            int iw = fixed2int_pixround(xrun + pdyx) - ix;
            if (iw < 0)
                ix += iw, iw = -iw;

            /* In this case, we can fill runs quickly. */
            /****** DOESN'T DO ADJUSTMENT ******/
            if (stop <= psrc)
                goto last;
            for (;;) {
                byte c = *psrc++;
                if (c != run) {
                    int iy = fixed2int_pixround(yrun);
                    int ih = fixed2int_pixround(ytf) - iy;
                    if (ih < 0)
                        iy += ih, ih = -ih;
                    switch (run)
                    {
                    case 0:
                        if (!color_is_pure(penum->icolor0))
                            goto ht_land;
                        code = (*fill_proc) (dev, ix, iy, iw, ih,
                                             penum->icolor0->colors.pure);
                        break;
                    case 0xff:
                        if (!color_is_pure(penum->icolor1))
                            goto ht_land;
                        code = (*fill_proc) (dev, ix, iy, iw, ih,
                                             penum->icolor1->colors.pure);
                        break;
                    default:
                        ht_land:
                        if (run != htrun) {
                            htrun = run;
#if USE_SET_GRAY_FUNCTION
                            code = image_set_gray(run,masked,mask_base,mask_limit,&pdevc,
                                    &cc,pcs,pgs,dev,gs_color_select_source,penum);
                            if (code < 0)
                                goto err;
#else
                            IMAGE_SET_GRAY(run);
#endif
                        }
                        code = gx_fill_rectangle_device_rop(ix, iy, iw, ih,
                                                            pdevc, dev, lop);
                    }
                    if (code < 0)
                        goto err;
                    yrun = ytf;
                    rsrc = psrc;
                    if (psrc > stop)
                        break;
                    run = c;
                }
                dda_next(next.y);
                if (psrc >= endp)
                    break;
            }
        } else {

            /******************************************
             * Slow case, not masked, not orthogonal. *
             ******************************************/

            /*
             * Since we have to check for the end after every pixel
             * anyway, we may as well avoid the last-run code.
             */
            stop = endp;
            for (;;) {
                /* We can't skip large constant regions quickly, */
                /* because this leads to rounding errors. */
                /* Just fill the region between xrun and xl. */
                if (run != htrun) {
                    htrun = run;
#if USE_SET_GRAY_FUNCTION
                    code = image_set_gray(run,masked,mask_base,mask_limit,&pdevc,
                        &cc,pcs,pgs,dev,gs_color_select_source,penum);
                    if (code < 0)
                        goto err;
#else
                    IMAGE_SET_GRAY(run);
#endif
                }
                code = (*fill_pgram) (dev, xrun, yrun, xl - xrun,
                                      ytf - yrun, pdyx, pdyy, pdevc, lop);
                if (code < 0)
                    goto err;
                yrun = ytf;
                xrun = xl;
                rsrc = psrc;
                if (psrc >= stop)
                    break;
                run = *psrc++;
                dda_next(next.x);
                dda_next(next.y);       /* harmless if no skew */
            }

        }
        /* Fill the last run. */
      last:if (stop < endp && (*stop || !masked)) {
            if (!masked) {
#if USE_SET_GRAY_FUNCTION
                    code = image_set_gray(*stop, masked,mask_base,mask_limit,&pdevc,
                        &cc,pcs,pgs,dev,gs_color_select_source,penum);
                    if (code < 0)
                        goto err;
#else
                    IMAGE_SET_GRAY(*stop);
#endif
            }
            dda_advance(next.x, endp - stop);
            dda_advance(next.y, endp - stop);
            code = (*fill_pgram) (dev, xrun, yrun, xl - xrun,
                                  ytf - yrun, pdyx, pdyy, pdevc, lop);
        }
#undef xl
#undef ytf

    } else {

        /**********************************************************
         * Fast case: no skew, and not imagemask with a halftone. *
         **********************************************************/

        const fixed adjust = penum->adjust;
        const fixed dxx = penum->dxx;
        fixed xa = (dxx >= 0 ? adjust : -adjust);
        const int yt = penum->yci, iht = penum->hci;

        dev_proc_fill_rectangle((*fill_proc)) =
            dev_proc(dev, fill_rectangle);
        int xmin = fixed2int_pixround(penum->clip_outer.p.x);
        int xmax = fixed2int_pixround(penum->clip_outer.q.x);
#define xl dda_current(next.x)

        if_debug2m('b', penum->memory, "[b]image y=%d  dda.y.Q=%lg\n",
                   penum->y + penum->rect.y, penum->dda.row.y.state.Q / 256.);
        /* Fold the adjustment into xrun and xl, */
        /* including the +0.5-epsilon for rounding. */
        xrun = xrun - xa + (fixed_half - fixed_epsilon);
        dda_translate(next.x, xa + (fixed_half - fixed_epsilon));
        xa <<= 1;
        /* Calculate multiples of the DDA step. */
        dxx2 = next.x.step;
        dda_step_add(dxx2, next.x.step);
        dxx3 = dxx2;
        dda_step_add(dxx3, next.x.step);
        dxx4 = dxx3;
        dda_step_add(dxx4, next.x.step);
        if (stop > psrc)
            for (;;) {          /* Skip large constant regions quickly, */
                /* but don't slow down transitions too much. */
              skf:if (psrc[0] == run) {
                    if (psrc[1] == run) {
                        if (psrc[2] == run) {
                            if (psrc[3] == run) {
                                psrc += 4;
                                dda_state_next(next.x.state, dxx4);
                                if (psrc >= endp)
                                    break;
                                goto skf;
                            } else {
                                psrc += 4;
                                dda_state_next(next.x.state, dxx3);
                            }
                        } else {
                            psrc += 3;
                            dda_state_next(next.x.state, dxx2);
                        }
                    } else {
                        psrc += 2;
                        dda_next(next.x);
                    }
                } else
                    psrc++;
                {               /* Now fill the region between xrun and xl. */
                    int xi = fixed2int_var(xrun);
                    int wi = fixed2int_var(xl) - xi;
                    int xei;

                    if (wi <= 0) {
                        if (wi == 0)
                            goto mt;
                        xi += wi, wi = -wi;
                    }
                    if ((xei = xi + wi) > xmax || xi < xmin) {  /* Do X clipping */
                        if (xi < xmin)
                            wi -= xmin - xi, xi = xmin;
                        if (xei > xmax)
                            wi -= xei - xmax;
                        if (wi <= 0)
                            goto mt;
                    }
                    switch (run) {
                        case 0:
                            if (masked)
                                goto mt;
                            if (!color_is_pure(penum->icolor0))
                                goto ht;
                            code = (*fill_proc) (dev, xi, yt, wi, iht,
                                                 penum->icolor0->colors.pure);
                            break;
                        case 255:       /* just for speed */
                            if (!color_is_pure(penum->icolor1))
                                goto ht;
                            code = (*fill_proc) (dev, xi, yt, wi, iht,
                                                 penum->icolor1->colors.pure);
                            break;
                        default:
                          ht:   /* Use halftone if needed */
                            if (run != htrun) {
#if USE_SET_GRAY_FUNCTION
                                code = image_set_gray(run, masked,mask_base,mask_limit,&pdevc,
                                    &cc,pcs,pgs,dev,gs_color_select_source,penum);
                                if (code < 0)
                                    goto err;
#else
                                IMAGE_SET_GRAY(run);
#endif
                                htrun = run;
                            }
                            code = gx_fill_rectangle_device_rop(xi, yt, wi, iht,
                                                                 pdevc, dev, lop);
                    }
                    if (code < 0)
                        goto err;
                  mt:xrun = xl - xa;    /* original xa << 1 */
                    rsrc = psrc - 1;
                    if (psrc > stop) {
                        --psrc;
                        break;
                    }
                    run = psrc[-1];
                }
                dda_next(next.x);
            }
        /* Fill the last run. */
        if (*stop != 0 || !masked) {
            int xi = fixed2int_var(xrun);
            int wi, xei;

            dda_advance(next.x, endp - stop);
            wi = fixed2int_var(xl) - xi;
            if (wi <= 0) {
                if (wi == 0)
                    goto lmt;
                xi += wi, wi = -wi;
            }
            if ((xei = xi + wi) > xmax || xi < xmin) {  /* Do X clipping */
                if (xi < xmin)
                    wi -= xmin - xi, xi = xmin;
                if (xei > xmax)
                    wi -= xei - xmax;
                if (wi <= 0)
                    goto lmt;
            }
#if USE_SET_GRAY_FUNCTION
            code = image_set_gray(*stop, masked,mask_base,mask_limit,&pdevc,
                &cc,pcs,pgs,dev,gs_color_select_source,penum);
            if (code < 0)
                goto err;
#else
            IMAGE_SET_GRAY(*stop);
#endif
            code = gx_fill_rectangle_device_rop(xi, yt, wi, iht,
                                                pdevc, dev, lop);
          lmt:;
        }

    }
#undef xl
    if (code >= 0)
        return 1;
    /* Save position if error, in case we resume. */
err:
    penum->used.x = rsrc - psrc_initial;
    penum->used.y = 0;
    return code;
}

#ifdef WITH_CAL
static int
image_render_mono_ht_cal_skip_line(gx_image_enum *penum,
                                   gx_device     *dev)
{
    return !cal_halftone_next_line_required(penum->cal_ht);
}

static int
image_render_mono_ht_cal(gx_image_enum * penum, const byte * buffer, int data_x,
    uint w, int h, gx_device * dev)
{
    const byte *input = buffer + data_x;

    if (buffer == NULL)
        return 0;

    return cal_halftone_process_planar(penum->cal_ht, penum->memory->non_gc_memory,
                                       (const byte * const *)&input, halftone_callback, dev);
}
#else
/*
 An image render case where the source color is monochrome or indexed and
 the output is to be halftoned.  If the source color requires decoding,
 an index look-up or ICC color managment, these operations have already been
 performed on the index values and we are ready now to halftone */
static int
image_render_mono_ht(gx_image_enum * penum_orig, const byte * buffer, int data_x,
                  uint w, int h, gx_device * dev)
{
    gx_image_enum *penum = penum_orig; /* const within proc */
    image_posture posture = penum->posture;
    int vdi;  /* amounts to replicate */
    fixed xrun;
    byte *thresh_align;
    int spp_out = penum->dev->color_info.num_components;
    byte *devc_contone[GX_DEVICE_COLOR_MAX_COMPONENTS];
    byte *devc_contone_gray;
    const byte *psrc = buffer + data_x;
    int dest_width, dest_height, data_length;
    byte *color_cache;
    int position, k, j;
    int offset_bits = penum->ht_offset_bits;
    int contone_stride = 0;  /* Not used in landscape case */
    fixed offset;
    int src_size;
    bool flush_buff = false;
    int offset_contone[GX_DEVICE_COLOR_MAX_COMPONENTS];    /* to ensure 128 bit boundary */
    int offset_threshold;  /* to ensure 128 bit boundary */
    gx_dda_fixed dda_ht;
    int xn, xr;		/* destination position (pixel, not contone buffer offset) */
    int code = 0;
    byte *dev_value;

    if (h == 0 || penum->line_size == 0) {      /* line_size == 0, nothing to do */
        if (penum->ht_landscape.count == 0 || posture == image_portrait) {
            return 0;
        } else {
            /* Need to flush the buffer */
            offset_bits = penum->ht_landscape.count;
            penum->ht_offset_bits = offset_bits;
            penum->ht_landscape.offset_set = true;
            flush_buff = true;
        }
    }
    src_size = penum->rect.w;

    /* Set up the dda.  We could move this out but the cost is pretty small */
    dda_ht = (posture == image_portrait) ? penum->dda.pixel0.x : penum->dda.pixel0.y;
    if (penum->dxx > 0)
        dda_translate(dda_ht, -fixed_epsilon);      /* to match rounding in non-fast code */

    switch (posture) {
        case image_portrait:
            /* Figure out our offset in the contone and threshold data
               buffers so that we ensure that we are on the 128bit
               memory boundaries when we get offset_bits into the data. */
            /* Can't do this earlier, as GC might move the buffers. */
            xrun = dda_current(dda_ht);
            dest_width = gxht_dda_length(&dda_ht, src_size);
            if (penum->x_extent.x < 0)
                xrun += penum->x_extent.x;
            vdi = penum->hci;
            contone_stride = penum->line_size;
            offset_threshold = (- (((long)(penum->thresh_buffer)) +
                                      penum->ht_offset_bits)) & 15;
            for (k = 0; k < spp_out; k ++) {
                offset_contone[k]   = (- (((long)(penum->line)) +
                                          contone_stride * k +
                                          penum->ht_offset_bits)) & 15;
            }
            data_length = dest_width;
            dest_height = fixed2int_var_rounded(any_abs(penum->y_extent.y));
#ifdef DEBUG
            /* Help in spotting problems */
            memset(penum->ht_buffer, 0x00, penum->ht_stride * vdi * spp_out);
#endif
            break;
        case image_landscape:
        default:
            /* Figure out our offset in the contone and threshold data buffers
               so that we ensure that we are on the 128bit memory boundaries.
               Can't do this earlier as GC may move the buffers.
             */
            vdi = penum->wci;
            contone_stride = penum->line_size;
            dest_width = fixed2int_var_rounded(any_abs(penum->y_extent.x));
            /* match height in gxht_thresh.c dev_width calculation */
            xrun = dda_current(dda_ht);            /* really yrun, but just used here for landscape */
            dest_height = gxht_dda_length(&dda_ht, src_size);
            data_length = dest_height;
            offset_threshold = (-(long)(penum->thresh_buffer)) & 15;
            for (k = 0; k < spp_out; k ++) {
                offset_contone[k] = (- ((long)(penum->line) +
                                          contone_stride * k)) & 15;
            }
            /* In the landscaped case, we want to accumulate multiple columns
               of data before sending to the device.  We want to have a full
               byte of HT data in one write.  This may not be possible at the
               left or right and for those and for those we have so send partial
               chunks */
            /* Initialize our xstart and compute our partial bit chunk so
               that we get in sync with the 1 bit mem device 16 bit positions
               for the rest of the chunks */
            if (penum->ht_landscape.count == 0) {
                /* In the landscape case, the size depends upon
                   if we are moving left to right or right to left with
                   the image data.  This offset is to ensure that we  get
                   aligned in our chunks along 16 bit boundaries */
                penum->ht_landscape.offset_set = true;
                if (penum->ht_landscape.index < 0) {
                    penum->ht_landscape.xstart = penum->xci + vdi - 1;
                    offset_bits = (penum->ht_landscape.xstart % 16) + 1;
                    /* xci can be negative, so allow for that */
                    if (offset_bits <= 0) offset_bits += 16;
                } else {
                    penum->ht_landscape.xstart = penum->xci;
                    /* xci can be negative, see Bug 692569. */
                    offset_bits = 16 - penum->xci % 16;
                    if (offset_bits >= 16) offset_bits -= 16;
                }
                if (offset_bits == 0 || offset_bits == 16) {
                    penum->ht_landscape.offset_set = false;
                    penum->ht_offset_bits = 0;
                } else {
                    penum->ht_offset_bits = offset_bits;
                }
            }
            break;
    }
    if (flush_buff)
        goto flush;  /* All done */

    /* Get the pointers to our buffers */
    for (k = 0; k < spp_out; k++) {
        if (posture == image_portrait) {
            devc_contone[k] = penum->line + contone_stride * k +
                              offset_contone[k];
        } else {
            devc_contone[k] = penum->line + offset_contone[k] +
                              LAND_BITS * k * contone_stride;
        }
    }
    xr = fixed2int_var_rounded(dda_current(dda_ht));	/* indexes in the destination (contone) */

    devc_contone_gray = devc_contone[0];
    if (penum->color_cache == NULL) {
        /* No look-up in the cache to fill the source buffer. Still need to
           have the data at device resolution.  Do these in quick small
           loops.  This likely could be a vectorized function.  Note that
           since the color_cache is NULL we must be in a case where we
           are going to a monochrome device. */
        switch (posture) {
            case image_portrait:
                if (penum->dst_width > 0) {
                    if (src_size == dest_width) {
                        memcpy(devc_contone_gray, psrc, data_length);
                    } else if (src_size * 2 == dest_width) {
                        const byte *psrc_temp = psrc;
                        for (k = 0; k < data_length; k+=2, devc_contone_gray+=2,
                             psrc_temp++) {
                            *devc_contone_gray = *(devc_contone_gray+1) = *psrc_temp;
                        }
                    } else {
                        /* Mono case, forward */
                        for (k=0; k<src_size; k++) {
                            byte c = *psrc++;
                            dda_next(dda_ht);
                            xn = fixed2int_var_rounded(dda_current(dda_ht));
                            while (xr < xn) {
                                *devc_contone_gray++ = c;
                                xr++;
                            }           /* at loop exit xn will be >= xr */
                        }
                    }
                } else {
                    /* Mono case, backwards */
                    devc_contone_gray += (data_length - 1);
                    for (k=0; k<src_size; k++) {
                        byte c = *psrc++;
                        dda_next(dda_ht);
                        xn = fixed2int_var_rounded(dda_current(dda_ht));
                        while (xr > xn) {
                            *devc_contone_gray-- = c;
                            xr--;
                        }           /* at loop exit xn will be >= xr */
                    }
                }
                break;
            case image_landscape:
                /* We store the data at this point into a column. Depending
                   upon our landscape direction we may be going left to right
                   or right to left. */
                if (penum->ht_landscape.flipy) {
                    position = penum->ht_landscape.curr_pos +
                                LAND_BITS * (data_length - 1);
                    for (k=0; k<src_size; k++) {
                        byte c = *psrc++;
                        dda_next(dda_ht);
                        xn = fixed2int_var_rounded(dda_current(dda_ht));
                        while (xr > xn) {
                            devc_contone_gray[position] = c;
                            position -= LAND_BITS;
                            xr--;
                        }           /* at loop exit xn will be <= xr */
                    }
                } else {
                    position = penum->ht_landscape.curr_pos;
                    /* Code up special cases for when we have no scaling
                       and 2x scaling which we will run into in 300 and
                       600dpi devices and content */
                    if (src_size == dest_height) {
                        for (k = 0; k < data_length; k++) {
                            devc_contone_gray[position] = psrc[k];
                            position += LAND_BITS;
                        }
                    } else if (src_size*2 == dest_height) {
                        for (k = 0; k < data_length; k+=2) {
                            offset = fixed2int_rounded(fixed_half * k);
                            devc_contone_gray[position] =
                                devc_contone_gray[position + LAND_BITS] = psrc[offset];
                            position += LAND_BITS*2;
                        }
                    } else {
                        /* use dda */
                        for (k=0; k<src_size; k++) {
                            byte c = *psrc++;
                            dda_next(dda_ht);
                            xn = fixed2int_var_rounded(dda_current(dda_ht));
                            while (xr < xn) {
                                devc_contone_gray[position] = c;
                                position += LAND_BITS;
                                xr++;
                            }           /* at loop exit xn will be >= xr */
                        }
                    }
                }
                /* Store the width information and update our counts */
                penum->ht_landscape.count += vdi;
                penum->ht_landscape.widths[penum->ht_landscape.curr_pos] = vdi;
                penum->ht_landscape.curr_pos += penum->ht_landscape.index;
                penum->ht_landscape.num_contones++;
                break;
            default:
                /* error not allowed */
                break;
            }
    } else {
        /* look-up in the cache to fill the source buffer.  If our spp_out
           is 4 then we need to write out the pixels in the color_cache into
           the planes */
        color_cache = penum->color_cache->device_contone;
        switch (posture) {
            case image_portrait:
                if (penum->dst_width > 0) {
                    /* loop filling contone values selected from the source */
                    if (spp_out == 1) {
                        /* Mono case, forward */
                        for (k=0; k<src_size; k++) {
                            byte c = color_cache[*psrc++];
                            dda_next(dda_ht);
                            xn = fixed2int_var_rounded(dda_current(dda_ht));
                            while (xr < xn) {
                                *devc_contone_gray++ = c;
                                xr++;
                            }           /* at loop exit xn will be >= xr */
                        }
                    } else {
                        /* CMYK case, forward */
                        for (k=0; k<src_size; k++) {
                            dev_value = &(color_cache[*psrc++ * spp_out]);
                            dda_next(dda_ht);
                            xn = fixed2int_var_rounded(dda_current(dda_ht));
                            while (xr < xn) {
                                for (j = 0; j < spp_out; j++) {
                                    *(devc_contone[j])++ = dev_value[j];
                                }
                                xr++;
                            }           /* at loop exit xn will be >= xr */
                        }
                    }
                } else {
                    if (spp_out == 1) {
                        /* Mono case, backwards */
                        devc_contone_gray += data_length - 1;		/* move to end */
                        for (k=0; k<src_size; k++) {
                            byte c = color_cache[*psrc++];
                            dda_next(dda_ht);
                            xn = fixed2int_var_rounded(dda_current(dda_ht));
                            while (xr > xn) {
                                *devc_contone_gray-- = c;
                                xr--;
                            }           /* at loop exit xn will be <= xr */
                        }
                    } else {
                        /* CMYK case, backwards */
                        /* Move to the other end and we will decrement */
                        for (j = 0; j < spp_out; j++) {
                            devc_contone[j] = devc_contone[j] + data_length - 1;
                        }
                        for (k=0; k<src_size; k++) {
                            dev_value = &(color_cache[*psrc++ * spp_out]);
                            dda_next(dda_ht);
                            xn = fixed2int_var_rounded(dda_current(dda_ht));
                            while (xr > xn) {
                                for (j = 0; j < spp_out; j++) {
                                    *(devc_contone[j])-- = dev_value[j];
                                }
                                xr--;
                            }           /* at loop exit xn will be <= xr */
                        }
                    }
                }
                break;
            case image_landscape:
                /* We store the data at this point into a column. Depending
                   upon our landscape direction we may be going left to right
                   or right to left. */
                if (penum->ht_landscape.flipy) {
                    position = penum->ht_landscape.curr_pos +
                                LAND_BITS * (data_length - 1);
                    /* use dda */
                    if (spp_out == 1) {
                        /* Mono case */
                        /* loop filling contone values selected from the source */
                        for (k=0; k<src_size; k++) {
                            byte c = color_cache[*psrc++];
                            dda_next(dda_ht);
                            xn = fixed2int_var_rounded(dda_current(dda_ht));
                            while (xr > xn) {
                                devc_contone_gray[position] = c;
                                position -= LAND_BITS;
                                xr--;
                            }           /* at loop exit xn will be <= xr */
                        }
                    } else {
                        /* CMYK case */
                        for (k=0; k<src_size; k++) {
                            dev_value = &(color_cache[*psrc++ * spp_out]);
                            dda_next(dda_ht);
                            xn = fixed2int_var_rounded(dda_current(dda_ht));
                            while (xr > xn) {
                                for (j = 0; j < spp_out; j++) {
                                    *(devc_contone[j] + position) = dev_value[j];
                                }
                                position -= LAND_BITS;
                                xr--;
                            }           /* at loop exit xn will be <= xr */
                        }
                    }
                } else {  /* Not flipped in Y */
                    position = penum->ht_landscape.curr_pos;
                    /* use dda */
                    if (spp_out == 1) {
                        /* Mono case */
                        /* loop filling contone values selected from the source */
                        for (k=0; k<src_size; k++) {
                            byte c = color_cache[*psrc++];
                            dda_next(dda_ht);
                            xn = fixed2int_var_rounded(dda_current(dda_ht));
                            while (xr < xn) {
                                devc_contone_gray[position] = c;
                                position += LAND_BITS;
                                xr++;
                            }           /* at loop exit xn will be >= xr */
                        }
                    } else {
                        /* CMYK case */
                        /* Apply initial offset */
                        for (k = 0; k < spp_out; k++) {
                            devc_contone[k] = devc_contone[k] + position;
                        }
                        /* CMYK case */
                        for (k=0; k<src_size; k++) {
                            dev_value = &(color_cache[*psrc++ * spp_out]);
                            dda_next(dda_ht);
                            xn = fixed2int_var_rounded(dda_current(dda_ht));
                            while (xr < xn) {
                                for (j = 0; j < spp_out; j++) {
                                    *(devc_contone[j] + position) = dev_value[j];
                                }
                                position += LAND_BITS;
                                xr++;
                            }           /* at loop exit xn will be >= xr */
                        }
                    }
                }
                /* Store the width information and update our counts */
                penum->ht_landscape.count += vdi;
                penum->ht_landscape.widths[penum->ht_landscape.curr_pos] = vdi;
                penum->ht_landscape.curr_pos += penum->ht_landscape.index;
                penum->ht_landscape.num_contones++;
                break;
            default:
                /* error not allowed */
                break;
        }
    }
    /* Apply threshold array to image data */
flush:
    thresh_align = penum->thresh_buffer + offset_threshold;
    code = gxht_thresh_planes(penum, xrun, dest_width, dest_height,
                              thresh_align, dev, offset_contone,
                              contone_stride);
    return code;
}
#endif