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
|
/* Copyright (C) 2001-2021 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.
*/
/* Extended halftone operators for Ghostscript library */
#include "memory_.h"
#include "string_.h"
#include "gx.h"
#include "gserrors.h"
#include "gsstruct.h"
#include "gsutil.h" /* for gs_next_ids */
#include "gzstate.h"
#include "gxdevice.h" /* for gzht.h */
#include "gzht.h"
/* Imports from gscolor.c */
void load_transfer_map(gs_gstate *, gx_transfer_map *, double);
/* Forward declarations */
static int process_spot(gx_ht_order *, gs_gstate *,
gs_spot_halftone *, gs_memory_t *);
static int process_threshold(gx_ht_order *, gs_gstate *,
gs_threshold_halftone *, gs_memory_t *);
static int process_threshold2(gx_ht_order *, gs_gstate *,
gs_threshold2_halftone *, gs_memory_t *);
static int process_client_order(gx_ht_order *, gs_gstate *,
gs_client_order_halftone *, gs_memory_t *);
/* Structure types */
public_st_halftone_component();
public_st_ht_component_element();
/* GC procedures */
static
ENUM_PTRS_WITH(halftone_component_enum_ptrs, gs_halftone_component *hptr) return 0;
case 0:
switch (hptr->type)
{
case ht_type_spot:
ENUM_RETURN((hptr->params.spot.transfer == 0 ?
hptr->params.spot.transfer_closure.data :
0));
case ht_type_threshold:
ENUM_RETURN_CONST_STRING_PTR(gs_halftone_component,
params.threshold.thresholds);
case ht_type_threshold2:
return ENUM_CONST_BYTESTRING(&hptr->params.threshold2.thresholds);
case ht_type_client_order:
ENUM_RETURN(hptr->params.client_order.client_data);
default: /* not possible */
return 0;
}
case 1:
switch (hptr->type) {
case ht_type_threshold:
ENUM_RETURN((hptr->params.threshold.transfer == 0 ?
hptr->params.threshold.transfer_closure.data :
0));
case ht_type_threshold2:
ENUM_RETURN(hptr->params.threshold2.transfer_closure.data);
case ht_type_client_order:
ENUM_RETURN(hptr->params.client_order.transfer_closure.data);
default:
return 0;
}
ENUM_PTRS_END
static RELOC_PTRS_WITH(halftone_component_reloc_ptrs, gs_halftone_component *hptr)
{
switch (hptr->type) {
case ht_type_spot:
if (hptr->params.spot.transfer == 0)
RELOC_VAR(hptr->params.spot.transfer_closure.data);
break;
case ht_type_threshold:
RELOC_CONST_STRING_VAR(hptr->params.threshold.thresholds);
if (hptr->params.threshold.transfer == 0)
RELOC_VAR(hptr->params.threshold.transfer_closure.data);
break;
case ht_type_threshold2:
RELOC_CONST_BYTESTRING_VAR(hptr->params.threshold2.thresholds);
RELOC_OBJ_VAR(hptr->params.threshold2.transfer_closure.data);
break;
case ht_type_client_order:
RELOC_VAR(hptr->params.client_order.client_data);
RELOC_VAR(hptr->params.client_order.transfer_closure.data);
break;
default:
break;
}
}
RELOC_PTRS_END
/* setcolorscreen */
int
gs_setcolorscreen(gs_gstate * pgs, gs_colorscreen_halftone * pht)
{
gs_halftone ht;
ht.type = ht_type_colorscreen;
ht.params.colorscreen = *pht;
return gs_sethalftone(pgs, &ht);
}
/* currentcolorscreen */
int
gs_currentcolorscreen(gs_gstate * pgs, gs_colorscreen_halftone * pht)
{
int code;
switch (pgs->halftone->type) {
case ht_type_colorscreen:
*pht = pgs->halftone->params.colorscreen;
return 0;
default:
code = gs_currentscreen(pgs, &pht->screens.colored.gray);
if (code < 0)
return code;
pht->screens.colored.red = pht->screens.colored.gray;
pht->screens.colored.green = pht->screens.colored.gray;
pht->screens.colored.blue = pht->screens.colored.gray;
return 0;
}
}
/* Set the halftone in the graphics state. */
int
gs_sethalftone(gs_gstate * pgs, gs_halftone * pht)
{
gs_halftone ht;
ht = *pht;
ht.rc.memory = pgs->memory;
return gs_sethalftone_allocated(pgs, &ht);
}
int
gs_sethalftone_allocated(gs_gstate * pgs, gs_halftone * pht)
{
gx_device_halftone dev_ht;
int code = gs_sethalftone_prepare(pgs, pht, &dev_ht);
if (code < 0)
return code;
dev_ht.rc.memory = pht->rc.memory;
if ((code = gx_ht_install(pgs, pht, &dev_ht)) < 0)
gx_device_halftone_release(&dev_ht, pht->rc.memory);
return code;
}
/* Prepare the halftone, but don't install it. */
int
gs_sethalftone_prepare(gs_gstate * pgs, gs_halftone * pht,
gx_device_halftone * pdht)
{
gs_memory_t *mem = pht->rc.memory;
gx_ht_order_component *pocs = 0;
int code = 0;
switch (pht->type) {
case ht_type_colorscreen:
{
gs_screen_halftone *phc =
pht->params.colorscreen.screens.indexed;
static const int cindex[4] = {3, 0, 1, 2};
static const char * color_names[4] = {"Gray", "Red", "Green", "Blue"};
int i;
pocs = gs_alloc_struct_array(mem, 4,
gx_ht_order_component,
&st_ht_order_component_element,
"gs_sethalftone");
if (pocs == 0)
return_error(gs_error_VMerror);
for (i = 0; i < 4; i++) {
gs_screen_enum senum;
int ci = cindex[i];
gx_ht_order_component *poc = &pocs[i];
code = gx_ht_process_screen_memory(&senum, pgs, &phc[ci],
gs_currentaccuratescreens(mem), mem);
if (code < 0)
break;
poc->corder = senum.order;
poc->comp_number = gs_color_name_component_number(pgs->device,
color_names[i], strlen(color_names[i]), pht->type);
poc->cname = 0; /* name index values are not known (or needed) */
if (i == 0) /* Gray = Default */
pdht->order = poc->corder; /* Save default value */
}
if (code < 0)
break;
pdht->components = pocs;
pdht->num_comp = 4;
}
break;
case ht_type_spot:
code = process_spot(&pdht->order, pgs, &pht->params.spot, mem);
if (code < 0)
return code;
pdht->components = 0;
break;
case ht_type_threshold:
code = process_threshold(&pdht->order, pgs,
&pht->params.threshold, mem);
if (code < 0)
return code;
pdht->components = 0;
break;
case ht_type_threshold2:
code = process_threshold2(&pdht->order, pgs,
&pht->params.threshold2, mem);
if (code < 0)
return code;
pdht->components = 0;
break;
case ht_type_client_order:
code = process_client_order(&pdht->order, pgs,
&pht->params.client_order, mem);
if (code < 0)
return code;
pdht->components = 0;
break;
case ht_type_multiple:
case ht_type_multiple_colorscreen:
{
uint count = pht->params.multiple.num_comp;
bool have_Default = false;
uint i;
gs_halftone_component *phc = pht->params.multiple.components;
gx_ht_order_component *poc_next;
pocs = gs_alloc_struct_array(mem, count,
gx_ht_order_component,
&st_ht_order_component_element,
"gs_sethalftone");
if (pocs == 0)
return_error(gs_error_VMerror);
poc_next = pocs + 1;
for (i = 0; i < count; i++, phc++) {
gx_ht_order_component *poc;
if (gs_debug['h']) {
int i;
byte* pname;
uint name_size;
pht->params.multiple.get_colorname_string(pgs, phc->cname, &pname, &name_size);
dmprintf(mem, "Colorant: ");
for (i = 0; i < name_size; i++)
dmprintf1(mem, "%c", pname[i]);
dmprintf(mem, "\n");
}
if (phc->comp_number == GX_DEVICE_COLOR_MAX_COMPONENTS) {
if (have_Default) {
/* Duplicate Default */
code = gs_note_error(gs_error_rangecheck);
break;
}
poc = pocs;
have_Default = true;
} else if (i == count - 1 && !have_Default) {
/* No Default */
code = gs_note_error(gs_error_rangecheck);
break;
} else
poc = poc_next++;
poc->comp_number = phc->comp_number;
poc->cname = phc->cname;
switch (phc->type) {
case ht_type_spot:
code = process_spot(&poc->corder, pgs,
&phc->params.spot, mem);
break;
case ht_type_threshold:
code = process_threshold(&poc->corder, pgs,
&phc->params.threshold, mem);
break;
case ht_type_threshold2:
code = process_threshold2(&poc->corder, pgs,
&phc->params.threshold2, mem);
break;
case ht_type_client_order:
code = process_client_order(&poc->corder, pgs,
&phc->params.client_order, mem);
break;
default:
code = gs_note_error(gs_error_rangecheck);
break;
}
if (code < 0)
break;
}
if (code < 0)
break;
pdht->order = pocs[0].corder; /* Default */
if (count == 1) {
/* We have only a Default; */
/* we don't need components. */
gs_free_object(mem, pocs, "gs_sethalftone");
pdht->components = 0;
pdht->num_comp = 0;
} else {
pdht->components = pocs;
pdht->num_comp = count;
}
}
break;
default:
return_error(gs_error_rangecheck);
}
if (code < 0)
gs_free_object(mem, pocs, "gs_sethalftone");
return code;
}
/* ------ Internal routines ------ */
/* Process a transfer function override, if any. */
static int
process_transfer(gx_ht_order * porder, gs_gstate * pgs,
gs_mapping_proc proc, gs_mapping_closure_t * pmc,
gs_memory_t * mem)
{
gx_transfer_map *pmap;
if (proc == 0 && pmc->proc == 0)
return 0;
/*
* The transfer funtion is referenced by the order, so start the
* reference count at 1.
*/
rc_alloc_struct_1(pmap, gx_transfer_map, &st_transfer_map, mem,
return_error(gs_error_VMerror),
"process_transfer");
pmap->proc = proc; /* 0 => use closure */
pmap->closure = *pmc;
pmap->id = gs_next_ids(mem, 1);
porder->transfer = pmap;
if (proc == gs_mapped_transfer)
return 0; /* nothing to load, the source is uninitialzed */
load_transfer_map(pgs, pmap, 0.0);
return 0;
}
/* Process a spot plane. */
static int
process_spot(gx_ht_order * porder, gs_gstate * pgs,
gs_spot_halftone * phsp, gs_memory_t * mem)
{
gs_screen_enum senum;
int code = gx_ht_process_screen_memory(&senum, pgs, &phsp->screen,
phsp->accurate_screens, mem);
if (code < 0)
return code;
*porder = senum.order;
return process_transfer(porder, pgs, phsp->transfer,
&phsp->transfer_closure, mem);
}
/* Construct the halftone order from a threshold array. */
void
gx_ht_complete_threshold_order(gx_ht_order * porder)
{
int num_levels = porder->num_levels;
uint *levels = porder->levels;
uint size = porder->num_bits;
gx_ht_bit *bits = porder->bit_data;
uint i, j;
/* The caller has set bits[i] = max(1, thresholds[i]). */
gx_sort_ht_order(bits, size);
/* We want to set levels[j] to the lowest value of i */
/* such that bits[i].mask > j. */
for (i = 0, j = 0; i < size; i++) {
if (bits[i].mask != j) {
if_debug3('h', "[h]levels[%u..%u] = %u\n",
j, (uint) bits[i].mask, i);
while (j < bits[i].mask)
levels[j++] = i;
}
}
while (j < num_levels)
levels[j++] = size;
gx_ht_construct_bits(porder);
}
int
gx_ht_construct_threshold_order(gx_ht_order * porder, const byte * thresholds)
{
return porder->procs->construct_order(porder, thresholds);
}
/* Process a threshold plane. */
static int
process_threshold(gx_ht_order * porder, gs_gstate * pgs,
gs_threshold_halftone * phtp, gs_memory_t * mem)
{
int code;
porder->params.M = phtp->width, porder->params.N = 0;
porder->params.R = 1;
porder->params.M1 = phtp->height, porder->params.N1 = 0;
porder->params.R1 = 1;
code = gx_ht_alloc_threshold_order(porder, phtp->width, phtp->height,
256, mem);
if (code < 0)
return code;
gx_ht_construct_threshold_order(porder, phtp->thresholds.data);
return process_transfer(porder, pgs, phtp->transfer,
&phtp->transfer_closure, mem);
}
/* Process an extended threshold plane. */
static int
process_threshold2(gx_ht_order * porder, gs_gstate * pgs,
gs_threshold2_halftone * phtp, gs_memory_t * mem)
{
int code;
/*
* There are potentially 64K different levels for this plane, but this
* is more than we're willing to handle. Try to reduce the number of
* levels by dropping leading or trailing zero bits from the thresholds;
* as a last resort, drop (possibly significant) trailing bits.
*/
#define LOG2_MAX_HT_LEVELS 14
#define MAX_HT_LEVELS (1 << LOG2_MAX_HT_LEVELS)
int bps = phtp->bytes_per_sample;
const byte *data = phtp->thresholds.data;
const int w1 = phtp->width, h1 = phtp->height, size1 = w1 * h1;
const int w2 = phtp->width2, h2 = phtp->height2, size2 = w2 * h2;
const uint size = size1 + size2;
const int d = (h2 == 0 ? h1 : igcd(h1, h2));
const int sod = size / d;
uint num_levels;
uint i;
int rshift = 0;
int shift;
{
uint mask = 0, max_thr = 0;
for (i = 0; i < size; ++i) {
uint thr =
(bps == 1 ? data[i] : (data[i * 2] << 8) + data[i * 2 + 1]);
mask |= thr;
max_thr = max(max_thr, thr);
}
if (mask == 0)
mask = 1, max_thr = 1;
while (!(mask & 1) || max_thr > MAX_HT_LEVELS)
mask >>= 1, max_thr >>= 1, rshift++;
num_levels = max_thr + 1;
}
/*
* Set nominal values for the params, and don't bother to call
* gx_compute_cell_values -- the values are only needed for spot
* halftones.
*/
porder->params.M = sod, porder->params.N = d;
porder->params.R = 1;
porder->params.M1 = d, porder->params.N1 = sod;
porder->params.R1 = 1;
/*
* Determine the shift between strips. We don't know a closed formula
* for this, so we do it by enumeration.
*/
shift = 0;
{
int x = 0, y = 0;
do {
if (y < h1)
x += w1, y += h2;
else
x += w2, y -= h1;
} while (y > d);
if (y)
shift = x;
}
code = gx_ht_alloc_ht_order(porder, sod, d, num_levels, size, shift,
&ht_order_procs_default, mem);
if (code < 0)
return code;
{
gx_ht_bit *bits = (gx_ht_bit *)porder->bit_data;
int row, di;
if_debug7m('h', mem, "[h]rect1=(%d,%d), rect2=(%d,%d), strip=(%d,%d), shift=%d\n",
w1, h1, w2, h2, sod, d, shift);
for (row = 0, di = 0; row < d; ++row) {
/* Iterate over destination rows. */
int dx, sy = row; /* sy = row mod d */
int w;
for (dx = 0; dx < sod; dx += w) {
/* Iterate within a destination row, over source rows. */
int si, j;
if (sy < h1) {
/* Copy a row from rect1. */
si = sy * w1;
w = w1;
sy += h2;
} else {
/* Copy a row from rect2. */
si = size1 + (sy - h1) * w2;
w = w2;
sy -= h1;
}
for (j = 0; j < w; ++j, ++si, ++di) {
uint thr =
(bps == 1 ? data[si] :
(data[si * 2] << 8) + data[si * 2 + 1])
>> rshift;
if_debug3('H', "[H]sy=%d, si=%d, di=%d\n", sy, si, di);
bits[di].mask = max(thr, 1);
}
}
}
}
gx_ht_complete_threshold_order(porder);
return process_transfer(porder, pgs, phtp->transfer, &phtp->transfer_closure, mem);
#undef LOG2_MAX_HT_LEVELS
#undef MAX_HT_LEVELS
}
/* Process a client-order plane. */
static int
process_client_order(gx_ht_order * porder, gs_gstate * pgs,
gs_client_order_halftone * phcop, gs_memory_t * mem)
{
int code = (*phcop->procs->create_order) (porder, pgs, phcop, mem);
if (code < 0)
return code;
return process_transfer(porder, pgs, NULL,
&phcop->transfer_closure, mem);
}
|