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
|
/*
*
* Very fast dither algorithm
*
* Copyright 1997-2003 Michael Sweet (mike@easysw.com) and
* Robert Krawitz (rlk@alum.mit.edu)
*
* 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.
*
* Revision History:
*
* See ChangeLog
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include <gutenprint/gutenprint.h>
#include "gutenprint-internal.h"
#include <gutenprint/gutenprint-intl-internal.h>
#include "dither-impl.h"
#include "dither-inlined-functions.h"
static inline void
print_color_very_fast(const stpi_dither_t *d, stpi_dither_channel_t *dc,
int val, int x, int y, unsigned bit, int length)
{
int i, j;
unsigned char *tptr = dc->ptr + d->ptr_offset;
/*
* Lay down all of the bits in the pixel.
*/
set_row_ends(dc, x);
for (i = 0, j = 1; i < dc->signif_bits; i++, j += j, tptr += length)
{
if (j & val)
tptr[0] |= bit;
}
}
void
stpi_dither_predithered(stp_vars_t *v,
int row,
const unsigned short *raw,
int duplicate_line,
int zero_mask,
const unsigned char *mask)
{
stpi_dither_t *d = (stpi_dither_t *) stp_get_component_data(v, "Dither");
int x,
length;
unsigned char bit;
int i;
int one_bit_only = 1;
int xerror, xstep, xmod;
if ((zero_mask & ((1 << CHANNEL_COUNT(d)) - 1)) ==
((1 << CHANNEL_COUNT(d)) - 1))
return;
length = (d->dst_width + 7) / 8;
bit = 128;
xstep = CHANNEL_COUNT(d) * (d->src_width / d->dst_width);
xmod = d->src_width % d->dst_width;
xerror = 0;
for (i = 0; i < CHANNEL_COUNT(d); i++)
{
stpi_dither_channel_t *dc = &(CHANNEL(d, i));
if (dc->signif_bits > 1)
{
one_bit_only = 0;
break;
}
}
if (one_bit_only)
{
for (x = 0; x < d->dst_width; x ++)
{
if (!mask || (*(mask + d->ptr_offset) & bit))
{
for (i = 0; i < CHANNEL_COUNT(d); i++)
{
if (raw[i] & 1)
{
set_row_ends(&(CHANNEL(d, i)), x);
CHANNEL(d, i).ptr[d->ptr_offset] |= bit;
}
}
}
ADVANCE_UNIDIRECTIONAL(d, bit, raw, CHANNEL_COUNT(d),
xerror, xstep, xmod);
}
}
else
{
for (x = 0; x < d->dst_width; x ++)
{
if (!mask || (*(mask + d->ptr_offset) & bit))
{
for (i = 0; i < CHANNEL_COUNT(d); i++)
{
if (CHANNEL(d, i).ptr && raw[i])
print_color_very_fast(d, &(CHANNEL(d, i)), raw[i], x, row,
bit, length);
}
}
ADVANCE_UNIDIRECTIONAL(d, bit, raw, CHANNEL_COUNT(d),
xerror, xstep, xmod);
}
}
}
|
