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
|
/* -*- Mode: c; c-basic-offset: 4; indent-tabs-mode: t; tab-width: 8; -*- */
/* cairo - a vector graphics library with display and print output
*
* Copyright © 2005 Red Hat, Inc
*
* This library is free software; you can redistribute it and/or
* modify it either under the terms of the GNU Lesser General Public
* License version 2.1 as published by the Free Software Foundation
* (the "LGPL") or, at your option, under the terms of the Mozilla
* Public License Version 1.1 (the "MPL"). If you do not alter this
* notice, a recipient may use your version of this file under either
* the MPL or the LGPL.
*
* You should have received a copy of the LGPL along with this library
* in the file COPYING-LGPL-2.1; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
* You should have received a copy of the MPL along with this library
* in the file COPYING-MPL-1.1
*
* The contents of this file are subject to the Mozilla Public License
* Version 1.1 (the "License"); you may not use this file except in
* compliance with the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY
* OF ANY KIND, either express or implied. See the LGPL or the MPL for
* the specific language governing rights and limitations.
*
* The Original Code is the cairo graphics library.
*
* The Initial Developer of the Original Code is Red Hat, Inc.
*
* Author(s):
* Kristian Høgsberg <krh@redhat.com>
*/
#include "cairoint.h"
#include "cairo-output-stream-private.h"
typedef struct _cairo_base85_stream {
cairo_output_stream_t base;
cairo_output_stream_t *output;
unsigned char four_tuple[4];
int pending;
} cairo_base85_stream_t;
static void
_expand_four_tuple_to_five (unsigned char four_tuple[4],
unsigned char five_tuple[5],
cairo_bool_t *all_zero)
{
uint32_t value;
int digit, i;
value = four_tuple[0] << 24 | four_tuple[1] << 16 | four_tuple[2] << 8 | four_tuple[3];
if (all_zero)
*all_zero = TRUE;
for (i = 0; i < 5; i++) {
digit = value % 85;
if (digit != 0 && all_zero)
*all_zero = FALSE;
five_tuple[4-i] = digit + 33;
value = value / 85;
}
}
static cairo_status_t
_cairo_base85_stream_write (cairo_output_stream_t *base,
const unsigned char *data,
unsigned int length)
{
cairo_base85_stream_t *stream = (cairo_base85_stream_t *) base;
const unsigned char *ptr = data;
unsigned char five_tuple[5];
cairo_bool_t is_zero;
while (length) {
stream->four_tuple[stream->pending++] = *ptr++;
length--;
if (stream->pending == 4) {
_expand_four_tuple_to_five (stream->four_tuple, five_tuple, &is_zero);
if (is_zero)
_cairo_output_stream_write (stream->output, "z", 1);
else
_cairo_output_stream_write (stream->output, five_tuple, 5);
stream->pending = 0;
}
}
return _cairo_output_stream_get_status (stream->output);
}
static cairo_status_t
_cairo_base85_stream_close (cairo_output_stream_t *base)
{
cairo_base85_stream_t *stream = (cairo_base85_stream_t *) base;
unsigned char five_tuple[5];
if (stream->pending) {
memset (stream->four_tuple + stream->pending, 0, 4 - stream->pending);
_expand_four_tuple_to_five (stream->four_tuple, five_tuple, NULL);
_cairo_output_stream_write (stream->output, five_tuple, stream->pending + 1);
}
/* Mark end of base85 data */
_cairo_output_stream_printf (stream->output, "~>");
return _cairo_output_stream_get_status (stream->output);
}
cairo_output_stream_t *
_cairo_base85_stream_create (cairo_output_stream_t *output)
{
cairo_base85_stream_t *stream;
if (output->status)
return _cairo_output_stream_create_in_error (output->status);
stream = malloc (sizeof (cairo_base85_stream_t));
if (stream == NULL) {
_cairo_error_throw (CAIRO_STATUS_NO_MEMORY);
return (cairo_output_stream_t *) &_cairo_output_stream_nil;
}
_cairo_output_stream_init (&stream->base,
_cairo_base85_stream_write,
_cairo_base85_stream_close);
stream->output = output;
stream->pending = 0;
return &stream->base;
}
|
