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
|
/* Copyright (C) 2001-2006 artofcode LLC.
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 that
license. Refer to licensing information at http://www.artifex.com/
or contact Artifex Software, Inc., 7 Mt. Lassen Drive - Suite A-134,
San Rafael, CA 94903, U.S.A., +1(415)492-9861, for further information.
*/
/* $Id$ */
/* Library "client" bitmap structures */
#ifndef gsbitmap_INCLUDED
#define gsbitmap_INCLUDED
#include "gsstype.h" /* for extern_st */
/*
* The Ghostscript library stores all bitmaps bit-big-endian (i.e., the 0x80
* bit of the first byte corresponds to x=0), as a sequence of bytes (i.e.,
* you can't do word-oriented operations on them if you're on a
* little-endian platform like the Intel 80x86 or VAX). The first scan line
* corresponds to y=0 in whatever coordinate system is relevant.
*
* The structures defined here are for APIs that don't impose any alignment
* restrictions on either the starting address or the raster (distance
* between scan lines) of bitmap data. The structures defined in gxbitmap.h
* do impose alignment restrictions, so that the library can use more
* efficient algorithms; they are declared with identical contents to the
* ones defined here, so that one can cast between them under appropriate
* circumstances (aligned to unaligned is always safe; unaligned to
* aligned is safe if one knows somehow that the data are actually aligned.)
*
* In this file we also provide structures that include depth information.
* It probably was a design mistake not to include this information in the
* gx structures as well.
*/
/*
* Drivers such as the X driver and the command list (band list) driver
* benefit greatly by being able to cache bitmaps (tiles and characters)
* and refer to them later. To help them recognize when a bitmap is the
* same as one that they have seen before, the core code passes an optional
* ID with the property that if two bitmaps have the same ID, they are
* guaranteed to have the same contents. (The converse is *not* true,
* however: two bitmaps may have different IDs and still be the same.)
*/
typedef gs_id gs_bitmap_id;
/* Define a special value to indicate "no identifier". */
#define gs_no_bitmap_id gs_no_id
/*
* In its simplest form, the client bitmap structure does not specify a
* depth, expecting it to be implicit in the context of use. In many cases
* it is possible to guess this by comparing size.x and raster, but of
* course code should not rely on this. See also gs_depth_bitmap below.
* Requirements:
* size.x > 0, size.y > 0
* If size.y > 1,
* raster >= (size.x * depth + 7) / 8
*/
#define gs_bitmap_common(data_type) \
data_type * data; /* pointer to the data */ \
int raster; /* increment between scanlines, bytes */ \
gs_int_point size; /* width and height */ \
gs_bitmap_id id /* usually unused */
typedef struct gs_bitmap_s {
gs_bitmap_common(byte);
} gs_bitmap;
typedef struct gs_const_bitmap_s {
gs_bitmap_common(const byte);
} gs_const_bitmap;
/*
* For bitmaps used as halftone tiles, we may replicate the tile in
* X and/or Y, but it is still valuable to know the true tile dimensions
* (i.e., the dimensions prior to replication). Requirements:
* size.x % rep_width = 0
* size.y % rep_height = 0
* Unaligned bitmaps are not very likely to be used as tiles (replicated),
* since most of the library procedures that replicate tiles expect them
* to be aligned.
*/
#define gs_tile_bitmap_common(data_type) \
gs_bitmap_common(data_type); \
ushort rep_width, rep_height /* true size of tile */
typedef struct gs_tile_bitmap_s {
gs_tile_bitmap_common(byte);
} gs_tile_bitmap;
typedef struct gs_const_tile_bitmap_s {
gs_tile_bitmap_common(const byte);
} gs_const_tile_bitmap;
/*
* There is no "strip" version for client bitmaps, as the strip structure is
* primarily used to efficiently store bitmaps rendered at an angle, and
* there is little reason to do so with client bitmaps.
*
* For client bitmaps it is not always apparent from context what the intended
* depth per sample value is. To provide for this, an extended version of the
* bitmap structure is provided, that handles both variable depth and
* interleaved color components. This structure is provided in both the
* normal and tiled version.
*
* Extending this line of thinking, one could also add color space information
* to a client bitmap structure. We have chosen not to do so, because color
* space is almost always derived from context, and to provide such a feature
* would involve additional memory-management complexity.
*/
#define gs_depth_bitmap_common(data_type) \
gs_bitmap_common(data_type); \
byte pix_depth; /* bits per sample */ \
byte num_comps /* number of interleaved components */ \
typedef struct gs_depth_bitmap_s {
gs_depth_bitmap_common(byte);
} gs_depth_bitmap;
typedef struct gs_const_depth_bitmap_s {
gs_depth_bitmap_common(const byte);
} gs_const_depth_bitmap;
#define gs_tile_depth_bitmap_common(data_type) \
gs_tile_bitmap_common(data_type); \
byte pix_depth; /* bits per sample */ \
byte num_comps /* number of interleaved components */ \
typedef struct gs_tile_depth_bitmap_s {
gs_tile_depth_bitmap_common(byte);
} gs_tile_depth_bitmap;
typedef struct gs_const_tile_depth_bitmap_s {
gs_tile_depth_bitmap_common(const byte);
} gs_const_tile_depth_bitmap;
/*
* For reasons that are no entirely clear, no memory management routines were
* provided for the aligned bitmap structures provided in gxbitmap.h. Since
* client bitmaps will, by nature, be created by different clients, so public
* memory management procedures are provided. Note that the memory management
* structure names retain the "gs_" prefix, to distinguish these structures
* from those that may be provided for the gx_*_bitmap structures.
*
* For historical reasons of no particular validity (this was where the client
* bitmap structure was first provided), the memory managment procedures for
* client bitmap structures are included in gspcolor.c.
*/
extern_st(st_gs_bitmap);
extern_st(st_gs_tile_bitmap);
extern_st(st_gs_depth_bitmap);
extern_st(st_gs_tile_depth_bitmap);
#define public_st_gs_bitmap() /* in gspcolor.c */ \
gs_public_st_ptrs1( st_gs_bitmap, \
gs_bitmap, \
"client bitmap", \
bitmap_enum_ptrs, \
bitmap_reloc_ptrs, \
data \
)
#define public_st_gs_tile_bitmap() /* in gspcolor.c */ \
gs_public_st_suffix_add0_local( st_gs_tile_bitmap, \
gs_tile_bitmap, \
"client tile bitmap", \
bitmap_enum_ptrs, \
bitmap_reloc_ptrs, \
st_gs_bitmap \
)
#define public_st_gs_depth_bitmap() /* in gspcolor.c */ \
gs_public_st_suffix_add0_local( st_gs_depth_bitmap, \
gs_depth_bitmap, \
"client depth bitmap", \
bitmap_enum_ptrs, \
bitmap_reloc_ptrs, \
st_gs_bitmap \
)
#define public_st_gs_tile_depth_bitmap()/* in gspcolor.c */ \
gs_public_st_suffix_add0_local( st_gs_tile_depth_bitmap, \
gs_tile_depth_bitmap, \
"client tile_depth bitmap", \
bitmap_enum_ptrs, \
bitmap_reloc_ptrs, \
st_gs_tile_bitmap \
)
#endif /* gsbitmap_INCLUDED */
|