summaryrefslogtreecommitdiff
path: root/coders/null.c
blob: 704d515c1793a8b7303bc6fb6db7b4252ca4fca2 (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
/*
% Copyright (C) 2003-2020 GraphicsMagick Group
% Copyright (C) 2002 ImageMagick Studio
% Copyright 1991-1999 E. I. du Pont de Nemours and Company
%
% This program is covered by multiple licenses, which are described in
% Copyright.txt. You should have received a copy of Copyright.txt with this
% package; otherwise see http://www.graphicsmagick.org/www/Copyright.html.
%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%                        N   N  U   U  L      L                               %
%                        NN  N  U   U  L      L                               %
%                        N N N  U   U  L      L                               %
%                        N  NN  U   U  L      L                               %
%                        N   N   UUU   LLLLL  LLLLL                           %
%                                                                             %
%                                                                             %
%                   Read/Write Image Of Uniform Color                         %
%                                                                             %
%                                                                             %
%                              Software Design                                %
%                                John Cristy                                  %
%                                 July 1992                                   %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%
*/

/*
  Include declarations.
*/
#include "magick/studio.h"
#include "magick/blob.h"
#include "magick/color.h"
#include "magick/color_lookup.h"
#include "magick/colormap.h"
#include "magick/magick.h"
#include "magick/pixel_cache.h"
#include "magick/utility.h"

/*
  Forward declarations.
*/
static unsigned int
  WriteNULLImage(const ImageInfo *,Image *) MAGICK_FUNC_PURE;

/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%   R e a d N U L L I m a g e                                                 %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  Method ReadNULLImage creates a constant image and initializes it to the
%  X server color as specified by the filename.  It allocates the memory
%  necessary for the new Image structure and returns a pointer to the new
%  image.
%
%  The format of the ReadNULLImage method is:
%
%      Image *ReadNULLImage(const ImageInfo *image_info,
%        ExceptionInfo *exception)
%
%  A description of each parameter follows:
%
%    o image:  Method ReadNULLImage returns a pointer to the image after
%      creating it. A null image is returned if there is a memory shortage
%      or if the image cannot be read.
%
%    o image_info: Specifies a pointer to a ImageInfo structure.
%
%    o exception: return any errors or warnings in this structure.
%
%
*/
static Image *ReadNULLImage(const ImageInfo *image_info,
  ExceptionInfo *exception)
{
  Image
    *image;

  unsigned int
    status;

  /*
    Initialize Image structure.
  */
  assert(image_info != (const ImageInfo *) NULL);
  assert(image_info->signature == MagickSignature);
  assert(exception != (ExceptionInfo *) NULL);
  assert(exception->signature == MagickSignature);
  image=AllocateImage(image_info);
  if (image->columns == 0)
    image->columns=1;
  if (image->rows == 0)
    image->rows=1;

  if (CheckImagePixelLimits(image, exception) != MagickPass)
    ThrowReaderException(ResourceLimitError,ImagePixelLimitExceeded,image);

  (void) strlcpy(image->filename,image_info->filename,MaxTextExtent);
  status=QueryColorDatabase((char *) image_info->filename,
    &image->background_color,exception);
  if (status == MagickFail)
    {
      /* Promote warning to error */
      exception->severity = OptionError;
      DestroyImage(image);
      return((Image *) NULL);
    }
  if (!AllocateImageColormap(image,1))
    ThrowReaderException(ResourceLimitError,MemoryAllocationFailed,image);
  image->colormap[0]=image->background_color;
  status=SetImageEx(image,OpaqueOpacity,exception);
  StopTimer(&image->timer);
  if (status == MagickFail)
    {
      DestroyImage(image);
      image=(Image *) NULL;
    }

  return(image);
}

/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%   R e g i s t e r N U L L I m a g e                                         %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  Method RegisterNULLImage adds attributes for the NULL image format to
%  the list of supported formats.  The attributes include the image format
%  tag, a method to read and/or write the format, whether the format
%  supports the saving of more than one frame to the same file or blob,
%  whether the format supports native in-memory I/O, and a brief
%  description of the format.
%
%  The format of the RegisterNULLImage method is:
%
%      RegisterNULLImage(void)
%
*/
ModuleExport void RegisterNULLImage(void)
{
  MagickInfo
    *entry;

  entry=SetMagickInfo("NULL");
  entry->decoder=(DecoderHandler) ReadNULLImage;
  entry->encoder=(EncoderHandler) WriteNULLImage;
  entry->adjoin=False;
  entry->description="Constant image of uniform color";
  entry->module="NULL";
  entry->coder_class=PrimaryCoderClass;
  entry->extension_treatment=IgnoreExtensionTreatment;
  (void) RegisterMagickInfo(entry);
}

/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%   U n r e g i s t e r N U L L I m a g e                                     %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  Method UnregisterNULLImage removes format registrations made by the
%  NULL module from the list of supported formats.
%
%  The format of the UnregisterNULLImage method is:
%
%      UnregisterNULLImage(void)
%
*/
ModuleExport void UnregisterNULLImage(void)
{
  (void) UnregisterMagickInfo("NULL");
}

/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%   W r i t e N U L L I m a g e                                               %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  Method WriteNULLImage writes no output at all. It is useful when specified
%  as an output format when profiling.
%
%  The format of the WriteNULLImage method is:
%
%      unsigned int WriteNULLImage(const ImageInfo *image_info,Image *image)
%
%  A description of each parameter follows.
%
%    o status: Always returns True.
%
%    o image_info: Specifies a pointer to a ImageInfo structure.
%
%    o image:  A pointer to an Image structure.
%
%
*/
static unsigned int WriteNULLImage(const ImageInfo *image_info,Image *image)
{
  assert(image_info != (const ImageInfo *) NULL);
  assert(image_info->signature == MagickSignature);
  assert(image != (Image *) NULL);
  assert(image->signature == MagickSignature);
  return(True);
}