/*

% 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.

%

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%                                                                             %

%                        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                           %

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%                                                                             %

%                   Read/Write Image Of Uniform Color                         %

%                                                                             %

%                                                                             %

%                              Software Design                                %

%                                John Cristy                                  %

%                                 July 1992                                   %

%                                                                             %

%                                                                             %

%                                                                             %

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%

%

*/

/*

  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;

/*

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%   R e a d N U L L I m a g e                                                 %

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%

%  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");

}

/*

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%   W r i t e N U L L I m a g e                                               %

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%

%  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);

}