coders/gradient.c - platform/external/ImageMagick - Gitiles

 /*
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 %                                                                             %
 %            GGGG  RRRR    AAA   DDDD   IIIII  EEEEE  N   N  TTTTT            %
 %           G      R   R  A   A  D   D    I    E      NN  N    T              %
 %           G  GG  RRRR   AAAAA  D   D    I    EEE    N N N    T              %
 %           G   G  R R    A   A  D   D    I    E      N  NN    T              %
 %            GGG   R  R   A   A  DDDD   IIIII  EEEEE  N   N    T              %
 %                                                                             %
 %                                                                             %
 %                   Read An Image Filled Using Gradient.                      %
 %                                                                             %
 %                              Software Design                                %
 %                                   Cristy                                    %
 %                                 July 1992                                   %
 %                                                                             %
 %                                                                             %
 %  Copyright 1999-2014 ImageMagick Studio LLC, a non-profit organization      %
 %  dedicated to making software imaging solutions freely available.           %
 %                                                                             %
 %  You may not use this file except in compliance with the License.  You may  %
 %  obtain a copy of the License at                                            %
 %                                                                             %
 %    http://www.imagemagick.org/script/license.php                            %
 %                                                                             %
 %  Unless required by applicable law or agreed to in writing, software        %
 %  distributed under the License is distributed on an "AS IS" BASIS,          %
 %  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.   %
 %  See the License for the specific language governing permissions and        %
 %  limitations under the License.                                             %
 %                                                                             %
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 %
 %
 */

 /*
   Include declarations.
 */
 #include "MagickCore/studio.h"
 #include "MagickCore/attribute.h"
 #include "MagickCore/blob.h"
 #include "MagickCore/blob-private.h"
 #include "MagickCore/channel.h"
 #include "MagickCore/color.h"
 #include "MagickCore/color-private.h"
 #include "MagickCore/colorspace-private.h"
 #include "MagickCore/draw.h"
 #include "MagickCore/exception.h"
 #include "MagickCore/exception-private.h"
 #include "MagickCore/image.h"
 #include "MagickCore/image-private.h"
 #include "MagickCore/list.h"
 #include "MagickCore/magick.h"
 #include "MagickCore/memory_.h"
 #include "MagickCore/paint.h"
 #include "MagickCore/pixel-accessor.h"
 #include "MagickCore/quantum-private.h"
 #include "MagickCore/static.h"
 #include "MagickCore/string_.h"
 #include "MagickCore/module.h"
 #include "MagickCore/studio.h"

 /*
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 %                                                                             %
 %                                                                             %
 %                                                                             %
 %   R e a d G R A D I E N T I m a g e                                         %
 %                                                                             %
 %                                                                             %
 %                                                                             %
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 %
 %  ReadGRADIENTImage creates a gradient image and initializes it to
 %  the color range 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 ReadGRADIENTImage method is:
 %
 %      Image *ReadGRADIENTImage(const ImageInfo *image_info,
 %        ExceptionInfo *exception)
 %
 %  A description of each parameter follows:
 %
 %    o image_info: the image info.
 %
 %    o exception: return any errors or warnings in this structure.
 %
 */
 static Image *ReadGRADIENTImage(const ImageInfo *image_info,
   ExceptionInfo *exception)
 {
   char
     colorname[MaxTextExtent];

   Image
     *image;

   MagickBooleanType
     icc_color,
     status;

   PixelInfo
     start_color,
     stop_color;

   /*
     Initialize Image structure.
   */
   assert(image_info != (const ImageInfo *) NULL);
   assert(image_info->signature == MagickSignature);
   if (image_info->debug != MagickFalse)
     (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",
       image_info->filename);
   assert(exception != (ExceptionInfo *) NULL);
   assert(exception->signature == MagickSignature);
   image=AcquireImage(image_info,exception);
   if ((image->columns == 0) || (image->rows == 0))
     ThrowReaderException(OptionError,"MustSpecifyImageSize");
   (void) SetImageAlpha(image,(Quantum) TransparentAlpha,exception);
   (void) CopyMagickString(image->filename,image_info->filename,MaxTextExtent);
   (void) CopyMagickString(colorname,image_info->filename,MaxTextExtent);
   (void) sscanf(image_info->filename,"%[^-]",colorname);
   icc_color=MagickFalse;
   if (LocaleCompare(colorname,"icc") == 0)
     {
       (void) ConcatenateMagickString(colorname,"-",MaxTextExtent);
       (void) sscanf(image_info->filename,"%*[^-]-%[^-]",colorname+4);
       icc_color=MagickTrue;
     }
   status=QueryColorCompliance(colorname,AllCompliance,&start_color,exception);
   if (status == MagickFalse)
     {
       image=DestroyImage(image);
       return((Image *) NULL);
     }
   (void) SetImageColorspace(image,start_color.colorspace,exception);
   (void) CopyMagickString(colorname,"white",MaxTextExtent);
   if (GetPixelInfoIntensity(&start_color) > (Quantum) (QuantumRange/2))
     (void) CopyMagickString(colorname,"black",MaxTextExtent);
   if (icc_color == MagickFalse)
     (void) sscanf(image_info->filename,"%*[^-]-%s",colorname);
   else
     (void) sscanf(image_info->filename,"%*[^-]-%*[^-]-%s",colorname);
   status=QueryColorCompliance(colorname,AllCompliance,&stop_color,exception);
   if (status == MagickFalse)
     {
       image=DestroyImage(image);
       return((Image *) NULL);
     }
   status=GradientImage(image,LocaleCompare(image_info->magick,"GRADIENT") == 0 ?
     LinearGradient : RadialGradient,PadSpread,&start_color,&stop_color,
     exception);
   if (status == MagickFalse)
     {
       image=DestroyImageList(image);
       return((Image *) NULL);
     }
   if ((start_color.alpha_trait != BlendPixelTrait) &&
       (stop_color.alpha_trait != BlendPixelTrait))
     (void) SetImageAlphaChannel(image,DeactivateAlphaChannel,exception);
   return(GetFirstImageInList(image));
 }

 /*
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 %                                                                             %
 %                                                                             %
 %                                                                             %
 %   R e g i s t e r G R A D I E N T I m a g e                                 %
 %                                                                             %
 %                                                                             %
 %                                                                             %
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 %
 %  RegisterGRADIENTImage() adds attributes for the GRADIENT 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 RegisterGRADIENTImage method is:
 %
 %      size_t RegisterGRADIENTImage(void)
 %
 */
 ModuleExport size_t RegisterGRADIENTImage(void)
 {
   MagickInfo
     *entry;

   entry=SetMagickInfo("GRADIENT");
   entry->decoder=(DecodeImageHandler *) ReadGRADIENTImage;
   entry->adjoin=MagickFalse;
   entry->raw=MagickTrue;
   entry->format_type=ImplicitFormatType;
   entry->description=ConstantString("Gradual linear passing from one shade to "
     "another");
   entry->module=ConstantString("GRADIENT");
   (void) RegisterMagickInfo(entry);
   entry=SetMagickInfo("RADIAL-GRADIENT");
   entry->decoder=(DecodeImageHandler *) ReadGRADIENTImage;
   entry->adjoin=MagickFalse;
   entry->raw=MagickTrue;
   entry->format_type=ImplicitFormatType;
   entry->description=ConstantString("Gradual radial passing from one shade to "
     "another");
   entry->module=ConstantString("GRADIENT");
   (void) RegisterMagickInfo(entry);
   return(MagickImageCoderSignature);
 }

 /*
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 %                                                                             %
 %                                                                             %
 %                                                                             %
 %   U n r e g i s t e r G R A D I E N T I m a g e                             %
 %                                                                             %
 %                                                                             %
 %                                                                             %
 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 %
 %  UnregisterGRADIENTImage() removes format registrations made by the
 %  GRADIENT module from the list of supported formats.
 %
 %  The format of the UnregisterGRADIENTImage method is:
 %
 %      UnregisterGRADIENTImage(void)
 %
 */
 ModuleExport void UnregisterGRADIENTImage(void)
 {
   (void) UnregisterMagickInfo("RADIAL-GRADIENT");
   (void) UnregisterMagickInfo("GRADIENT");
 }
	/*
	%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
	% %
	% %
	% %
	% GGGG RRRR AAA DDDD IIIII EEEEE N N TTTTT %
	% G R R A A D D I E NN N T %
	% G GG RRRR AAAAA D D I EEE N N N T %
	% G G R R A A D D I E N NN T %
	% GGG R R A A DDDD IIIII EEEEE N N T %
	% %
	% %
	% Read An Image Filled Using Gradient. %
	% %
	% Software Design %
	% Cristy %
	% July 1992 %
	% %
	% %
	% Copyright 1999-2014 ImageMagick Studio LLC, a non-profit organization %
	% dedicated to making software imaging solutions freely available. %
	% %
	% You may not use this file except in compliance with the License. You may %
	% obtain a copy of the License at %
	% %
	% http://www.imagemagick.org/script/license.php %
	% %
	% Unless required by applicable law or agreed to in writing, software %
	% distributed under the License is distributed on an "AS IS" BASIS, %
	% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. %
	% See the License for the specific language governing permissions and %
	% limitations under the License. %
	% %
	%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
	%
	%
	*/

	/*
	Include declarations.
	*/
	#include "MagickCore/studio.h"
	#include "MagickCore/attribute.h"
	#include "MagickCore/blob.h"
	#include "MagickCore/blob-private.h"
	#include "MagickCore/channel.h"
	#include "MagickCore/color.h"
	#include "MagickCore/color-private.h"
	#include "MagickCore/colorspace-private.h"
	#include "MagickCore/draw.h"
	#include "MagickCore/exception.h"
	#include "MagickCore/exception-private.h"
	#include "MagickCore/image.h"
	#include "MagickCore/image-private.h"
	#include "MagickCore/list.h"
	#include "MagickCore/magick.h"
	#include "MagickCore/memory_.h"
	#include "MagickCore/paint.h"
	#include "MagickCore/pixel-accessor.h"
	#include "MagickCore/quantum-private.h"
	#include "MagickCore/static.h"
	#include "MagickCore/string_.h"
	#include "MagickCore/module.h"
	#include "MagickCore/studio.h"

	/*
	%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
	% %
	% %
	% %
	% R e a d G R A D I E N T I m a g e %
	% %
	% %
	% %
	%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
	%
	% ReadGRADIENTImage creates a gradient image and initializes it to
	% the color range 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 ReadGRADIENTImage method is:
	%
	% Image ReadGRADIENTImage(const ImageInfo image_info,
	% ExceptionInfo *exception)
	%
	% A description of each parameter follows:
	%
	% o image_info: the image info.
	%
	% o exception: return any errors or warnings in this structure.
	%
	*/
	static Image ReadGRADIENTImage(const ImageInfo image_info,
	ExceptionInfo *exception)
	{
	char
	colorname[MaxTextExtent];

	Image
	*image;

	MagickBooleanType
	icc_color,
	status;

	PixelInfo
	start_color,
	stop_color;

	/*
	Initialize Image structure.
	*/
	assert(image_info != (const ImageInfo *) NULL);
	assert(image_info->signature == MagickSignature);
	if (image_info->debug != MagickFalse)
	(void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",
	image_info->filename);
	assert(exception != (ExceptionInfo *) NULL);
	assert(exception->signature == MagickSignature);
	image=AcquireImage(image_info,exception);
	if ((image->columns == 0) \|\| (image->rows == 0))
	ThrowReaderException(OptionError,"MustSpecifyImageSize");
	(void) SetImageAlpha(image,(Quantum) TransparentAlpha,exception);
	(void) CopyMagickString(image->filename,image_info->filename,MaxTextExtent);
	(void) CopyMagickString(colorname,image_info->filename,MaxTextExtent);
	(void) sscanf(image_info->filename,"%[^-]",colorname);
	icc_color=MagickFalse;
	if (LocaleCompare(colorname,"icc") == 0)
	{
	(void) ConcatenateMagickString(colorname,"-",MaxTextExtent);
	(void) sscanf(image_info->filename,"%*[^-]-%[^-]",colorname+4);
	icc_color=MagickTrue;
	}
	status=QueryColorCompliance(colorname,AllCompliance,&start_color,exception);
	if (status == MagickFalse)
	{
	image=DestroyImage(image);
	return((Image *) NULL);
	}
	(void) SetImageColorspace(image,start_color.colorspace,exception);
	(void) CopyMagickString(colorname,"white",MaxTextExtent);
	if (GetPixelInfoIntensity(&start_color) > (Quantum) (QuantumRange/2))
	(void) CopyMagickString(colorname,"black",MaxTextExtent);
	if (icc_color == MagickFalse)
	(void) sscanf(image_info->filename,"%*[^-]-%s",colorname);
	else
	(void) sscanf(image_info->filename,"%[^-]-%[^-]-%s",colorname);
	status=QueryColorCompliance(colorname,AllCompliance,&stop_color,exception);
	if (status == MagickFalse)
	{
	image=DestroyImage(image);
	return((Image *) NULL);
	}
	status=GradientImage(image,LocaleCompare(image_info->magick,"GRADIENT") == 0 ?
	LinearGradient : RadialGradient,PadSpread,&start_color,&stop_color,
	exception);
	if (status == MagickFalse)
	{
	image=DestroyImageList(image);
	return((Image *) NULL);
	}
	if ((start_color.alpha_trait != BlendPixelTrait) &&
	(stop_color.alpha_trait != BlendPixelTrait))
	(void) SetImageAlphaChannel(image,DeactivateAlphaChannel,exception);
	return(GetFirstImageInList(image));
	}

	/*
	%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
	% %
	% %
	% %
	% R e g i s t e r G R A D I E N T I m a g e %
	% %
	% %
	% %
	%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
	%
	% RegisterGRADIENTImage() adds attributes for the GRADIENT 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 RegisterGRADIENTImage method is:
	%
	% size_t RegisterGRADIENTImage(void)
	%
	*/
	ModuleExport size_t RegisterGRADIENTImage(void)
	{
	MagickInfo
	*entry;

	entry=SetMagickInfo("GRADIENT");
	entry->decoder=(DecodeImageHandler *) ReadGRADIENTImage;
	entry->adjoin=MagickFalse;
	entry->raw=MagickTrue;
	entry->format_type=ImplicitFormatType;
	entry->description=ConstantString("Gradual linear passing from one shade to "
	"another");
	entry->module=ConstantString("GRADIENT");
	(void) RegisterMagickInfo(entry);
	entry=SetMagickInfo("RADIAL-GRADIENT");
	entry->decoder=(DecodeImageHandler *) ReadGRADIENTImage;
	entry->adjoin=MagickFalse;
	entry->raw=MagickTrue;
	entry->format_type=ImplicitFormatType;
	entry->description=ConstantString("Gradual radial passing from one shade to "
	"another");
	entry->module=ConstantString("GRADIENT");
	(void) RegisterMagickInfo(entry);
	return(MagickImageCoderSignature);
	}

	/*
	%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
	% %
	% %
	% %
	% U n r e g i s t e r G R A D I E N T I m a g e %
	% %
	% %
	% %
	%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
	%
	% UnregisterGRADIENTImage() removes format registrations made by the
	% GRADIENT module from the list of supported formats.
	%
	% The format of the UnregisterGRADIENTImage method is:
	%
	% UnregisterGRADIENTImage(void)
	%
	*/
	ModuleExport void UnregisterGRADIENTImage(void)
	{
	(void) UnregisterMagickInfo("RADIAL-GRADIENT");
	(void) UnregisterMagickInfo("GRADIENT");
	}