granicus.if.org Git - imagemagick/blob - coders/gradient.c

   1 /*
   2 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
   3 %                                                                             %
   4 %                                                                             %
   5 %                                                                             %
   6 %            GGGG  RRRR    AAA   DDDD   IIIII  EEEEE  N   N  TTTTT            %
   7 %           G      R   R  A   A  D   D    I    E      NN  N    T              %
   8 %           G  GG  RRRR   AAAAA  D   D    I    EEE    N N N    T              %
   9 %           G   G  R R    A   A  D   D    I    E      N  NN    T              %
  10 %            GGG   R  R   A   A  DDDD   IIIII  EEEEE  N   N    T              %
  11 %                                                                             %
  12 %                                                                             %
  13 %                   Read An Image Filled Using Gradient.                      %
  14 %                                                                             %
  15 %                              Software Design                                %
  16 %                                John Cristy                                  %
  17 %                                 July 1992                                   %
  18 %                                                                             %
  19 %                                                                             %
  20 %  Copyright 1999-2012 ImageMagick Studio LLC, a non-profit organization      %
  21 %  dedicated to making software imaging solutions freely available.           %
  22 %                                                                             %
  23 %  You may not use this file except in compliance with the License.  You may  %
  24 %  obtain a copy of the License at                                            %
  25 %                                                                             %
  26 %    http://www.imagemagick.org/script/license.php                            %
  27 %                                                                             %
  28 %  Unless required by applicable law or agreed to in writing, software        %
  29 %  distributed under the License is distributed on an "AS IS" BASIS,          %
  30 %  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.   %
  31 %  See the License for the specific language governing permissions and        %
  32 %  limitations under the License.                                             %
  33 %                                                                             %
  34 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  35 %
  36 %
  37 */
  38 \f
  39 /*
  40   Include declarations.
  41 */
  42 #include "MagickCore/studio.h"
  43 #include "MagickCore/attribute.h"
  44 #include "MagickCore/blob.h"
  45 #include "MagickCore/blob-private.h"
  46 #include "MagickCore/color.h"
  47 #include "MagickCore/color-private.h"
  48 #include "MagickCore/colorspace-private.h"
  49 #include "MagickCore/draw.h"
  50 #include "MagickCore/exception.h"
  51 #include "MagickCore/exception-private.h"
  52 #include "MagickCore/image.h"
  53 #include "MagickCore/image-private.h"
  54 #include "MagickCore/list.h"
  55 #include "MagickCore/magick.h"
  56 #include "MagickCore/memory_.h"
  57 #include "MagickCore/paint.h"
  58 #include "MagickCore/pixel-accessor.h"
  59 #include "MagickCore/quantum-private.h"
  60 #include "MagickCore/static.h"
  61 #include "MagickCore/string_.h"
  62 #include "MagickCore/module.h"
  63 #include "MagickCore/studio.h"
  64 \f
  65 /*
  66 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  67 %                                                                             %
  68 %                                                                             %
  69 %                                                                             %
  70 %   R e a d G R A D I E N T I m a g e                                         %
  71 %                                                                             %
  72 %                                                                             %
  73 %                                                                             %
  74 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  75 %
  76 %  ReadGRADIENTImage creates a gradient image and initializes it to
  77 %  the color range as specified by the filename.  It allocates the memory
  78 %  necessary for the new Image structure and returns a pointer to the new
  79 %  image.
  80 %
  81 %  The format of the ReadGRADIENTImage method is:
  82 %
  83 %      Image *ReadGRADIENTImage(const ImageInfo *image_info,
  84 %        ExceptionInfo *exception)
  85 %
  86 %  A description of each parameter follows:
  87 %
  88 %    o image_info: the image info.
  89 %
  90 %    o exception: return any errors or warnings in this structure.
  91 %
  92 */
  93 static Image *ReadGRADIENTImage(const ImageInfo *image_info,
  94   ExceptionInfo *exception)
  95 {
  96   char
  97     colorname[MaxTextExtent];
  98
  99   Image
 100     *image;
 101
 102   MagickBooleanType
 103     icc_color,
 104     status;
 105
 106   PixelInfo
 107     start_color,
 108     stop_color;
 109
 110   /*
 111     Initialize Image structure.
 112   */
 113   assert(image_info != (const ImageInfo *) NULL);
 114   assert(image_info->signature == MagickSignature);
 115   if (image_info->debug != MagickFalse)
 116     (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",
 117       image_info->filename);
 118   assert(exception != (ExceptionInfo *) NULL);
 119   assert(exception->signature == MagickSignature);
 120   image=AcquireImage(image_info,exception);
 121   if ((image->columns == 0) || (image->rows == 0))
 122     ThrowReaderException(OptionError,"MustSpecifyImageSize");
 123   (void) SetImageAlpha(image,(Quantum) TransparentAlpha,exception);
 124   (void) CopyMagickString(image->filename,image_info->filename,MaxTextExtent);
 125   (void) CopyMagickString(colorname,image_info->filename,MaxTextExtent);
 126   (void) sscanf(image_info->filename,"%[^-]",colorname);
 127   icc_color=MagickFalse;
 128   if (LocaleCompare(colorname,"icc") == 0)
 129     {
 130       (void) ConcatenateMagickString(colorname,"-",MaxTextExtent);
 131       (void) sscanf(image_info->filename,"%*[^-]-%[^-]",colorname+4);
 132       icc_color=MagickTrue;
 133     }
 134   status=QueryColorCompliance(colorname,AllCompliance,&start_color,exception);
 135   if (status == MagickFalse)
 136     {
 137       image=DestroyImage(image);
 138       return((Image *) NULL);
 139     }
 140   (void) CopyMagickString(colorname,"white",MaxTextExtent);
 141   if (GetPixelInfoIntensity(&start_color) > (Quantum) (QuantumRange/2))
 142     (void) CopyMagickString(colorname,"black",MaxTextExtent);
 143   if (icc_color == MagickFalse)
 144     (void) sscanf(image_info->filename,"%*[^-]-%s",colorname);
 145   else
 146     (void) sscanf(image_info->filename,"%*[^-]-%*[^-]-%s",colorname);
 147   status=QueryColorCompliance(colorname,AllCompliance,&stop_color,exception);
 148   if (status == MagickFalse)
 149     {
 150       image=DestroyImage(image);
 151       return((Image *) NULL);
 152     }
 153   status=GradientImage(image,LocaleCompare(image_info->magick,"GRADIENT") == 0 ?
 154     LinearGradient : RadialGradient,PadSpread,&start_color,&stop_color,
 155     exception);
 156   if (status == MagickFalse)
 157     {
 158       image=DestroyImageList(image);
 159       return((Image *) NULL);
 160     }
 161   if ((start_color.matte == MagickFalse) && (stop_color.matte == MagickFalse))
 162     (void) SetImageAlphaChannel(image,DeactivateAlphaChannel,exception);
 163   return(GetFirstImageInList(image));
 164 }
 165 \f
 166 /*
 167 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 168 %                                                                             %
 169 %                                                                             %
 170 %                                                                             %
 171 %   R e g i s t e r G R A D I E N T I m a g e                                 %
 172 %                                                                             %
 173 %                                                                             %
 174 %                                                                             %
 175 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 176 %
 177 %  RegisterGRADIENTImage() adds attributes for the GRADIENT image format
 178 %  to the list of supported formats.  The attributes include the image format
 179 %  tag, a method to read and/or write the format, whether the format
 180 %  supports the saving of more than one frame to the same file or blob,
 181 %  whether the format supports native in-memory I/O, and a brief
 182 %  description of the format.
 183 %
 184 %  The format of the RegisterGRADIENTImage method is:
 185 %
 186 %      size_t RegisterGRADIENTImage(void)
 187 %
 188 */
 189 ModuleExport size_t RegisterGRADIENTImage(void)
 190 {
 191   MagickInfo
 192     *entry;
 193
 194   entry=SetMagickInfo("GRADIENT");
 195   entry->decoder=(DecodeImageHandler *) ReadGRADIENTImage;
 196   entry->adjoin=MagickFalse;
 197   entry->raw=MagickTrue;
 198   entry->format_type=ImplicitFormatType;
 199   entry->description=ConstantString("Gradual linear passing from one shade to "
 200     "another");
 201   entry->module=ConstantString("GRADIENT");
 202   (void) RegisterMagickInfo(entry);
 203   entry=SetMagickInfo("RADIAL-GRADIENT");
 204   entry->decoder=(DecodeImageHandler *) ReadGRADIENTImage;
 205   entry->adjoin=MagickFalse;
 206   entry->raw=MagickTrue;
 207   entry->format_type=ImplicitFormatType;
 208   entry->description=ConstantString("Gradual radial passing from one shade to "
 209     "another");
 210   entry->module=ConstantString("GRADIENT");
 211   (void) RegisterMagickInfo(entry);
 212   return(MagickImageCoderSignature);
 213 }
 214 \f
 215 /*
 216 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 217 %                                                                             %
 218 %                                                                             %
 219 %                                                                             %
 220 %   U n r e g i s t e r G R A D I E N T I m a g e                             %
 221 %                                                                             %
 222 %                                                                             %
 223 %                                                                             %
 224 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 225 %
 226 %  UnregisterGRADIENTImage() removes format registrations made by the
 227 %  GRADIENT module from the list of supported formats.
 228 %
 229 %  The format of the UnregisterGRADIENTImage method is:
 230 %
 231 %      UnregisterGRADIENTImage(void)
 232 %
 233 */
 234 ModuleExport void UnregisterGRADIENTImage(void)
 235 {
 236   (void) UnregisterMagickInfo("RADIAL-GRADIENT");
 237   (void) UnregisterMagickInfo("GRADIENT");
 238 }