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/blob.h"
  44 #include "MagickCore/blob-private.h"
  45 #include "MagickCore/color.h"
  46 #include "MagickCore/color-private.h"
  47 #include "MagickCore/colorspace-private.h"
  48 #include "MagickCore/draw.h"
  49 #include "MagickCore/exception.h"
  50 #include "MagickCore/exception-private.h"
  51 #include "MagickCore/image.h"
  52 #include "MagickCore/image-private.h"
  53 #include "MagickCore/list.h"
  54 #include "MagickCore/magick.h"
  55 #include "MagickCore/memory_.h"
  56 #include "MagickCore/paint.h"
  57 #include "MagickCore/pixel-accessor.h"
  58 #include "MagickCore/quantum-private.h"
  59 #include "MagickCore/static.h"
  60 #include "MagickCore/string_.h"
  61 #include "MagickCore/module.h"
  62 #include "MagickCore/studio.h"
  63 \f
  64 /*
  65 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  66 %                                                                             %
  67 %                                                                             %
  68 %                                                                             %
  69 %   R e a d G R A D I E N T I m a g e                                         %
  70 %                                                                             %
  71 %                                                                             %
  72 %                                                                             %
  73 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  74 %
  75 %  ReadGRADIENTImage creates a gradient image and initializes it to
  76 %  the color range as specified by the filename.  It allocates the memory
  77 %  necessary for the new Image structure and returns a pointer to the new
  78 %  image.
  79 %
  80 %  The format of the ReadGRADIENTImage method is:
  81 %
  82 %      Image *ReadGRADIENTImage(const ImageInfo *image_info,
  83 %        ExceptionInfo *exception)
  84 %
  85 %  A description of each parameter follows:
  86 %
  87 %    o image_info: the image info.
  88 %
  89 %    o exception: return any errors or warnings in this structure.
  90 %
  91 */
  92 static Image *ReadGRADIENTImage(const ImageInfo *image_info,
  93   ExceptionInfo *exception)
  94 {
  95   char
  96     colorname[MaxTextExtent];
  97
  98   Image
  99     *image;
 100
 101   MagickBooleanType
 102     status;
 103
 104   PixelInfo
 105     start_color,
 106     stop_color;
 107
 108   /*
 109     Initialize Image structure.
 110   */
 111   assert(image_info != (const ImageInfo *) NULL);
 112   assert(image_info->signature == MagickSignature);
 113   if (image_info->debug != MagickFalse)
 114     (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",
 115       image_info->filename);
 116   assert(exception != (ExceptionInfo *) NULL);
 117   assert(exception->signature == MagickSignature);
 118   image=AcquireImage(image_info,exception);
 119   if ((image->columns == 0) || (image->rows == 0))
 120     ThrowReaderException(OptionError,"MustSpecifyImageSize");
 121   (void) SetImageAlpha(image,(Quantum) TransparentAlpha,exception);
 122   (void) CopyMagickString(image->filename,image_info->filename,MaxTextExtent);
 123   (void) CopyMagickString(colorname,image_info->filename,MaxTextExtent);
 124   (void) sscanf(image_info->filename,"%[^-]",colorname);
 125   status=QueryColorCompliance(colorname,AllCompliance,&start_color,exception);
 126   if (status == MagickFalse)
 127     {
 128       image=DestroyImage(image);
 129       return((Image *) NULL);
 130     }
 131   (void) CopyMagickString(colorname,"white",MaxTextExtent);
 132   if (GetPixelInfoIntensity(&start_color) > (Quantum) (QuantumRange/2))
 133     (void) CopyMagickString(colorname,"black",MaxTextExtent);
 134   (void) sscanf(image_info->filename,"%*[^-]-%s",colorname);
 135   status=QueryColorCompliance(colorname,AllCompliance,&stop_color,exception);
 136   if (status == MagickFalse)
 137     {
 138       image=DestroyImage(image);
 139       return((Image *) NULL);
 140     }
 141   if (IssRGBColorspace(start_color.colorspace) != MagickFalse)
 142     {
 143       start_color.red=QuantumRange*DecompandsRGB(QuantumScale*
 144         start_color.red);
 145       start_color.green=QuantumRange*DecompandsRGB(QuantumScale*
 146         start_color.green);
 147       start_color.blue=QuantumRange*DecompandsRGB(QuantumScale*
 148         start_color.blue);
 149     }
 150   if (IssRGBColorspace(stop_color.colorspace) != MagickFalse)
 151     {
 152       stop_color.red=QuantumRange*DecompandsRGB(QuantumScale*
 153         stop_color.red);
 154       stop_color.green=QuantumRange*DecompandsRGB(QuantumScale*
 155         stop_color.green);
 156       stop_color.blue=QuantumRange*DecompandsRGB(QuantumScale*
 157         stop_color.blue);
 158     }
 159   status=GradientImage(image,LocaleCompare(image_info->magick,"GRADIENT") == 0 ?
 160     LinearGradient : RadialGradient,PadSpread,&start_color,&stop_color,
 161     exception);
 162   if (status == MagickFalse)
 163     {
 164       image=DestroyImageList(image);
 165       return((Image *) NULL);
 166     }
 167   (void) SetImageColorspace(image,start_color.colorspace,exception);
 168   if ((start_color.matte == MagickFalse) && (stop_color.matte == MagickFalse))
 169     (void) SetImageAlphaChannel(image,DeactivateAlphaChannel,exception);
 170   if (IssRGBColorspace(start_color.colorspace) != MagickFalse)
 171     {
 172       (void) SetImageColorspace(image,RGBColorspace,exception);
 173       (void) TransformImageColorspace(image,sRGBColorspace,exception);
 174     }
 175   return(GetFirstImageInList(image));
 176 }
 177 \f
 178 /*
 179 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 180 %                                                                             %
 181 %                                                                             %
 182 %                                                                             %
 183 %   R e g i s t e r G R A D I E N T I m a g e                                 %
 184 %                                                                             %
 185 %                                                                             %
 186 %                                                                             %
 187 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 188 %
 189 %  RegisterGRADIENTImage() adds attributes for the GRADIENT image format
 190 %  to the list of supported formats.  The attributes include the image format
 191 %  tag, a method to read and/or write the format, whether the format
 192 %  supports the saving of more than one frame to the same file or blob,
 193 %  whether the format supports native in-memory I/O, and a brief
 194 %  description of the format.
 195 %
 196 %  The format of the RegisterGRADIENTImage method is:
 197 %
 198 %      size_t RegisterGRADIENTImage(void)
 199 %
 200 */
 201 ModuleExport size_t RegisterGRADIENTImage(void)
 202 {
 203   MagickInfo
 204     *entry;
 205
 206   entry=SetMagickInfo("GRADIENT");
 207   entry->decoder=(DecodeImageHandler *) ReadGRADIENTImage;
 208   entry->adjoin=MagickFalse;
 209   entry->raw=MagickTrue;
 210   entry->format_type=ImplicitFormatType;
 211   entry->description=ConstantString("Gradual linear passing from one shade to "
 212     "another");
 213   entry->module=ConstantString("GRADIENT");
 214   (void) RegisterMagickInfo(entry);
 215   entry=SetMagickInfo("RADIAL-GRADIENT");
 216   entry->decoder=(DecodeImageHandler *) ReadGRADIENTImage;
 217   entry->adjoin=MagickFalse;
 218   entry->raw=MagickTrue;
 219   entry->format_type=ImplicitFormatType;
 220   entry->description=ConstantString("Gradual radial passing from one shade to "
 221     "another");
 222   entry->module=ConstantString("GRADIENT");
 223   (void) RegisterMagickInfo(entry);
 224   return(MagickImageCoderSignature);
 225 }
 226 \f
 227 /*
 228 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 229 %                                                                             %
 230 %                                                                             %
 231 %                                                                             %
 232 %   U n r e g i s t e r G R A D I E N T I m a g e                             %
 233 %                                                                             %
 234 %                                                                             %
 235 %                                                                             %
 236 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 237 %
 238 %  UnregisterGRADIENTImage() removes format registrations made by the
 239 %  GRADIENT module from the list of supported formats.
 240 %
 241 %  The format of the UnregisterGRADIENTImage method is:
 242 %
 243 %      UnregisterGRADIENTImage(void)
 244 %
 245 */
 246 ModuleExport void UnregisterGRADIENTImage(void)
 247 {
 248   (void) UnregisterMagickInfo("RADIAL-GRADIENT");
 249   (void) UnregisterMagickInfo("GRADIENT");
 250 }