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 1999-2011 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/draw.h"
  48 #include "MagickCore/exception.h"
  49 #include "MagickCore/exception-private.h"
  50 #include "MagickCore/image.h"
  51 #include "MagickCore/image-private.h"
  52 #include "MagickCore/list.h"
  53 #include "MagickCore/magick.h"
  54 #include "MagickCore/memory_.h"
  55 #include "MagickCore/paint.h"
  56 #include "MagickCore/pixel-accessor.h"
  57 #include "MagickCore/quantum-private.h"
  58 #include "MagickCore/static.h"
  59 #include "MagickCore/string_.h"
  60 #include "MagickCore/module.h"
  61 #include "MagickCore/studio.h"
  62 \f
  63 /*
  64 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  65 %                                                                             %
  66 %                                                                             %
  67 %                                                                             %
  68 %   R e a d G R A D I E N T I m a g e                                         %
  69 %                                                                             %
  70 %                                                                             %
  71 %                                                                             %
  72 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  73 %
  74 %  ReadGRADIENTImage creates a gradient image and initializes it to
  75 %  the color range as specified by the filename.  It allocates the memory
  76 %  necessary for the new Image structure and returns a pointer to the new
  77 %  image.
  78 %
  79 %  The format of the ReadGRADIENTImage method is:
  80 %
  81 %      Image *ReadGRADIENTImage(const ImageInfo *image_info,
  82 %        ExceptionInfo *exception)
  83 %
  84 %  A description of each parameter follows:
  85 %
  86 %    o image_info: the image info.
  87 %
  88 %    o exception: return any errors or warnings in this structure.
  89 %
  90 */
  91 static Image *ReadGRADIENTImage(const ImageInfo *image_info,
  92   ExceptionInfo *exception)
  93 {
  94   char
  95     colorname[MaxTextExtent];
  96
  97   Image
  98     *image;
  99
 100   MagickBooleanType
 101     status;
 102
 103   PixelPacket
 104     start_color,
 105     stop_color;
 106
 107   /*
 108     Initialize Image structure.
 109   */
 110   assert(image_info != (const ImageInfo *) NULL);
 111   assert(image_info->signature == MagickSignature);
 112   if (image_info->debug != MagickFalse)
 113     (void) LogMagickEvent(TraceEvent,GetMagickModule(),"%s",
 114       image_info->filename);
 115   assert(exception != (ExceptionInfo *) NULL);
 116   assert(exception->signature == MagickSignature);
 117   image=AcquireImage(image_info,exception);
 118   if ((image->columns == 0) || (image->rows == 0))
 119     ThrowReaderException(OptionError,"MustSpecifyImageSize");
 120   (void) SetImageAlpha(image,(Quantum) TransparentAlpha);
 121   (void) CopyMagickString(image->filename,image_info->filename,MaxTextExtent);
 122   (void) CopyMagickString(colorname,image_info->filename,MaxTextExtent);
 123   (void) sscanf(image_info->filename,"%[^-]",colorname);
 124   status=QueryColorCompliance(colorname,AllCompliance,&start_color,exception);
 125   if (status == MagickFalse)
 126     {
 127       image=DestroyImage(image);
 128       return((Image *) NULL);
 129     }
 130   (void) CopyMagickString(colorname,"white",MaxTextExtent);
 131   if (GetPixelPacketIntensity(&start_color) > (Quantum) (QuantumRange/2))
 132     (void) CopyMagickString(colorname,"black",MaxTextExtent);
 133   (void) sscanf(image_info->filename,"%*[^-]-%s",colorname);
 134   status=QueryColorCompliance(colorname,AllCompliance,&stop_color,exception);
 135   if (status == MagickFalse)
 136     {
 137       image=DestroyImage(image);
 138       return((Image *) NULL);
 139     }
 140   (void) GradientImage(image,LocaleCompare(image_info->magick,"GRADIENT") == 0 ?
 141     LinearGradient : RadialGradient,PadSpread,&start_color,&stop_color,
 142     exception);
 143   return(GetFirstImageInList(image));
 144 }
 145 \f
 146 /*
 147 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 148 %                                                                             %
 149 %                                                                             %
 150 %                                                                             %
 151 %   R e g i s t e r G R A D I E N T I m a g e                                 %
 152 %                                                                             %
 153 %                                                                             %
 154 %                                                                             %
 155 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 156 %
 157 %  RegisterGRADIENTImage() adds attributes for the GRADIENT image format
 158 %  to the list of supported formats.  The attributes include the image format
 159 %  tag, a method to read and/or write the format, whether the format
 160 %  supports the saving of more than one frame to the same file or blob,
 161 %  whether the format supports native in-memory I/O, and a brief
 162 %  description of the format.
 163 %
 164 %  The format of the RegisterGRADIENTImage method is:
 165 %
 166 %      size_t RegisterGRADIENTImage(void)
 167 %
 168 */
 169 ModuleExport size_t RegisterGRADIENTImage(void)
 170 {
 171   MagickInfo
 172     *entry;
 173
 174   entry=SetMagickInfo("GRADIENT");
 175   entry->decoder=(DecodeImageHandler *) ReadGRADIENTImage;
 176   entry->adjoin=MagickFalse;
 177   entry->raw=MagickTrue;
 178   entry->format_type=ImplicitFormatType;
 179   entry->description=ConstantString("Gradual linear passing from one shade to "
 180     "another");
 181   entry->module=ConstantString("GRADIENT");
 182   (void) RegisterMagickInfo(entry);
 183   entry=SetMagickInfo("RADIAL-GRADIENT");
 184   entry->decoder=(DecodeImageHandler *) ReadGRADIENTImage;
 185   entry->adjoin=MagickFalse;
 186   entry->raw=MagickTrue;
 187   entry->format_type=ImplicitFormatType;
 188   entry->description=ConstantString("Gradual radial passing from one shade to "
 189     "another");
 190   entry->module=ConstantString("GRADIENT");
 191   (void) RegisterMagickInfo(entry);
 192   return(MagickImageCoderSignature);
 193 }
 194 \f
 195 /*
 196 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 197 %                                                                             %
 198 %                                                                             %
 199 %                                                                             %
 200 %   U n r e g i s t e r G R A D I E N T I m a g e                             %
 201 %                                                                             %
 202 %                                                                             %
 203 %                                                                             %
 204 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 205 %
 206 %  UnregisterGRADIENTImage() removes format registrations made by the
 207 %  GRADIENT module from the list of supported formats.
 208 %
 209 %  The format of the UnregisterGRADIENTImage method is:
 210 %
 211 %      UnregisterGRADIENTImage(void)
 212 %
 213 */
 214 ModuleExport void UnregisterGRADIENTImage(void)
 215 {
 216   (void) UnregisterMagickInfo("RADIAL-GRADIENT");
 217   (void) UnregisterMagickInfo("GRADIENT");
 218 }