coders/label.c

/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%                     L       AAA   BBBB   EEEEE  L                           %
%                     L      A   A  B   B  E      L                           %
%                     L      AAAAA  BBBB   EEE    L                           %
%                     L      A   A  B   B  E      L                           %
%                     LLLLL  A   A  BBBB   EEEEE  LLLLL                       %
%                                                                             %
%                                                                             %
%                      Read ASCII String As An Image.                         %
%                                                                             %
%                              Software Design                                %
%                                John Cristy                                  %
%                                 July 1992                                   %
%                                                                             %
%                                                                             %
%  Copyright 1999-2012 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/annotate.h"
#include "MagickCore/blob.h"
#include "MagickCore/blob-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/property.h"
#include "MagickCore/quantum-private.h"
#include "MagickCore/static.h"
#include "MagickCore/string_.h"
#include "MagickCore/module.h"
#include "MagickCore/utility.h"

/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%   R e a d L A B E L I m a g e                                               %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  ReadLABELImage() reads a LABEL image file and returns it.  It
%  allocates the memory necessary for the new Image structure and returns a
%  pointer to the new image.
%
%  The format of the ReadLABELImage method is:
%
%      Image *ReadLABELImage(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 *ReadLABELImage(const ImageInfo *image_info,
  ExceptionInfo *exception)
{
  char
    geometry[MaxTextExtent],
    *property;

  const char
    *label;

  DrawInfo
    *draw_info;

  Image
    *image;

  MagickBooleanType
    status;

  TypeMetric
    metrics;

  size_t
    height,
    width;

  /*
    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);
  (void) ResetImagePage(image,"0x0+0+0");
  property=InterpretImageProperties(image_info,image,image_info->filename,
    exception);
  (void) SetImageProperty(image,"label",property,exception);
  property=DestroyString(property);
  label=GetImageProperty(image,"label",exception);
  draw_info=CloneDrawInfo(image_info,(DrawInfo *) NULL);
  draw_info->text=ConstantString(label);
  if ((*label != '\0') && (image->rows != 0) && (image_info->pointsize == 0.0))
    {
      double
        high,
        low;

      /*
        Auto fit text into bounding box.
      */
      status=GetMultilineTypeMetrics(image,draw_info,&metrics,exception);
      for ( ; ; )
      {
        (void) FormatLocaleString(geometry,MaxTextExtent,"%+g%+g",
          -metrics.bounds.x1,metrics.ascent);
        if (draw_info->gravity == UndefinedGravity)
          (void) CloneString(&draw_info->geometry,geometry);
        status=GetMultilineTypeMetrics(image,draw_info,&metrics,exception);
        (void) status;
        width=(size_t) floor(metrics.width+draw_info->stroke_width+0.5);
        height=(size_t) floor(metrics.height+draw_info->stroke_width+0.5);
        if ((width > image->columns) && (height > image->rows))
          break;
        draw_info->pointsize*=2.0;
      }
      high=draw_info->pointsize/2.0;
      low=high/2.0;
      while ((high-low) > 1.0)
      {
        draw_info->pointsize=(low+high)/2.0;
        (void) FormatLocaleString(geometry,MaxTextExtent,"%+g%+g",
          -metrics.bounds.x1,metrics.ascent);
        if (draw_info->gravity == UndefinedGravity)
          (void) CloneString(&draw_info->geometry,geometry);
        status=GetMultilineTypeMetrics(image,draw_info,&metrics,exception);
        width=(size_t) floor(metrics.width+draw_info->stroke_width+0.5);
        height=(size_t) floor(metrics.height+draw_info->stroke_width+0.5);
        if ((width <= image->columns) && (height <= image->rows))
          low=draw_info->pointsize+1.0;
        else
          high=draw_info->pointsize-1.0;
      }
      for (draw_info->pointsize=(low+high)/2.0; ; )
      {
        (void) FormatLocaleString(geometry,MaxTextExtent,"%+g%+g",
          -metrics.bounds.x1,metrics.ascent);
        if (draw_info->gravity == UndefinedGravity)
          (void) CloneString(&draw_info->geometry,geometry);
        status=GetMultilineTypeMetrics(image,draw_info,&metrics,exception);
        width=(size_t) floor(metrics.width+draw_info->stroke_width+0.5);
        height=(size_t) floor(metrics.height+draw_info->stroke_width+0.5);
        if ((width <= image->columns) && (height <= image->rows))
          break;
        draw_info->pointsize--;
      }
      draw_info->pointsize=floor(draw_info->pointsize);
    }
  status=GetMultilineTypeMetrics(image,draw_info,&metrics,exception);
  if (status == MagickFalse)
    {
      image=DestroyImageList(image);
      return((Image *) NULL);
    }
  if (image->columns == 0)
    image->columns=(size_t) (metrics.width+draw_info->stroke_width+1.5);
  if (image->columns == 0)
    image->columns=(size_t) (draw_info->pointsize+draw_info->stroke_width+1.5);
  if (draw_info->gravity == UndefinedGravity)
    {
      (void) FormatLocaleString(geometry,MaxTextExtent,"%+g%+g",
        -metrics.bounds.x1+draw_info->stroke_width/2.0,metrics.ascent+
        draw_info->stroke_width/2.0);
      (void) CloneString(&draw_info->geometry,geometry);
    }
  if (draw_info->direction == RightToLeftDirection)
    {
      if (draw_info->direction == RightToLeftDirection)
        (void) FormatLocaleString(geometry,MaxTextExtent,"%+g%+g",
          image->columns-(metrics.bounds.x2+draw_info->stroke_width/2.0),
          metrics.ascent+draw_info->stroke_width/2.0);
      (void) CloneString(&draw_info->geometry,geometry);
    }
  if (image->rows == 0)
    image->rows=(size_t) floor(metrics.height+draw_info->stroke_width+0.5);
  if (image->rows == 0)
    image->rows=(size_t) floor(draw_info->pointsize+draw_info->stroke_width+
      0.5);
  if (SetImageBackgroundColor(image,exception) == MagickFalse)
    {
      image=DestroyImageList(image);
      return((Image *) NULL);
    }
  (void) AnnotateImage(image,draw_info,exception);
  if (image_info->pointsize == 0.0)
    {
      char
        pointsize[MaxTextExtent];

      (void) FormatLocaleString(pointsize,MaxTextExtent,"%.20g",
        draw_info->pointsize);
      (void) SetImageProperty(image,"label:pointsize",pointsize,exception);
    }
  draw_info=DestroyDrawInfo(draw_info);
  return(GetFirstImageInList(image));
}

/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%   R e g i s t e r L A B E L I m a g e                                       %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  RegisterLABELImage() adds properties for the LABEL image format to
%  the list of supported formats.  The properties 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 RegisterLABELImage method is:
%
%      size_t RegisterLABELImage(void)
%
*/
ModuleExport size_t RegisterLABELImage(void)
{
  MagickInfo
    *entry;

  entry=SetMagickInfo("LABEL");
  entry->decoder=(DecodeImageHandler *) ReadLABELImage;
  entry->adjoin=MagickFalse;
  entry->format_type=ImplicitFormatType;
  entry->description=ConstantString("Image label");
  entry->module=ConstantString("LABEL");
  (void) RegisterMagickInfo(entry);
  return(MagickImageCoderSignature);
}

/*
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%                                                                             %
%                                                                             %
%                                                                             %
%   U n r e g i s t e r L A B E L I m a g e                                   %
%                                                                             %
%                                                                             %
%                                                                             %
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%  UnregisterLABELImage() removes format registrations made by the
%  LABEL module from the list of supported formats.
%
%  The format of the UnregisterLABELImage method is:
%
%      UnregisterLABELImage(void)
%
*/
ModuleExport void UnregisterLABELImage(void)
{
  (void) UnregisterMagickInfo("LABEL");
}