Extent and geometry

[rmabry]

Below is the latest code in Magick.xs, around line 9695. Notice the placement of these two lines, about 15 lines into the snippet:

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geometry.x=(-geometry.x);
geometry.y=(-geometry.y);

This negation puzzles me, but no matter; it is in the regular API, too, not just in PerlMagick. But it seems to me that those two lines need to be moved down, perhaps just before the call to ExtentImage. Otherwise there is a difference between entering x and y separately versus embedded in a geometry string.

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        case 93:  /* Extent */
        {
          if (attribute_flag[7] != 0)
            image->gravity=(GravityType) argument_list[7].integer_reference;
          if (attribute_flag[0] != 0)
            {
              int
                flags;

              flags=ParseGravityGeometry(image,
                argument_list[0].string_reference,&geometry,exception);
              if (geometry.width == 0)
                geometry.width=image->columns;
              if (geometry.height == 0)
                geometry.height=image->rows;
              geometry.x=(-geometry.x);
              geometry.y=(-geometry.y);
            }
          if (attribute_flag[1] != 0)
            geometry.width=argument_list[1].integer_reference;
          if (attribute_flag[2] != 0)
            geometry.height=argument_list[2].integer_reference;
          if (attribute_flag[3] != 0)
            geometry.x=argument_list[3].integer_reference;
          if (attribute_flag[4] != 0)
            geometry.y=argument_list[4].integer_reference;
          if (attribute_flag[5] != 0)
            image->fuzz=SiPrefixToDouble(argument_list[5].string_reference,
              QuantumRange);
          if (attribute_flag[6] != 0)
            (void) QueryColorDatabase(argument_list[6].string_reference,
              &image->background_color,exception);
          image=ExtentImage(image,&geometry,exception);
          break;

I discovered this when an old program suddenly didn't run anymore. If I negate the x and y it works, but it makes no sense (to me) to do that. That is, the following Perl code used to work.

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	 $subImage->Extent(width => 2*$r+1, height => 2*$r+1, x => $x0-$r, y => $y0-$r); 

Both of these now work, but the first seems wrong:

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	 $subImage->Extent(width => 2*$r+1, height => 2*$r+1, x => -($x0-$r), y => -($y0-$r)); 

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	my $extGeom = sprintf("%dx%d+%d+%d", 2*$r+1, 2*$r+1, $x0-$r, $y0-$r);
	$subImage->Extent(geometry => $extGeom); 

Bug?

Rick

[magick]

We'll get a patch into ImageMagick 6.6.4-2 Beta by sometime tomorrow to fix the problem you reported. Thanks.