EMF Import: Semi-transparent object disappear

Confirmed on WIndows XP, Inkscape rev. 21460.

partial solution committed to bzr rev 10136. The proper solution would involve applying a dib pattern brush. Since I don't know how to do that, I have applied a solid color instead, which also helps with 4 rectangles in Bug 382420 as well.

r10136 was backported to the 0.48.x branch in revision 9803 (milestone 0.48.2).

- attached is the file Percentage Graph_12472.svg, obtained by importing the file Percentage Graph.emf into Windows XP, Inkscape rev 12472
   - this is a partially correct solution, as mentioned in comment 3 above

- attached is the file Percentage Graph_12496.svg, obtained by importing the file Percentage Graph.emf into Windows XP, Inkscape rev 12496
  - this file has two separate problems:
   - 1. the svg file appears to be blank, due to the same white rectangle that is present in Bug 481242
  - 2. after moving the rectangle, the underlying bar graph is black instead of the desired blue.

  It is not clear whether the bar graph is being displayed as a solid color or a dib pattern brush. It would probably be necessary to fix the first two problems before addressing the issue of pattern brush.

When built on Windows the preview for EMF files is apparently using the GDI libraries. GDI can handle all of the paint aspects of EMF files, Inkscape cannot. When Inkscape reads the EMF file it has to make objects out of the series of records, and when those records consist largely of raster mixing operations, the resulting import will not be very good. That is the case with this example.

On Linux and presumably OS X preview is "not available" and the discrepancy does not occur.

the behaviour of the preview is not relevant to this bug report. As mentioned in comment 5, the regression in behaviour is in the loaded file, not the preview.

OK. This is another file that uses umpteen BitBlt operations to set the color of rectangular areas. It will not work properly in Inkscape as those are intrinsically raster paint operations. Use Metafile Explorer to step through it and you will see that it does 3 bitblt's per graph bar. Note also that this example does not render the same in Metafile Explorer as it does in XP Preview, having a dither like pattern in the former, and solid bars in the latter.

On the plus side, this one does have EMF+ records, and those are simple - just rectangular draws with RGBA colors. So if I ever finish the EMF+ implementation the file should read in more cleanly that way. (They ditched the bitblt nonsense in EMF+.)