Offscreen Screencapture? <-- issues that affect image rendering

[Richard Gaskin]

Scott Rossi wrote:
>>>> Not only does it work on XP but on OSX 3.9 as well (tested on 2 machines).
>>>> I know earlier versions of OSX/Rev were said to cause problems, but it seems
>>>> to work as expected here on both platforms, thus this tip really *is*
>>>> godlike.
>>> Crashes here with a kernel protection fault:
>>>
>>> OS X 10.4.4
>>> PowerBook G4 1Ghz
>> Bummer.  Works here, in Rev and MC, OX 10.3.9, Rev 2.6.6, buildNumber 152 (not
>> sure what the latest version is).
> 
> I just tested here with OSX 10.4.4 under MC and the export worked fine.  How
> about I send you my test stack and see if you get a different result.

Works great in your version.

I double-checked the differences between your code and the code on Ken's 
site, and I found that if I just move the line that restores the 
alwaysBuffer of the stack to after the export, it works:


on mouseUp
   put "/Applications/MetaCard/_testers/export wd buffer.rev" into tStack
   put "/Users/richardgaskin/Desktop/stackimage.png" into tPath
   put "PNG" into tType
   ExportCard tStack, tPath, tType
end mouseUp

on ExportCard pStackPath,pExportPath,pImageType
   -- pStackPath is the path to the stack whose card you want to export
   -- pExportPath is where you want the image to go
   -- pImageType is one of the three formats supported by the export
   --   command: paint, png or jpeg
   put the alwaysBuffer of stack pStackPath into tOldBuffer
   -- The next two lines force the current card image
   -- into the offscreen buffer
   set the alwaysBuffer of stack pStackPath to false
   set the alwaysBuffer of stack pStackPath to true
   create invisible image
   -- Here's the 'meat' of the handler:
   set the imagePixMapID of last image to \
      (the pixMapID of stack pStackPath)
   select last image
   --!NOT HERE  set the alwaysBuffer of stack pStackPath to tOldBuffer

   do "export" && pImageType && "to file pExportPath"
   delete last image

   -- HERE INSTEAD:
   set the alwaysBuffer of stack pStackPath to tOldBuffer

   choose browse tool
end ExportCard



-- 
  Richard Gaskin
  Fourth World Media Corporation
  ___________________________________________________________
  Ambassador at FourthWorld.com       http://www.FourthWorld.com