Chagall Reference  Block parameters <Control-B>)  12.5.93
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   The block parameters are relevant for working 
   with virtually all block functions: You can
   reach this dialog not only via the corresponding 
   entry in the 'Options' menu, but also by a 
   double-click on any desired button in the
   Toolbox Functions..\..\MENU\TOOLBOX\FUNCTION\FUNCTION.

   'White is transparent'
     ensures that when you paste a block, white areas
     are not solid but transparent (i.e. they do not 
     cover the underlying picture). This allows you 
     to insert objects that do not have a rectangular 
     boundary easily into a picture withoput destroying 
     the existing background.
     Selecting a 'Tolerance' value ensures that not 
     only pure white, but -- depending on the tolerance
     level -- also 'dirty' off-white tones have this 
     property. A tolerance of 0% means that only true
     pure white will act as transparent.
    
   'Swap blocks'
     is always helpful when you move a block from
     one picture into another picture in which a 
     block is already defined. If the 'Swap blocks'
     option has been activated earlier, then Chagall
     exchanges the blocks between the two pictures,
     rather than overwriting the block in the target
     picture.
   
   'Move in real time'
     is a practical function, which however takes up 
     a relatively long calculation time and should 
     therefore be used only when it is really needed
     (e.g. for accurately fitting a block into place): 
     It ensures that when moving a block not just the 
     frame, but the complete block contents will be  
     displayed.

   'Use Clipboard'
     If this option is activated, Chagall will use the
     GEM-Clipboard to store a block. This allows simple 
     exchange of data with other programs that also 
     the Clipboard. However, since the GEM-Clipboard 
     basically works slower than the internal block-buffer, 
     you should activate this option only if you really 
     want to use the GEM-Clipboard.
   
   'Monochrome XOR'
     permits the insertion of monochrome blocks with a
     logical exclusive-or combination.
     
   'Coverage'
     Here you can choose if the block should be pasted in 
     as solid or transparent. Values between 0 - 100% are 
     selectable for this.
     
   'Respect mask during Cut'
   'Respect mask during Paste'
     decides to what extent the mask will be taken account
     of during block operations. If the mask is respected 
     during the cut (or copy) operation then the resulting 
     block will contain that part of the picture that arises 
     from applying the mask at the source. In contrast to 
     this, respecting the mask during the paste operation
     results in the mask at the target position being 
     applied to the block before it is pasted in.
