[etoys-dev] Etoys: Morphic-bf.12.mcz

[commits at source.squeak.org]

Bert Freudenberg uploaded a new version of Morphic to project Etoys:
http://source.squeak.org/etoys/Morphic-bf.12.mcz

==================== Summary ====================

Name: Morphic-bf.12
Author: bf
Time: 30 May 2010, 11:53:56 pm
UUID: a7f4a3c2-17fc-4976-ba3d-d4bc1c11880d
Ancestors: Morphic-kfr.11

 - move overlapsShadowForm:bounds: back to Morphic package

=============== Diff against Morphic-kfr.11 ===============

Item was added:
+ ----- Method: Morph>>overlapsShadowForm:bounds: (in category 'geometry') -----
+ overlapsShadowForm: itsShadow bounds: itsBounds
+ 	"Answer true if itsShadow and my shadow overlap at all"
+ 	| overlapExtent overlap myRect myShadow goalRect goalShadow bb |
+ 	overlap _ self fullBounds intersect: itsBounds.
+ 	overlapExtent _ overlap extent.
+ 	overlapExtent > (0 @ 0)
+ 		ifFalse: [^ false].
+ 	myRect := overlap translateBy: 0 @ 0 - self topLeft.
+ 	myShadow := (self imageForm contentsOfArea: myRect) stencil.
+ 	goalRect := overlap translateBy: 0 @ 0 - itsBounds topLeft.
+ 	goalShadow := (itsShadow contentsOfArea: goalRect) stencil.
+ 
+ 			"compute a pixel-by-pixel AND of the two stencils.  Result will be black 
+ 			(pixel value = 1) where black parts of the stencils overlap"
+ 			bb := BitBlt toForm: myShadow.
+ 			bb 
+ 				copyForm: goalShadow
+ 				to: 0 @ 0
+ 				rule: Form and.
+ 	
+ 	^(bb destForm tallyPixelValues second) > 0 !