[Vm-dev] VM Maker: VMMaker-tpr.325.mcz

[commits at source.squeak.org]

tim Rowledge uploaded a new version of VMMaker to project VM Maker:
http://source.squeak.org/VMMaker/VMMaker-tpr.325.mcz

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

Name: VMMaker-tpr.325
Author: tpr
Time: 17 September 2013, 5:24:10.53 pm
UUID: 98b93ca5-c360-48e2-8fda-fc64fb165085
Ancestors: VMMaker-dtl.324

(probable) fix for Mantis http://bugs.squeak.org/view.php?id=7247 BitBlt Bug in alphaSourceBlendBits8

=============== Diff against VMMaker-dtl.324 ===============

Item was changed:
  ----- Method: BitBltSimulation>>alphaSourceBlendBits8 (in category 'inner loop') -----
  alphaSourceBlendBits8
  	"This version assumes 
  		combinationRule = 34
  		sourcePixSize = 32
  		destPixSize = 8
  		sourceForm ~= destForm.
  	Note: This is not real blending since we don't have the source colors available.
  	"
  	| srcIndex dstIndex sourceWord srcAlpha destWord deltaX deltaY 
  	srcY dstY dstMask srcShift adjust mappingTable mapperFlags |
  	<inline: false>
  	<var: #mappingTable type:'unsigned int *'>
  	mappingTable := self default8To32Table.
  	mapperFlags := cmFlags bitAnd: ColorMapNewStyle bitInvert32.
  	deltaY := bbH + 1. "So we can pre-decrement"
  	srcY := sy.
  	dstY := dy.
  	mask1 := ((dx bitAnd: 3) * 8).
  	destMSB ifTrue:[mask1 := 24 - mask1].
  	mask2 := AllOnes bitXor:(16rFF << mask1).
  	(dx bitAnd: 1) = 0 
  		ifTrue:[adjust := 0]
  		ifFalse:[adjust := 16r1F1F1F1F].
  	(dy bitAnd: 1) = 0
  		ifTrue:[adjust := adjust bitXor: 16r1F1F1F1F].
  	"This is the outer loop"
  	[(deltaY := deltaY - 1) ~= 0] whileTrue:[
  		adjust := adjust bitXor: 16r1F1F1F1F.
  		srcIndex := sourceBits + (srcY * sourcePitch) + (sx * 4).
  		dstIndex := destBits + (dstY * destPitch) + (dx // 4 * 4).
  		deltaX := bbW + 1. "So we can pre-decrement"
  		srcShift := mask1.
  		dstMask := mask2.
  
  		"This is the inner loop"
  		[(deltaX := deltaX - 1) ~= 0] whileTrue:[
  			sourceWord := ((self srcLongAt: srcIndex) bitAnd: (adjust bitInvert32)) + adjust.
  			srcAlpha := sourceWord >> 24.
  			srcAlpha > 31 ifTrue:["Everything below 31 is transparent"
  				srcAlpha < 224 ifTrue:["Everything above 224 is opaque"
  					destWord := self dstLongAt: dstIndex.
  					destWord := destWord bitAnd: dstMask bitInvert32.
  					destWord := destWord >> srcShift.
  					destWord := mappingTable at: destWord.
  					sourceWord := self alphaBlendScaled: sourceWord with: destWord.
  				].
  				sourceWord := self mapPixel: sourceWord flags: mapperFlags.
  				sourceWord := sourceWord << srcShift.
  				"Store back"
  				self dstLongAt: dstIndex put: sourceWord mask: dstMask.
  			].
  			srcIndex := srcIndex + 4.
  			destMSB ifTrue:[
  				srcShift = 0 
  					ifTrue:[dstIndex := dstIndex + 4.
  							srcShift := 24.
  							dstMask := 16r00FFFFFF]
  					ifFalse:[srcShift := srcShift - 8.
  							dstMask := (dstMask >> 8) bitOr: 16rFF000000].
  			] ifFalse:[
+ 				srcShift = 24
- 				srcShift = 32
  					ifTrue:[dstIndex := dstIndex + 4.
  							srcShift := 0.
  							dstMask := 16rFFFFFF00]
  					ifFalse:[srcShift := srcShift + 8.
  							dstMask := dstMask << 8 bitOr: 255].
  			].
  			adjust := adjust bitXor: 16r1F1F1F1F.
  		].
  		srcY := srcY + 1.
  		dstY := dstY + 1.
  	].!