Marcel Taeumel uploaded a new version of Graphics to project The Trunk:
http://source.squeak.org/trunk/Graphics-kfr.530.mcz

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

Name: Graphics-kfr.530
Author: kfr
Time: 9 August 2022, 7:12:20.983085 am
UUID: ee4a3ab4-fc38-f349-b0bc-f6f109ba9d01
Ancestors: Graphics-kfr.529

Avoid call to allButFirstDo: in Rectangle class>>encompassing: and Rectangle class>>merging:. 
But keep the call to Rectangle class>>origin: corner: so subclasses can use these methods

=============== Diff against Graphics-kfr.527 ===============

Item was added:
+ ----- Method: Form>>at:bias: (in category 'processing') -----
+ at: aPoint bias: aQuantError 
+ 	| x y color point oldColor |
+ 	x := aPoint x.
+ 	y := aPoint y.
+ 	
+ 	point := (x + 1 min: self width)@ y.
+ 	oldColor := self colorAt: point.
+ 	color := oldColor +  (aQuantError *  0.4375). "7/16"
+ 	self colorAt: point put: color.
+ 	
+ 	point :=  (x - 1 max: 0)@ (y + 1 min: self height).
+ 	oldColor := self colorAt: point.
+ 	color := oldColor +  (aQuantError *  0.1875)."3/16"
+ 	self colorAt: point put: color.
+ 	
+ 	point := x @ (y + 1 min: self height).
+ 	oldColor := self colorAt: point.
+ 	color := oldColor +  (aQuantError *  0.3125 ) ."5/16"
+ 	self colorAt: point put: color.
+ 	
+ 	point := (x + 1 min: self width) @ (y + 1  min: self height).
+ 	oldColor := self colorAt: point.
+ 	color := oldColor +  (aQuantError *  0.0625 ) ."1/16"
+ 	self colorAt: point put: color.
+ 	!

Item was added:
+ ----- Method: Form>>dither: (in category 'processing') -----
+ dither: aDepth
+ 	| newColor oldColor quantError result |
+ 	"Floyd Steinberg dithering for depth 1 to 8 bits"
+ 	result := self copy.
+ 	(0 to: height) do:[:y|
+ 	(0 to: width) do:[:x|
+ 		oldColor := (result colorAt: x at y).
+ 		newColor := Color  colorFromPixelValue: (oldColor pixelValueForDepth: aDepth) depth: aDepth.
+ 		result colorAt: x at y put: newColor.
+ 		quantError := (oldColor - newColor).
+ 		result at: x at y bias: quantError]].
+ ^result.!

Item was changed:
  ----- Method: Form>>processUsingKernel:factor:bias: (in category 'processing') -----
  processUsingKernel: filter factor: factor bias: bias
+ 	| image result color |
- 	| image result |
  
  	image := self.
  	result := Form extent: image extent depth: image depth.
  
  	0 to: image height - 1 do: [:y |
  		0 to: image width - 1 do: [:x |
  			| r g b |
  			r := g := b := 0.0.
  
  			0 to: filter rowCount - 1 do: [:filterY |
  				0 to: filter columnCount - 1 do: [:filterX |
  					| imageX imageY |
  					imageX := (x - (filter columnCount // 2) + filterX + image width) \\
  								image width.
  					imageY := (y - (filter rowCount // 2) + filterY + image height) \\
  								image height.
+ 					color := image colorAt: imageX at imageY.
+ 					r := r + (color red *
- 					r := r + ((image colorAt: imageX at imageY) red *
  								(filter at: filterY + 1 at: filterX + 1)).
+ 					g := g + (color green *
- 					g := g + ((image colorAt: imageX at imageY) green *
  								(filter at: filterY + 1 at: filterX + 1)).
+ 					b := b + (color blue *
- 					b := b + ((image colorAt: imageX at imageY) blue *
  								(filter at: filterY + 1 at: filterX + 1))]].
  
  			result colorAt: x at y put: (Color
  				r: ((factor * r + bias) min: 1.0 max: 0.0)
  				g: ((factor * g + bias) min: 1.0 max: 0.0)
  				b: ((factor * b + bias) min: 1.0 max: 0.0))]].
  	^ result
  !

Item was changed:
  ----- Method: Rectangle class>>encompassing: (in category 'instance creation') -----
  encompassing: listOfPoints
  	"A number of callers of encompass: should use this method."
  	| topLeft bottomRight |
+ 	topLeft := bottomRight := nil.
+ 	listOfPoints do:
+ 		[:p | topLeft == nil
+ 			ifTrue: [topLeft := bottomRight := p]
+ 			ifFalse: [topLeft := topLeft min: p.
+ 					bottomRight := bottomRight max: p]].
+ 	^self origin: topLeft corner: bottomRight!
- 	topLeft := bottomRight := listOfPoints first.
- 	listOfPoints allButFirstDo:
- 		[:p |topLeft := topLeft min: p.
- 					bottomRight := bottomRight max: p].
- 	^self origin: topLeft corner: bottomRight
- 	!

Item was changed:
  ----- Method: Rectangle class>>merging: (in category 'instance creation') -----
  merging: listOfRects 
  	"A number of callers of merge: should use this method."
+ 	| minX minY maxX maxY |
- 	| bottomRight topLeft |
- 	topLeft := listOfRects first topLeft.
- 	bottomRight := listOfRects first bottomRight.
  	listOfRects
+ 		do: [:r | minX
+ 				ifNil: [minX := r topLeft x. minY := r topLeft y.
+ 					maxX := r bottomRight x. maxY := r bottomRight y]
+ 				ifNotNil: [minX := minX min: r topLeft x. minY := minY min: r topLeft y.
+ 					maxX := maxX max: r bottomRight x. maxY := maxY max: r bottomRight y]].
+ 	^self origin: minX at minY corner: maxX at maxY!
- 		allButFirstDo: [:r | topLeft := topLeft min: r topLeft.
- 			bottomRight := bottomRight max: r bottomRight].
- 	^self origin: topLeft corner: bottomRight.
- 	!