The Trunk: Balloon-cmm.18.mcz

Chris Muller uploaded a new version of Balloon to project The Trunk:
http://source.squeak.org/trunk/Balloon-cmm.18.mcz

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

Name: Balloon-cmm.18
Author: cmm
Time: 4 December 2010, 3:42:43.35 pm
UUID: 32897871-0fdd-4147-b269-9453d80f2c5d
Ancestors: Balloon-ar.17

Integrated InterpolatedGradientFillStyle from Pharo to support NewColorPicker.

=============== Diff against Balloon-ar.17 ===============

Item was added:
+ GradientFillStyle subclass: #InterpolatedGradientFillStyle
+ instanceVariableNames: ''
+ classVariableNames: ''
+ poolDictionaries: ''
+ category: 'Balloon-Fills'!
+
+ !InterpolatedGradientFillStyle commentStamp: 'gvc 5/18/2007 12:49' prior: 0!
+ Gradient fill style that uses proper alpha-aware interpolation.!

Item was added:
+ ----- Method: InterpolatedGradientFillStyle>>computePixelRampOfSize: (in category 'as yet unclassified') -----
+ computePixelRampOfSize: length
+ "Compute the pixel ramp in the receiver."
+
+ | bits ramp lastColor lastIndex lastWord |
+ ramp := colorRamp asSortedCollection:[:a1 :a2| a1 key < a2 key].
+ bits := Bitmap new: length.
+ lastColor := ramp first value.
+ lastWord := lastColor pixelWord32.
+ lastIndex := 0.
+ ramp do:[:assoc| | distance nextColor theta nextWord nextIndex step |
+ nextIndex := (assoc key * length) rounded.
+ nextColor := assoc value.
+ nextWord := nextColor pixelWord32.
+ distance := nextIndex - lastIndex.
+ distance = 0 ifTrue: [distance := 1].
+ step := 1.0 / distance.
+ theta := 0.0.
+ lastIndex+1 to: nextIndex do: [:i|
+ theta := theta + step.
+ bits at: i put: (self interpolatedAlphaMix: theta of: lastWord and: nextWord)].
+ lastIndex := nextIndex.
+ lastColor := nextColor.
+ lastWord := nextWord].
+ lastIndex+1 to: length do: [:i| bits at: i put: lastWord].
+ ^bits!

Item was added:
+ ----- Method: InterpolatedGradientFillStyle>>interpolatedAlphaMix:of:and: (in category 'as yet unclassified') -----
+ interpolatedAlphaMix: ratio of: rgba1 and: rgba2
+ "Answer a proper interpolated value between two RGBA color words.
+ Theta is 0..1.."
+
+ | a1 a2 ra ira rgb1 rgb2 alpha br1 br2 bg1 bg2 bb1 bb2 result |
+ a1 := rgba1 bitShift: -24. a2 := rgba2 bitShift: -24.
+ alpha := ratio * (a2 - a1) + a1.
+ ra := ratio * alpha.
+ ira := (1.0 - ratio) * alpha.
+ rgb1 := rgba1 bitAnd: 16rFFFFFF. rgb2 := rgba2 bitAnd: 16rFFFFFF.
+ br1 := (rgb1 bitAnd: 255). br2 := (rgb2 bitAnd: 255).
+ bg1 := ((rgb1 bitShift:  -8) bitAnd: 255). bg2 := ((rgb2 bitShift: -8) bitAnd: 255).
+ bb1 := ((rgb1 bitShift: -16) bitAnd: 255). bb2 := ((rgb2 bitShift: -16) bitAnd: 255).
+ result :=  (ra * br2 + (ira * br1)) rounded // 255.
+ result :=  result bitOr: ((ra * bg2 + (ira * bg1)) rounded // 255 bitShift: 8).
+ result :=  result bitOr: ((ra * bb2 + (ira * bb1)) rounded // 255 bitShift: 16).
+ ^result bitOr: (alpha rounded bitShift: 24)!