BlTransformAnimation rotate: xxx beInfinite doesn't work

[Nyan11]

Hello,

I found a bug with the animation

element :=  BlElement new
		  background: Color black;
		  yourself.

element addAnimation: (BlTransformAnimation rotate: 180) beInfinite.

space := BlSpace new useAlexandrieMorphicWindowHost.

space addChild: element.
space show.

It does the first 180 spin but the debugger open with Instance of BlElementCachedExplicitTransformation did not understand #is2D.

I tested it with rotate:, scale: and translate:. Same bug each time.

I didn't manage to investigate futher. I'm on the dev-1.0 branch at d0ec7a0

[tinchodias]

I got the debugger too. Investigating it...

[tinchodias]

I fixed (or workaround) the is2D MNU and other similar subsequent, and the behavior is weird... it doesn't look like infinitely rotating an element!

Screen.Recording.2022-11-16.at.18.24.26.mov

(Code: http://ws.stfx.eu/L8NTBL0CG3QO)

For the record, what I did are two changes in BlElementCompositeTransformation:

"testing"
is2D
	"Return true if my current transformation is in 2D space, false otherwise"

	^ elementTransformations allSatisfy: [ :each | 
		  each asElementTransformation is2D ]

and:

"computation"
computeMatrix: aBlMatrix in: aRectangle

	elementTransformations reverseDo: [ :each |
		each asElementTransformation computeMatrix: aBlMatrix in: aRectangle ]

[tinchodias]

Only changing the angle from 180º to 40º, this happens:
(but also set animation duration to 100ms to speedup demo by 10x)
(watch up to the final)

Screen.Recording.2022-11-16.at.18.29.20.mov

(Code: http://ws.stfx.eu/N5AHZ9V9CJT)

This bug is reproducible 100% and was canvas-independent.

[tinchodias]

An infinite sequence animation of absolute animations DOES work:

element :=
	BlElement new
		relocate: 100@100;
		background: Color green;
		yourself.

cwAnimation := (BlTransformAnimation rotate: 180) absolute.
ccwAnimation := (BlTransformAnimation rotate: 0) absolute.

element addAnimation: (BlSequentialAnimation 
	with: cwAnimation
	with: ccwAnimation)
	beInfinite;
	yourself.

space := BlSpace new.
space addChild: element.
space show.

[tinchodias]

Hi, while debugging this issue, I discovered more, and reported them here:

• Does BlSequentialAnimation restart too early? Unexpected acceleration on infinite relative translating BlTransformAnimation #195
• Unexpected acceleration on infinite relative translating BlTransformAnimation: BlSequentialAnimation with delay stops too early #194

For the record, I mentioned this issue on the weekly update: https://pharoweekly.wordpress.com/2022/11/22/bloc-update-2/

[Nyan11]

The BlNumberTransition animation does work too:

backgroundGeometry := BlAnnulusSectorGeometry new
	innerRadius: 0.9;
	outerRadius: 100;
	startAngle: 0;
	endAngle: 360;
	yourself.

background := BlElement new
	geometry: backgroundGeometry;
	background: (Color white alpha: 0.1);
	size: 100 @ 100;
	yourself.

shape := BlElement new
	geometry: (BlAnnulusSectorGeometry new
		innerRadius: 0.9;
		outerRadius: 100;
		startAngle: 0;
		endAngle: 225;
		yourself);
	background: Color blue;
	size: 100 @ 100;
	yourself.

container := BlElement new
	size: 100 @ 100;
	addChild: background;
	addChild: shape;
	yourself.
	
space := BlSpace new.
space addChild: container.
space root background: Color black.
space show.

animation := BlNumberTransition new
	from: 0;
	to: 360;
	by: 1;
	onStepDo: [ :val :el | 
		el geometry: (backgroundGeometry
			startAngle: 0 + val % 360;
			endAngle: 225 + val % 360;
			yourself)
	];
	beInfinite;
	yourself.

shape addAnimation: animation.

[tinchodias]

Related: #196