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Add documentation for SequenceEffect

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This commit is contained in:
Lukas Klingsbo
2020-05-25 20:14:05 +02:00
parent 932e974028
commit ba5ab70cf0
3 changed files with 36 additions and 15 deletions
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18
doc/effects.md
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@ -65,6 +65,24 @@ square.addEffect(RotateEffect(
curve: Curves.easeInOut, curve: Curves.easeInOut,
)); ));
``` ```
## SequenceEffect
This effect is a combination of other effects. You provide it with a list of your predefined effects, that are not added to a component.
Note that no effects added to the sequence can have their `isInfinite` property set to `true`, because then naturally the sequence will get stuck once it gets to that effect.
You can make the sequence go in a loop by setting both `isInfinite: true` and `isAlternating: true`.
Usage example:
```dart
final sequence = SequenceEffect(
effects: [move1, scale, move2, rotate],
isInfinite: true,
isAlternating: true);
myComponent.addEffect(sequence);
```
An example of how to use the SequenceEffect can be found [here](/doc/examples/effects/sequence_effect).
# Examples # Examples

3
doc/examples/effects/sequence_effect/lib/main.dart
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@ -67,7 +67,8 @@ class MyGame extends BaseGame with TapDetector {
final sequence = SequenceEffect( final sequence = SequenceEffect(
effects: [move1, scale, move2, rotate], effects: [move1, scale, move2, rotate],
isInfinite: true, isAlternating: true); isInfinite: true,
isAlternating: true);
greenSquare.addEffect(sequence); greenSquare.addEffect(sequence);
} }
} }

30
lib/effects/sequence_effect.dart
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@ -10,7 +10,7 @@ import '../position.dart';
class SequenceEffect extends PositionComponentEffect { class SequenceEffect extends PositionComponentEffect {
final List<PositionComponentEffect> effects; final List<PositionComponentEffect> effects;
int _currentIndex = 0; int _currentIndex = 0;
PositionComponentEffect _currentEffect; PositionComponentEffect currentEffect;
bool _currentWasAlternating; bool _currentWasAlternating;
double _driftModifier = 0.0; double _driftModifier = 0.0;
@ -38,12 +38,14 @@ class SequenceEffect extends PositionComponentEffect {
currentSize = Position.fromSize(effect.size); currentSize = Position.fromSize(effect.size);
} }
}); });
travelTime = effects.fold(0, (time, effect) => time + effect.travelTime * travelTime = effects.fold(
(effect.isAlternating ? 2 : 1)); 0,
(time, effect) =>
time + effect.travelTime * (effect.isAlternating ? 2 : 1));
component.setBySize(originalSize); component.setBySize(originalSize);
component.setByPosition(originalPosition); component.setByPosition(originalPosition);
_currentEffect = effects.first; currentEffect = effects.first;
_currentWasAlternating = _currentEffect.isAlternating; _currentWasAlternating = currentEffect.isAlternating;
} }
@override @override
@ -53,11 +55,11 @@ class SequenceEffect extends PositionComponentEffect {
} }
super.update(dt); super.update(dt);
_currentEffect.update(dt + _driftModifier); currentEffect.update(dt + _driftModifier);
_driftModifier = 0.0; _driftModifier = 0.0;
if (_currentEffect.hasFinished()) { if (currentEffect.hasFinished()) {
_driftModifier = _currentEffect.driftTime; _driftModifier = currentEffect.driftTime;
_currentEffect.isAlternating = _currentWasAlternating; currentEffect.isAlternating = _currentWasAlternating;
_currentIndex++; _currentIndex++;
final iterationSize = isAlternating ? effects.length * 2 : effects.length; final iterationSize = isAlternating ? effects.length * 2 : effects.length;
if (_currentIndex != 0 && _currentIndex % iterationSize == 0) { if (_currentIndex != 0 && _currentIndex % iterationSize == 0) {
@ -66,14 +68,14 @@ class SequenceEffect extends PositionComponentEffect {
} }
final orderedEffects = final orderedEffects =
curveDirection.isNegative ? effects.reversed.toList() : effects; curveDirection.isNegative ? effects.reversed.toList() : effects;
_currentEffect = orderedEffects[_currentIndex % effects.length]; currentEffect = orderedEffects[_currentIndex % effects.length];
_currentWasAlternating = _currentEffect.isAlternating; _currentWasAlternating = currentEffect.isAlternating;
if (isAlternating && if (isAlternating &&
!_currentEffect.isAlternating && !currentEffect.isAlternating &&
curveDirection.isNegative) { curveDirection.isNegative) {
// Make the effect go in reverse // Make the effect go in reverse
_currentEffect.isAlternating = true; currentEffect.isAlternating = true;
_currentEffect.percentage = 1.0; currentEffect.percentage = 1.0;
} }
} }
} }