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Inheritance example for contact callbacks

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This commit is contained in:
Lukas Klingsbo
2020-05-03 12:34:21 +02:00
parent d431cf6c24
commit ac6abfcd24
1 changed files with 47 additions and 6 deletions
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53
doc/examples/box2d/contact_callbacks/lib/main.dart
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@ -17,6 +17,7 @@ void main() async {
class Ball extends BodyComponent {
Paint originalPaint, currentPaint;
bool giveNudge = false;
Ball(Vector2 position, Box2DComponent box) : super(box) {
originalPaint = _randomPaint();
@ -66,16 +67,30 @@ class Ball extends BodyComponent {
Offset(math.sin(angle) * radius, math.cos(angle) * radius);
c.drawLine(p, p + lineRotation, blue);
}
@override
void update(double t) {
super.update(t);
if (giveNudge) {
body.applyLinearImpulse(Vector2(0, 10000), body.getLocalCenter(), true);
giveNudge = false;
}
}
}
class BallContactCallback implements ContactCallback<Ball, Ball> {
@override
ContactTypes types = ContactTypes(Ball, Ball);
BallContactCallback();
class WhiteBall extends Ball {
WhiteBall(Vector2 position, Box2DComponent box) : super(position, box) {
originalPaint = BasicPalette.white.paint;
currentPaint = originalPaint;
}
}
class BallContactCallback extends ContactCallback<Ball, Ball> {
@override
void begin(Ball ball1, Ball ball2, Contact contact) {
if (ball1 is WhiteBall || ball2 is WhiteBall) {
return;
}
if (ball1.currentPaint != ball1.originalPaint) {
ball1.currentPaint = ball2.currentPaint;
} else {
@ -87,11 +102,33 @@ class BallContactCallback implements ContactCallback<Ball, Ball> {
void end(Ball ball1, Ball ball2, Contact contact) {}
}
class WhiteBallContactCallback extends ContactCallback<Ball, WhiteBall> {
@override
void begin(Ball ball, WhiteBall whiteBall, Contact contact) {
ball.giveNudge = true;
}
@override
void end(Ball ball, WhiteBall whiteBall, Contact contact) {}
}
class BallWallContactCallback extends ContactCallback<Ball, Wall> {
@override
void begin(Ball ball, Wall wall, Contact contact) {
wall.paint = ball.currentPaint;
}
@override
void end(Ball ball1, Wall wall, Contact contact) {}
}
class MyGame extends Box2DGame {
MyGame(Box2DComponent box) : super(box) {
final List<BodyComponent> boundaries = createBoundaries(box);
boundaries.forEach(add);
addContactCallback(BallContactCallback());
addContactCallback(BallWallContactCallback());
addContactCallback(WhiteBallContactCallback());
}
@override
@ -99,7 +136,11 @@ class MyGame extends Box2DGame {
super.onTapDown(details);
final Vector2 position =
Vector2(details.globalPosition.dx, details.globalPosition.dy);
add(Ball(position, box));
if (math.Random().nextInt(10) < 2) {
add(WhiteBall(position, box));
} else {
add(Ball(position, box));
}
}
}