updateTrajectory method
Implementation
void updateTrajectory(Vector2 startPos, Vector2 velocity, double gravity) {
_points.clear();
const int count = 20;
const double step = 0.075;
for (int i = 0; i < count; i++) {
final t = i * step;
_points.add(Vector2(
startPos.x + velocity.x * t,
startPos.y + velocity.y * t + 0.5 * gravity * t * t,
));
}
}