Rotate Animation speed - android

I want my animation to only spin for one rotation. Everytime I adjust the duration it just spins at the same speed for longer/slower. Where am I going wrong?
private static final float ROTATE_FROM = 0.0f;
private static final float ROTATE_TO = -10.0f * 360.0f;
protected RotateAnimation r = new RotateAnimation(ROTATE_FROM, ROTATE_TO,
Animation.RELATIVE_TO_SELF, 0.5f,
Animation.RELATIVE_TO_SELF, 0.5f);
r.setDuration(5000);
r.setRepeatCount(0);
r.setInterpolator(this, android.R.anim.linear_interpolator);
r.setAnimationListener(AndroidVideoPlayer.this);
favicon.startAnimation(r);

I believe what you are looking for is repeatCount
r.setRepeatCount(0)
http://developer.android.com/reference/android/view/animation/Animation.html#setRepeatCount(int)
From the documentation:
Sets how many times the animation should be repeated. If the repeat
count is 0, the animation is never repeated. If the repeat count is
greater than 0 or INFINITE, the repeat mode will be taken into
account. The repeat count is 0 by default.
Or are you saying that the animation continues to rotate for whatever duration you set? (i.e., you set it for 5000 it rotates for 5 seconds even if it overshoots the "end"). What if you set that value to less than the amount of time it takes to rotate your animation?
In that case it's probably your LinearInterpolator that's animating for a constant rate of change. You could maybe print the value of computeDurationHint() to see if the application is able to guess how long the duration should be.
P.S. What are your ROTATE_FROM and ROTATE_TO values?

It was the -10.0f that was the problem!

Related

Android alpha animation: override initial alpha value

Basically I want something to fade-in and then fade-out. Initially it should be invisible, and when the animation is ended, it should also be invisible.
targetView.alpha = 0f;
var aa = AlphaAnimation(0f, 1.0f);
aa.duration=2000;
aa.repeatMode = Animation.REVERSE;
aa.repeatCount = 1;
I have tried the code above, but it did not work. it seems that the alpha animation is multiplying the initial alpha with that animation. So, 0f * 1.0f = 0f = invisible.
After searching for an answer, I have tried this, but it did not work.
aa.fillBefore= true;
aa.fillAfter=true;
How can I make the animation ignore the initial alpha value? Is it impossible, and I should change the visibility at the start/end of the animation manually?
Yes you are right about "it seems that the alpha animation is multiplying the initial alpha with that animation. So, 0f * 1.0f = 0f = invisible.".
Just don't use targetView.alpha = 0f;, use targetView.setVisibility(View.INVISIBLE); instead.

Android ValueAnimator Sin wave

I've got a Custom ViewGroup class and an image I've added to it. When the screen is tapped I want to animate the added image to travel across the screen in a wavelike pattern. What I have now is below but though the image moves in a wavelike pattern it jumps around too quickly and is a blur. How can I slow it down to move in a steady wave?
ValueAnimator animator = ValueAnimator.ofFloat(0, 1); // values from 0 to 1
if(animateImage) {
incrementalValue = 0f;
animator.setDuration(4000);
animator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
#Override
public void onAnimationUpdate(ValueAnimator animation) {
float value = ((Float) (animation.getAnimatedValue()))
.floatValue();
float amplitude = 100f;
mImage.setTranslationX(incrementalValue);
mImage.setTranslationY((float) (amplitude * Math.sin((incrementalValue) * Math.PI)));
incrementalValue += 5f;
}
});
animator.setTarget(mImage);
animator.start();
}
You declare a float value in onAnimationUpdate and never use it again. The calcualtion for the image translation is mImage.setTranslationY((float) (amplitude * Math.sin((incrementalValue) * Math.PI)));. If you insert the values and incrementalValue ( = 0) doesn't change, this calculation will always return 0 because sin(0) = 0 and one 0 in a multiplication makes the product 0. You should insert animator.getAnimatedValue for incrementalValue. Besides, i suggest you change the calculation to sin(animator.getAnimatedValue()*PI*2) this makes the wavelength of the sine 1 and the image will move up and down once per repetition of the animation and it won't jump when the aimation restarts.
Note you can still multiply with amplitude to make the image move a certain distance.

android translateAnimation setDuration() doesn't work

I'm trying to create a translate animation to an imageView. The animation works but not according to the value I'm putting in the setDuration()
This is the code
/* flipping the images out of the screen */
float outOfScreenX = currentImageLocationX * DRAG_ACTION_SCREEN_BOUNDS_THREASHOLD;
float outOfScreenY = currentImageLocationY * DRAG_ACTION_SCREEN_BOUNDS_THREASHOLD;
translate = new TranslateAnimation(0, outOfScreenX, 0, outOfScreenY);
long velocity = Math.max(Math.abs((int) vTracker.getXVelocity()), Math.abs((int) vTracker.getYVelocity())) / 10;
velocity = (long) Math.min(velocity, 200);
translate.setDuration(velocity);
translate.setFillAfter(true);
mDragView.clearAnimation();
mDragView.startAnimation(translate);
imageStack.removeView(mOriginator);
The value of "velocity" derived from the vTracker, the speed of the user's touch on the view. It's always between 200-600 proximately, but the view moves much faster than this(and also a little flickering but this is another topic).

Sprite Jump in my Game Play Andengine

Hy, I have started a Game in andengine for android, I want to apply a jump functionality on a sprite which will be like some projectile motion , up and forward as well . I have applied move modifier to gain that functionality. But that is not in projectile motion.
How can i achieve that and while the jump of my sprite by tapping again it cant jump again until it completes it jump.i dont want to use delay function on scene touch .any help .
final Entity playerEntity = move;
final float jumpDuration = 1;
final float startX = playerEntity.getX();
final float jumpHeight = 60;
move.getTextureRegion().setFlippedVertical(true);
final MoveModifier jumpForwardUp = new MoveModifier(jumpDuration/2, startX, startX - jumpHeight, playerEntity.getY(), playerEntity.getY() + 130);
final MoveModifier jumpForwardDown = new MoveModifier(jumpDuration/2, startX - jumpHeight, startX, playerEntity.getY() + 130, playerEntity.getY() + 170);
final SequenceEntityModifier modifier = new SequenceEntityModifier(jumpForwardUp ,jumpForwardDown);
playerEntity.registerEntityModifier(modifier);
Try using JumpModifier and for some real physics work, go for Box2d Extension of AndEngine and go through some of AndEngine examples code.
Edit:
AndEngine have list of modifiers. JumpModifier is one of them. Maintain a class level or project level flag that is true when your object is in jump and is false when object is in normal state.
Every modifier takes an object of IModifierListner set that flag to true in onStart of IModifierListner and set that to false at onEnd of IModifierListner. at every tap check if that flag is true then simple return and do nothing.

How to prepare curve translate animation for android?

There are 4 types of animations in android - rotate, alpha,scale and translate.
I want to prepare curved translate animation.
Is it possible.?
What Android version do you use? Since API level 11 you can use custom Animators which can easily implement your curve translation.
If you use a version below that there is afaik only the possibility to manually concatenate multiple linear translations using the translate animation and setting animation listeners
EDIT:
Example:
View view;
animator = ValueAnimator.ofFloat(0, 1); // values from 0 to 1
animator.setDuration(5000); // 5 seconds duration from 0 to 1
animator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener()
{
#Override
public void onAnimationUpdate(ValueAnimator animation) {
float value = ((Float) (animation.getAnimatedValue()))
.floatValue();
// Set translation of your view here. Position can be calculated
// out of value. This code should move the view in a half circle.
view.setTranslationX((float)(200.0 * Math.sin(value*Math.PI)));
view.setTranslationY((float)(200.0 * Math.cos(value*Math.PI)));
}
});
I hope it works. Just copied & pasted (and shortened and changed) the code from one of my apps.
Here are the animators I use:
Purpose: Move View "view" along Path "path"
Android v21+:
// Animates view changing x, y along path co-ordinates
ValueAnimator pathAnimator = ObjectAnimator.ofFloat(view, "x", "y", path)
Android v11+:
// Animates a float value from 0 to 1
ValueAnimator pathAnimator = ValueAnimator.ofFloat(0.0f, 1.0f);
// This listener onAnimationUpdate will be called during every step in the animation
// Gets called every millisecond in my observation
pathAnimator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
float[] point = new float[2];
#Override
public void onAnimationUpdate(ValueAnimator animation) {
// Gets the animated float fraction
float val = animation.getAnimatedFraction();
// Gets the point at the fractional path length
PathMeasure pathMeasure = new PathMeasure(path, true);
pathMeasure.getPosTan(pathMeasure.getLength() * val, point, null);
// Sets view location to the above point
view.setX(point[0]);
view.setY(point[1]);
}
});
Similar to: Android, move bitmap along a path?
Consider the following web link. It is a game in C. You need to isolate the projectile() function and try to understand the variables defined within it. Once you get that try implementing it in your own code.
http://www.daniweb.com/software-development/c/code/216266

Categories

Resources