Graphics & Animation in Android

1. Graphics & Animationin Android

2. Androidrenderingoptions • The Canvas API • Renderscript • OpenGL wrappers • NDK OpenGL http://graphics-geek.blogspot.com/2011/06/android-rendering-options.html

3. The Canvas API • Standard rendering for a typical SDK application that uses View objects (standard and custom) • consists of calls to each View's onDraw() method. This method takes a single parameter, Canvas, which is the object used by the view to draw its content. http://graphics-geek.blogspot.com/2011/06/android-rendering-options.html

4. Renderscript • Introduced in Android 3.0 • API targeted  high-performance 3D rendering and compute operations • a3D rendering API on top of hardware acceleration, languageC99 • executing native code on the device still cross-platform • use of extensions that are placed into the application package http://graphics-geek.blogspot.com/2011/06/android-rendering-options.html

5. Renderscript • Live Wallpapers, the video wall view in the YouTube application, and the Books application (including that beautiful page-turn effect). • http://www.youtube.com/watch?v=uQ5NumRfHN4 http://graphics-geek.blogspot.com/2011/06/android-rendering-options.html

6. Open GL Wrappers • OpenGL APIs at the SDK level • not a recommended practice as a general approach for complex scenes that require high-performance graphics • difficult to achieve high performance levels equivalent to native access to OpenGL due to the overhead of calling down from the SDK • Music application that shipped with Android 3.0 used this approach http://graphics-geek.blogspot.com/2011/06/android-rendering-options.html

7. NDK OpenGL • no access to the View objects, or the events, or the rest of the infrastructure that is provided in the SDK APIs • graphics environment sufficient for some specific purposes: game developers • compiles applications to specific CPU architectures http://graphics-geek.blogspot.com/2011/06/android-rendering-options.html

8. Animations • Animations prior to Android 3.0 • android.view.animation • move, scale, rotate, and fade Views • combine multiple animations together in an AnimationSet • specify animations in a LayoutAnimationControllerto get automatically staggered animation  • use Interpolator implementations like AccelerateInterpolator and Bounce to get natural, nonlinear timing behavior http://android-developers.blogspot.com/2011/02/animation-in-honeycomb.html

9. Animations • Animations prior to Android 3.0 • you can animate Views... and that's it • Howtoanimatethe position of a Drawable in a customdrawing? Ortranslucency? • you can move, rotate, scale, and fade a View... and that's it. • animating the background color of a View? • hard-coded set of things they were able to do, and you could not make them do anything else. http://android-developers.blogspot.com/2011/02/animation-in-honeycomb.html

10. Animations • Animations in Android 3.0 • not specific to Views • animates values over time • assigning those values to any target objects and properties • http://www.youtube.com/watch?feature=player_embedded&v=-9nxx066eHE#! http://android-developers.blogspot.com/2011/02/animation-in-honeycomb.html

11. Animations • Animator • superclass for classes which provide basic support for animations which can be started, ended, and have AnimatorListeners added to them

12. Animations • AnimatorSet •  choreograph multiple animators together into a single animation • animations can be set up to play together, in sequence, or after a specified delay • “It is possible to set up a AnimatorSet with circular dependencies between its animations… results of this configuration are undefined… circular dependencies should be avoided” http://android-developers.blogspot.com/2011/02/animation-in-honeycomb.html

13. Animations • ValueAnimator •  runs the internal timing loop that causes all of a process's animations to calculate and set values • two pieces to animating properties: calculating the animated values and setting those values on the object and property in question. ValueAnimator takes care of the first part; calculating the values http://android-developers.blogspot.com/2011/02/animation-in-honeycomb.html

14. Animations • ObjectAnimator • takes care of the second part : setting animating values on the object and property • main class in the new animation system • ObjectAnimator.ofFloat(myObject, "alpha", 0f).start(); public void setAlpha(float value);public float getAlpha(); http://android-developers.blogspot.com/2011/02/animation-in-honeycomb.html

15. Animations • View properties • addednew properties to the View class in Honeycomb • translationX and translationY • rotation, rotationX, and rotationY • scaleX and scaleY • pivotX and pivotY • x and y • alpha http://android-developers.blogspot.com/2011/02/animation-in-honeycomb.html

16. Animations • AnimatorSet • choreograph multiple animations ObjectAnimatorfadeOut = ObjectAnimator.ofFloat(v1, "alpha", 0f); ObjectAnimator mover = ObjectAnimator.ofFloat(v2, "translationX", -500f, 0f); ObjectAnimatorfadeIn = ObjectAnimator.ofFloat(v2, "alpha", 0f, 1f); AnimatorSetanimSet = new AnimatorSet().play(mover).with(fadeIn).after(fadeOut); http://android-developers.blogspot.com/2011/02/animation-in-honeycomb.html

17. Animations • TypeEvaluator • The system knows how to animate float and int values, but otherwise it needs some help knowing how to interpolate between the values you give it • add this interface to the ValueEvaluator Interface TypeEvaluator { public abstract T evaluate (float fraction, T startValue, T endValue)   } http://android-developers.blogspot.com/2011/02/animation-in-honeycomb.html