《Pro Android Graphics》读书笔记之第四节

Posted 2020-07-02 phlsheji

android Procedural Animation: : XML, Concepts and Optimization

Procedural Animation Concepts: Tweens and Interpolators 

Interpolator：http://developer.android.com/reference/android/animation/TimeInterpolator.html

Procedural Animation Data Values: Ranges and Pivot Point 

范围和中心点

Procedural Animation Transforms: Rotate, Scale, Translate

scale：One of them involves size

rotation：involves orientation (which direction that something is facing)

translation：involves movement

Procedural Animation Compositing: Alpha Blending 

Procedural Animation Timing: Using Duration and Offsets 

Procedural Animation Loops: RepeatCount and RepeatMode 

repeatCount interger（loop forever use infinite(-1)）

RepeatMode：restart (1)

reverse (2)

The <set> Tag: Using XML to Group Procedural Animation 

android.view.animation

  rule of thumb is to apply your transformational parameters locally

Procedural Animation vs. Frame Animation: The Trade-Off 

Frame Animation

memory intensive（须要很多其它内存）：Displaying the image from memory onto the View is fairly straightforward and does not require any complex calculations, so all processing involves moving each frame’s image asset from memory over to display screen.

Procedural animation 

tends to be more processing intensive（须要很多其它计算）

Creating a Procedural Animation Definition Using XML

Animation pagAni = AnimationUtils.loadAnimation(this, R.anim.pag_anim);
（view）pag.startAnimation(pagAni);

Using Set to Create a More Complex Procedural Animation 

Rotation Transformation: Going a Bit Too Far with FX 

Tweaking Transform Values: The Ease of Adjusting XML