79 lines
2.8 KiB
Plaintext
79 lines
2.8 KiB
Plaintext
|
The _Frame Rate API_ allows applications to communicate their desired frame rate to the _Android platform_ to enhance the user experience. The API is useful since many devices now offer varying refresh rates like 60Hz, 90Hz, or 120Hz.
|
||
|
|
|
||
|
|
== Why is this an issue?
|
||
|
|
|
||
|
|
Standard applications don't require a display refresh rate above 60Hz, hence it is advisable to avoid higher frequencies to avoid unnecessary energy consumption.
|
||
|
|
|
||
|
|
The rule flags an issue when `setFrameRate()` is invoked with a frameRate higher than 60Hz for `android.view.Surface` and `android.view.SurfaceControl.Transaction`.
|
||
|
|
|
||
|
|
It's important to note that the scheduler considers several factors when determining the display refresh rate. Therefore, using `setFrameRate()` doesn't guarantee your app will achieve the requested frame rate.
|
||
|
|
|
||
|
|
=== What is the potential impact?
|
||
|
|
|
||
|
|
* _Usability_: the device may run out of battery faster than expected.
|
||
|
|
* _Sustainability_: the extra battery usage has a negative impact on the environment.
|
||
|
|
|
||
|
|
== How to fix it
|
||
|
|
|
||
|
|
Use a frame rate of maximum 60Hz, unless you have a strong reason to used higher rates.
|
||
|
|
Valid exceptions are _gaming apps_, especially those with fast-paced action or high-quality graphics, or _AR/VR apps_.
|
||
|
|
|
||
|
|
=== Code examples
|
||
|
|
|
||
|
|
==== Noncompliant code example
|
||
|
|
|
||
|
|
[source,java,diff-id=1,diff-type=noncompliant]
|
||
|
|
----
|
||
|
|
public class MainActivity extends AppCompatActivity {
|
||
|
|
|
||
|
|
@Override
|
||
|
|
protected void onCreate(Bundle savedInstanceState) {
|
||
|
|
super.onCreate(savedInstanceState);
|
||
|
|
setContentView(R.layout.activity_main);
|
||
|
|
|
||
|
|
SurfaceView surfaceView = findViewById(R.id.my_surface_view);
|
||
|
|
Surface surface = surfaceView.getHolder().getSurface();
|
||
|
|
|
||
|
|
surface.setFrameRate(90.0f, Surface.FRAME_RATE_COMPATIBILITY_FIXED_SOURCE); // Noncompliant
|
||
|
|
}
|
||
|
|
}
|
||
|
|
----
|
||
|
|
|
||
|
|
==== Compliant solution
|
||
|
|
|
||
|
|
[source,java,diff-id=1,diff-type=compliant]
|
||
|
|
----
|
||
|
|
public class MainActivity extends AppCompatActivity {
|
||
|
|
|
||
|
|
@Override
|
||
|
|
protected void onCreate(Bundle savedInstanceState) {
|
||
|
|
super.onCreate(savedInstanceState);
|
||
|
|
setContentView(R.layout.activity_main);
|
||
|
|
|
||
|
|
SurfaceView surfaceView = findViewById(R.id.my_surface_view);
|
||
|
|
Surface surface = surfaceView.getHolder().getSurface();
|
||
|
|
|
||
|
|
surface.setFrameRate(60.0f, Surface.FRAME_RATE_COMPATIBILITY_FIXED_SOURCE); // Compliant
|
||
|
|
}
|
||
|
|
}
|
||
|
|
----
|
||
|
|
|
||
|
|
//=== How does this work?
|
||
|
|
|
||
|
|
//=== Pitfalls
|
||
|
|
|
||
|
|
//=== Going the extra mile
|
||
|
|
|
||
|
|
|
||
|
|
== Resources
|
||
|
|
=== Documentation
|
||
|
|
|
||
|
|
* https://developer.android.com/media/optimize/performance/frame-rate[Android for Developers: Frame Rate]
|
||
|
|
* https://developer.apple.com/library/archive/documentation/3DDrawing/Conceptual/MTLBestPracticesGuide/FrameRate.html#//apple_ref/doc/uid/TP40016642-CH23-SW1[Developer Apple - Frame Rate]
|
||
|
|
|
||
|
|
//=== Articles & blog posts
|
||
|
|
//=== Conference presentations
|
||
|
|
//=== Standards
|
||
|
|
//=== External coding guidelines
|
||
|
|
//=== Benchmarks
|