flutter::VsyncWaiterIOS Class Reference

#include <vsync_waiter_ios.h>

Inheritance diagram for flutter::VsyncWaiterIOS:

Public Member Functions
	VsyncWaiterIOS (const flutter::TaskRunners &task_runners)
	~VsyncWaiterIOS () override
double	GetRefreshRate () const override

Static Public Member Functions
static CFTimeInterval	SnapDuration (CFTimeInterval duration, double max_refresh_rate)

Detailed Description

Definition at line 18 of file vsync_waiter_ios.h.

Constructor & Destructor Documentation

VsyncWaiterIOS()

flutter::VsyncWaiterIOS::VsyncWaiterIOS ( const flutter::TaskRunners &  task_runners )

explicit

Definition at line 18 of file vsync_waiter_ios.mm.

    : VsyncWaiter(task_runners) {
  auto vsyncCallback = ^(CFTimeInterval startTime, CFTimeInterval targetTime) {
    // Compute delay using the same CACurrentMediaTime() clock.
    CFTimeInterval delay = CACurrentMediaTime() - startTime;
    if (delay < 0.0) {
      delay = 0.0;
    }
 
    // Align the start time to the C++ steady_clock used by fml::TimePoint.
    fml::TimePoint start_time = fml::TimePoint::Now() - fml::TimeDelta::FromSecondsF(delay);
 
    // Snap to the nearest whole Hz value to avoid floating point errors.
    CFTimeInterval duration =
        VsyncWaiterIOS::SnapDuration(targetTime - startTime, max_refresh_rate_);
 
    // Align target time to the C++ steady_clock used by fml::TimePoint.
    fml::TimePoint target_time = start_time + fml::TimeDelta::FromSecondsF(duration);
    FireCallback(start_time, target_time, true);
  };
  FlutterFMLTaskRunner* uiTaskRunner =
      [[FlutterFMLTaskRunner alloc] initWithTaskRunner:task_runners_.GetUITaskRunner()];
  client_ = [[FlutterVSyncClient alloc]
                initWithTaskRunner:uiTaskRunner
      isVariableRefreshRateEnabled:FlutterDisplayLinkManager.maxRefreshRateEnabledOnIPhone
                    maxRefreshRate:FlutterDisplayLinkManager.displayRefreshRate
                          callback:vsyncCallback];
  max_refresh_rate_ = FlutterDisplayLinkManager.displayRefreshRate;
}

References SnapDuration().

~VsyncWaiterIOS()

flutter::VsyncWaiterIOS::~VsyncWaiterIOS ( )

override

Definition at line 48 of file vsync_waiter_ios.mm.

                                {
  // This way, we will get no more callbacks from the display link that holds a weak (non-nilling)
  // reference to this C++ object.
  [client_ invalidate];
}

Member Function Documentation

GetRefreshRate()

double flutter::VsyncWaiterIOS::GetRefreshRate ( ) const

override

Definition at line 64 of file vsync_waiter_ios.mm.

                                            {
  return client_.refreshRate;
}

SnapDuration()

CFTimeInterval flutter::VsyncWaiterIOS::SnapDuration ( CFTimeInterval  duration, double  max_refresh_rate  )

static

Definition at line 68 of file vsync_waiter_ios.mm.

                                                                                            {
  if (duration > 0.0) {
    double roundedRefreshRate = round(1.0 / duration);
    return 1.0 / roundedRefreshRate;
  }
  double fallbackRefreshRate = max_refresh_rate > 0.0 ? max_refresh_rate : 60.0;
  return 1.0 / fallbackRefreshRate;
}

Referenced by VsyncWaiterIOS().

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The documentation for this class was generated from the following files:

• shell/platform/darwin/ios/framework/Source/vsync_waiter_ios.h
• shell/platform/darwin/ios/framework/Source/vsync_waiter_ios.mm