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Switched the flywheel to suffix underscores.

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This commit is contained in:
Thomas Harte 2016-11-21 11:48:31 +08:00
parent e1285028aa
commit 340607e13e
1 changed files with 40 additions and 40 deletions
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80
Outputs/CRT/Internals/Flywheel.hpp
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@ -31,13 +31,13 @@ struct Flywheel
@param sync_error_window The permitted deviation of sync timings from the norm. @param sync_error_window The permitted deviation of sync timings from the norm.
*/ */
Flywheel(unsigned int standard_period, unsigned int retrace_time, unsigned int sync_error_window) : Flywheel(unsigned int standard_period, unsigned int retrace_time, unsigned int sync_error_window) :
_standard_period(standard_period), standard_period_(standard_period),
_retrace_time(retrace_time), retrace_time_(retrace_time),
_sync_error_window(sync_error_window), sync_error_window_(sync_error_window),
_counter(0), counter_(0),
_expected_next_sync(standard_period), expected_next_sync_(standard_period),
_counter_before_retrace(standard_period - retrace_time), counter_before_retrace_(standard_period - retrace_time),
_number_of_surprises(0) {} number_of_surprises_(0) {}
enum SyncEvent { enum SyncEvent {
/// Indicates that no synchronisation events will occur in the queried window. /// Indicates that no synchronisation events will occur in the queried window.
@ -66,22 +66,22 @@ struct Flywheel
// do we recognise this hsync, thereby adjusting future time expectations? // do we recognise this hsync, thereby adjusting future time expectations?
if(sync_is_requested) if(sync_is_requested)
{ {
if(_counter < _sync_error_window || _counter > _expected_next_sync - _sync_error_window) if(counter_ < sync_error_window_ || counter_ > expected_next_sync_ - sync_error_window_)
{ {
unsigned int time_now = (_counter < _sync_error_window) ? _expected_next_sync + _counter : _counter; unsigned int time_now = (counter_ < sync_error_window_) ? expected_next_sync_ + counter_ : counter_;
_expected_next_sync = (3*_expected_next_sync + time_now) >> 2; expected_next_sync_ = (3*expected_next_sync_ + time_now) >> 2;
} }
else else
{ {
_number_of_surprises++; number_of_surprises_++;
if(_counter < _retrace_time + (_expected_next_sync >> 1)) if(counter_ < retrace_time_ + (expected_next_sync_ >> 1))
{ {
_expected_next_sync = (3*_expected_next_sync + _standard_period + _sync_error_window) >> 2; expected_next_sync_ = (3*expected_next_sync_ + standard_period_ + sync_error_window_) >> 2;
} }
else else
{ {
_expected_next_sync = (3*_expected_next_sync + _standard_period - _sync_error_window) >> 2; expected_next_sync_ = (3*expected_next_sync_ + standard_period_ - sync_error_window_) >> 2;
} }
} }
} }
@ -90,16 +90,16 @@ struct Flywheel
unsigned int proposed_sync_time = cycles_to_run_for; unsigned int proposed_sync_time = cycles_to_run_for;
// will we end an ongoing retrace? // will we end an ongoing retrace?
if(_counter < _retrace_time && _counter + proposed_sync_time >= _retrace_time) if(counter_ < retrace_time_ && counter_ + proposed_sync_time >= retrace_time_)
{ {
proposed_sync_time = _retrace_time - _counter; proposed_sync_time = retrace_time_ - counter_;
proposed_event = SyncEvent::EndRetrace; proposed_event = SyncEvent::EndRetrace;
} }
// will we start a retrace? // will we start a retrace?
if(_counter + proposed_sync_time >= _expected_next_sync) if(counter_ + proposed_sync_time >= expected_next_sync_)
{ {
proposed_sync_time = _expected_next_sync - _counter; proposed_sync_time = expected_next_sync_ - counter_;
proposed_event = SyncEvent::StartRetrace; proposed_event = SyncEvent::StartRetrace;
} }
@ -117,14 +117,14 @@ struct Flywheel
*/ */
inline void apply_event(unsigned int cycles_advanced, SyncEvent event) inline void apply_event(unsigned int cycles_advanced, SyncEvent event)
{ {
_counter += cycles_advanced; counter_ += cycles_advanced;
switch(event) switch(event)
{ {
default: return; default: return;
case StartRetrace: case StartRetrace:
_counter_before_retrace = _counter - _retrace_time; counter_before_retrace_ = counter_ - retrace_time_;
_counter = 0; counter_ = 0;
return; return;
} }
} }
@ -137,14 +137,14 @@ struct Flywheel
*/ */
inline unsigned int get_current_output_position() inline unsigned int get_current_output_position()
{ {
if(_counter < _retrace_time) if(counter_ < retrace_time_)
{ {
unsigned int retrace_distance = (_counter * _standard_period) / _retrace_time; unsigned int retrace_distance = (counter_ * standard_period_) / retrace_time_;
if(retrace_distance > _counter_before_retrace) return 0; if(retrace_distance > counter_before_retrace_) return 0;
return _counter_before_retrace - retrace_distance; return counter_before_retrace_ - retrace_distance;
} }
return _counter - _retrace_time; return counter_ - retrace_time_;
} }
/*! /*!
@ -152,7 +152,7 @@ struct Flywheel
*/ */
inline unsigned int get_current_time() inline unsigned int get_current_time()
{ {
return _counter; return counter_;
} }
/*! /*!
@ -160,7 +160,7 @@ struct Flywheel
*/ */
inline bool is_in_retrace() inline bool is_in_retrace()
{ {
return _counter < _retrace_time; return counter_ < retrace_time_;
} }
/*! /*!
@ -168,7 +168,7 @@ struct Flywheel
*/ */
inline unsigned int get_scan_period() inline unsigned int get_scan_period()
{ {
return _standard_period - _retrace_time; return standard_period_ - retrace_time_;
} }
/*! /*!
@ -176,7 +176,7 @@ struct Flywheel
*/ */
inline unsigned int get_standard_period() inline unsigned int get_standard_period()
{ {
return _standard_period; return standard_period_;
} }
/*! /*!
@ -185,8 +185,8 @@ struct Flywheel
*/ */
inline unsigned int get_and_reset_number_of_surprises() inline unsigned int get_and_reset_number_of_surprises()
{ {
unsigned int result = _number_of_surprises; unsigned int result = number_of_surprises_;
_number_of_surprises = 0; number_of_surprises_ = 0;
return result; return result;
} }
@ -195,19 +195,19 @@ struct Flywheel
*/ */
inline bool is_near_expected_sync() inline bool is_near_expected_sync()
{ {
return abs((int)_counter - (int)_expected_next_sync) < (int)_standard_period / 50; return abs((int)counter_ - (int)expected_next_sync_) < (int)standard_period_ / 50;
} }
private: private:
unsigned int _standard_period; // the normal length of time between syncs unsigned int standard_period_; // the normal length of time between syncs
const unsigned int _retrace_time; // a constant indicating the amount of time it takes to perform a retrace const unsigned int retrace_time_; // a constant indicating the amount of time it takes to perform a retrace
const unsigned int _sync_error_window; // a constant indicating the window either side of the next expected sync in which we'll accept other syncs const unsigned int sync_error_window_; // a constant indicating the window either side of the next expected sync in which we'll accept other syncs
unsigned int _counter; // time since the _start_ of the last sync unsigned int counter_; // time since the _start_ of the last sync
unsigned int _counter_before_retrace; // the value of _counter immediately before retrace began unsigned int counter_before_retrace_; // the value of _counter immediately before retrace began
unsigned int _expected_next_sync; // our current expection of when the next sync will be encountered (which implies velocity) unsigned int expected_next_sync_; // our current expection of when the next sync will be encountered (which implies velocity)
unsigned int _number_of_surprises; // a count of the surprising syncs unsigned int number_of_surprises_; // a count of the surprising syncs
/* /*
Implementation notes: Implementation notes: