CAST II Game Engine

Class TTimer

Unit

Declaration

type TTimer = class(TSubsystem)

Description

Timer service class

The class can be used to measure time intervals as well as to bind a message generation or a delegate call.
Default implementation uses GetPerformanceCounter from OSUtils if available or less precise GetCurrentMs() otherwise. A custom implemetation can be easily connected.
ToDo: Make the class thread-safe.

Fields

	Name	Description
	`MaxInterval`	This variable limits the time interval on which recurring events will be processed to prevent too much computations when a lot of time passed since last Process() call. Default value is 3 seconds.
	`TimerQueryFunc`	Timer query delegate. Can be overwritten to use a custom timer implementation

Methods

Overview

	`constructor Create(AMessageHandler: TMessageHandler);`
	`function GetInterval(var TimeMark: TTimeMark; ModifyMark: Boolean): TSecond;`
	`procedure HandleMessage(const Msg: TMessage); override;`
	`function IsIntervalPassed(var TimeMark: TTimeMark; ModifyMark: Boolean; Interval: TSecond): Boolean;`
	`function Process: TSecond;`
	`procedure RemoveRecurringEvent(EventID: Integer);`
	`procedure SetEvent(const Delay: TSecond; Delegate: TTimerDelegate; EventID: Integer); overload;`
	`procedure SetEvent(const Delay: TSecond; MessageClass: CMessage); overload;`
	`function SetRecurringEvent(const Delay: TSecond; MessageClass: CMessage): Integer; overload;`
	`function SetRecurringEvent(const Delay: TSecond; Delegate: TTimerDelegate; EventID: Integer): Integer; overload;`
	`procedure SetRecurringEventInterval(EventID: Integer; const Delay: TSecond);`

Description

constructor Create(AMessageHandler: TMessageHandler);

function GetInterval(var TimeMark: TTimeMark; ModifyMark: Boolean): TSecond;

Returns time passed from previous call of the method with the same TimeMark variable and ModifyMark set to True. First call (with uninitialized TimeMark) returns 0 and performs initialization of the TimeMark.

procedure HandleMessage(const Msg: TMessage); override;

Message handler. No messages need to be handled so it's empty.

function IsIntervalPassed(var TimeMark: TTimeMark; ModifyMark: Boolean; Interval: TSecond): Boolean;

Returns True if more then Intervak time passed from previous call of the method with the same TimeMark variable and ModifyMark set to True. First call (with uninitialized TimeMark) returns True and performs initialization of the TimeMark.

function Process: TSecond;

Processes timer events and returns delay to the nearest event. Events will be processed and therefore can emerge only within this method.

procedure RemoveRecurringEvent(EventID: Integer);

Removes the specified recurring event

procedure SetEvent(const Delay: TSecond; Delegate: TTimerDelegate; EventID: Integer); overload;

Sets (binds) the specified delegate to call in Delay seconds. EventID is an application-specific identification number to supply the delegate with.

procedure SetEvent(const Delay: TSecond; MessageClass: CMessage); overload;

Sets (binds) a message of the specified class to generate in Delay seconds

function SetRecurringEvent(const Delay: TSecond; MessageClass: CMessage): Integer; overload;

Sets (binds) a message of the specified class to generate every Delay seconds starting from the moment of call. Returns an ID of the new event.

function SetRecurringEvent(const Delay: TSecond; Delegate: TTimerDelegate; EventID: Integer): Integer; overload;

Sets (binds) the specified delegate to call every Delay seconds starting from the moment of call. EventID is an application-specific identification number to supply the delegate with. Returns an ID of the new event.

procedure SetRecurringEventInterval(EventID: Integer; const Delay: TSecond);

Changes interval of the specified recurring event

Properties

Overview

	`property TotalEvents: Integer;`
	`property TotalRecurringEvents: Integer;`

Description

property TotalEvents: Integer;

Number of active events not including recurring ones

property TotalRecurringEvents: Integer;

Number of active recurring events