uk.co.javagear
Class Throttle

java.lang.Object
  uk.co.javagear.Throttle

public final class Throttle
extends java.lang.Object

Provides the speed throttling functionality based on System.currentTimeMillis() and Thread.sleep(). Heavily based on code by Arnon Cardoso.

Author:

Erik Duijs, Arnon Goncalves Cardoso

Field Summary

(package private) static boolean	autoFS Auto frame skip.
(package private) static float	avgFPS Average FPS.
(package private) static int	DEFAULT_TARGET_FPS Throttle, frameskip constants.
(package private) static int	DEFAULT_THROTTLE_STEP Throttle, frameskip constants.
(package private) static long	fps Frames per second.
(package private) static int	frameDuration Amount of ms.
(package private) static int	frameNumber Framenumber relative to last recalc.
(package private) static int	FRAMES_UNTIL_THROTTLE_RECALC Throttle, frameskip constants.
(package private) static int	fskip Frame skip.
(package private) static float	MAX_FPS_DEVIATION Throttle, frameskip constants.
(package private) static int	MAX_FRAME_SKIP Throttle, frameskip constants.
(package private) static int	MAX_THROTTLE_STEP Throttle, frameskip constants.
(package private) static int	maxFPS Maximum FPS.
(package private) static int	MIN_THROTTLE_STEP Throttle, frameskip constants.
(package private) static int	minFPS Minimum FPS.
(package private) static long	minimumSleep Minimum sleeptime to have effect on the JVM.
(package private) static long	recalcCount Count recalc for measuring avg fps.
(package private) static long	sleep Amount of sleep time in ms.
(package private) static long	sumFPS Sum frames per second for measuring avg FPS.
(package private) static long	t Time in ms.
(package private) static int	targetFPS The FPS that needs to be throttled to.
(package private) static long	tempT Time in ms.
(package private) static java.lang.Thread	thread The thread to throttle.
(package private) static boolean	throttle Throttle is enabled by default.
(package private) static int	throttleStep How fast the throttle changes sleep time.
(package private) static boolean	TRY_ALT_SKIP_CALC Throttle, frameskip constants.

Constructor Summary

private

Throttle() This class only provides static methods and variables.

Method Summary

static void	enable(boolean enable) Enable throttle.
static void	enableAutoFrameSkip(boolean enable) Enable/disable automatic frame skip.
static float	getAverageFPS() Get the average FPS.
static int	getFPS() Get current FPS.
static int	getFrameSkip() Get current amount of frames to be skipped.
static int	getPercentage()
static long	getSleep() Get current sleep time in ms.
static int	getTargetFPS() Get the target FPS.
static void	init(int fps, java.lang.Thread thread) Initialize the throttle.
static boolean	isAutoFrameSkip() Returns true if automatic frame skip is enabled, false otherwise.
static boolean	isEnabled() Returns true if throttling is enabled and false otherwise.
private static void	recalcTiming() Called after FRAMES_UNTIL_THROTTLE_RECALC is reached.
static void	setFrameSkip(int skip) Set the amount of frames to skip.
static boolean	skipFrame() Returns true if a frame needs to be skipped, false otherwise.
static void	throttle() Call this method each frame.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

MAX_THROTTLE_STEP

static final int MAX_THROTTLE_STEP

Throttle, frameskip constants.

See Also:

Constant Field Values

MIN_THROTTLE_STEP

static final int MIN_THROTTLE_STEP

Throttle, frameskip constants.

See Also:

Constant Field Values

DEFAULT_THROTTLE_STEP

static final int DEFAULT_THROTTLE_STEP

Throttle, frameskip constants.

See Also:

Constant Field Values

DEFAULT_TARGET_FPS

static final int DEFAULT_TARGET_FPS

Throttle, frameskip constants.

See Also:

Constant Field Values

FRAMES_UNTIL_THROTTLE_RECALC

static final int FRAMES_UNTIL_THROTTLE_RECALC

Throttle, frameskip constants.

See Also:

Constant Field Values

MAX_FRAME_SKIP

static final int MAX_FRAME_SKIP

Throttle, frameskip constants.

See Also:

Constant Field Values

MAX_FPS_DEVIATION

static final float MAX_FPS_DEVIATION

Throttle, frameskip constants.

See Also:

Constant Field Values

TRY_ALT_SKIP_CALC

static final boolean TRY_ALT_SKIP_CALC

Throttle, frameskip constants.

See Also:

Constant Field Values

throttle

static boolean throttle

Throttle is enabled by default.

autoFS

static boolean autoFS

Auto frame skip.

fps

static long fps

Frames per second.

sumFPS

static long sumFPS

Sum frames per second for measuring avg FPS.

avgFPS

static float avgFPS

Average FPS.

sleep

static long sleep

Amount of sleep time in ms.

targetFPS

static int targetFPS

The FPS that needs to be throttled to.

throttleStep

static int throttleStep

How fast the throttle changes sleep time.

minFPS

static int minFPS

Minimum FPS.

maxFPS

static int maxFPS

Maximum FPS.

minimumSleep

static long minimumSleep

Minimum sleeptime to have effect on the JVM.

fskip

static int fskip

Frame skip.

frameDuration

static int frameDuration

Amount of ms. of one frame.

t

static long t

Time in ms.

tempT

static long tempT

Time in ms.

frameNumber

static int frameNumber

Framenumber relative to last recalc.

recalcCount

static long recalcCount

Count recalc for measuring avg fps.

thread

static java.lang.Thread thread

The thread to throttle.

Constructor Detail

Throttle

private Throttle()

This class only provides static methods and variables.

Method Detail

init

public static void init(int fps,
                        java.lang.Thread thread)

Initialize the throttle.

Parameters:

fps - the target number of frames persecond.

thread - the thread to throttle.

throttle

public static void throttle()

Call this method each frame. Here the actual throttling takes place.

getSleep

public static long getSleep()

Get current sleep time in ms.

Returns:

current sleep time in ms.

skipFrame

public static boolean skipFrame()

Returns true if a frame needs to be skipped, false otherwise.

Returns:

true if a frame needs to be skipped, false otherwise.

enableAutoFrameSkip

public static void enableAutoFrameSkip(boolean enable)

Enable/disable automatic frame skip.

Parameters:

enable - true to enable automatic frame skip, false to disable.

isAutoFrameSkip

public static boolean isAutoFrameSkip()

Returns true if automatic frame skip is enabled, false otherwise.

Returns:

true if automatic frame skip is enabled, false otherwise.

enable

public static void enable(boolean enable)

Enable throttle.

Parameters:

enable - true to enable throttle, false to disable.

isEnabled

public static boolean isEnabled()

Returns true if throttling is enabled and false otherwise.

Returns:

true if throttling is enabled and false otherwise.

setFrameSkip

public static void setFrameSkip(int skip)

Set the amount of frames to skip.

Parameters:

skip - the number of frames to skip.

getFrameSkip

public static int getFrameSkip()

Get current amount of frames to be skipped.

Returns:

the current number of frames to skip.

getFPS

public static int getFPS()

Get current FPS.

Returns:

the current FPS.

getTargetFPS

public static int getTargetFPS()

Get the target FPS.

Returns:

the target FPS.

getAverageFPS

public static float getAverageFPS()

Get the average FPS.

Returns:

the average FPS.

getPercentage

public static int getPercentage()

recalcTiming

private static void recalcTiming()

Called after FRAMES_UNTIL_THROTTLE_RECALC is reached. Here the sleep time and auto frame skip is re-evaluated.