Peanuts NeXT Software Archives/Peanuts-Update.iso/Rhapsody/developer/examples/LocalizationExample.5.0.m.I.bs.tz/LocalizationExample.5.0.m.I.bs/LocalizationExample.5.0.I.bs/Source/Animator.m

Text File | 1997-10-22 | 4.9 KB | 232 lines

//  Animator.m
//  Object for general timing, animation, and dynamics.
//  Author: R. E. Crandall, Educational Technology Center
//  10-Apr-88
//  Revised by Bluce Blumberg for 0.8, 29-Sep-88
//  Revised for 1.0 by Ali Ozer, 13-Jun-89
//  Revised for 2.0 by Jayson Adams, 14-Oct-90
//
// You may freely copy, distribute and reuse the code in this example.
// NeXT disclaims any warranty of any kind, expressed or implied, as to its
// fitness for any particular use.

/*
 *  An 'Animator' controls the timing for your action method of choice.
 *  The object may function as a general timer object; i.e.
 *  graphics are neither expected nor required by the class.
 *  When you create an Animator with +newChronon, you specify
 *  the time interval between calls, the adaptation time constant (see below),
 *  the target to which the method belongs, the action name, whether to
 *  automatically start up the timing upon creation, and an event mask (if you
 *  plan to break conditionally out of loops within the action method).
 *
 *  The Animator has adaptive means for adjusting to harsh operating
 *  environments.  An adaptation constant d > 0. will invoke dynamical
 *  correction of entry times, on-the-fly, so that the desired chronon
 *  will be realized in a real-time sense.
 *
 *  Functionality and applications are discussed in Report ETC-0008.
 */

#import "Animator.h"

#import <sys/time.h>
#import <objc/objc-runtime.h>

@interface Animator(private_methods)

- (void)_timerFunction:(NSTimer *)theTimer;

@end

@implementation Animator

- (void)_timerFunction:(NSTimer *)theTimer
{
    gettimeofday(&entrytime, NULL);
    if (howOften > 0.0) {
        [self adapt];
    }

    [target performSelector:action withObject:self];
}

- initChronon:(double)dt    /* The time increment desired. */
  adaptation:(double)howoft    /* Adaptive time constant (0.deactivates).*/
  target:(id)targ        /* Target to whom proc belongs. */
  action:(SEL)act        /* The action. */
  autoStart:(int)start        /* Automatic start of timed entry? */
  eventMask:(int)eMask        /* Mask for optional check in "shouldBreak". */
{
    [super init];
    ticking = NO;
    desireddt = dt;
    [self setIncrement:dt];
    [self setAdaptation:howoft];
    [self setTarget:targ];
    [self setAction:act];

    if (start) {
    [self startEntry];
    }

    mask = eMask;
    [self resetRealTime];

    return self;
}

- resetRealTime
/* After this call, getDoubleRealTime is the real time that ensues. */
{
    struct timeval    realtime;

    gettimeofday(&realtime, NULL);
    synctime = realtime.tv_sec + realtime.tv_usec / 1000000.0;
    passcounter = 0;
    t0 = 0.0;

    return self;
}

- (double)getSyncTime
{
    return synctime;
}

- (double)getDoubleEntryTime
/* Returns real time since "resetrealTime". */
{
    return (- synctime + entrytime.tv_sec + entrytime.tv_usec / 1000000.0);
}

- (double)getDoubleRealTime
/* Returns real time since "resetrealTime". */
{
    struct timeval    realtime;
    struct timezone    tzone;

    gettimeofday(&realtime, &tzone);
    return (- synctime + realtime.tv_sec + realtime.tv_usec / 1000000.0);
}

- (double)getDouble
{
    return [self getDoubleRealTime];
}

- adapt
/* Adaptive time-step algorithm. */
{
    double t;

    if (!ticking) {
    return self;
    }

    ++passcounter;
    t = [self getDoubleEntryTime];

    if (t - t0 >= howOften) {
    adapteddt *= desireddt * passcounter / (t - t0);
    [self setIncrement:adapteddt];
    [self startEntry];
    passcounter = 0;
    t0 = t;
    }
    return self;
}

- setBreakMask:(int)eventMask
{
    mask = eventMask;
    return self;
}

- (int)getBreakMask
{
    return mask;
}

- (int)isTicking
{
    return ticking;
}

- (int)shouldBreak
/* Call this to see if you want to exit a loop in your action method. */
{
    NSEvent *e, *event;

    e = (event = [NSApp nextEventMatchingMask:mask untilDate:[NSDate dateWithTimeIntervalSinceNow:0.0] inMode:NSEventTrackingRunLoopMode dequeue:NO]);

    return (e ? 1: 0);
}

- setIncrement:(double)dt
{
    adapteddt = dt;
    interval = dt;

    return self;
}

- (double)getIncrement
{
    return adapteddt;
}

- setAdaptation:(double)oft
{
    howOften = oft;
    return self;
}

- (void)setTarget:(id)targ
{
    target = targ;
}

- (void)setAction:(SEL)aSelector
{
    action = aSelector;
}

- startEntry
{
    [self stopEntry];
    teNum = [[NSTimer timerWithTimeInterval:interval target:self selector:@selector(_timerFunction:) userInfo:nil repeats:YES] retain];
    [[NSRunLoop currentRunLoop] addTimer:teNum forMode:NSDefaultRunLoopMode];
    [[NSRunLoop currentRunLoop] addTimer:teNum forMode:NSModalPanelRunLoopMode];
    [[NSRunLoop currentRunLoop] addTimer:teNum forMode:NSEventTrackingRunLoopMode];
    ticking = YES;

    return self;
}

- stopEntry
{
    if (ticking) {
        [teNum invalidate];
        [teNum release];
        teNum = nil;
    }
    ticking = NO;

    return self;
}

- (void)dealloc
{
    if (ticking) {
        [teNum invalidate];
        [teNum release];
        teNum = nil;
    }

    [super dealloc];
    return;
}

@end