gistfile1.m

#import "TGScoreLabel.h"

-(void) setupPercentComplete {
	TGScoreLabel * myScoreLabel = [TGScoreLabel scoreLabelWithFormatString:@"%d%%!" score:0 dimensions:CGSizeMake(380, 45) alignment:UITextAlignmentRight fontName:@"TacoGraveyard" fontSize:36];
	myScoreLabel.position = myScoreLabelPosition;
	[self addChild:myScoreLabel];
	[myScore rollToScore: percentComplete];
}

rollToScore.m

-(void) rollToScore:(int)newScore {
	self.score = newScore;
	if (!updating_) {
		updating_ = TRUE;
		[self schedule:@selector(update_:) interval:interval_];
	}
}

TGScoreLabel.h

#import <Foundation/Foundation.h>
#import "cocos2d.h"

@interface TGScoreLabel : CCLabelTTF {
	double curScore_; // the current score value of the label
	BOOL updating_; // if we currently have an update running
	double interval_; // how long we wait between updates
	
	int score; // the target score
	NSString * formatString; // the string that we format
	int pointsPerSecond; // how fast we update
}

@property int score;
@property (nonatomic, retain) NSString * formatString;
@property int pointsPerSecond;

// give me that object!
+(id) scoreLabelWithFormatString:(NSString*)formatString score:(int)score dimensions:(CGSize)dimensions alignment:(CCTextAlignment)alignment fontName:(NSString*)name fontSize:(CGFloat)size;

// start rolling up
-(void) rollToScore:(int)newScore;

// internal stuff
-(void) update_;
-(void) setup_:(int)score formatString:(NSString *)formatString;

@end

TGScoreLabel.m

#import "TGScoreLabel.h"


@implementation TGScoreLabel

@synthesize score, formatString, pointsPerSecond;

+(id) scoreLabelWithFormatString:(NSString*)formatString score:(int)score dimensions:(CGSize)dimensions alignment:(CCTextAlignment)alignment fontName:(NSString*)name fontSize:(CGFloat)size {
	TGScoreLabel * l;
	if ( (l=[[[super alloc] initWithString:[NSString stringWithFormat:formatString, score] dimensions:dimensions alignment:alignment fontName:name fontSize:size] autorelease]) ) {
		[l setup_:score formatString:formatString];
	}
	return l;
}

-(void) setup_:(int)score formatString:(NSString*)formatString {
	self.score = score;
	self.formatString = formatString;
	self.pointsPerSecond = 30;
	curScore_ = score;
	interval_ = 0.05;
	updating_ = FALSE;
}

-(void) rollToScore:(int)newScore {
	self.score = newScore;
	if (!updating_) {
		updating_ = TRUE;
		[self schedule:@selector(update_:) interval:interval_];
	}
}

-(void) update_:(ccTime)dt {
	int direction = 1; // the score can roll in either direction
	if (self.score < curScore_) {
		direction = -1;
	}
	double pointChange = self.pointsPerSecond * direction * dt;
	curScore_ += pointChange;
	
	// don't let it overrun the target
	if (direction == -1 && curScore_ < self.score) {
		curScore_ = self.score;
	} else if (direction == 1 && curScore_ > self.score) {
		curScore_ = self.score;
	}
	
	// update the string
	// this is as costly as creating a new label
	// we should be using cclabelatlas
	[self setString:[NSString stringWithFormat:self.formatString, (int)curScore_]]; 
	
	// if we are at the score then stop updating
	if (self.score == curScore_) {
		[self unschedule:@selector(update_:)];
		updating_ = FALSE;
	}
}

-(void) dealloc {
	if (updating_) {
		[self unschedule:@selector(update_:)];
	}
	
	[self.formatString release];
	
	[super dealloc];
}

@end

update.m

-(void) update_:(ccTime)dt {
	int direction = 1; // the score can roll in either direction
	if (self.score < curScore_) {
		direction = -1;
	}
	double pointChange = self.pointsPerSecond * direction * dt;
	curScore_ += pointChange;
	
	// don't let it overrun the target
	if (direction == -1 && curScore_ < self.score) {
		curScore_ = self.score;
	} else if (direction == 1 && curScore_ > self.score) {
		curScore_ = self.score;
	}
	
	// update the string
	// this is as costly as creating a new label
	// we should be using cclabelatlas
	[self setString:[NSString stringWithFormat:self.formatString, (int)curScore_]]; 
	
	// if we are at the score then stop updating
	if (self.score == curScore_) {
		[self unschedule:@selector(update_:)];
		updating_ = FALSE;
		return;
	}
}