obj-c classes and sub classes (Cocos2d) conversion
- by Lewis
Hi I'm using this version of cocos2d:
https://github.com/krzysztofzablocki/CCNode-SFGestureRecognizers
Which supports the UIGestureRecognizer within a CCLayer in a cocos2d scene like so:
@interface HelloWorldLayer : CCLayer <UIGestureRecognizerDelegate>
{
}
Now I want to make this custom gesture work within the scene, attaching it to a sprite in cocos2d:
#import <Foundation/Foundation.h>
#import <UIKit/UIGestureRecognizerSubclass.h>
@protocol OneFingerRotationGestureRecognizerDelegate <NSObject>
@optional
- (void) rotation: (CGFloat) angle;
- (void) finalAngle: (CGFloat) angle;
@end
@interface OneFingerRotationGestureRecognizer : UIGestureRecognizer
{
CGPoint midPoint;
CGFloat innerRadius;
CGFloat outerRadius;
CGFloat cumulatedAngle;
id <OneFingerRotationGestureRecognizerDelegate> target;
}
- (id) initWithMidPoint: (CGPoint) midPoint
innerRadius: (CGFloat) innerRadius
outerRadius: (CGFloat) outerRadius
target: (id) target;
- (void)reset;
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event;
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event;
- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event;
- (void)touchesCancelled:(NSSet *)touches withEvent:(UIEvent *)event;
@end
#include <math.h>
#import "OneFingerRotationGestureRecognizer.h"
@implementation OneFingerRotationGestureRecognizer
// private helper functions
CGFloat distanceBetweenPoints(CGPoint point1, CGPoint point2);
CGFloat angleBetweenLinesInDegrees(CGPoint beginLineA,
CGPoint endLineA,
CGPoint beginLineB,
CGPoint endLineB);
- (id) initWithMidPoint: (CGPoint) _midPoint
innerRadius: (CGFloat) _innerRadius
outerRadius: (CGFloat) _outerRadius
target: (id <OneFingerRotationGestureRecognizerDelegate>) _target
{
if ((self = [super initWithTarget: _target action: nil]))
{
midPoint = _midPoint;
innerRadius = _innerRadius;
outerRadius = _outerRadius;
target = _target;
}
return self;
}
/** Calculates the distance between point1 and point 2. */
CGFloat distanceBetweenPoints(CGPoint point1, CGPoint point2)
{
CGFloat dx = point1.x - point2.x;
CGFloat dy = point1.y - point2.y;
return sqrt(dx*dx + dy*dy);
}
CGFloat angleBetweenLinesInDegrees(CGPoint beginLineA,
CGPoint endLineA,
CGPoint beginLineB,
CGPoint endLineB)
{
CGFloat a = endLineA.x - beginLineA.x;
CGFloat b = endLineA.y - beginLineA.y;
CGFloat c = endLineB.x - beginLineB.x;
CGFloat d = endLineB.y - beginLineB.y;
CGFloat atanA = atan2(a, b);
CGFloat atanB = atan2(c, d);
// convert radiants to degrees
return (atanA - atanB) * 180 / M_PI;
}
#pragma mark - UIGestureRecognizer implementation
- (void)reset
{
[super reset];
cumulatedAngle = 0;
}
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
[super touchesBegan:touches withEvent:event];
if ([touches count] != 1)
{
self.state = UIGestureRecognizerStateFailed;
return;
}
}
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
{
[super touchesMoved:touches withEvent:event];
if (self.state == UIGestureRecognizerStateFailed) return;
CGPoint nowPoint = [[touches anyObject] locationInView: self.view];
CGPoint prevPoint = [[touches anyObject] previousLocationInView: self.view];
// make sure the new point is within the area
CGFloat distance = distanceBetweenPoints(midPoint, nowPoint);
if ( innerRadius <= distance
&& distance <= outerRadius)
{
// calculate rotation angle between two points
CGFloat angle = angleBetweenLinesInDegrees(midPoint, prevPoint, midPoint, nowPoint);
// fix value, if the 12 o'clock position is between prevPoint and nowPoint
if (angle > 180)
{
angle -= 360;
}
else if (angle < -180)
{
angle += 360;
}
// sum up single steps
cumulatedAngle += angle;
// call delegate
if ([target respondsToSelector: @selector(rotation:)])
{
[target rotation:angle];
}
}
else
{
// finger moved outside the area
self.state = UIGestureRecognizerStateFailed;
}
}
- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
{
[super touchesEnded:touches withEvent:event];
if (self.state == UIGestureRecognizerStatePossible)
{
self.state = UIGestureRecognizerStateRecognized;
if ([target respondsToSelector: @selector(finalAngle:)])
{
[target finalAngle:cumulatedAngle];
}
}
else
{
self.state = UIGestureRecognizerStateFailed;
}
cumulatedAngle = 0;
}
- (void)touchesCancelled:(NSSet *)touches withEvent:(UIEvent *)event
{
[super touchesCancelled:touches withEvent:event];
self.state = UIGestureRecognizerStateFailed;
cumulatedAngle = 0;
}
@end
Header file for view controller:
#import "OneFingerRotationGestureRecognizer.h"
@interface OneFingerRotationGestureViewController : UIViewController <OneFingerRotationGestureRecognizerDelegate>
@property (nonatomic, strong) IBOutlet UIImageView *image;
@property (nonatomic, strong) IBOutlet UITextField *textDisplay;
@end
then this is in the .m file:
gestureRecognizer = [[OneFingerRotationGestureRecognizer alloc] initWithMidPoint: midPoint
innerRadius: outRadius / 3
outerRadius: outRadius
target: self];
[self.view addGestureRecognizer: gestureRecognizer];
Now my question is, is it possible to add this custom gesture into the cocos2d project found on that github, and if so, what do I need to change in the OneFingerRotationGestureRecognizerDelegate to get it to work within cocos2d. Because at the minute it is setup in a standard iOS project and not a cocos2d project and I do not know enough about UIViews and classing/ sub classing in obj-c to get this to work. Also it seems to inherit from a UIView where cocos2d uses CCLayer.
Kind regards,
Lewis.
I also realise I may have not included enough code from the custom gesture project for readers to interpret it fully, so the full project can be found here:
https://github.com/melle/OneFingerRotationGestureDemo
