Wie erreicht man diese Animation mit Spritekit?

Question

Frage:

Wie diese Animation mit Spritekit erreichen?

Was ich getan habe:

Problem:

1) Ich kann alle vier Blütenblätter ziehen, aber sobald ich hebe meine Finger Zeichne den Kreis, es wird immer noch eine Linie vom vorherigen Punkt erzeugt, wo ich meinen Finger an den neuen Berührungen Anfangspunkt hebe. siehe unten gif:

2) Wie die feste orange Linie aus der Sicht entfernen inkrementell (Mine ist zu abrupt)?

3) Sie müssen die Eigenschaften der .sks-Datei anpassen.

4) https://stackoverflow.com/questions/29792443/set-the-initial-state-of-skemitternode

Dies ist mein Code:

#import "GameScene.h" 

@interface GameScene() 

@property (nonatomic) SKEmitterNode* fireEmmitter; 
@property (nonatomic) SKEmitterNode* fireEmmitter2; 

@end 

@implementation GameScene 

NSMutableArray *_wayPoints; 
NSTimer* myTimer; 

-(void)didMoveToView:(SKView *)view { 

_wayPoints = [NSMutableArray array]; 

//Setup a background 
self.backgroundColor = [UIColor blackColor]; 

//setup a fire emitter 
NSString *fireEmmitterPath = [[NSBundle mainBundle] pathForResource:@"magic" ofType:@"sks"]; 
_fireEmmitter = [NSKeyedUnarchiver unarchiveObjectWithFile:fireEmmitterPath]; 
_fireEmmitter.position = CGPointMake(self.frame.size.width/2, self.frame.size.height/2 - 200); 
_fireEmmitter.name = @"fireEmmitter"; 
_fireEmmitter.zPosition = 1; 
_fireEmmitter.targetNode = self; 
_fireEmmitter.particleBirthRate = 0; 
[self addChild: _fireEmmitter]; 

//setup another fire emitter 
NSString *fireEmmitterPath2 = [[NSBundle mainBundle] pathForResource:@"fireflies" ofType:@"sks"]; 
_fireEmmitter2 = [NSKeyedUnarchiver unarchiveObjectWithFile:fireEmmitterPath2]; 
_fireEmmitter2.position = CGPointMake(self.frame.size.width/2, self.frame.size.height/2); 
_fireEmmitter2.name = @"fireEmmitter"; 
_fireEmmitter2.zPosition = 1; 
_fireEmmitter2.targetNode = self; 
_fireEmmitter2.particleBirthRate = 0; 
[self addChild: _fireEmmitter2]; 


//Setup a LightNode 
SKLightNode* light = [[SKLightNode alloc] init]; 
light.categoryBitMask = 1; 
light.falloff = 1; 
light.ambientColor = [UIColor whiteColor]; 
light.lightColor = [[UIColor alloc] initWithRed:1.0 green:1.0 blue:0.0 alpha:0.5]; 
light.shadowColor = [[UIColor alloc] initWithRed:0.0 green:0.0 blue:0.0 alpha:0.3]; 
[_fireEmmitter addChild:light]; 

} 

-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event { 

CGPoint touchPoint = [[touches anyObject] locationInNode:self.scene]; 

CGMutablePathRef ref = CGPathCreateMutable(); 

CGPoint p = touchPoint; 
p = [self.scene convertPointToView:p]; 
CGPathMoveToPoint(ref, NULL, p.x, p.y); 

_fireEmmitter.position = CGPointMake(touchPoint.x, touchPoint.y); 
_fireEmmitter.particleBirthRate = 2000; 

} 

-(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event { 

CGPoint touchPoint = [[touches anyObject] locationInNode:self.scene]; 

//On Dragging make the emitter with the attached light follow the position 
for (UITouch *touch in touches) { 
    [self addPointToMove:touchPoint]; 

    CGPoint location = [touch locationInNode:self]; 
    [self childNodeWithName:@"fireEmmitter"].position = CGPointMake(location.x, location.y); 
} 
} 

-(void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event{ 
_fireEmmitter.particleBirthRate = 0; 

[self performSelector:@selector(userHasCompletedTheDrawing) withObject:nil afterDelay:3]; 
} 

- (void)userHasCompletedTheDrawing{ 
CGMutablePathRef path = CGPathCreateMutable(); 
if (_wayPoints && _wayPoints.count > 0) { 
    CGPoint p = [(NSValue *)[_wayPoints objectAtIndex:0] CGPointValue]; 
    //p = [self.scene convertPointToView:p]; 
    CGPathMoveToPoint(path, nil, p.x, p.y); 

    _fireEmmitter2.position = CGPointMake(p.x,p.y); 
    _fireEmmitter2.particleBirthRate = 1000; 

    for (int i = 0; i < _wayPoints.count; ++i) { 
     p = [(NSValue *)[_wayPoints objectAtIndex:i] CGPointValue]; 
     CGPathAddLineToPoint(path, nil, p.x, p.y); 
    } 
    SKAction *followTrack = [SKAction followPath:path asOffset:NO orientToPath:YES duration:1]; 
    [_fireEmmitter2 runAction:followTrack completion:^{ 

     _fireEmmitter2.particleBirthRate = 0; 

     [_fireEmmitter2 runAction:[SKAction waitForDuration:1] completion:^{ 
      //_fireEmmitter2.particleBirthRate = 0; 
     }]; 
    }]; 
} 


//myTimer = [NSTimer scheduledTimerWithTimeInterval: 0.01 target: self selector: @selector(removePointToMove) userInfo: nil repeats: YES]; 
[self performSelector:@selector(removeAllPointToMove) withObject:nil afterDelay:1]; 

} 

- (void)addPointToMove:(CGPoint)point { 
[_wayPoints addObject:[NSValue valueWithCGPoint:point]]; 
} 

- (void)removeAllPointToMove{ 
[_wayPoints removeAllObjects]; 
} 

- (void)removePointToMove{ 

if ([_wayPoints count]>0) { 
    [_wayPoints removeObjectAtIndex:0]; 
} 
} 

- (void)drawLines { 
//1 

NSMutableArray *temp = [NSMutableArray array]; 
for(CALayer *layer in self.view.layer.sublayers) { 
    if([layer.name isEqualToString:@"line"]) { 
     [temp addObject:layer]; 
    } 
} 

[temp makeObjectsPerformSelector:@selector(removeFromSuperlayer)]; 

//3 
CAShapeLayer *lineLayer = [CAShapeLayer layer]; 
lineLayer.name = @"line"; 
lineLayer.strokeColor = [UIColor orangeColor].CGColor; 
lineLayer.fillColor = nil; 
lineLayer.lineWidth = 3; 
lineLayer.lineJoin = kCALineJoinRound; /* The join style used when stroking the path. Options are `miter', `round' 
             * and `bevel'. Defaults to `miter'. */ 
lineLayer.zPosition = -1; 

//4 
CGPathRef path = [self createPathToMove]; 
lineLayer.path = path; 
CGPathRelease(path); 
[self.view.layer addSublayer:lineLayer]; 

} 

- (CGPathRef)createPathToMove { 
//1 
CGMutablePathRef ref = CGPathCreateMutable(); 

//2 
for(int i = 0; i < [_wayPoints count]; ++i) { 
    CGPoint p = [_wayPoints[i] CGPointValue]; 
    p = [self.scene convertPointToView:p]; 
    //3 
    if(i == 0) { 
     CGPathMoveToPoint(ref, NULL, p.x, p.y); 
    } else { 
     CGPathAddLineToPoint(ref, NULL, p.x, p.y); 
    } 
} 

return ref; 
} 

-(void)update:(CFTimeInterval)currentTime { 
/* Called before each frame is rendered */ 

[self drawLines]; 

if ([_wayPoints count]==0) { 
    [myTimer invalidate]; 
} 

} 
@end 

Dies ist meine .sks Dateien Eigenschaften:

Answer 1

Con Bei der ersten Frage müssen Sie Ihren CGPathRef in mehrere Unterpfade aufteilen, so dass keine Linie zwischen den Petalen und dem Mittelpunkt gezogen wird. Verwenden Sie die CGPathCloseSubpath Funktion, wenn Sie fertig sind, die Blütenblätter zu zeichnen, so dass Sie danach CGPathMoveToPoint und CGPathAddLineToPoint aufrufen können.