I have a CGMuatbleCGPathRef and I am trying to create a path ref to move my alien. I'm keeping it simple right now, but these will be complex later on.
I have the code below to move the SpriteNode to one point, but he never moves. Can someone point out what i'm doing wrong? I have an animation action running on him with repeat action also.
Method called first to start the animation texture frames ( works )
-(void)walkingBear
{
//This is our general runAction method to make our bear walk.
[spaceMosquito runAction:[SKAction repeatActionForever:
[SKAction animateWithTextures:moqFrames
timePerFrame:0.4f
resize:NO
restore:YES]] withKey:#"walkingInPlaceBear"];
return;
}
The Action to move the alien
-(void) normalStance {
CGMutablePathRef cgpath = CGPathCreateMutable();
CGPoint endPos = CGPointMake(300, 600);
CGPoint startPos = CGPointMake(700, 900);
CGPathMoveToPoint(cgpath, nil, startPos.x, startPos.y);
CGPathMoveToPoint(cgpath, nil, endPos.x, endPos.y);
[spaceMosquito runAction:[SKAction followPath:cgpath duration:5.0f ] withKey:#"moveme"];
CGPathRelease(cgpath);
}
You are not creating a path in your code! You are just moving the start of the path from start point to end point but no path is created.
Replace the second call of CGPathMoveToPoint by CGPathAddLineToPoint
The will create a line path your sprite could follow.
Related
i have this method that makes the Lines
lineaGuida_Img = [SKTexture textureWithImageNamed:#"LineaGuida copia.jpeg"];
_Linea = [SKNode node];
_Linea.position = CGPointMake((self.frame.size.width / 7 ) * 2, self.frame.size.height / 2 );
_Linea.zPosition = -10;
SKSpriteNode * linea = [SKSpriteNode spriteNodeWithTexture:lineaGuida_Img];
linea.position = CGPointMake(0,0);
linea.physicsBody = [SKPhysicsBody bodyWithRectangleOfSize:linea.size];
linea.physicsBody.dynamic = FALSE;
linea.physicsBody.collisionBitMask = 0;
linea.physicsBody.categoryBitMask = CollisionEnemy;
[_Linea addChild:linea];
[self addChild:_Linea];
In the touchesBegan method when i touch the screen, the player is always on the center of screen, and those lines behind him have to move by -x.
[_Linea runAction:[SKAction moveByX: -(self.size.width/8) y:0 duration:0.1]];
[self spawn_Lines];
But this action is only executed by the last SKNode. I need to apply this to all Lines simultaneously. After that, when the line's position is less then the player's position, the line must be deleted.
SpriteKit uses a tree based model, so whatever the parent node does, the children fall suit. Create an SKNode to house all of your lines, add all of your lines to this SKNode, then apply the actions to the SKNode, not the lines.
Add them to NSMutableArray to keep the reference and use for each loop to make each one run the action. I would recommend you to use NSTimer to provide [SKAction moveByX: -1 y:0 duration:0]] with constant speed which will result in the same motion as you already used. Each time this NSTimer execute you will check all positions of object from your NSMutableArray and than delete it if it fits your conditions. Be careful when you want to lose the reference completely use [object removeFromParent]; and remove it also from your NSMutableArray to avoid lose of performance later on. For this I use rather forLoop with continue method
I am making a game and I want an enemy to move in a circle but the enemy should have constant movement to the left as well. I have tried to create a circle path with CGPath and make it follow that path and then added a SKAction with constant left movement. But it seems that the node is just following the CGPath without left movement.
Is there any other way to make this possible?
This is my code at the moment:
CGMutablePathRef circle = CGPathCreateMutable();
CGPathAddArc(circle, NULL, 0, 0, 80, 0, 2*M_PI, true);
CGPathCloseSubpath(circle);
SKAction *followTrack = [SKAction followPath:circle asOffset:NO orientToPath:NO duration:1.5];
SKAction *forever = [SKAction repeatActionForever:followTrack];
[enemy runAction:[SKAction moveByX:-1000 y:0 duration:3.0]];
[enemy runAction:forever];
You can't move the same node with 2 move actions. What you can do is place the node in a container node. Then move the container node left while its child moves in a circle.
Another option is to not use SKActions and use something more dynamic and real-time by computing the centripetal velocity manually and shifting the centripetal point overtime. You can see an example of this in my answer here.
I am creating a relatively complicated animation sequence. In it, a certain SKSpriteNode (shark) does two rotations. At the beginning of the animation, it rotates around a certain anchor point ap1, then later rotates around a different anchor point ap2. How should I change anchor points midway through an animation sequence?
Some initial thoughts:
I could change the anchor point outside of SKActions, in the update: loop perhaps.
I could use multiple SKSpriteNodes for the same shark sprite (with their respective anchor points), switching (hiding/showing) the sprite nodes when I need to change the anchor point.
Since changing a sprite's anchor point affects where it's rendered, you will likely need to make some sort of adjustment to prevent the sprite from appearing to suddenly move to a new location. Here's one way to do that:
Create action that changes the anchor point
SKAction *changeAnchorPoint = [SKAction runBlock:^{
[self updatePosition:sprite withAnchorPoint:CGPointMake(0, 0)];
}];
SKAction *rotate = [SKAction rotateByAngle:2*M_PI duration: 2];
Run action to rotate, change the anchor point, and rotate
[sprite runAction:[SKAction sequence:#[rotate,changeAnchorPoint,rotate]] completion:^{
// Restore the anchor point
[self updatePosition:sprite withAnchorPoint:CGPointMake(0.5, 0.5)];
}];
This method adjusts a sprite's position to compensate for the anchor point change
- (void) updatePosition:(SKSpriteNode *)node withAnchorPoint:(CGPoint)anchorPoint
{
CGFloat dx = (anchorPoint.x - node.anchorPoint.x) * node.size.width;
CGFloat dy = (anchorPoint.y - node.anchorPoint.y) * node.size.height;
node.position = CGPointMake(node.position.x+dx, node.position.y+dy);
node.anchorPoint = anchorPoint;
}
As Julio Montoya said, the easiest way to do this is to just "translate" code into an SKAction with the method [SKAction runBlock:myBlock].
How do I make an object grow in one direction is SpriteKit?
Ultimately, I would like to have a node be inserted where the user touches and have each end of a line scale until it hits another object in the same category or hits the edge of the screen. I understand how to have it scale on an axis and I can then cancel the scaling after one collision is detected but I want both directions to scale independently until a collision is made for each. I am new to SpriteKit so my searches may be using the wrong terms but I have not been able to find anything relevant.
Code to add a "wall" where the user touches
-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
for (UITouch * touch in touches) {
CGPoint location = [touch locationInNode:self];
[self addWallAtLocation:location];
}
}
-(void)addWallAtLocation:(CGPoint)location{
int odd_or_even = arc4random() % 2;
SKSpriteNode * wall = [SKSpriteNode spriteNodeWithColor:[UIColor whiteColor] size:CGSizeMake(2, 2)];
wall.position = location;
wall.physicsBody = [SKPhysicsBody bodyWithRectangleOfSize:CGSizeMake(2, 2)];
wall.physicsBody.dynamic = NO;
wall.physicsBody.categoryBitMask = wallCategory;
wall.physicsBody.contactTestBitMask = ballCategory;
[self addChild:wall];
SKAction * grow;
if (odd_or_even == 1) {
grow = [SKAction scaleYTo:300 duration:2];
} else {
grow = [SKAction scaleXTo:300 duration:2];
}
[wall runAction:grow];
}
How I want it to work:
Touch 1 makes the horizontal line from a point which shoots out in both directions on the x-axis until both ends hit the edge of the screen. Touch 2 would then create a point which shoots out in both directions on the y-axis until the lower end hits the wall created by Touch 1 and the upper end hits the edge of the screen. The lines (scaled points) are generated where the user touches. So I do not want the part of the vertical line that is highlighted by the red box to be there.
Scaling in one direction is just a solution I see to this problem, if there is a better way of going about it I will certainly try that other solution.
EDIT FOR UPDATED QUESTION:
It sounds like you might be asking "how to scale a thing in a single axis, but then stop the scaling of that single axis in one direction only when it collides with another thing"? There isn't a simple way to do that just using actions, but you you could do some slight of hand by manipulating the anchor point of a sprite. Or, probably more appropriately, you should use 2 sprites per touch, with one action sending one north, and another action sending the other one south. Maybe like this:
-(void)someMethod{
SKSpriteNode *touch2TopPart = [SKSpriteNode node];
SKSpriteNode *touch2BottomPart = [SKSpriteNode node];
touch2TopPart.anchorPoint = CGPointMake(.5, 0);
touch2BottomPart.anchorPoint = CGPointMake(.5, 1);
touch2TopPart.name = #"touch2TopPart";
touch2BottomPart.name = #"touch2BottomPart";
SKAction *sendTopPartUp = [SKAction scaleYTo:100 duration:2];
SKAction *sendBottomPartDown = [SKAction scaleYTo:100 duration:2];
[touch2TopPart runAction:sendTopPartUp withKey:#"sendTopPartUp"];
[touch2BottomPart runAction:sendBottomPartDown withKey:#"sendBottomPartDown"];
}
-(void)whateverTheCollisonMethodIsCalledBetweenThingAandThingB
{
SKSpriteNode *somePartMovingInASingleDirection = thingAOrWhatever;
[somePartMovingInASingleDirection removeAllActions];
}
---ORIGINAL ANSWER
I'm not exactly sure what you're asking, but you already have the actions for scaling in just X or Y, so here's the simple usage for removing one of those actions after physics is simulated. You might be looking for how to detect a specific collision between two entities, but I can't be sure.
-(void)someMethod{
SKSpriteNode *thisSprite = [SKSpriteNode node];
thisSprite.name = #"spriteRunningActions";
SKAction *growX = [SKAction scaleXTo:100 duration:2];
SKAction *growY = [SKAction scaleYTo:100 duration:2];
[thisSprite runAction:growX withKey:#"actionCurrentlyScalingX"];
[thisSprite runAction:growY withKey:#"actionCurrentlyScalingY"];
}
-(void)didSimulatePhysics
{
SKSpriteNode *thatSprite = (SKSpriteNode*)[self childNodeWithName:#"spriteRunningActions"];
//stop a given action
[thatSprite removeActionForKey:#"actionCurrentScalingX"];
[thatSprite removeActionForKey:#"actionCurrentScalingY"];
}
Setting the anchor point like below made the "lines" scale in one direction.
wall.anchorPoint = CGPointMake(0, 0);
i want to make a parallax effect on my background title screen with mountains moving. The "trick" i want to make is when a mountain goes to the end of the screen, instead of destroying the node and create it again at the begining position, i just want to change it's position to the begining position and loop the rest of actions. For this i create my moutain sprite at the begining of the createSceneContents() function and i pass the sprite to a method animate() wich do allways the same combo of actions forever: animate to the right, then when it's at x position, change mountain.position.x to the begining...
-(void)createSceneContents{
//crear
SKSpriteNode *mountain = [SKSpriteNode spriteNodeWithImageNamed:#"mountain.png"];
mountain.name = #"mountain";
//initial position
mountain.position = CGPointMake(-161.5,15);
//animate
SKAction *animRight = [SKAction moveToX:801.5 duration:4];
SKAction *comboActions = [SKAction repeatActionForever:[SKAction performSelector:#selector(animate:mountain) onTarget:#"mountain"]];
And here i have my method declaration:
- (void) animate:(SKSpriteNode*)mountain
{
// code....
}
My problem is i'm allways having errors passing the SKSpriteNode *mountain in my method and
I'm going crazy trying everithing.
You can avoid performSelector action, using a custom action like this.
SKAction* parallaxMoveAction = [SKAction sequence:#[[SKAction moveToX:801.5 duration:4.0f],[SKAction customActionWithDuration:0 actionBlock:^(SKNode* node, CGFloat elapsedTime){
[node setPosition:CGPointMake(-161.5,15)];
}]]];
If you set custom action duration to 0 it will be performed only once.
On the other hand your perform selector action should look like this:
[SKAction performSelector:#selector(animate:) onTarget:self]
As far as i know you can't pass arguments to it.