I have an aeroplane sprite (consider a paper plane, pointing towards right direction), which rotates up a little when tapped on the screen, and after that, rotates back down the same amount of degrees by which it rotated upwards. I have accomplished this by using the following code:
-(void)ccTouchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
//Plane move up on touch
UITouch *touch = [touches anyObject];
[plane stopAllActions];
[plane runAction:[CCSequence actions:[CCRotateBy actionWithDuration:0.15 angle:-20],
[CCMoveBy actionWithDuration:1 position:ccp(0,location.y)],
[CCRotateBy actionWithDuration:0.15 angle:20],
[CCCallBlock actionWithBlock:
^{
[self startDownMovement];
}],nil]];}
And then
-(void)startDownMovement {
[plane runAction:[CCSequence actions:[CCMoveBy actionWithDuration:2 position:ccp(0,-plane.position.y)],nil]];
}
The problem is: If I tap for example 2 times, the plane moves up by 20 degrees twice, but rotates down by 20 degrees just once only. I only want the plane to rotate up by 20 degrees, no matter how many times the screen has been tapped, it should stay up by 20 degrees and then come back to 0 degrees.
Please help.
Thanks in anticipation.
Works by checking the current rotation of the plane at every tap. if it is != 0 then do not rotate further, rather just keep going up. And then at startDownMovement, Set the rotation to 0. It works now.
Read the current rotation attribute of plane.
//float currentRotation = plane.rotation;
//Calculate new Rotation Value :
// float newRotation = currentRotation - offset; (offset in your case = 20)
//Use CCRotateTo in place of CCRotateBy
[plane runAction:[CCSequence actions:[CCRotateTo actionWithDuration:0.15 angle:-20],
[CCMoveBy actionWithDuration:1 position:ccp(0,location.y)],
[CCRotateTo actionWithDuration:0.15 angle:20],
[CCCallBlock actionWithBlock:
^{
[self startDownMovement];
}],nil]];}
Related
For the sake of simplicity, the scene has a circle sprite and a square sprite. The square sprite is the child of an SKNode that follows around the circle sprite so that rotation of the square always happens around the circle. However, when the node is rotated, the square randomly drifts upwards. This behavior stops once the rotation makes its way all the way around. Here is the code:
_square = [SKSpriteNode spriteNodeWithImageNamed:#"square"];
_circle = [SKSpriteNode spriteNodeWithImageNamed:#"circle"];
_circle.position = CGPointMake(-200, 300);
[self addChild:_circle];
_rotateNode = [SKNode node];
_rotateNode.position = CGPointMake(300, 300);
[self addChild:_rotateNode];
[_rotateNode addChild:_square];
SKAction *moveBall = [SKAction moveTo:CGPointMake(1200, 300) duration:12];
[_circle runAction:moveBall];
-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
SKAction *rotate = [SKAction rotateByAngle:-M_PI_2 duration:0.2];
[_rotateNode runAction:rotate];
}
-(void)update:(CFTimeInterval)currentTime {
_rotateNode.position = _circle.position;
double xOffset = (300 -_circle.position.x);
double yOffset = (300 - _circle.position.y);
_square.position = CGPointMake(xOffset, yOffset);
}
Anyone know why this is happening?
If I understand the question, you are asking why the square moves in unexpected ways? The circle is moving, but on every frame you are setting the rotateNode's position to be the same as the circle, and they both have the same parent: self, so we can ignore circle for any debugging because it just executes its action every frame to get a new position.
The oddness, most likely, comes in because you are manually repositioning rotateNode, which would then move all of its children, including square. But in every frame you are also repositioning square manually. So rotateNode rotates, changes the position of square because it rotated, and then you reposition square to have a fixed offset. Further complicated depending on whether your goal is to position the square in world space or in parent space. But it's not clear what your goal is there.
So I'm trying to implement a method into a game where if a player has their finger touching the screen at lets say 50 on the y axis or lower, an SKAction will run to move the character sprite down, and if their finger is touching above the 50, another action will run moving the sprite up. I don't know how you have it recognize a touch and hold though. Help please.
You will need to capture the touch event of the user in order to pull this off. I suggest checking out the excellent tutorial provided by RayWenderlich at: Animating Textures and Moving Them With Touch Events
If you don't have time for that this is what your code might look like:
First the knowledge that you will need is that the two most generic touch events are the:
-(void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
and the:
-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
Basically the touches began method is called when the user places their finger on the screen whereas the touches ended method will be triggered when the user takes their finger off the screen.
For this example I will use touchesEnded, but feel free to change it if you want, its as easy as switching the "Ended" with "Began".
All of the code I am about to show you will take place within the scenes implementation file:
If you just want the sprite to move up when above a certain point and down when below a certain point use the following:
-(void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
{
//capture the location of the touch
CGPoint location = [[touches anyObject] locationInNode:self];
//used to hold the location to travel
CGPoint moveLocation;
//check if the Y location is less than 50
if(location.y < 50)
{
//the the location to the bottom of the screen
moveLocation = CGPointMake(sprite.position.x, 0);
}
//and then if its more than 50
else
{
//set the locaiton to the top of the screen
moveLocation = CGPointMake(sprite.position.x, self.frame.size.height);
}
//move the sprite
//Check if their already moving
if(sprite actionForKey:#"moving")
{
//If they are stop them so they can move in the new direction
[sprite removeActionForKey:#"moving"];
}
SKAction *moveAction = [SKAction moveTo:location duration:5.0f];
//remember to give the action a key so that we can check for it during the above if statement
[sprite runAction:moveAction withKey:#"moving"];
}
And there you have it. The only flaw is that it will always take 5 seconds to reach the location regardless of your distance from it, read on if you would like hints on how to correct that, or if you would like to see how to make the sprite travel to any touched location on the screen.
-(void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
{
//capture the location of the touch
CGPoint location = [[touches anyObject] locationInNode:self];
//move the sprite
//Check if their already moving
if(sprite actionForKey:#"moving")
{
//If they are stop them so they can move in the new direction
[sprite removeActionForKey:#"moving"];
}
SKAction *moveAction = [SKAction moveTo:location duration:5.0f];
//remember to give the action a key so that we can check for it during the above if statement
[sprite runAction:moveAction withKey:#"moving"];
}
That code will make it so that for 5 seconds the sprite will move to the location touched on the screen. Just remember to replace the instances of "sprite" with the name of your SKSpriteNode variable. For more complex movement try the following:
-(void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
{
//capture the location of the touch
CGPoint location = [[touches anyObject] locationInNode:self];
//set the velocity of the subject
float velocity = self.frame.size.width/3.0;
//The above will ensure that it will take the sprite 3 seconds to travel the distance of the screen
//Determine the difference between the point touched and the sprites position
CGPoint moveDifference = CGPointMake(location.x - sprite.position.x, location.y - sprite.position.y);
//Use pythagorean theorem to figure out the actual length to move
float distanceToMove = sqrtf(moveDifference.x * moveDifference.x + moveDifference.y*moveDifference.y);
//Use the distance to travel and the velocity to determine how long the sprite should move for
float moveDuration = distanceToMove / velocity;
//and finally move the sprite
if(sprite actionForKey:#"moving")
{
[sprite removeActionForKey:#"moving"];
}
SKAction *moveAction = [SKAction moveTo:location duration:moveDuration];
[sprite runAction:moveAction withKey:#"moving"];
}
That will set a velocity for the sprite, determine the length of the travel, and how long it will take to get to the new location.
If you want to involve textures I highly suggest reading the link I provided.
Upon request I would be glad to offer examples using forces to control movement speed as well.
I hope that helps, let me know if there are any problems I wasn't in a position where I could run the code but I am sure that it is fine.
İ have a 3d object.
i am rotating it with touches like this :
-(void) touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
UITouch *touch = [touches anyObject];
CGPoint location = [touch locationInView:self.view];
CGPoint lastLoc = [touch previousLocationInView:self.view];
CGPoint diff = CGPointMake(lastLoc.x - location.x, lastLoc.y - location.y);
float rotX = -1 * GLKMathDegreesToRadians( diff.y / 2.0 );
float rotY = GLKMathDegreesToRadians( diff.x / 3.0 );
GLKVector3 yAxis = GLKMatrix4MultiplyAndProjectVector3(GLKMatrix4Invert(_rotMatrix, &isInvertible), GLKVector3Make(0, 0, 1) );
_rotMatrix = GLKMatrix4Rotate(_rotMatrix, rotY, yAxis.x, yAxis.y, yAxis.z);
GLKVector3 xAxis = GLKVector3Make(1, 0, 0);
_rotMatrix = GLKMatrix4Rotate(_rotMatrix, rotX, xAxis.x, xAxis.y, xAxis.z);
}
and setting matrices like this :
_modelViewMatrix = GLKMatrix4Identity;
_modelViewMatrix = GLKMatrix4Translate(_modelViewMatrix, 0.0f, 0.0f, -60.0f);
_modelViewMatrix = GLKMatrix4Translate(_modelViewMatrix, 0.0f, 5.5f, -4.0f);
// i know i can to this by one code
//çevirme işlemleri ilki klimanın kameraya doğru bakması için
//ikincisi parmak hareketlerinden gelen transform matrisi
// 90 derece döndermeyi kapatıyorum
_modelViewMatrix = GLKMatrix4RotateX(_modelViewMatrix, GLKMathDegreesToRadians(90.0f));
_modelViewMatrix = GLKMatrix4Multiply(_modelViewMatrix, _rotMatrix);
_modelViewMatrix = GLKMatrix4Translate(_modelViewMatrix, 0.0f, -5.5f, +4.0f);
self.reflectionMapEffect.transform.modelviewMatrix = _modelViewMatrix;
i am translating modelViewMatrix to objects centre. rotating it. than translating back. than translating -65 on z. but everytime i tried to do it. it's rotates like on the same vector. i think object has it's own centre. and rotating with it's own center and scene's center.
how can i change object's centre with code or how can i rotate this object properly?
The way the matrix multiplication works is considering the object base vectors. You can imagine it as looking form a first person perspective (from the object/model that is). If you first move the object (translate) and then rotate the object will still be at the same position but facing a different rotation, that means it will not simulate the orbiting. If you change the operations to rotate first and then move it will simulate orbiting (but rotating as well). For instance if you rotate the model to face your right and than translate forward it will seem as if translated to your right. So a true orbiting consists of first rotating by some angle, then translating by radius and then rotating by same negative angle. Again, try looking as from the model perspective.
I hope this helps as you did not explain what exactly is it you want/need to accomplish.
I am working on the basis of Ray Wenderlich's tutorial on rotating turrets in Cocos 2d (see here: http://www.raywenderlich.com/25791/rotating-turrets-how-to-make-a-simple-iphone-game-with-cocos2d-2-x-part-2). I need my game to be in portrait mode so I have managed to get the position of the turret correctly:
The turret manages to shoot right, but not left. Here is my code:
- (void)ccTouchesEnded:(NSSet *)touches withEvent:(UIEvent *)event {
if (_nextProjectile != nil) return;
// Choose one of the touches to work with
UITouch *touch = [touches anyObject];
CGPoint location = [self convertTouchToNodeSpace:touch];
// Set up initial location of projectile
CGSize winSize = [[CCDirector sharedDirector] winSize];
_nextProjectile = [[CCSprite spriteWithFile:#"projectile2.png"] retain];
_nextProjectile.position = ccp(160, 20);
// Determine offset of location to projectile
CGPoint offset = ccpSub(location, _nextProjectile.position);
// Bail out if you are shooting down or backwards
if (offset.x <= 0) return;
// Determine where you wish to shoot the projectile to
int realX = winSize.width + (_nextProjectile.contentSize.width/2);
float ratio = (float) offset.y / (float) offset.x;
int realY = (realX * ratio) + _nextProjectile.position.y;
CGPoint realDest = ccp(realX, realY);
// Determine the length of how far you're shooting
int offRealX = realX - _nextProjectile.position.x;
int offRealY = realY - _nextProjectile.position.y;
float length = sqrtf((offRealX*offRealX)+(offRealY*offRealY));
float velocity = 480/1; // 480pixels/1sec
float realMoveDuration = length/velocity;
// Determine angle to face
float angleRadians = atanf((float)offRealY / (float)offRealX);
float angleDegrees = CC_RADIANS_TO_DEGREES(angleRadians);
float cocosAngle = -1 * angleDegrees;
float rotateDegreesPerSecond = 180 / 0.5; // Would take 0.5 seconds to rotate 180 degrees, or half a circle
float degreesDiff = _player.rotation - cocosAngle;
float rotateDuration = fabs(degreesDiff / rotateDegreesPerSecond);
[_player runAction:
[CCSequence actions:
[CCRotateTo actionWithDuration:rotateDuration angle:cocosAngle],
[CCCallBlock actionWithBlock:^{
// OK to add now - rotation is finished!
[self addChild:_nextProjectile];
[_projectiles addObject:_nextProjectile];
// Release
[_nextProjectile release];
_nextProjectile = nil;
}],
nil]];
// Move projectile to actual endpoint
[_nextProjectile runAction:
[CCSequence actions:
[CCMoveTo actionWithDuration:realMoveDuration position:realDest],
[CCCallBlockN actionWithBlock:^(CCNode *node) {
[_projectiles removeObject:node];
[node removeFromParentAndCleanup:YES];
}],
nil]];
_nextProjectile.tag = 2;
}
Thanks for the help!
You are checking x axis instead of Y
// Bail out if you are shooting down or backwards
if (offset.x <= 0) return
;
Did you actually set the application to run in portrait mode or have you just rotated the simulator and repositioned the turret?
If you didn't explicitly set the app to run in portrait your x and y coordinates will be swapped (x will run from the ios button to the top of the phone, not accross as you would expect).
If it is converted properly I have answered this question before :)
This issue here is that you've copy-pasted the math instead of editing it properly for your purposes. There are some assumptions made in Ray's code that rely on you shooting always to the right of the turret instead of up, down, or left.
Here's the math code you should be looking at:
// Determine offset of location to projectile
CGPoint offset = ccpSub(location, _nextProjectile.position);
// Bail out if you are shooting down or backwards
if (offset.x <= 0) return;
Note here that you will have an offset.x less than 0 if the tap location is to the left of the turret, so this is an assumption you took from Ray but did not revise. As gheesse said, for your purposes this should be set to offset.y as you don't want them shooting south of the projectile's original location. But this is only part of the problem here.
// Determine where you wish to shoot the projectile to
int realX = winSize.width + (_nextProjectile.contentSize.width/2);
Here's your other big issue. You did not revise Ray's math for determining where the projectile should go. In Ray's code, his projectile will always end up on a location that is off the screen to the right, so he uses the width of the screen and projectile's size to determine the real location he wants the projectile to go. This is causing your issue since you don't have the assumption that your projectile will always head right - yours will always go up (hint, code similar to this should be used for your realY)
float ratio = (float) offset.y / (float) offset.x;
int realY = (realX * ratio) + _nextProjectile.position.y;
Again, Ray makes assumptions in his math for his game and you haven't corrected it in this realY. Your code has the turret turning in ways that will effect the realX coordinate instead of the realY, which is the coordinate that Ray's always shoot right turret needed to effect.
You need to sit down and re-do the math.
I making an app which sets the sleep timer with a clock .Basically it is clock which has a single hand which user can move to set his sleep time .I tried to rotate the image with uitouch but it rotates from middle but i want it to rotate from the tip.Secondly i want that the image only rotates when user is touching the tip of the image but in my project the image is also rotating when use touches any part of the screen.Also i want to rotate the image in both directions but in my project it moves only clockwise due to this method
image.transform = CGAffineTransformRotate(image.transform, degreesToRadians(1));
Can anybody give me hints or solutions about how can it be done?
- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event{
//
touch = [[event allTouches] anyObject];
touchLocation = [touch locationInView:touch.view];
NSLog(#"began");
}
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
// get touch event
[image.layer setAnchorPoint:CGPointMake(0.0,0.0)];
if ([touch view] == image) {
image.transform = CGAffineTransformRotate(image.transform, degreesToRadians(1));
//image.center = touchLocation;
}
}
- (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event{
NSLog(#"end");
}
In detail, you can custom a rotateView,then:
1: In the delegate method of "touchesBegan", get initialPoint of finger and initialAngle.
2: During "touchesMoved",get the newPoint of finger:
CGPoint newPoint = [[touches anyObject] locationInView:self];
[self pushTouchPoint:thePoint date:[NSDate date]];
double angleDif = [self angleForPoint:newPoint] - [self angleForPoint:initialPoint];
self.angle = initialAngle + angleDif;
[[imageView layer] setTransform:CATransform3DMakeRotation(angle, 0, 0, 1)];
3: At last, in "touchesEnded" you can calculate final AngularVelocity.
If anything being confused, for more detail, you can write back.
To rotate it the other way you just use:
image.transform = CGAffineTransformRotate(image.transform, degreesToRadians(1));
And to rotate form the tip you should use setAnchorPoint (like you used in your code, but i think you should do: [image setAnchorPoint]).
more on the subject: setAnchorPoint for UIImage?
I tried to rotate the image with uitouch but it rotates from middle but i want it to rotate from the tip
I dont know any way in SDK to rotate an element on its extreme end. If you want to have that effect take the clock handle image you have twice in length with half portion transparent. It is not a direct solution, but a workaround.
Also i want to rotate the image in both directions but in my project it moves only clockwise due to this method
As per iOS developer documentation, a positive angle value specifies counterclockwise rotation and a negative value specifies clockwise rotation.