Im working on a little game in IOS which involves a scrolling tilemap.
I have gotten my background picture to scroll like so
- (void)moveBg
{
[self enumerateChildNodesWithName:#"scroll" usingBlock:
^(SKNode *node, BOOL *stop) {
SKSpriteNode * bg = (SKSpriteNode *) node;
CGPoint bgVelocity = CGPointMake(-BG_POINTS_PER_SEC, 0.0);
CGPoint amtToMove = CGPointMultiplyScalar(bgVelocity, _dt);
bg.position = CGPointAdd(bg.position, amtToMove);
}];
}
however if i load my tilemap and name it "scroll" as i have below
- (TileMapLayer *)createLandScape
{
_tileMap = [JSTileMap mapNamed:#"level1.tmx"];
_tileMap.name=#"scroll";
return [[TmxTileMapLayer alloc]
initWithTmxLayer:[_tileMap layerNamed:#"Background"]];
}
I am lead to believe that tilemap scrolling is then different from background image scrolling. Id like if someone could help me or point me to the right direction ton accomplish ths.
Thanks!
Added a background of SKNode and added the tilemap as a child. Now when the scroll background code is called it scrolls the tilemmap along with is
SKSpriteNode * bg =
[SKSpriteNode spriteNodeWithImageNamed:#"bg"];
bg.anchorPoint = CGPointZero;
bg.position = CGPointZero;
bg.name = #"bg";
[self addChild:bg];
[bg addChild:_tileMap];
Since the JSTileMap extends from SKNode, you should be able to apply actions as if you would any other node.
Anyway, you're casting your tilemap into an SKSpriteNode. Not only that, but you're also wrapping your tilemap to the TmxTileMapLayer class. Not sure why you're doing this, but the problem is that your JSTileMap is out of scope once you cast it.
You might want to try this:
- (void)moveBg
{
[self enumerateChildNodesWithName:#"scroll" usingBlock:
^(SKNode *node, BOOL *stop) {
JSTileMap * bg = (JSTileMap *) node;
CGPoint bgVelocity = CGPointMake(-BG_POINTS_PER_SEC, 0.0);
CGPoint amtToMove = CGPointMultiplyScalar(bgVelocity, _dt);
bg.position = CGPointAdd(bg.position, amtToMove);
}];
}
You might also be able to move your entire wrapper class by casting it as well (if TmxTileMapLayer extends from SKNode)
TmxTileMapLayer * bg = (TmxTileMapLayer *) node;
A different way of scrolling your tilemap is just as simple as:
_tiledMap = [JSTileMap mapNamed:#"level1.tmx"];
if (_tiledMap) {
[self addChild:_tiledMap];
}
_tiledMap.position = CGPointMake(ORIGINPOINT);
SKAction *scroll = [SKAction moveTo:CGPointMake(MOVETOPOINT) duration:SPEED];
[_tiledMap scroll];
And even better way (move a map layer instead of the entire tileMap):
_tiledMap = [JSTileMap mapNamed:#"level1.tmx"];
if (_tiledMap) {
[self addChild:_tiledMap];
}
_tiledMap.position = CGPointMake(ORIGINPOINT);
TMXLayer *someLayer = [_tiledMap layerNamed:#"someLayer"];
SKAction *scroll = [SKAction moveTo:CGPointMake(MOVETOPOINT) duration:SPEED];
[someLayer scroll];
Related
I am building a game using sprite kit and its a game where you send balls into a bucket and grow the bucket. As the buckets grow the balls (SKSpriteNodes) stay on the scene. Im trying to see how to keep high performance while managing thousands of nodes. Any idea how i can do this? After 700 or so the FPS in simulator goes below 10 tps.
Here is my code from my scene. Any help is appreciated.
//
// GameScene.m
//
#import "GameScene.h"
#implementation GameScene
#synthesize _flowIsON;
NSString *const kFlowTypeRed = #"RED_FLOW_PARTICLE";
const float kRED_DELAY_BETWEEN_PARTICLE_DROP = 0.1; //delay for particle drop in seconds
static const uint32_t kRedParticleCategory = 0x1 << 0;
static const uint32_t kInvisbleWallCategory = 0x1 << 1;
NSString *const kStartBtn = #"START_BTN";
NSString *const kLever = #"Lever";
NSString *const START_BTN_TEXT = #"Start Game";
CFTimeInterval lastTime;
-(void)didMoveToView:(SKView *)view {
[self initializeScene];
}
-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event {
for (UITouch *touch in touches) {
CGPoint location = [touch locationInNode: self];
SKNode *node = [self nodeAtPoint:location];
if ([node.name isEqualToString:kStartBtn]) {
[node removeFromParent];
//initalize to ON
_flowIsON = YES;
//[self initializeScene];
} else if ([node.name isEqualToString:kLever]) {
_leverNode = (SKSpriteNode *)node;
[self selectNodeForTouch:location];
}
}
}
- (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
UITouch *touch = [touches anyObject];
CGPoint positionInScene = [touch locationInNode:self];
CGPoint previousPosition = [touch previousLocationInNode:self];
CGPoint translation = CGPointMake(positionInScene.x - previousPosition.x, positionInScene.y - previousPosition.y);
[self panForTranslation:translation];
}
-(void)update:(CFTimeInterval)currentTime {
float deltaTimeInSeconds = currentTime - lastTime;
//NSLog(#"Time is %f and flow is %d",deltaTimeInSeconds, _flowIsON);
if ((deltaTimeInSeconds > kRED_DELAY_BETWEEN_PARTICLE_DROP) && _flowIsON) {
[self startFlow:kFlowTypeRed];
//only if its been past 1 second do we set the lasttime to the current time
lastTime = currentTime;
}
}
- (void) initializeScene {
SKLabelNode *startBtn = [SKLabelNode labelNodeWithFontNamed:#"Chalkduster"];
startBtn.text = START_BTN_TEXT;
startBtn.name = kStartBtn;
startBtn.fontSize = 45;
startBtn.position = CGPointMake(CGRectGetMidX(self.frame),
CGRectGetMidY(self.frame));
[self addChild:startBtn];
//init to flow off
_flowIsON = NO;
// Set physics body delegate
self.physicsWorld.contactDelegate = self;
self.shouldRasterize = YES;
self.view.showsDrawCount = YES;
self.view.showsQuadCount = YES;
//Set collision mask for invisible wall
_nonWallNode = (SKSpriteNode *) [self.scene childNodeWithName:#"NonWall"];
_nonWallNode.physicsBody.categoryBitMask = kInvisbleWallCategory;
_nonWallNode.physicsBody.collisionBitMask = kRedParticleCategory;
_nonWallNode.physicsBody.contactTestBitMask = kRedParticleCategory | kInvisbleWallCategory;
}
- (void) startFlow:(NSString *)flowKey {
// //SKSpriteNode *redParticleEmitter = [SKSpriteNode spriteNodeWithImageNamed:#"RedFlowParticles"];
//
// SKShapeNode *redParticleEmitter = [[SKShapeNode alloc] init];
//
// CGMutablePathRef myPath = CGPathCreateMutable();
// CGPathAddArc(myPath, NULL, 0,0, 15, 0, M_PI*2, YES);
// redParticleEmitter.path = myPath;
//
// redParticleEmitter.lineWidth = 1.0;
// redParticleEmitter.fillColor = [SKColor blueColor];
// redParticleEmitter.strokeColor = [SKColor whiteColor];
// redParticleEmitter.glowWidth = 0.5;
//
// //set size to 20px x 20px
// //redParticleEmitter.size = CGSizeMake(10, 10);
SKSpriteNode *redParticleEmitter = [SKSpriteNode spriteNodeWithImageNamed:#"RedFlowParticles"];
//set size to 20px x 20px
redParticleEmitter.size = CGSizeMake(10, 10);
SKPhysicsBody *redParticleEmitterPB = [SKPhysicsBody bodyWithCircleOfRadius:redParticleEmitter.frame.size.width/2];
redParticleEmitterPB.categoryBitMask = kRedParticleCategory;
redParticleEmitterPB.collisionBitMask = kRedParticleCategory;
redParticleEmitterPB.contactTestBitMask = kRedParticleCategory | kInvisbleWallCategory;
//set this to 5% of the width of the scene
redParticleEmitter.position = CGPointMake(self.frame.size.width*0.05, self.frame.size.height);
redParticleEmitter.physicsBody =redParticleEmitterPB;
redParticleEmitter.name = #"RedParticle";
[self addChild:redParticleEmitter];
}
- (void)selectNodeForTouch:(CGPoint)touchLocation {
//1
SKSpriteNode *touchedNode = (SKSpriteNode *)[self nodeAtPoint:touchLocation];
//2
if(![_leverNode isEqual:touchedNode]) {
[_leverNode removeAllActions];
[_leverNode runAction:[SKAction rotateToAngle:0.0f duration:0.1]];
_leverNode = touchedNode;
//3
if([[touchedNode name] isEqualToString:kLever]) {
SKAction *sequence = [SKAction sequence:#[[SKAction rotateByAngle:degToRad(-4.0f) duration:0.1],
[SKAction rotateByAngle:0.0 duration:0.1],
[SKAction rotateByAngle:degToRad(4.0f) duration:0.1]]];
[_leverNode runAction:[SKAction repeatActionForever:sequence]];
}
}
}
float degToRad(float degree) {
return degree / 180.0f * M_PI;
}
- (CGPoint)boundLayerPos:(CGPoint)newPos {
CGSize winSize = self.size;
CGPoint retval = newPos;
retval.x = MIN(retval.x, 0);
retval.x = MAX(retval.x, -[self size].width+ winSize.width);
retval.y = [self position].y;
return retval;
}
- (void)panForTranslation:(CGPoint)translation {
CGPoint position = [_leverNode position];
if([[_leverNode name] isEqualToString:kLever]) {
[_leverNode setPosition:CGPointMake(position.x + translation.x, position.y + translation.y)];
}
// else {
// CGPoint newPos = CGPointMake(position.x + translation.x, position.y + translation.y);
// [_background setPosition:[self boundLayerPos:newPos]];
// }
}
# pragma mark -- SKPhysicsContactDelegate Methods
- (void)didBeginContact:(SKPhysicsContact *) contact {
if (([contact.bodyA.node.name isEqualToString:#"RedParticle"] && [contact.bodyB.node.name isEqualToString:#"NonWall"]) ||
([contact.bodyB.node.name isEqualToString:#"RedParticle"] && [contact.bodyA.node.name isEqualToString:#"NonWall"])) {
//NSLog(#"Red particle Hit nonwall");
//contact.bodyA.node.physicsBody.pinned = YES;
//once red particle passes the invisible wall we need to stop it from going back through the wall
}
}
- (void)didEndContact:(SKPhysicsContact *) contact {
//NSLog(#"didEndContact called");
if (([contact.bodyA.node.name isEqualToString:#"RedParticle"] && [contact.bodyB.node.name isEqualToString:#"NonWall"]) ||
([contact.bodyB.node.name isEqualToString:#"RedParticle"] && [contact.bodyA.node.name isEqualToString:#"NonWall"])) {
//NSLog(#"Red particle left");
contact.bodyB.collisionBitMask = kRedParticleCategory | kInvisbleWallCategory;
//once red particle passes the invisible wall we need to stop it from going back through the wall
}
}
#end
Try this:
Create an additional sprite node on screen to display all your static balls as a whole (explained below).
Create an array of CGPoint to keep track of the positions of all balls that stopped.
At regular intervals, check all active ball sprites to see which ones have come to a stop.
For each ball that has stopped, remove that srpite from the scene and instead add its position (CGPoint) to the array described in #2.
Render an image consisting of one ball instance at each position in the array, and assign that image (texture) to the sprite node described in #1.
Go back to #3 and repeat.
Note: I haven't used SpriteKit for a while and I'm not sure how to implement point #5, but it shouldn't be too difficult. SKEffectNode has an option (shouldRasterize) to cache its appearance -i.e., render once and reuse the same image on all subsequent frames.
Regarding the "regular intervals" described in step #3, the actual value (for example, every 10 frames) will depend on your measured performance and the dynamics of your actual game; you need to find it yourself. If it is too often, the overhead of rendering the static balls texture over and over will cause a performance hit. Too far apart, and you will spend more frames than necessary rendering many still, separate sprites that could have otherwise been "grouped".
Alternative Solution:
Instead of removing the sprites from screen when each ball becomes static, you could instead move them into a different container node (as children of it), and have that node be rasterized instead of rendering anew each frame.
This keeps each ball as a separate SKSpriteNode instance (even when the ones that are stopped) and allows for SpriteKit physics bodies (not sure if sprites with different parents can collide with each other, though. Never used SpriteKit physics).
In any case, the performance hit due to collision detection will increase with the number of balls, independent of whether you draw them each frame or not.
I don't know exactly what optimizations SpriteKit's physics does (e.g., prunning, etc.), but the naïve approach to collision between n objects is to test each object against every other object, so the worse case is O(n^2).
Final Thoughts:
Because you can safely assume that still balls do not move anymore, the "group" of still balls remains in the same shape all along (until new balls stop and are added, that is).
Ideally, you could calculate the "envelope" (a possibly non-convex polygon, with rounded corners) and collision-test the moving balls against that. Still not a trivial task, but at least it helps you skip collision-testing against the static balls in the inside of the group, which should never collide anyway (they are "shielded" by the balls in the boundary of the group).
Well your problem here is all those physics bodies, you have a 1000 sprites checking 1000 other sprites whether or not they need to be colliding. One way you can make this a little faster is to break your screen into sub sets and having your nodes collission detection only check the surrounding neighbor quadrants and its own for sprites. EG. break the screen into 9 sections, the top left section has its own bit mask, and can only collide with sprites in the top left,middle top, middle center, and let center sections. If this sprite moves to the middle top section, its category becomes middle top, and will only check sprites in the top left, middle top, top right, left center, middle center, and right center. The less checks the nodes have to make the better.
I want to keep my sprite just moving in the range of the screen. So I create a edge loop by bodyWithEdgeLoopFromRect, also the collision bit mask has been set to make them collide with each other.
static const uint32_t kRocketCategory = 0x1 << 0;
static const uint32_t kEdgeCategory = 0x1 << 6;
I use the pan recognizer to move the sprite and here is the current code that sets the properties of all the things.
- (void)didMoveToView:(SKView *)view
{
// Pan gesture
self.panRecognizer = [[UIPanGestureRecognizer alloc] initWithTarget:self action:#selector(handlePanFrom:)];
[self.view addGestureRecognizer:self.panRecognizer];
// Edge
self.backgroundColor = [SKColor blackColor];
self.physicsWorld.gravity = CGVectorMake(0.0f, 0.0f);
self.physicsWorld.contactDelegate = self;
self.physicsBody = [SKPhysicsBody bodyWithEdgeLoopFromRect:self.frame];
self.physicsBody.categoryBitMask = kEdgeCategory;
self.physicsBody.contactTestBitMask = kRocketCategory;
self.physicsBody.collisionBitMask = kRocketCategory;
self.physicsBody.usesPreciseCollisionDetection = YES;
self.physicsBody.restitution = 0;
// Rocket
SKTexture *texture = [SKTexture textureWithImageNamed:#"Rocketship-v2-1"];
texture.filteringMode = SKTextureFilteringNearest;
self.rocketSprite = [SKSpriteNode spriteNodeWithTexture:texture];
self.rocketSprite.position = CGPointMake(CGRectGetMidX(self.scene.frame), CGRectGetMaxY(self.scene.frame)*0.3); // 30% Y-axis
self.rocketSprite.name = #"rocketNode";
self.rocketSprite.xScale = 2;
self.rocketSprite.yScale = 2;
self.rocketSprite.physicsBody = [SKPhysicsBody bodyWithRectangleOfSize:self.rocketSprite.size];
self.rocketSprite.physicsBody.categoryBitMask = kRocketCategory;
self.rocketSprite.physicsBody.contactTestBitMask = kEdgeCategory;
self.rocketSprite.physicsBody.collisionBitMask = kEdgeCategory;
self.rocketSprite.physicsBody.usesPreciseCollisionDetection = YES;
self.rocketSprite.physicsBody.allowsRotation = NO;
self.rocketSprite.physicsBody.restitution = 0;
[self addChild:self.rocketSprite];
}
Pan recognizer code:
- (void)handlePanFrom:(UIPanGestureRecognizer *)recognizer
{
if (recognizer.state == UIGestureRecognizerStateBegan) {
self.selectedRocket = self.rocketSprite;
} else if (recognizer.state == UIGestureRecognizerStateChanged) {
CGPoint translation = [recognizer translationInView:recognizer.view];
translation = CGPointMake(translation.x, -translation.y);
[self panForTranslation:translation];
[recognizer setTranslation:CGPointZero inView:recognizer.view];
} else if (recognizer.state == UIGestureRecognizerStateEnded) {
}
}
- (void)panForTranslation:(CGPoint)translation
{
CGPoint position = self.selectedRocket.position;
if ([self.selectedRocket.name isEqualToString:#"rocketNode"]) {
self.selectedRocket.position = CGPointMake(position.x + translation.x, position.y);
}
}
Now the problem is when I move the sprite (rocketship) slowly, the edge will stop the sprite going out of the screen. However, when I move the sprite very quickly, the sprite will rush out the range. See the animation below. I have read some solutions to the similar problem but I still don't know what's wrong with my code. Do the edge loop and collision bit mask not enough for the situation here?
Your attempt is similar to what I've found when searching online, and having read what you've tried it looks like you've pretty much covered most of the more common problems (Not using SKAction, for instance).
I don't currently use a contact Bitmask to handle collisions on the side of my scene, but I do use a loop that actively checks positions.
Here's the method I use to reposition objects: (Repositions everything, you can specify it to move only the rocket.
-(void)repositionObjects
{
for (CXSpriteNode *i in self.sceneObjects) // CXSpriteNode is a certain subclass
{
CGPoint position = i.position;
if (position.x > self.background.size.width || position.x < 0)
{
CGPoint newPosition;
if (position.x > self.background.size.width)
{
newPosition = CGPointMake(self.background.size.width-1, position.y);
} else {
newPosition = CGPointMake(1, position.y);
}
[i runAction:[SKAction moveTo:newPosition duration:0.0f]];
}
if (position.y > self.background.size.height || position.y < 0)
{
CGPoint newPosition;
if (position.y > self.background.size.height)
{
newPosition = CGPointMake(self.background.size.height-1, 1);
} else {
newPosition = CGPointMake(position.x, 1);
}
[i runAction:[SKAction moveTo:newPosition duration:0.0f]];
}
}
}
This gets called from the SKScene loop as such:
-(void)update:(NSTimeInterval)currentTime
{
[self repositionObjects];
}
Now, it's evidently not as elegant as your desired outcome, and I have a feeling it might still induce flickering, but I'd give it a try anyways.
Also, it might be worth trying to disable/cancel the gesture once it goes out of range momentarily to stop repeated swipes that may cause flickering.
Hope this helps.
Use SpriteKit actions instead of directly modifying the position of the sprite.
What is happening is that the recognizer isn't sending updates fast enough. The sprite's bounds never intersect with the edge in any one frame.
In one update, the recognizer says that the touch is within the bounds of the edge loop. But in the next update, the touch has moved way beyond the edge loop. This leaves no frame in which the sprite's bounds intersect the edge, so no collision gets detected.
I do not use sprite kit in daily life, but you could for example solve it the hard way by adding something like this in your sprite's update method
(Pseudo code)
CGFloat x = clamp(self.position.x, minXValue, maxXValue);
CGFloat y = clamp(self.position.y, minYValue, maxYValue);
self.position = CGPointMake(x, y);
I have my background set and it is scrolling horizontally, here is my code:
-(void)initalizingScrollingBackground
{
for (int i = 0; i < 2; i++)
{
SKSpriteNode *bg = [SKSpriteNode spriteNodeWithImageNamed:#"background"];
bottomScrollerHeight = bg.size.height;
bg.position = CGPointMake(i * bg.size.width, 0);
bg.anchorPoint = CGPointZero;
bg.name = #"background";
[self addChild:bg];
}
}
and also this code:
- (void)moveBottomScroller
{
[self enumerateChildNodesWithName:#"background" usingBlock: ^(SKNode *node, BOOL *stop)
{
SKSpriteNode * bg = (SKSpriteNode *) node;
CGPoint bgVelocity = CGPointMake(-BG_VELOCITY, 0);
CGPoint amtToMove = CGPointMultiplyScalar(bgVelocity,_dt);
bg.position = CGPointAdd(bg.position, amtToMove);
//Checks if bg node is completely scrolled off the screen, if yes then put it at the end of the other node
if (bg.position.x <= -bg.size.width)
{
bg.position = CGPointMake(bg.position.x + bg.size.width*2,
bg.position.y);
}
[bg removeFromParent];
[self addChild:bg]; //Ordering is not possible. so this is a hack
}];
}
The second part makes the background scroll. Without it, the background is still.
Also, without the movebottomscroller, my sprite appears on top of the background. With the movebottomscroller, he appears behind the scrolling background. Is there any command to bring him to the front, above any other backgrounds?
Thank you!
Try the approach below, hope that works for you.
#interface GameScene()
#property (nonatomic) NSTimeInterval lastTimeSceneRefreshed;
#end
#implementation GameScene
- (instancetype)initWithSize:(CGSize)size {
if (self = [super initWithSize:size]) {
[self buildBackground];
[self startScrolling];
}
return self;
}
// This method will add 3 background nodes
- (void)buildBackground {
float centerX = CGRectGetMidX(self.frame);
SKSpriteNode *firstBackgroundNode = [SKSpriteNode spriteNodeWithImageNamed:#"background"];
firstBackgroundNode.name = #"background";
firstBackgroundNode.position = CGPointMake(centerX,
firstBackgroundNode.size.height*firstBackgroundNode.anchorPoint.y);
[self addChild:firstBackgroundNode];
float previousYPosition = firstBackgroundNode.position.y;
for (int i = 0; i < 2; i++) {
SKSpriteNode *backgroundNode = [SKSpriteNode spriteNodeWithImageNamed:#"background"];
backgroundNode.position = CGPointMake(centerX,
previousYPosition + backgroundNode.frame.size.height);
previousYPosition = backgroundNode.position.y;
backgroundNode.name = #"background";
[self addChild:backgroundNode];
}
}
- (void)update:(CFTimeInterval)currentTime {
// Updating background nodes
// We don't want to update backgrounds each frame (60 times per second)
// Once per second is enough. This will reduce CPU usage
if (currentTime - self.lastTimeSceneRefreshed > 1) {
[self backgroundNodesRepositioning];
self.lastTimeSceneRefreshed = currentTime;
}
}
- (void)backgroundNodesRepositioning {
[self enumerateChildNodesWithName:#"background" usingBlock: ^(SKNode *node, BOOL *stop)
{
SKSpriteNode *backgroundNode = (SKSpriteNode *)node;
if (backgroundNode.position.y + backgroundNode.size.height < 0) {
// The node is out of screen, move it up
backgroundNode.position = CGPointMake(backgroundNode.position.x, backgroundNode.position.y + backgroundNode.size.height * 3);
}
}];
}
- (void)startScrolling {
SKAction *moveAction = [SKAction moveByX:0 y:-200 duration:1];
[self enumerateChildNodesWithName:#"background" usingBlock: ^(SKNode *node, BOOL *stop)
{
[node runAction:[SKAction repeatActionForever:moveAction] withKey:#"movement"];
}];
}
I don't fully understand your approach here, but I can answer your question so I'll just go ahead and do that - I hope I haven't misunderstood.
SKNode has a method insertChild:atIndex: that would allow you to put the background nodes at the back, or put the sprite at the front.
SKNode Class Reference
Okay guys, I have two sprites one the enemy who moves to pick up items around the map as the items appear and it does that using SKActions then also I have the wall which he shouldn't go through. anyway. all I am trying to do is to make him bounce out if he hits the wall. How would I go about that?
Here is the code below:
// for the Enemy wall I have this code:
- (void) EnemyBelongings {
EnemyWall = [SKSpriteNode spriteNodeWithImageNamed:#"EnemyWall#2x"];
EnemyWall.name = #"hisWall";
EnemyWall.position = CGPointMake(512, 260);
EnemyWall.xScale = 0.09;
EnemyWall.yScale = 0.09;
EnemyWall.physicsBody.categoryBitMask = PhysicsCategoryEnemyWall;
EnemyWall.physicsBody.contactTestBitMask = PhysicsCategoryEnemy;
EnemyWall.physicsBody.collisionBitMask = 0;
[self addChild:EnemyWall];
}
// For the enemy character I have this code
- (void) Enemy {
_Enemy = [SKSpriteNode spriteNodeWithImageNamed:#"enemy"];
_Enemy.position = CGPointMake(520, _Enemy.size.height/1.50);
_Enemy.physicsBody = [SKPhysicsBody bodyWithCircleOfRadius:self.size.width];
_Enemy.physicsBody.usesPreciseCollisionDetection = YES;
_Enemy.physicsBody.categoryBitMask = PhysicsCategoryEnemy;
_Enemy.physicsBody.contactTestBitMask = PhysicsCategoryEnemyWall;
_Enemy.physicsBody.collisionBitMask = 0;
[self addChild:_Enemy];
}
// For the enemy movement I have this code
- (void) EnemySpawner {
[ForEnemy runAction:appear2 completion:^{
SKAction *wait = [SKAction waitForDuration:1.0];
[_Enemy runAction:wait];
SKAction *actionXMove2 = [SKAction moveToX:ForEnemy.position.x duration:0.14];
SKAction *actionYMove2 = [SKAction moveToY:ForEnemy.position.y duration:0.14];
[_Enemy runAction:actionYMove2];
[_Enemy runAction:actionXMove2];
}];
}
-(void)didBeginContact:(SKPhysicsContact *)contact
{
if (contact.bodyA.categoryBitMask == PhysicsCategoryEnemy && contact.bodyB.categoryBitMask
== PhysicsCategoryEnemyWall)
{
SKNode *enemy = contact.bodyA.node; // a is the enemy here
// Code here
SKNode *wall = contact.bodyB.node; // b is the enemy's wall here
// Code here
}
else if (contact.bodyB.categoryBitMask == PhysicsCategoryEnemy &&
contact.bodyA.categoryBitMask == PhysicsCategoryEnemyWall)
{
SKNode *enemy = contact.bodyB.node;
// Code here
SKNode *wall = contact.bodyA.node;
// Code here
}
}
You need to applyImpulse on the node's physicsBody to make it simulate naturally and interact with other physicsBodies.
Please look at my answer here on how to do the same.
Copy the rwAdd, rwSub, rwMult, rwLength and the rwNormalize methods from this tutorial by Ray Wenderlich.
Then, try using this code:
[ForEnemy runAction:appear2 completion:^{
SKAction *wait = [SKAction waitForDuration:1.0];
CGPoint offset = rwSub(location, ForEnemy.position);
CGPoint direction = rwNormalize(offset);
float forceValue = 200; //Edit this value to get the desired force.
CGPoint shootAmount = rwMult(direction, forceValue);
CGVector impulseVector = CGVectorMake(shootAmount.x, shootAmount.y);
[_Enemy.physicsBody applyImpulse:impulseVector];
}];
PhysicsWorld should simulate bounces automatically. Just set your nodes' physics properties accordingly. Look for the 'restitution' property. It will determine the bounciness of your objects.
And don't use SKAction to move your enemies. This will just "teleport" your nodes around. They don't get to have any real velocity in the physicsWorld (and hence don't bounce). Instead, apply forces to your bodies (or set velocity vector manually).
I am attempting to make a side scrolling game using Apple's SpriteKit. When wanting to make a endless scrolling background I came across this answer.
After implementing the solution it does appear to work although it drops my FPS significantly. This is probably due to the fact that the images positions are being recalculated on every frame.
I feel like it would be much better if I could use one or more SKAction calls to take care of this animation for me but I'm not certain how to implement it.
Thoughts?
The code I have so far in my scene class (this only animates the background across the screen once though)
- (void)addBackgroundTileAtPoint:(CGPoint)point {
SKSpriteNode *bg = [SKSpriteNode spriteNodeWithImageNamed:#"background"];
bg.anchorPoint = CGPointZero;
bg.position = point;
bg.name = #"background";
bg.zPosition = -99;
[self addChild:bg];
SKAction *sequence = [SKAction sequence:#[
[SKAction moveByX:-(bg.size.width * 2) y:0 duration:10],
[SKAction removeFromParent]
]];
[bg runAction: sequence];
}
I did a small component called SKScrollingNode for that particular need in my last open source project : SprityBird.
FPS was not an issue even with 3 or 4 layers (for parallax), but you may need to try it yourself.
To use it you just have to add it like any other node and giving it a scrollingSpeed likeso :
back = [SKScrollingNode scrollingNodeWithImageNamed:#"back" inContainerWidth:WIDTH(self)];
[back setScrollingSpeed:BACK_SCROLLING_SPEED];
[self addChild:back];
SKScrollingNode.h
#interface SKScrollingNode : SKSpriteNode
#property (nonatomic) CGFloat scrollingSpeed;
+ (id) scrollingNodeWithImageNamed:(NSString *)name inContainerWidth:(float) width;
- (void) update:(NSTimeInterval)currentTime;
#end
SKScrollingNode.m
#implementation SKScrollingNode
+ (id) scrollingNodeWithImageNamed:(NSString *)name inContainerWidth:(float) width
{
UIImage * image = [UIImage imageNamed:name];
SKScrollingNode * realNode = [SKScrollingNode spriteNodeWithColor:[UIColor clearColor] size:CGSizeMake(width, image.size.height)];
realNode.scrollingSpeed = 1;
float total = 0;
while(total<(width + image.size.width)){
SKSpriteNode * child = [SKSpriteNode spriteNodeWithImageNamed:name ];
[child setAnchorPoint:CGPointZero];
[child setPosition:CGPointMake(total, 0)];
[realNode addChild:child];
total+=child.size.width;
}
return realNode;
}
- (void) update:(NSTimeInterval)currentTime
{
[self.children enumerateObjectsUsingBlock:^(SKSpriteNode * child, NSUInteger idx, BOOL *stop) {
child.position = CGPointMake(child.position.x-self.scrollingSpeed, child.position.y);
if (child.position.x <= -child.size.width){
float delta = child.position.x+child.size.width;
child.position = CGPointMake(child.size.width*(self.children.count-1)+delta, child.position.y);
}
}];
}
#end
I've been working on a library for an infinite tile scroller, you can easily use it to create a scrolling background. Take a look at it:
RPTileScroller
I made an effort to make it the most efficient possible, but I am not a game developer. I tried it with my iPhone 5 with random colors tiles of 10x10 pixels, and is running on a solid 60 fps.