I'm relatively new to iphone programming, and I've been starting out with cocos2d. I was wondering if there was a way to set opacity for multiple sprites at once? I noticed that opacity isn't implemented for CCLayer, and opacity doesn't seem to propagate down to children of class CCSprite.
Is there any better way to do this than to override setOpacity on a custom ccnode and iterate through and set opacities individually? Or perhaps overriding draw and setting the blending mode manually?
Thanks!
You can loop through all the sprites in your scene, check if they are the sprites you want, then set their opacity like this (assuming you set their tag to OPACITY_SPRITE_TAG when you create the sprites)
for(CCSprite* sprite in [self children])
{
if([sprite tag] == OPACITY_SPRITE_TAG)
{
[sprite setOpacity:NEW_OPACITY];
}
}
Couldn't you just increment through an array of sprites that you want to change. Something like:
for(int i = 0; i < [myArray count]; i++){
CCSprite *mySprite = [myArray objectAtIndex:i];
[mySprite setOpacity:100];
}
Related
I asked a question recently that sort of involved implementing power-ups; however, I have decided that I want to go about it a different way.
In my game, I have an endless scrolling background and the main character moving to the right while collecting coins.
When the player hits the blue coin, the power-up, I want 1. the character to change to a blue color (I have the frames for this), 2. the background to go blue, and 3. the platform to change blue (have images for this); I would like all these factors to take place for a 20 second period of time.
I planned to do this by having a Blue class with a blue instance variable (public variable) that I would set to YES and NO accordingly (if a blue coin has been hit) in my other classes (Platform class, Player class). However, it is not efficient and does not work for when I incorporate a timer.
Does anyone have an idea on how to implement the power-up?
This is my code for when the blue coin is hit by the player:
// try remove blue coin
- (void) tryRemoveBluecoin
{
NSMutableArray * currentBluecoinArray = [self getcurrentBluecoinArr];
if(currentBluecoinArray)
{
int playerY = ((CCLayer*)(self.player)).position.y;
for(int x=0; x<[currentBluecoinArray count];x++)
{
CCSprite *bluecoin = [currentBluecoinArray objectAtIndex:x];
if(abs(bluecoin.position.x+bluecoin.parent.position.x-[Player initX])<50)
{
if(abs(bluecoin.position.y+bluecoin.parent.position.y-playerY)<30 && bluecoin.visible && bluecoin.visible)
{
[bluecoin.parent removeChild:bluecoin cleanup:YES];
CGSize winSize = [[CCDirector sharedDirector] winSize];
[[SimpleAudioEngine sharedEngine] playEffect:#"jump.wav" pitch:1 pan:0 gain:1];
// SET BLUE VARIABLE TO YES
NSLog(#"BEGIN BLUE POWER UP EFFECTS FOR 20 SECONDS");
}
}
}
}
[self hitTestOB];
}
Thanks for any ideas you have!
Now, it has been some time since I last used Cocos2d, but you are aware that you can actually set color-information to nodes, right? This sounds like a much more sensible way to go down. Design your sprites with this in mind and keep an array with all elements you need to color.
Have a method defining the new color based on your game state, the game state enums can be matched with an NSInteger property on your power-ups for instance.
ccColor3B color;
// _state being an NSInteger ivar
// the different states defined in an enum
switch (_state) {
case gameStateBlue:
color = ccc3(0, 0, 255);
break;
case gameStateGreen:
color = ccc3(0, 255, 0);
break;
default:
break;
// etc.
}
send this color information to a method which handles your array of sprites like this:
for (CCSprite *sprite in _arrayOfSpritesToChangeColor) {
sprite.color = color;
}
This will demand planning ahead with your assets, but a lot more flexibility down the line if you want to experiment with different colors and effects. It is a lot less taxing as well as you won't need to swap a bunch of assets to achieve what you want. Now, my Cocos is rather rusty so I might have messed some details up, but the general idea should be sound.
Edit: An alternative to holding reference to the sprites in an array is to have your own sprite subclass and let that subclass have a CCSprite colorSprite property. Then you could loop through the children of your scene and change the sprites that have this property.
I created a new project with cocos2d, and then create a layer and a sprite.
I am trying to apply an animation to my sprite, and I found some samples about that. But I don't understand the difference between CCAnimation and CCAnimate, so I haven't applied any animation for my sprite yet.
What is the difference between these two and what is the real meaning of them? How to use them?
Can any one explain me about that? Please help me.
Here is code from "Working with Sprites, and Sprite batch nodes" in cocos2d-iphone Programming Guide:
......
NSMutableArray *animFrames = [NSMutableArray array];
for(int i = 1; i < 15; i++) {
CCSpriteFrame *frame = [[CCSpriteFrameCache sharedSpriteFrameCache] spriteFrameByName:[NSString stringWithFormat:#"grossini_dance_%02d.png",i]];
[animFrames addObject:frame];
}
CCAnimation *animation = [CCAnimation animationWithName:#"dance" delay:0.2f frames:animFrames];
[sprite runAction:[CCRepeatForever actionWithAction:[CCAnimate actionWithAnimation:animation restoreOriginalFrame:NO]]];
As you can see, you need to use both CCAnimate and CCAnimation to run a CCSpriteFrame-based animation on the sprite. Per description of CCAnimation:
The CCAnimation object contains CCSpriteFrame objects, and a possible delay between the frames. You can animate a CCAnimation object by using the CCAnimate action. Example:
[sprite runAction:[CCAnimate actionWithAnimation:animation]];
Generally speaking, CCAnimation is a wrapper of frame container. CCAnimate is the action that the sprite need to do - in fact it is a subclass of CCAction, which represents an action that a sprite can "run", such as moving, jumping, rotating, etc. You can use its other subclasses to do some kinds of animation on your sprite without creating the frames yourself. Have a try with something like CCFadeIn, CCRotateBy, etc.
I have an iOS game, and when a ball hits a target it explodes.
What would be the best way to animate this explosion?
If you're looking for something simple.
Make a series of images that animate the explosion. Add those to a UIImageView and start the animation. Something like this:
UIImage *image0 = [UIImage imageNamed:#"explosion0.png"];
UIImage *image1 = [UIImage imageNamed:#"explosion1.png"];
UIImage *image2 = [UIImage imageNamed:#"explosion2.png"];
UIImage *image3 = [UIImage imageNamed:#"explosion3.png"];
myImageView.animationImages = [NSArray arrayWithObjects:image0, image1, image2, image3, nil];
[myImageView setAnimationDuration:0.75f];
[myImageView startAnimation];
For a bouncing ball game, the Cocos2D game- and Box2d physics- (included with Cocos2D) engines are a great way to go.
Ray Wenderlich has three great tutorials on exactly what you want to do:
Intro to Box2D with Cocos2D Tutorial: Bouncing Balls
How To Create A Breakout Game with Box2D and Cocos2D Tutorial: Part 1
How To Create A Breakout Game with Box2D and Cocos2D Tutorial: Part 2
Once you get past the basics of working with Box2d objects, the key step is to create a Contact Listener (as described in the tutorials) which will tell you when you have a collision. Check (by iterating over contacts in your tick method) if the colliding objects are the ones you want for the explosion, and if so add them to a vector of objects to be destroyed (we can't do this while iterating over contacts or we will invalidate the iterator). Remember the coordinates of the collision and set a flag for explosion.
After exiting the loop destroy the bodies and run the explosion effect at the saved position.
Cocos2D has some very nice built-in explosion effects, and the one I am using for my project is CCParticleSun. You can find some screenshots of someone using this effect here. (The curiously named CCParticleExplosion just gave a lot of confetti flying around the screen.)
Here is the relevant portion from some preliminary code I have working, which is mostly from the tutorial. You will still need to do everything else, eg. create and set up your world and bodies in your init method, update positions, apply forces, and draw in your tick method, implement your Contact Listener class, etc. For all this refer to the tutorials.
std::vector<b2Body *>toDestroy;
std::vector<MyContact>::iterator pos;
CGPoint p;
bool explode = FALSE;
for(pos = _contactListener->_contacts.begin();
pos != _contactListener->_contacts.end(); ++pos) {
MyContact contact = *pos;
if ((contact.fixtureA->GetBody() == _moonBody && contact.fixtureB->GetBody() == _moon2Body) ||
(contact.fixtureA->GetBody() == _moon2Body && contact.fixtureB->GetBody() == _moonBody)) {
NSLog(#"Moons collided!");
explode = TRUE;
p = CGPointMake(PTM_RATIO*(_moonBody->GetPosition().x + _moon2Body->GetPosition().x)/2.,PTM_RATIO*(_moonBody->GetPosition().y + _moon2Body->GetPosition().y)/2.);
if (std::find(toDestroy.begin(), toDestroy.end(), _moonBody) == toDestroy.end()) {
toDestroy.push_back(_moonBody);
}
if (std::find(toDestroy.begin(), toDestroy.end(), _moon2Body) == toDestroy.end()) {
toDestroy.push_back(_moon2Body);
}
}
}
std::vector<b2Body *>::iterator pos2;
for(pos2 = toDestroy.begin(); pos2 != toDestroy.end(); ++pos2) {
b2Body *body = *pos2;
if (body->GetUserData() != NULL) {
CCSprite *sprite = (CCSprite *) body->GetUserData();
[sprite.parent removeChild:sprite cleanup:YES]; }
world->DestroyBody(body);
}
if (explode)
{
explosion = [[CCParticleSun alloc]initWithTotalParticles:250];
explosion.texture = [[CCTextureCache sharedTextureCache] addImage:#"fire.png"];
explosion.autoRemoveOnFinish = YES;
explosion.startSize = 15.0f;
explosion.speed = 30.0f;
explosion.position = p;
explosion.duration = 1.0f;
[self addChild:explosion z:self.zOrder+1];
}
What you want, then, is a way to create a particle emission system. My suggestion is to use a CAEmitterLayer. Ray Wenderlich has a great tutorial: UIKit Particle Systems in iOS 5 Tutorial
iPhone Programming Tutorial: Animating a Game Sprite
If you need to make an explosion another alternative would to use Cocos2d and do:
CCParticleSun *anExplosion=[CCParticleGalaxy node];
[kk setPosition:ball.position];
[self addChild:anExplosion];
Not really an animation, also, from the question you don't seem to be using Cocos2d, but if you start using it you can do this...
Hey guys, I'm new to cocos2d and iPhone development, im currently trying to create a game like "PapiJump",
What I'm currently having problems with, is animating the character CCSprite in my game,
I have created 3 images of my character, character pointing right, left and middle (http://i53.tinypic.com/ngzoyh.png)
so when the character changes its direction (left or right), it wont "jump" directly to the other direction but will animate..
In my code im using the TouchesEnded method, in this method im setting a variable named "touchState",
so if the user touched the right side of the screen it will set "touchState" to 1, otherwise it sets it to 2 (means left).
then in the "init" method i created a "schedule" that runs another method every 0.5 sec that is named: "updateGame",
the "updateGame" method updates the player's position, it works like that:
player.position = ccp(player.position.x , player.position.y - playerGravity.y);
I've read Ray's tutorial on animating CCSprites but i have no idea how to achieve the result that i need..
Thanks in advance and sorry for my bad english!
NSMutableArray *walkAnimFrames = [NSMutableArray array];
for(int i = 1; i <= 4; ++i)
{
[walkAnimFrames addObject: [[CCSpriteFrameCache sharedSpriteFrameCache] spriteFrameByName: [NSString stringWithFormat:#"spr_fillin_0%d.png", i]]];
}
CCAnimation *walkAnim = [CCAnimation animationWithFrames:walkAnimFrames delay:0.0333f];
_sprite = [CCSprite spriteWithSpriteFrameName:#"spr_fillin_01.png"];
[_sprite runAction:[CCRepeatForever actionWithAction: [CCAnimate actionWithAnimation:walkAnim restoreOriginalFrame:NO]]];
[<CCLAYER OR BATCH NODE> addChild:_sprite];
Edit: Looks like you're talking about just flipping the image around. You can just refetch a sprite with
_sprite = [CCSprite spriteWithSpriteFrameName:#"<New Sprite File>"];
(Or cache them and switch)
Can you clarify your question? If you want to set a different sprite frame, you can use setDisplayFrame:
CCSpriteFrame *spriteFrame = [[CCSpriteFrameCache sharedSpriteFrameCache] spriteFrameByName:frameName];
[sprite setDisplayFrame:frame];
or if you have an animation:
[sprite runAction:[CCAnimate actionWithAnimation:runAnimation restoreOriginalFrame:NO]];
But I feel like the question is a little vague.
if i got your question properly i can suggest two ways to solve your problem:
first you could rotate your object to till it is upside down, and the continue your previous animations using FlipX(or FlipY) flag marks as true or you can add an animation wich animates only characters rotation and when ever it's finnished change the FLipX(or FlipY) status.
everyone, I made a shooting game just like 1942(classic shooting game),but here's the question, FPS drops to 5~6 when the fighter shoot out a straight line of bullet,about 7~8 bullets in the screen,Actually, only 8 bullets of player will appear in games, when bullets fly out of the screen they would reset to the fighter's center and become invisible,all bullets are individual sprites, just like:
Sprites * bullet1 = [Sprite spriteWithFile:#"bullet.png"];
........
Sprites * bullet8 = [Sprite spriteWithFile:#"bullet.png"];
Is there any method can store a lots of bullets instead of defining them one by one??
Because enemies may fire too, I can imagine the FPS may get closer to zero.....
Can anyone help me??
you could do something like have a "bullet pool" in there, as you are using cocos, what I would do is to allocate lot's of bullets when I start the game. Check how many bullets do you need approximately, pre allocate those.
When an Entity in your game needs to fire a bullet, it just asks for a bullet to this pool, you give the properties to the "pre allocated" bullet, the bullet appears on the screen, and when it impacts/disappear you then return that bullet to your bullet pool.
if you need some code:
/*You pre-allocate your bullets.*/
for(int i = 0; i < MAX_BULLETS; i++)
{
Bullet *aBullet = [[Bullet alloc] init];
[bulletsArray addObject:aBullet];
[aBullet release];
}
//Then in game when you fire:
Bullet *aBullet = [PoolManager bulletWithSprite:myBulletSprite]; // Where myBulletSprite is PRE allocated and you don't allocate sprites in Game.
You can store the sprites in an array:
NSMutableArray * bulletsBuilder = [[NSArray alloc] init];
for(int i = 0; i < MAX_NUMBER_OF_SPRITES; ++i) {
[bullets addObject:[Sprite spriteWithFile:#"bullet.png"]];
}
NSArray * bullets = [NSArray arrayWithArray:bulletsBuilder];
[bulletsBuilder release];
And access them later using their identifier:
Sprite * spr = [bullets objectAtIndex:spriteIndex];
What's a problem? Use sprite batching! It's kind of special layer that allow you to speed up the rendering of the multiple sprites.
CCSpriteBatchNode* batch = [CCSpriteBatchNode batchNodeWithFile:#"bullet.png"];
Unless you're not Texture Atlas you cannot use different sprites to render them.
Then load one sprite and add to the batch itself as many sprites as you need.
for(;i>10;){[batch addSprite:sprite];}
Add to self.
Core Animation layers are lightweight and should help your performance. You can load the image once and then load the bullets image into the contents of an array of CALayers. Something like this:
// bulletImage is an instance variable
bulletImage = [UIImage imageNamed:#"bullet.png"];
bulletLayers = [[NSMutableArray alloc] init];
for (i = 0; i < 9; ++i)
{
CALayer *bulletLayer = [CALayer layer];
[bulletLayer setBounds:[bulletImage bounds]];
[bulletLayer setPosition:gunBarrelOrigin];
[bulletLayer setContents:(id)[bulletImage CGImage]];
[bulletLayers addObject:bulletLayer];
}
// Use the array of layers.
// ...
You don't specify whether you are using views or layers in your Sprite class, but if you are loading the same image multiple times, you're definitely creating unnecessary overhead.