Question

I thought doing a simple animation would be easy but is is taking hours and Im not getting even close to have the expected effect…

I need to simulate a simple Flash Motion Tween like for iphone/ipad using xcode

this is the desired effect: http://www.swfcabin.com/open/1340330187

I already tried setup a timer adding X position and it doens’t get the same effect, my cooworkers suggested me cocos 2d to do this using actions and sprites, which might would be fine although I wouldn’t like to third party frameworks, but if there is a way to do the same with cocos I would definitively use it.

Does anybody have any suggestions, I feel like it might be simpler than I thought

thanks all

Answer 1

If there is no troubles to you, that you will have to do it insinge OpenGL view, it is really very simple. To show some info, you need CCLabel class. To change it’s position, you need CCMoveTo/CCMoveBy action, to change opacity, you need CCFadeTo/CCFadeIn/CCFadeOut actions, to make delay you need CCDelayTime. To make it all work together you need CCSpawn and CCSequence.

CCSpawn will run several actions at the same time(for example fade in and move from right to the center), CCSequence will run several actions one by one (sequence to fade in + move to center, delay for same time, sequence to fade out + move from center to the left). Then you should only schedule method, that will create labels and run actions on them. In code it will be something like

lets define full animation time

#define ANIMATION_TIME 4.f

schedule method in any place you want to start animation

[self schedule:@selector(runNextMessage) interval:ANIMATION_TIME];

it will call runNextMessage method every ANIMATION_TIME seconds

- (void) runNextMesage
{
    NSString* message = //get next message

    CCLabelTTF* label = [CCLabelTTF labelWithString:message 
                                         dimensions:desiredDimensionsOfTheLabel 
                                          alignment:UITextAlignmentLeft 
                                      lineBreakMode:UILineBreakModeWordWrap 
                                           fontName:@"Arial" 
                                           fontSize:20.f];
    CGSize winSize = [[CCDirector sharedDirector] winSize];
    // place the label out the right border 
    [label setPosition: ccp(winSize.width + label.contentSize.width, winSize.height / 2)];

    // adding it to the screen
    [self addChild:label];

    ccTime spawnTime = ANIMATION_TIME / 3;
    // create actions to run
    id appearSpawn = [CCAction actionOne:[CCMoveTo actionWithDuration:spawnTime]
                                     two:[CCFadeIn actionWithDuration:spawnTime]];

    // create show action and disappear action

    // create result sequence
    id sequence = [CCSequence actions: appearSpawn, showAction, disappearAction, nil];
    [label runAction: sequence];
}