I try create game use parallax scroll, I put sprites in the screen and after it the same sprites again, when first sprite go out of the screen I move it to the end of the sprite that in the screen. one of my sprites is a sun, I want show him once in minute. what is the better way to implement the parallax scrolling with the sun? when the sun go out of the screen place him before the screen with distance or use timer or something?
I would advise to use a timer. It's not too much of a hassle, so I would not say this is premature optimization. You will avoid the (really low) overhead of having a sprite moving outside the screen when there is no need to do so.
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I am making a Sprite Kit game where the player (basically a stickman) has a running animation and a parallax scrolling background.
Now I have enemies that come near my player. To destroy these enemies sometimes I have to touch the enemies node to launch a rocket or attack them with an attack button or just jump over them.
Everything is working fine, but I want to add some extra moves to destroy them. I want some enemies that you can just destroy if you have drawn a whole circle around them. So imagine they come and you make a circle and then my player launch a laser or something. The problem is I have no idea where to start.
I haven't found anything on the internet. If it's too complicated or almost impossible how about touching my player node and dragging to the enemy?
EDIT: I think I have to create a custom GestureRecognizer that recognizes if a circle is drawn around a sprite and then runs the code. I don't know how this works ?
Yes, it's too complex. Not just from a coding point of view, but also from that of the player's experience.
Anything that requires complex gestures over a large amount of glass is annoying for the player because they're never going to have the same experience. Their finger's moisture and oil content always changes, as does the ambient temperature and cleanliness of their screen.
So big gestures required to be performed quickly (a gaming input like this) will sometimes be fun and smooth, and other times degrade as an experience based on the nature of the above properties.
Best to avoid them for a game's best possible experience.
If you must do it, there's two ways to research how.
Seek out "custom gesture" creation and utilisation through documentation and google, etc.
Think about using some kind of array to store all the points where the player's finger moves through during that circle gesture and attempt to discern if an enemy is within that space and then act accordingly.
--- probably other ways, too. But these jump to mind.
I have a game where a user is dragging around my main sprite. The main sprite collides with other sprites just fine except when the user drags the main sprite very quickly. Sometimes when the main sprite is moving quickly, the physics bodies just pass right through each other and the two sprites suddenly overlap. I have a breakpoint set that logs the hit count at didBeginContact, and it is not hit.
Is there a limit to how fast a sprite can move and still be covered by didBeginContact? Am I allowing the user to move the sprite faster than the game cycle can handle the collisions?
Again, when the sprite is moving at slow speeds, the physics are working perfectly.
Remember, these things are all calculated frame by frame. You're probably moving the sprite so fast that its ending up on the other side of the screen in too few frames to count as a collision. If someone is spastically moving their finger around it might not catch it. You could put some kind of speed limit on the sprite or something.
try to set physic body with usesPreciseCollisionDetection = YES
I'm new to iOS programming and I made a little game.
I have some sprites in the background of my scene which I want to move slowly from left to right.
Right now I'm doing this in the MainScene:
[self performSelectorInBackground:#selector(doBackgroundAnimation:) withObject:sprite];
and the method in which the animation takes place looks like this:
-(void)doBackgroundAnimation:(CCNode *)sprite {
while (//sprite is still in the scene) {
//move sprite a little bit right
}
}
This solution is not really what I was looking for, since the time it takes to run through the while-loop varies from device to device.
Is there a way to make sure that the animation takes an exact amount of time e.g. 5 seconds?
Something like:
performSelectorInBackground:#selector(doBackgroundAnimation:) withObject:turtle inTime:5.0
Thank you for your help!
It's been a while since I did game stuff but you have to adjust the distance you move the sprite according to the time since the last update of the screen. So you have a var called speed that you * by the time since the last refresh and then move the sprite that distance.
There are methods in sprite kit that deal with this. There are lots of tutorials on YouTube that cover this.
I'm trying to do a menu like the one that "Contre Jour" game has, with 3 elements spinning in a circle when user drags left and right. I'm using CALayers with CATransforms to position them in a 3d spinning wheel (no problem so far).
I need a way (maybe with NSTimers?) to calculate in-between values, because CoreAnimation just interpolates values, but if you NSLog them, it's just gonna show the start and the end, or just the end. I need all the in-between values, I need to snap the wheel movement when I release the finger (touches ends)in one position (there are 3 elements, each one shoud be at 120 degrees.
My guess and am quite sure I'm correct is that they are using a game engine such as Unity3D or Cocos2D or any other of the many to manage their sprites, animations, textures, physics and basically everything. Trying to replicate it outside of game engine will most likely result in crummy performance and a lot of hair pulling. I would suggest looking into a dedicated game engine and give it a shot there.
I am not sure I understand exactly what Contre Jour does with the spinners, anyway, I think that a reasonable approach for your case is using a UIPanGestureRecognizers to update the status of your spinning wheels according to the panning.
Now, it is not clear what you do to animate the spinning wheel (if you could provide some code, this would help understanding exactly what you are trying to do), but the idea would be this: instead of specifying an animation ending point far away from the starting point (and letting Core Animation do all the handling for you, even when the dragging has stopped), you would only modify the status of the spinning wheel in small increments.
If your only issue is stopping the animation when the dragging stops, you could try calling removeAnimationForKey on your layer to halt a specific animation.
Look into CADisplayLink. This works very much like an NSTimer, except its refresh rate is tied to that of the display, so your animations will be smoother than if you were to use timers. This will allow you to calculate all the in-between values and update your control.
I'm not clear what you are asking, but I do have one insight for you: To get the in-between values of an in-flight animation, query the layer's presentationLayer property. the property that's being animated will have a value that's a close approximation of it's on-screen appearance at the moment you fetch the value.
Is it true that for Angry Birds or Cut the Rope, they draw the whole frame of the whole screen first (the whole view), and then paint the whole frame onto the screen, making the animation smooth?
That's because if we animate a metal ball, of size 20 x 20 pixel, and if we erase the ball first, and then draw the ball at a new location, then there might be some flickering very subtle but noticeable.
The same might be if it is animated by drawRect, which will erase the whole screen, and then draw everything in their new locations, which might have even more flicker than above?
Going back to the drawing whole frame method: if a ball was at coordinate (100,100), and now the ball is painted on top of the whole screenshot (with the new background exposed), at coordinate (103, 100), then it is very unnoticeable for the changes. (no disappearing and then reappearing happening at all).
How can smooth animation be achieved that looks like Angry Birds or Cut the Rope game?
They make use of OpenGL, which is a lot faster than any of the Quartz methods (ie. drawRect) since it makes use of the GPU instead of the CPU for rendering. Using Quartz can be hundreds or thousands of times slower depending on what you are doing exactly.
If you do not want to resort to OpenGL. You can put the object inside a UIView and then animate it. As long as the contents of the view is static, this is plenty fast for most applications. For example, making the background a view, and the metal ball a view, you can move that view around and achieve very smooth animations without problems.
Use CALayers. They are more lightweight than views.
If an app uses OpenGL, the answer is yes, it does its rendering before the frame buffer is presented to the screen. I think the other ways to draw to the screen use the same technique of drawing to an off-screen buffer before transferring the completed image to the screen, but I'm not so sure about that.