this is my first ever question so apologies if it's not descriptive enough.
I currently have an object that can be moved along an x axis with dragging. I need to limit it's movement to half of the screen.
Can anyone help
Well that is simple. Assuming we are talking about moving a UIView:
// Only move the object if its right bounding box position is
// in the first half of the screen
if ((someObjectView.frame.origin.x + someObjectView.frame.size.width) <
(containingView.bounds.size.width / 2.0) {
// Move the object
}
You fill in the blanks :-)
Related
I want to create 2d game. The game is similar to the Scale Puzzle. I've already created nearly all the functionality. Only the last remains.
.
This is example.
And that's how I draw shapes.
.
I click inside a white square, and after 1 seconds a square is drawn regardless of the position of the ball. (x,y).
Square is created programmatically, and it is added to the parent element "SquaresList" with name New Game Object.
How can i do, so that the violet field becomes larger, and in the middle of the screen.
I made it so that for every 3 clicks, "SquaresList" increases Scale by 0.25f, and get negative position of the ball. Example:
SquareList.transform.position = new Vector2(-ball.pos.x, -ball.pos.y)
This does not work correctly.
What options can be? (intersections, find the max/min point, math formulas) ?
Hi NoName :) Your method
SquareList.transform.position = new Vector2(-ball.pos.x, -ball.pos.y)
would work perfectly if your object does not inherit other objects and there positions. To fix this make sure that you reset the position of all other game objects that you use as containers.
I am trying to make a snake kind of game on the iPhone. For that I plan to have a simple dot as the sprite which draws a line. The dot is controlled by two buttons on the left and the right of the screen enabling it to turn left or right. Now I really do not have any idea how to make the sprite move automatically forward and how to program the turning. It should not be exactly as in snake where it abruptly turns left or right but it should more be a smooth curve. I hope you're getting my point and I'd appreciate all kinds of thoughts! Thanks a lot!
Somewhat trying to make it like this:
http://www.bnet.im/images/screen_curve.png
There are a lot of ways of doing this, but one simple way would be to store the angle of the snake's trajectory (I've called it theta) and move it a fixed amount in every call to Update.
Assuming that the snake class inherits from CCNode:
-(void)Update:(ccTime)dt {
self.position = ccp(self.position.x + cos(theta)*dt,
self.position.y + sin(theta)*dt);
}
You could then update theta from your event handling logic by increasing it or decreasing it when the user taps to turn left or right.
I'm trying to add a box to the centre of the screen in a zoom view. E.g. if I move into an area of the content view and try using the offset coordinates, it becomes erratic if I zoom in or out. I can't seem to figure out the right mathematical formula for this.
If you are working with a UIView or one of it's subclasses. You'll always have a center property available for you. That property is a CGPoint and you can do something like this to test if it is the required result you seek:
CGPoint center = [YourUIViewOrSubclass center];
NSLog(#"Center x is '%f' and y is '%f', center.c, center.y);
I hope this helps you. Otherwise try and rephrase your question and include a little context.
In the touchesMoved method, what is the math to have an object on the screen move along a dragging touch vector? For instance, if I touch beneath my object (Y > object.y), and drag "up", I want the object to move from its current x,y location along the same vector that my finger moves.
Currently I have it working that the drag motion snaps my object to my finger's location, but sometimes my finger hits the edge of the screen before I get my object positioned correctly.
If I know my "touch down location" and the "current touch location" what is the math to determine where to move object.position?
I hope that you have already received the answer of figured it out yourself, but.
Assume that your object's Upper Left Corner (ULC) is at Object.X, ObjectY.
Assume that the CGPoint returned by touchsBegan is Touch.X, Touch.Y.
The offset (Delta) will be:
Delta.X = Touch.X - Object.X
Delta.Y = Touch.Y - Object.X
Subtract these from each point returned by touchesMoved and your ULC should move as you expect rather than snapping to your finger.
Good luck.
I would look into UIPanGestureRecognizer. It's what I use when I want to accomplish something like what you are describing.
This is what I used to learn about them but then took it further in other forms:
http://www.cocoanetics.com/2010/11/draggable-buttons-labels/
Good luck!
Fairly simple question that Im sure you will laugh at me for.
I have two rectangles playerRect and wall.
I have an if statement with the condition being ..
if (CGRectIntersectsRect(playerRect,wall)) {
//handle collision here
}
The problem I'm having is working out which side actually hit the wall rectangle.
I need to know because then I stop te player from moving depending on which side hit.
Thanks for any help
Disco
I would add some direction property to my 'Player' object. This way when you detect a collision, you just check to see which way the player was moving prior to the collision and react accordingly.
Create a CGRect for each side of your object with just a width of 1 (or height of 1 depending on the side) and look for intersections with the sides instead of the entire object. If your object is moving faster than 1 pixel per collision check, then you would check the sides in addition to checking the entire object