I'm creating a pop out action effect on a window after I click on some button in LibGdx.
May I know, Is there any methods available to scale the actor, in a way that keeping its center position at the center (scales in both direction of x and also both direction of y)?
addAction(sequence(scaleTo(1.3f,1.3f,0.2f),scaleTo(1f,1f,0.2f)));
This is the basic scaling method I used.
↑
O →
But I want something like this:
......↑
← O →
......↓
You need to set actor's origin to its center. First set the size, and then call:
actor.setOrigin(Align.center);
Note, that if your actor is a Table (and classes like Button, ImageButton extend Table), then you need to call:
actor.setTransform(true); // But keep in mind that has a performance impact "because {#link Batch#flush()} must be done before and after the transform"
Related
My player's arm is programmed to follow my mouse and rotate accordingly and I've programmed bullets to be fired using this rotational value
(Math.atan2(this._dy, this._dx) * 180 / Math.PI
where _dy is the y location of the mouse (-) the y of my player's arm and the _dx is the x location of mouse (-) the y of my player's arm.
However, when I program the player to reflect when the mouse has crossed the x-coordinates, the bullet angle is also reflected. How would I fix this issue?
I've already tried subtracting 180 from the angle but it still doesn't fire towards the direction of the mouse.
First, make sure you have this parent-child-sibling relationship:
"A" should be the parent of "B" and "C". "B" and "C" should have no direct link. Their connection is that they have the same parent. So when you want to move the character, move the parent, and both will move. Now, for the good stuff:
Use key frames and sibling relationship
beginner level approach
Make the character and the arm both children of the same parent display object container (Movie Clip in this case). Now, instead of flipping anything by xScale, which I assume you did, you can just have both MC children (arm and character) go to frame 2 (or whatever is available) where the graphics are flipped.
xScale body, move arm to frame 2, change z order
moderate level approach (best result)*
Alternatively, you could do that same "sibling" setup as above, and then scale the character but not the arm (I think scaling the arm will mess it up again, but you could have the arm go to frame 2 and have it drawn reversed so the thumb and handle are pointing the right way. Bonus points for changing the z stacking order so the arm goes to the other side of the body. xScale for only the body allows you to only have one set of frames for animation of his legs and torso etc. but also avoid scaling the arm at all).
Global properties
advanced approach
A third option is to use global rotation and global points. I won't illustrate that here because I'm not that advanced and it would take me a while to figure out the exact syntax. If you already have mastered global properties, try this; if not, try one of the ones above.
* Example (best result)
if (facingRight == true && stage.mouseX < totalChar.x){
// totalChar is on the stage
// and contains two children:
// armAndGun and bodyHeadLegs
totalChar.armAndGun.gotoAndStop(2);
// in frame 2 of the arm MC, draw the
// arm and gun in the flipped orientation
totalChar.addChild(bodyHeadLegs);
// re-ads body to parent so it's
// z-order is above the arm;
totalChar.bodyHeadLegs.xScale = -1;// flips body and any animation of legs and head
facingRight = false;
// use a variable or property like this
// to keep him from constantly flipping
}
You'll need similar code to flip him back the other way.
I'm trying to make a hotkey type button which has a main image, a number in the top left indicating the hotkey button, and a number in the bottom right indicating the quantity of the item. I could use a Table to place these but they wouldn't be overlapping. I'd like to have the numbers on top of the main image so I used a stack, unfortunately it doesn't look like there's a way to control the actors on a stack - they all get placed at 0,0 within the biggest actor in the stack. Is there a way to place the actors in the appropriate positions or do I have to use table?
By definition, Stack puts its children in 0,0 coordinates and trying to stretch them to fill Stack.
You can use Group, for more control over actors you putting in:
You can simply get X and Y coordinates of inserted Actor by getX() and getY() methods. With little bit of help by getHeight() and getWidth() methods you can make simple table layout.
So I am super stoked to start using LibGDX for my first android title for OUYA and PC, but I am running into some snags with LibGDX. (All of my questions can be answered by looking at source, but I am really trying to understand the design choices as well).
To start with, the coordinate system. I created a project using the Project Setup jar, and it creates an OrthographicCamera like so
camera = new OrthographicCamera(1, h/w);
From my reading, I understand that LibGdx uses bottom left corner for 0,0 and yUp. Fine.
I see that it is pretty easy to change to y down if I want to, but I am not understanding the next bit of code that was created.
For the default sprite that gets created the position is set like so.
logoSprite.setOrigin(logoSprite.getWidth()/2, logoSprite.getHeight()/2);
logoSprite.setPosition(-logoSprite.getWidth()/2, -logoSprite.getHeight()/2);
When I run this basic program, I see the logo image I have added is centered on the screen. What I am trying to understand is why the values are negative in set position, and why is it using the sprite width and height instead of the graphics w and h of the view port? If I change to the screen width and height, then the image is drawn in some odd position in the lower right hand side of the screen.
My next question is sprite.setSize vs sprite.setScale. Why is the difference between the two? (They appear to do the same thing, except setScale leaves getWidth and getHeight unchanged).
Since my game will be using a 2D camera heavily for panning, zooming and rotation, I am trying to understand as much as I can about the libgdx framework before I start writing any code.
As a side note, I have a game development and math background and I have made several 2D and 3D games using XNA. I am finding LibGdx a bit frustrating as it does not abstract away OpenGL as much as I was expecting it to, and so far the 2D drawing I have been experimenting with seems to be more confusing than it should be!
I also wanted to note that I am planning to use spine for my animations. Should that change my choice to use y-up or y-down?
If you want to draw a sprite in center of screen, do this in your create method
logosprite.setposition(scrw/2-logosprite.getwidth()/2,scrh/2-logosprite.getheight/2);
here scrw is your viewport's width,
and scrh is your viewport's height,
this way your sprite will be in center of screen
sprite.setsize is used for setting size of the sprite and sprite.setscale is used when we scale a large/small texture so that its quality remains good in all devices(hdpi.mdpi,xhdpi,ldpi)..
no need to worry if you are using spine it works smoothly in libgdx..
You can use just this code if possible
logoSprite.setPosition(Gdx.graphics.getWidth()/2 - image.getWidth()/2,
Gdx.graphics.getHeight()/2 - image.getHeight()/2);
To center the sprite into the middle of the screen Where "image" is the Texture you have loaded/declared initially.
As for why it is coming in a odd position is due to the fact that you are using a camera.
Which changes the view a lot just go through the documentations of libgdx about camera here
In my case, I needed to set position of camera and then call update() method.
Then never forget camera's (0,0) is its center. Everything is being placed that way. My camera code:
private void cameralariUpdateEt() {
cameraGame.position.set(cameraGame.viewportWidth * 0.5f,
cameraGame.viewportHeight * 0.5f, 0);
cameraGame.update();
cameraScore.position.set(cameraScore.viewportWidth * 0.5f,
cameraScore.viewportHeight * 0.5f, 0);
cameraScore.update();
}
Call this method from inside render();
Step 1: Set the sprite origin to the position you would like it to rotate around.
// camera center point is (c.x, c.y)
logoSprite.setOrigin(c.x, c.y);
Step 2: make sure to set your sprite center to origin
logoSprite.setOriginCenter();
Step 3: Rotate your sprite
logoSprite.setRotation(Angle);
Step 4: Set the sprite position, [subtract half the sprites width and height to center the sprite]
logoSprite.setPosition(c.x - logoSprite.getWidth() / 2, c.y - logoSprite.getHeight() / 2)
In my cocos2dx game, I have a CCLayer that contains another CCLayer. The sublayer just cover part of the container layer. I 'think' I achieve this through:
this->setContentSize( CCSizeMake( 100, 200 ) );
however, the sublayer always capture touches even though it is outside its size and position area... Is it common?
I can filter through the touches position by comparing it inside the ccTouch** functions, but I think it is a hack, what is the proper way to set the sublayer to properly cover just the partial area of its parent?
The only thing i can think of straight away is making this inner layer a CCNODE and also extent it with CCTouchDelegate.
Now with this, when u register with the TouchDispatcher, you make sure it doesn't Swallowtouches(the boolean value given as the last parameter)...
This way when you receive a touch ... just see if it is within the boundary of this inner layer of urs and if it is not, send let the parent class use this touch.
Hope this helps.
This should be fairly simple I'd think, I'm just not that familiar with actionscript haha.
I have a game where I have the background moving behind a character that stays in one position on screen. I'm relatively new to actionscript 3 but I'm wanting to have text boxes pop up whenever the player presses a key over certain objects passing in the background.
So, basically the background itself is a movie clip, and I have other graphics and movie clips within the background mc.
I was thinking of getting the player.x and y position and then "comparing" that position (>= and <=, etc.) with the graphic/movie clip in the background. But I just don't know how to obtain the x and y coordinate of the graphics/movie clips in the background mc.
You could try to target your movie clips in the background by getting their coordinates, then removing their parent's position (the background container).
Something like :
var finalXPosition:int = targetMovieClip.x - backgroundContainer.x;
var finalYPosition:int = targetMovieClip.y - backgroundContainer.y;
By substracting the target movieclip parent's position to its position, you gain the final position in the parent's scope coordinates.
It should work for you as soon as your character and your background container are situated at the same level of the display list.
Here is a quick diagram of what I try to explain (please forgive my inaptitude to draw nice and explicit drawings ^^)
Usually, when I stumble upon such a case, I try to make a quick and even dirty drawing, starting with what I want, then breaking down every useful data I have to achieve that result, you should keep that method in mind and try it the next time ! :-)