I am making a game in cocos2dx(c++).Here i have to make dynamic sprites that are falling top to down and on touch i have to kill them.I mean the sprites are of insects and they will be killed on touch
The problem is that I am unable to get the idea on how to implement them as on increasing the level the insects will be falling more and with more speed.
I have made for one insect.But don't know how to handle for multiple insects
Suppose, your 1st Sprite is coming from y height and it fell to -y/2 with a velocity of 10.
Then, you have to make several sprites with differnt velocities and different positions of x.
You can move a sprite in cocos2dx with the help CCMoveTo()
You can use this custome method to move sprite
void GameLayer::_mov(CCSprite *cp, float x, float y)
{
cp->setPositionX(cp->getPositionX()-x);
cp->setPositionY(cp->getPositionY()-y);
}
In this method we passing sprite which we have to move and x is how much change in sprite position and y is how much change in sprite position. In this I subtract x and y from the current position of sprite but you can add also according to your requirement.
You have to call this method in your update method.
Related
I am creating a game like bounce ball using cocos2d-x and box2d. I have different objects like rectangle, square etc.. I am able to detect collision, but i want to detect collision only on top of the objects. What exactly i want is, when the ball is on the top of the object, then only i want to jump the ball.
But, when the ball is collide on remaining side(bottom or left or right) i don't want to jump the ball.
In touchbegan, i am using the following code to the bounce ball. So every touch it is jumping when it collide with remaining side.
if(_ball->boundingBox().intersectsRect(rect->boundingBox()))
{
b2Vec2 force = b2Vec2(0, 550);
_body->ApplyLinearImpulse(force, _body->GetPosition());
}
Any advice?
Following steps can solve your problem-
1) CCRect projectileRect = CCRect(float x, float y, float width, float height);
if(_ball->boundingBox().intersectsRect(projectileRect))
{
b2Vec2 force = b2Vec2(0, 550);
_body->ApplyLinearImpulse(force, _body->GetPosition());
}
2) - Make body of an object and then check their collision.
I got the solution for my question from the below link.
http://www.raywenderlich.com/28606/how-to-create-a-breakout-game-with-box2d-and-cocos2d-2-x-tutorial-part-2
I'm new to ActionScript 3 and I have a character which you can control, the screen scrolls right along the stage and he can fire missiles.
The problem I'm getting is the missiles are created via these co-ords:
bullet.x = hero.mc.x;
bullet.y = hero.mc.y
These work fine untill the screen has scrolled to the right. I assume it's because the bullets are being spawned as a result of them using the canvas x,y and not the stages x,y
So i'm wondering how to find out the x and y of my hero in relative to the canvas so i can spawn the missiles on top of him!
Thanks, and if you need any more information let me know, I'm new to all this. Thank you.
You can do that with localToGlobal and globalToLocal. Your solution would be something like:
bulletPos = bullet.parent.localToGlobal(new Point(bullet.x, bullet.y));
Beware, though, as those are last resort functions. Normally, you'd have all your elements using the same 'layer', so comparisons are easier and faster.
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)
I have a bit problem with rotationX and rotationY.
It's cool if i just do a roationX and rotaionY below
_eventParent.rotationY =_differentX;
_eventParent.rotationX =_differentY;
However once i have assign a mouse move to the _eventParent. The roationX and roationY change perspectively while the mouse is moving. so instead the item remain the same size. it increase and decrease size prospectively. any idea why is it doing this? is there a possibility to stop this behavior?
Thanks
Please find the image below.
Perspective allows part of your shape to look closer to you than other parts. The problem is that perspective has a center, or "vanishing point" and by default, it is fixed. As you move your shape farther away from the vanishing point, the perspective changes, causing your shape to widen or narrow.
You can fix this by updating the vanishing point so that it is always at the same coordinates as your shape. Since the shape will always be at the vanishing point, the perspective shouldn't change.
To do this, create a perspectiveProjection for your shape:
_eventParent.transform.perspectiveProjection = new PerspectiveProjection();
PerspectiveProjection is located in the flash.geom package, so don't forget to import it.
Then whenever you update your shape's position, update it's vanishing point:
_eventParent.transform.perspectiveProjection.projectionCenter =
new Point(_eventParent.x, _eventParent.y);
You might need to offset the vanishing point by a set number of pixels to get the perspective looking the way you want it to.
Correct me if I misunderstood your question. Your question is that if you apply rotation to the movieClip object, then why does the size appear to be changing?
For simplification, Let's not apply rotation on both X and Y axis. Let's take a rectangular movie clip and onMouseMove we do ++myMovieClip.rotationX;
Now, this statement is going to apply rotation on the object about the X-axis and one would get a perspective of the movie clip flipping across X -axis and this flipping will show as change in size of the object.
The same applies to rotating across y-axis.
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 ! :-)