I'm writing an arcade multi-level game with Slick2D and I'm writing the code of the entities. I'm trying to flip horizontally the sprite. The first time I designed 2 images for the same sprite, the first facing right and the second facing left.
Now I'm trying to flip horizontally the sprite with the getFlippedCopy() function, but I cannot rotate the entire animation, I can rotate only a frame.
How can I solve?
If you are drawing an animation, it can be best to utilize the getCurrentFrame() method, as that's what's about to be displayed anyway.
Do something like this:
animation.getCurrentFrame().getFlippedCopy(direction, false).draw(x, y);
With this in your render method, you set the orientation of the image based on the direction they are face. So if they are facing left, 'direction' could be true, so the current animation image will draw flipped at that x and y (which is what you want), and if facing right, direction would be false, in which no flipped orientation would occur and it would show the player facing right (depending on the image; if they are facing left in the original spritesheet, the opposite will be true).
If you are doing a bit more complex orientation changes, such as 4 directional movement:
anim.getCurrentFrame().setRotation(90*(direction));
anim.getCurrentFrame().draw(x, y);
where 'direction' is a North/East/South/West representative integer, 0-3. Such as 0 = North, 1 = East, etc etc.
Related
I create a class for the DynamicBody balls and other for the walls, every class are according to tutorials and they work, the balls fall, but the problem is that the geometric shape use by box2d are not at the same place as the sprites, for what I search on google has something to do with the world of box2d not been using the camera or the camera vewport
other point is that when I create the world I use this
world = new World(new Vector2(0, -9.8f), true);
I was expecting that aggravation behaves like in the real world but appears much slower.
When creating box2d objects the origin is in the centre so a 2 wide object will have 1 unit left of the position set and one right. Textures are usually drawn with the lower left corner at the position so a 2 unit wide texture would have both units to the right of the position.
To fix this you just need to draw the image 1/2 the width to the left and 1/2 the hight to the bottom. e.g
draw(texture, position.x-(width/2),position.y-(height/2));
For your second question: the box2d world uses meters and kilograms for the calculations.
So if you give the physical world data in pixel space, like an impulse vector (100px, 100px), the world sees this as (100m, 100m). Then everything behaves like it's gigantic and from a far away view. So it seems slow from that point of view.
What you have to do is define a conversion rate (like 100px = 1m) and apply the conversion everywhere you like to move screen objects with box2d.
EDIT: See also: https://github.com/libgdx/libgdx/wiki/box2d#creating-a-world:
"In Box2D 1 unit = 1 meter."
While working on Projectiles I thought that it would be a good idea to rotate the sprite as well, to make it look nicer.
I am currently using a 1-Dimensional Array, and the sprite's width and height can and will vary, so it makes it a bit more difficult for me to figure out on how to do this correctly.
I will be honest and straight out say it: I have absolutely no idea on how to do this. There have been a few searches that I have done to try to find some stuff, and there were some things out there, but the best I found was this:
DreamInCode ~ Rotating a 1-dimensional Array of Pixels
This method works fine, but only for square Sprites. I would also like to apply this for non-square (rectangular) Sprites. How could I set it up so that rectangular sprites can be rotated?
Currently, I'm attempting to make a laser, and it would look much better if it didn't only go along a vertical or horizontal axis.
You need to recalculate the coordinate points of your image (take a look here). You've to do a matrix product of every point of your sprite (x, y) for the rotation matrix, to get the new point in the space x' and y'.
You can assume that the bottom left (or the bottom up, depends on your system coordinate orientation) of your sprite is at (x,y) = (0,0)
And you should recalculate the color too (because if you have a pure red pixel surrounded by blue pixel at (x,y)=(10,5) when you rotate it can move for example to (x, y)=(8.33, 7.1) that it's not a real pixel position because pixel haven't float coordinate. So the pixel at real position (x, y)=(8, 7) will be not anymore pure red, but a red with a small percentage of blue)... but one thing for time.
It's easier than you think: you only have to copy the original rectangular sprites centered into bigger square ones with transparent background. .png files have that option and I think you may use them.
I have a little tech game I am messing around with and I can't figure out the formula to position 1 object given another objects origin.
So I have a Spaceship and a Cannon. I have the game setup to use units, so 1 unit = 16 pixels (pixel art).
Basically my cannon should be placed 0.5625 units on the X and 0 on the Y relative to the origin of the Spaceship, which is located at 0, 0 (bottom left corner).
The cannon should is independent on the angle of the spaceship, it can aim in different directions rather than being fixed to aim the way of the spaceship.
I have it constantly following the cursor, which works fine. Now when I rotate the Spaceship, obviously the origin of the Spaceship is changing in world coordinates, so my formula to place the cannon is all messed up, like so:
protected Vector2 weaponMount = new Vector2();
weaponMount.set(getBody().getPosition().x + 0.5625f, getBody()
.getPosition().y);
Obviously if I position the ship at a 90° angle, X is going to be different and the cannon would be waaaayyy off the ship. Here is a screenshot example of what I mean:
What would be the formula for this? I have tried using cos/sin but that does not work.
Any ideas?
weaponMount.set(0.5625f,0).setAngle(SpaceshipAngle).add(getBody().getPosition());
Where SpaceshipAngle is the angle of your Spaceship.
The origin of the spaceship is the point, arround which the spaceship will rotate and scale (the Texture of it). The position instead is always the lower left corner of the Texture and does not depend on the rotation.
Your problem is, that your offset does not depent on the rotation of your spaceship.
To take care about this rotation you should store a Vector2 offset, which describes your weapons offset (in your case it is a Vector2(0.5625f, 0)).
Next store a float angle describing your spaceships rotation.
Then you can rotate the offset by using: offset.setAngle(rotation).
The last thing is to set the weapons position. The code for this did not change so much:
weaponMount.set(getBody().getPosition().x + offset.x, getBody()
.getPosition().y + offset.y);
I write simple game with libGdx. I have a hero, which always is in screen center and I must move my background sprite (or region?) to make move illusion. But my background sprite isn't infinity.
How can I create illusion of seamless infinity world?
Of course I can add several background sprites to try to cover all empty space of screen. But I must to draw out of the sceen a lot of all another objects: Houses, monsters, others heroes, etc. So I have a second question:
When I try to draw other object (a lot of objects!) out of the screen, how badly it affects memory? How to draw it correctly?
I know that OrthographicCamera in libgdx draw only viewportWidth-viewportHeight area. If it's right, then I must to move my camera and all my sprites too. I think it's not correctly.
How can I render infinity world in libgdx with OrthographicCamera?
How can I create illusion of seamless infinity world?
Create a tile background. Tile background means that if it was besides or top or bottom of itself, the edges of sticking line will not be visible to viewer.
To do this open your background image in photoshop and go to Filters > Other > Offset.
Set the offset filter to offset the background to center then try using photoshop tools to hide the edges (the + shape in image). Now again go to offset and return to 0, 0 and save your background.
When I try to draw other object (a lot of objects!) out of the screen,
how badly it affects memory? How to draw it correctly?
I have checked this and that was not much fps loosing on my test. So don't worry about it.
How can I render infinity world in libgdx with OrthographicCamera?
Move camera where-ever you want any x, y. Every time see where is camera and calculate needing tile backgrounds to draw (for example every time draw 3x3=9 backgrounds sticking together).
This is about animation in JAVA. I had success when using same dimension on all picture. But if i keep all picture dimension on same size(width and height) i get some bug which when player punch. Before player's hand touch enemy body, enemy died
But others with my case where idle, run, and punch has an different
dimension. Punching animation facing to the left became very strange.
Should his hand hit to the left but his body shifts to the right. This
is because I draw on the x & y are the same.
How can I fix it? Need instructions :D
I use png coz support transparent
I think this can fix with 2 option
1. Fix my collision detection
2. Fix of drawing position my image when some condition occur
Trying to picture your problem, hope this helps.
I am typeing directly from my head, so there are might errors in code
fixing coalision decection
i would try this
Image fist
Image enemy
//in paint
g2D.drawImage(fist,x,y,this);
g2D.drawImage(enemy,x1,y1,this);
Rectangle2D myFist = new Rectangle2D.Double(x,y,fist.getWidth(this),fist.getHeight(this));
Rectangle2D myEnemy = new Rectangle2D.Double(x1,y1,enemy.getWidth(this),enemy.getHeight(this));
if (myEnemy.contains(myFist){
//action u want to happend
}
I think something like this should fix coalision problems
I am seeing this as mario a game on sega
Fix of drawing position
//arm image can be the same image if u want
Image leftArm;
Image rightArm;
image headLegsAndTorsoLeft;
image headLegsAndTorsoRight;
//where am i looking in game if true i look to the leftside of user thats playing
boolean turnedLeft
//in paint
if(turnedLeft){
//this lets it look like he is turned to the left with his right arm in the visible behind his left.
//draw right arm
g2D.drawImage(rightArm,x,y,this);
//draw body moved a bit in x coor
g2D.drawImage(headLegsAndTorsoLeft,x-3,y,this);
// draw left arm a bit more in x coor
g2D.drawImage(leftArm,x-6,y,this);
}else{
//this lets it look like he is turned to the right with his left arm in the visible behind his right.
// draw left arm
g2D.drawImage(leftArm,x,y,this);
//draw body moved a bit in x coor
g2D.drawImage(headLegsAndTorsoRight,x-3,y,this);
//draw right arm a bit more in x coor
g2D.drawImage(rightArm,x-6,y,this);
}
same order for animation of arms, ultimatly i would use different methods animations for torso, leftarm, rightarm
something like keypressed leftarrow torso does walking animation left, hit left arm key moves left arm,hit right arm key moves right arm,thats 3 for lets say left arm, now u need another 3 for when ur char is moved to the right.
Thats how i would try to do things.