When using a TextureAtlas to create a Sprite with the createSprite method, the LibGDX documentation says: This method uses string comparison to find the region and constructs a new sprite, so the result should be cached rather than calling this method multiple times.
How do I cache these results? Is it just a variable I create to store the created sprite? If so then how do I create different copies of the same sprite?
Each time you use the createSprite method, a new Sprite gets created. Usually you'd have one sprite per enemy for example. Let's say that you have a class Frog which is one of your enemies. It should look like this (pseudo-code):
public class Frog {
private Sprite sprite;
public Frog(TextureAtlas atlas) {
sprite = atlas.createSprite("frog");
}
public void update(float deltaTime) {
// update the sprite position
}
public void render(Batch batch) {
sprite.draw(batch);
}
}
Now each Frog would have its own Sprite. This is necessary, since all frogs can be in different places. The position will be configured via the Sprite. You will create the sprite just once in the constructor and all of those sprites share the same TextureRegion of the same TextureAtlas, which will result in a good performance, since there won't be many texture switches on the graphics card, when you render your frogs.
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I have 3(Three) BoxCollider2D components where 2(two) have OnTrigger checked in my Object and both have different functions. Due to having OnTrigger on both, the projectiles I am casting collide with the wrong collider and instead activate that function. Is there a way to ignore 1(one) OnTrigger collider?
I have already tried Layer-based collision detection and set up a layer. Unfortunately, the object now collides with the collider which eliminates the player on collision
However, there are several ways to solve this problem. All kinds of physics.checks as well as raycasts but this code helps you to ignore the obstacle collider.
public Collider2D playerCollider;
public Collider2D obstacleCollider;
public void Start() => Physics2D.IgnoreCollision(playerCollider, obstacleCollider);
I have a very simple script I use to handle collisions in my games.
It's very easy to setup because it makes everything drop and draggable, which is a much easier way to program.
Below is the script and below that is instructions on how to use. Note it is a layer based system, but you can select multiple layers.
[System.Serializable]
public class TriggerEvent : UnityEvent<Collider> { }
[System.Serializable]
public class CollisionEvent : UnityEvent<Collision>{ }
public class EnterEvent: MonoBehaviour
{
public TriggerEvent TriggerEnteredEvent;
public CollisionEvent CollisionEnteredEvent;
[SerializedField]private LayerMask validLayers;
// Initalize Event System
void Awake()
{
if (OnTriggerEnter == null)
{
TriggerEnteredEvent = new TriggerEvent();
}
if (OnCollisionEnter == null)
{
CollisionEnteredEvent = new CollisionEvent();
}
}
// Called if transform is a trigger
void OnTriggerEnter(Collider collider)
{
if (validLayers == (validLayers | 1 << collider.gameObject.layer))
{
TriggerEnteredEvent?.Invoke(collider);
}
}
// Called if transform is not a trigger
void OnCollisionEnter(Collision collision)
{
if (validLayers == (validLayers | 1 << collision.gameObject.layer))
{
CollisionEnteredEvent?.Invoke(collision);
}
}
}
This is how it would work, and in this example I will be "coding" it from the perspective of a Bullet.
Basically I want to check if I (The Bullet) hits either the terrain or an enemy then call the relevent funcitons in the Bullet class respectively.
Obviously if I hit an enemy I want to deal damage.
So this will be my example bullet class
public class Bullet : MonoBehaviour
{
public int BulletDamage = 10;
public int BulletSpeed = 5;
void FixedUpdate() => transform.position = Vector3.Lerp(transform.position, transform.position + transform.forward * speed * Time.deltaTime, 1f);
public void OnEnemyHit(Collision collision)
{
// Try to get the enemy script
Enemy enemy = collision.gameObject.transform.GetComponent<Enemy>();
if (enemy != null)
{
enemy.DealDamage(this.BulletDamage);
}
}
public void OnTerrainHit(Collision collision)
{
Destroy(this.gameObject);
}
}
Add the EnterEvent script to the bullet.
Add the Bullet Script to the bullet.
There will be a space on the Inspecter where you can add your events. It should have a Plus and Minus in the top right corner. Press the plus.
From the inspector drag the bullet in game GameObject to the open space provider.
In the dropdown to the right, click on it, look for the Bullet Script, and select the OnEnemyHit function from it.
Create another event, do the exact same, but this time select the OnTerrainHit funciton instead - now but would be called in the order you added them.
Just underneath the event system should be the be able to see a dropdown for the Layers. Select all the layers you want your bullet to interact with. In this case it will be the Enemy and Terrain.
Finally remember to setup your layers properly. Ensure the Enemy has an Enemy Layer, the Terrain has a Terrain Layer, Bullet bullet layer and Player has a Player Layer
So I created a plane to be my floor in my unity project. I also assigned that with a mesh collider and a box collider and set it with convex but not as trigger.
I then created an item with also a mesh and sphere collider and set it to use gravity, since I wanted the item to fall onto the floor. But when I start the game, it still falling past the floor.
I have tried to find a solution already in YT, here and other places, but the only ideas they give is assigning a collider. This doesn't work as for me.
I also tried to fill the colliders with materials but cannot assign anything with it.
I also tried to write a code, but this does not help either.
Does anyone have an idea how to solve it?
public class IsGrounded : MonoBehaviour
{
Vector3 velocity;
public float gravity = -9.81f;
public Transform groundCheck;
public float groundDistance = 0.4f;
public LayerMask groundMask;
bool isGrounded;
// Start is called before the first frame update
void Start()
{
}
// Update is called once per frame
void Update()
{
isGrounded = Physics.CheckSphere(groundCheck.position, groundDistance, groundMask);
if (isGrounded && velocity.y < 0)
{
velocity.y = -2f;
}
}
}
So finally, I manage to find the solution from a helpful yt video.
What I needed to change was to deactivate both, the floor and the items, the trigger event. Since Unity does not allow you to use without kinematic and convex, I just clicked on convex and nothing changes. Now, items will not fall down the plane (still can happen, like when I throw the item down, it will sometimes go through).
I have a Textured2D loaded which is represented in ETC_RGB4 how can I change this to another format? say RGBA32. Basically I want to switch from 3 channels to 4 and from 4 bit per channel to 8 per channel.
Thanks
You can change texture format during run-time.
1.Create new empty Texture2D and provide RGBA32 to the TextureFormat argument. This will create an empty texture with the RGBA32 format.
2.Use Texture2D.GetPixels to obtain the pixels of the old texture that's in ETC_RGB4 format then use Texture2D.SetPixels to put those pixels in the newly created Texture from #1.
3.Call Texture2D.Apply to apply the changes. That's it.
A simple extension method for this:
public static class TextureHelperClass
{
public static Texture2D ChangeFormat(this Texture2D oldTexture, TextureFormat newFormat)
{
//Create new empty Texture
Texture2D newTex = new Texture2D(2, 2, newFormat, false);
//Copy old texture pixels into new one
newTex.SetPixels(oldTexture.GetPixels());
//Apply
newTex.Apply();
return newTex;
}
}
USAGE:
public Texture2D theOldTextue;
// Update is called once per frame
void Start()
{
Texture2D RGBA32Texture = theOldTextue.ChangeFormat(TextureFormat.RGBA32);
}
I'm developing for Windows Phone XNA and would like to load textures with a smaller size to decrease memory impact where the full image isn't required.
My current solution is to use a rendertarget to draw and return that rendertarget as a smaller texture to use:
public static Texture2D LoadResized(string texturePath, float scale)
{
Texture2D texLoaded = Content.Load<Texture2D>(texturePath);
Vector2 resizedSize = new Vector2(texLoaded.Width * scale, texLoaded.Height * scale);
Texture2D resized = ResizeTexture(texLoaded, resizedSize);
//texLoaded.Dispose();
return resized;
}
public static Texture2D ResizeTexture(Texture2D toResize, Vector2 targetSize)
{
RenderTarget2D renderTarget = new RenderTarget2D(
GraphicsDevice, (int)targetSize.X, (int)targetSize.Y);
Rectangle destinationRectangle = new Rectangle(
0, 0, (int)targetSize.X, (int)targetSize.Y);
GraphicsDevice.SetRenderTarget(renderTarget);
GraphicsDevice.Clear(Color.Transparent);
SpriteBatch.Begin();
SpriteBatch.Draw(toResize, destinationRectangle, Color.White);
SpriteBatch.End();
GraphicsDevice.SetRenderTarget(null);
return renderTarget;
}
This works in that the texture gets resized but from memory usage it looks like the Texture "texLoaded" doesn't get freed. When using the uncommented Dispose method the SpriteBatch.End() will throw a disposed exception.
Any other way to load the texture resized for less memory usage?
Your code is almost ok. There's a minor bug in it.
You'll probably notice that it only throws that exception the second time that you call LoadResized for any given texture. This is because ContentManager keeps an internal cache of content that it loads - it "owns" everything that it loads. That way, if you load something twice, it just gives you back the cached object. By calling Dispose you are disposing the object in its cache!
The solution, then, is to not use ContentManager to load your content - at least not the default implementation. You can inherit your own class from ContentManager that does not cache items, like so (code is based on this blog post):
class FreshLoadContentManager : ContentManager
{
public FreshLoadContentManager(IServiceProvider s) : base(s) { }
public override T Load<T>(string assetName)
{
return ReadAsset<T>(assetName, (d) => { });
}
}
Pass in Game.Services to create one. Don't forget to set the RootDirectory property.
Then use this derived content manager to load your content. You now can safely (and now should!) Dispose of all content that you load from it yourself.
You may also wish to attach an event handler to the RenderTarget2D.ContentLost event, so that, in the event the graphics device is "lost", the resized texture gets recreated.
I'm setting out to create a weather model display tool (web application), and from what I've seen, I'm really liking the idea of using Google Web Tools, and especially the SmartGWT toolkit. My one biggest sticking point at this point is finding some way to create a sort of image "looper" (displaying all images in a particular "set" one after another, not unlike a slide show). For reference, I need functionality (at least on a basic level) similar to this: http://rapidrefresh.noaa.gov/hrrrconus/jsloop.cgi?dsKeys=hrrr:&runTime=2012053007&plotName=cref_sfc&fcstInc=60&numFcsts=16&model=hrrr&ptitle=HRRR%20Model%20Fields%20-%20Experimental&maxFcstLen=15&fcstStrLen=-1&resizePlot=1&domain=full&wjet=1 (though it certainly need not be exactly like that).
Does anyone know of (ideally) some sort of GWT module that can do image looping? Or if not, does it sound like something an intermediate programmer could figure out without too much trouble (I'm willing to accept a challenge), even if I've never explicitly used GWT before? I'm sure I could whip together something that pulls each image in as it goes through a loop, but prefetching them would be even more ideal.
Please comment if you need clarification on anything!
As far as I'm aware there's not a pre-fab solution to do this, although maybe SmartGWT has something I don't know about. In any case, it won't be too hard to roll your own. Here's some code to get you started:
public class ImageLooper extends Composite {
// List of images that we will loop through
private final String[] imageUrls;
// Index of the image currently being displayed
private int currentImage = 0;
// The image element that will be displayed to the user
private final Image image = new Image();
// The Timer provides a means to execute arbitrary
// code after a delay or at regular intervals
private final Timer imageUpdateTimer = new Timer() {
public void run() {
currentImage = (currentImage + 1) % images.length;
image.setUrl(imageUrls[currentImage]);
}
}
// Constructor. I'll leave it to you how you're going to
// build your list of image urls.
public ImageLooper(String[] imageUrls) {
this.imageUrls = imageUrls;
// Prefetching the list of images.
for (String url : imageUrls)
Image.prefetch(url);
// Start by displaying the first image.
image.setUrl(imageUrls[0]);
// Initialize this Composite on the image. That means
// you can attach this ImageLooper to the page like you
// would any other Widget and it will show up as the
// image.
initWidget(image);
}
// Call this method to start the animation
public void playAnimation() {
// Update the image every two seconds
imageUpdateTimer.scheduleRepeating(2000);
}
// Call this method to stop the animation
public void stopAnimation() {
imageUpdateTimer.cancel();
}
}
One annoying thing with this implementation is that you have no way of knowing when your list of images has finished loading; Image.prefetch doesn't have a callback to help you here.