Best method of setting text alpha in libgdx - libgdx

I'm currently resetting a GlyphLayout every frame to propagate the opacity changes in BitmapFont, however this seems to be dragging down performance a lot since it needs to calcualate the width and height every time.
Is there a better way to change text opacity?
#Override
public void render(float delta) {
bitmapFont.setColor(1, 1, 1, opacity);
glyphLayout.setText(bitmapFont, text); // <-- performance bottleneck
bitmapFont.draw(batch, glyphLayout, posX, posY);
}

Related

Libgdx: Draw a Sprite on touchdown

I want to draw A Sprite when touchDown event occurs and disposed when touchUp occurs. I tried following code:
public class Connect4Screen implements Screen {
SpriteBatch batch;
Connect4Screen(){
batch = new SpriteBatch();
camera = new OrthographicCamera(30, 20);
camera.update();
batch.setProjectionMatrix(camera.combined);
Gdx.input.setInputProcessor(new InputAdapter(){
#Override
public boolean touchDown(int screenX, int screenY, int pointer, int button) {
drawChip();
}
}
}
public void drawChip(){
batch.begin();
batch.draw(new Texture("Images/yellow.png"), 0, 5, 1.4f,1.4f);
batch.end();
}
}
I scrapped off unnecessary code.
What is wrong here?
If you simply draw something as a one-time event, it will only be visible for 1/60 of a second. Games redraw the screen over and over in a loop, so to cause something to appear and stay on the screen, you need to set a member Boolean that indicates it should be drawn, and then in your render method you draw that item if the Boolean is true.
That's a very simplified explanation. Games tend to have many different items to draw that come and go, and keeping separate Booleans for each of them is impractical. So typically you'll have a list of items to draw, and you can add and remove items from the list based on events in the game. In your render method, you would loop through the list and draw everything in it.
Also, you must not create a new Texture without keeping a member reference to it so you can dispose() it later. Textures use native memory on the GPU and must be disposed of or they will leak memory. In LibGDX, any object that can leak memory implements Disposable, and must be disposed before you lose track of the reference.

libgdx - ClickListener not affected by actor scale?

Here's a constructor for a card class I was making. When I create one that is scaled and click on it, only clicks within the 1.0x scaled area are actually registered. i.e. if I pass in 1.5 for the scale, clicks on the borders don't work. Why not? I've scaled the actor itself.
public Card(float x, float y, float scale)
{
this.setPosition(x, y);
faceSprite = new Sprite(MyResources.getInstance().cardTextureRegion);
faceSprite.setPosition(x, y);
faceSprite.setScale(scale);
borderSprite = new Sprite(MyResources.getInstance().cardBorderTextureRegion);
borderSprite.setPosition(x, y);
borderSprite.setScale(scale);
// Set boundaries for ourselves (the actor). Note that we have to match the scale of the sprites.
setSize(borderSprite.getWidth(), borderSprite.getHeight());
setScale(scale);
// Add ClickListener
final Card thisCard = this;
addListener(new ClickListener() {
public void clicked(InputEvent event, float x, float y) {
((MyStage)(thisCard.getStage())).cardClicked(thisCard);
}
});
}
Basic Actor class might be missing some functionalities, including proper scale handling. If all you want is displaying some images (judging by the Sprite objects you use), I'd suggest using the existing classes rather than making custom actors - especially since you might have trouble rendering Sprites with exact Actor parameters if you use a lot of custom actions.
Image allows you to display "sprites" - although somewhat simplified, it should be enough. To store the images, you can use a Table (more flexible) or a Stack (will work with multiple images of the same size).
If you really want to stick with the custom actor approach, try this instead of changing the scale:
setSize(borderSprite.getWidth() * scale, borderSprite.getHeight() * scale);
If you don't change Card scale manually in runtime (only set it up during creation), it should just work.
You Can use image Class to display Images.
Texture texture=new Texture("test.jpg");
Image image=new Image(texture);
//you can use setsize() or setBounds() as per your requirement.
image.setScale(scale);
image.addListener(new ClickListener(){
#Override
public void clicked(InputEvent event, float x, float y) {
((MyStage)(thisCard.getStage())).cardClicked(event.getTarget());
}
});

Java libgdx 1.20 version texture bug

For 2 days I've been trying to fix bug with fickering and distored textures in my game. I was serching on the internet and i tried a few solutions like using scene2d, but it didn't work. What should i do ?
This screenshot shows the problem: as the character moves, one eye is sometimes bigger than the other:
edit:
I still got the problem widthdistored eye when i use sprite.setPosition((int) sprite.getX(), (int) sprite.getY()); every time before i render my character.
When i use custom viewport from the answer i see nothing on the game window what i do wrong?
package com.mygdx.redHoodie;
import com.badlogic.gdx.Gdx;
import com.badlogic.gdx.Screen;
import com.badlogic.gdx.graphics.GL20;
import com.badlogic.gdx.graphics.OrthographicCamera;
import com.badlogic.gdx.graphics.g2d.SpriteBatch;
import com.badlogic.gdx.utils.viewport.StretchViewport;
public class GameScreen implements Screen {
public static final int GAME_WIDTH = 800;
public static final int GAME_HEIGHT= 480 ;
SpriteBatch batch;
Background background;
public Hoodie hoodie;
public PixelMultipleViewport viewport;
OrthographicCamera camera;
public int gameMode; // 0 normalna gra, 1 level up, 2 end game
public GameScreen(){
camera= new OrthographicCamera(GAME_WIDTH,GAME_HEIGHT);
viewport = new PixelMultipleViewport(GAME_WIDTH, GAME_HEIGHT, camera);
viewport.update();
camera.setToOrtho(false, GAME_WIDTH, GAME_HEIGHT);
batch = new SpriteBatch();
//klasy wyswietlane
background= new Background(this);
hoodie = new Hoodie(this);
startNewGame();
}
#Override
public void render(float delta) {
// TODO Auto-generated method stu
Gdx.gl.glClearColor(1, 1, 0, 1);
Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT);
batch.setProjectionMatrix(camera.projection);
batch.setTransformMatrix(camera.view);
camera.update();
//batch.setProjectionMatrix(camera.combined);
this.update(delta);
this.batch.begin();
toRender(delta);
this.batch.end();
}
public void update(float delta){
hoodie.update(delta);
}
public void toRender(float delta){
background.render();
hoodie.render();
}
public void startNewGame(){
}
public void startNevLevel(){
}
#Override
public void resize(int width, int height) {
// TODO Auto-generated method stub
viewport.update(width, height,false);
}
#Override
public void show() {
// TODO Auto-generated method stub
}
#Override
public void hide() {
// TODO Auto-generated method stub
}
#Override
public void pause() {
// TODO Auto-generated method stub
}
#Override
public void resume() {
// TODO Auto-generated method stub
}
#Override
public void dispose() {
// TODO Auto-generated method stub
}
}
When loading your texture, use linear filtering and mip-mapping. The default filter is Nearest/Nearest, which will cause the issue you're seeing.
Texture myTexture = new Texture("textureFilename", true); //must enable mip-mapping in constructor
myTexture.setFilter(TextureFilter.MipMapLinearNearest, TextureFilter.Linear);
EDIT:
I realize now, looking at your screenshot, that you are doing pixelated graphics in a larger window. In order to do this, yes you need to keep the Nearest/Nearest filtering, instead of what I suggested.
To avoid having the some of the pixels vary in size, you must round off character movement and camera movement to the nearest world unit. When your character is partway between pixels, the size of the sprite pixels varies because they don't line up with the screen pixels.
You have your world scaled so one unit equals one of your large pixels. So whenever you draw anything, you need to first round its position to the nearest integer in the x and the y, as well as the camera position. So after you move the camera or the sprites, you must do something like this:
sprite.position.set((int)sprite.position.x,(int)sprite.position.y,sprite.position.z);
As far as your Viewport goes, if you don't want any black bars, you will probably need a custom Viewport class that tries to match your desired resolution as closely as possible and then extends it outwards to avoid distortion. ExtendViewport does something similar, but the difference with pixellated graphics is that you need the world resolution to be an integer multiple of the screen's resolution so the edges of pixels look crisp rather than fuzzy.
I think this will do what you want. It takes your desired screen resolution and shrinks it to fit where the size of each of your pixels in screen pixels is an integer. Then it extends the view beyond your desired resolution to avoid distortion and black bars. This class makes the assumption that all screen dimensions are always a multiple of 4. I think that's true. If you want to get fancy, you could use OpenGL scissoring to round down the viewport size to the nearest multiples of 4, to be safe. At most you would be having 2 pixels of black bar, which I don't think would be noticeable.
public class PixelMultipleViewport extends Viewport {
private int minWorldWidth, minWorldHeight;
public PixelMultipleViewport (int minWorldWidth, int minWorldHeight, Camera camera) {
this.minWorldHeight = minWorldHeight;
this.minWorldWidth = minWorldWidth;
this.camera = camera;
}
#Override
public void update (int screenWidth, int screenHeight, boolean centerCamera) {
viewportWidth = screenWidth;
viewportHeight = screenHeight;
int maxHorizontalMultiple = screenWidth / minWorldWidth;
int maxVerticalMultiple = screenHeight / minWorldHeight;
int pixelSize = Math.min(maxHorizontalMultiple, maxVerticalMultiple);
worldWidth = (float)screenWidth/(float)pixelSize;
worldHeight = (float)screenHeight/(float)pixelSize;
super.update(screenWidth, screenHeight, centerCamera);
}
}
Here's a different option I just came across. This is a way to draw your scene at the scale you like without black bars, at any resolution.
The visual quality will be slightly worse than in my other answer (where you draw at an integer multiple of your desired scene scale), but significantly better than using straight nearest filtering like in your screenshot.
The basic idea is to draw everything to a small FrameBuffer at the scale you want, and then draw the FrameBuffer's color texture to the screen using an upscaling shader that (unlike linear filtering) interpolates pixel colors only along the edges of sprite pixels.
The explanation is here. I have not ported this to Libgdx or tested it. And I'm not sure how well this shader would run on mobile. It involves running four dependent texture look-ups per screen fragment.
I know this topic is old but as my search led me here, there may be more people following in the future. I was having the same pixel tearing issue, but only on my iOS 9 iPhone 4S. It was rendering fine on my Android 9 Pixel 2. Tried many things (especially rounding to full pixels) but even using an unzoomed fullscreen orthographic camera it suffered from the artefacts.
Forcing my texture to be POT (power of two) fixed the issue!

LibGDX Android Game - displaying fixed text (ie Score) over a scrolling screen

I am beginning to write a game in LibGDX, only just beginning. I have got a basic tile map loaded, a player sprite and can move the character around and the screen (camera) scrolls around - perfect.
I have two overlayed textures in the bottom right of the screen, a left and right arrow, which are used as the joypad to control the character. I position these in relation to the players.x position, which is always fixed to the centre of the screen. Cool so far .... As below:
/////////////////////////////////////////////////////////////////
private void renderJoypad(float deltaTime)
{
batch.draw(Assets.leftJoypad, blockman.position.x-14, 1, 3, 3);
batch.draw(Assets.rightJoypad, blockman.position.x-9, 1, 3, 3);
}
I am now trying to put the player's score in the top left of the screen. The score is made of a Bitmap font, as below.
font = new BitmapFont(Gdx.files.internal("fonts/minecrafter.fnt"),Gdx.files.internal("fonts/minecrafter.png"),false);
font.setScale(0.02f);
In my render() method I cam calling some other methods to update, like the positions of the
leftJoypad etc, as in renderJoypad(). I am also calling my draw font method to update the position of the score, however, when I scroll it is all jerky, and sometimes it shows less characters than there should be.
public void drawScore(float deltaTime)
{
font.draw(batch, "00000", blockman.position.x, 10);
}
I believe that I need to place the score (and any other on screen texts, HUD etc) into a stage, but I cannot understand how to get it working with my existing code.
My show method is as follows:
public void show()
{
//load assets class to get images etc
Assets Assets = new Assets();
//start logging Framerate
Gdx.app.log( GameScreen.LOG, "Creating game" );
fpsLogger = new FPSLogger();
//set the stage - bazinga
Gdx.input.setInputProcessor(stage);
//stage.setCamera(camera);
//stage.setViewport(480, 360, false);
batch = new SpriteBatch();
//load the Joypad buttons
loadJoypad();
//background image
loadBackground();
//sounds
jumpSound = Gdx.audio.newSound(Gdx.files.internal("sounds/slime_jump.mp3"));
//LOAD block man here
// load the map, set the unit scale to 1/16 (1 unit == 16 pixels)
loadMap();
//draw the score
font = new BitmapFont(Gdx.files.internal("fonts/minecrafter.fnt"),Gdx.files.internal("fonts/minecrafter.png"),false);
font.setScale(0.02f);
// create an orthographic camera, shows us 30x20 units of the world
camera = new OrthographicCamera();
camera.setToOrtho(false, 30, 20);
camera.update();
// create the Blockman we want to move around the world
blockman = new Blockman();
blockman.position.set(25, 8);
}
and my render() method is as follows:
public void render(float delta)
{
// get the delta time
float deltaTime = Gdx.graphics.getDeltaTime();
stage.act(deltaTime);
stage.draw();
// clear the screen
Gdx.gl.glClearColor(0.3f, 0.3f, 0.3f, 1);
Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT);
renderBackground(deltaTime);
batch = renderer.getSpriteBatch();
//updateBlockman(deltaTime);
blockman.update(deltaTime);
// let the camera follow the blockMan, x-axis only
camera.position.x = blockman.position.x;
camera.update();
// set the tile map rendere view based on what the
// camera sees and render the map
renderer.setView(camera);
renderer.render();
//start the main sprite batch
batch.begin();
// render the blockMan
renderBlockman(deltaTime);
renderJoypad(deltaTime);
drawScore(deltaTime);
batch.end();
fpsLogger.log();
}
I have tried to change the way things work with relation to the Spritebatch etc and just cannot seem to get it working as I require.
Can anyone suggest how I may approach getting a stage and actors to work, or a second camera or something to help me achieve a fixed score display in the corner.
Do I need to use Scene 2D or something - aahhh! My head is exploding....
I look forward and thank you in advance.
Regards
James
I have a couple of suggestions:
Check to see if you have setUseIntegerPositions set to true
(the default) when you draw your font. If you do, and you're scaling
it, then it can cause some odd effects similar to those that you
describe. Set it to false and see if it fixes the problem.
Reset your spritebatch's matrices before drawing the text, that way you won't need to adjust it for the scrolling.
I'd even go as far as to recommend not scaling the font if you can help it, because fonts often look a little odd after being scaled.

Canvas repaint should be called by itself

I have an application with jTabbedPane. There are two tab (JPanel) in jTabbedPane. First tab includes canvas and second one includes simple JLabel. Button draws rectangle into canvas.
Every thing is fine until then. However, when switching tabs, canvas would lose everything. It should be repainted by itself.
Rectangle should exist after changing tabs. Do you have any idea about the problem?
My button code is here:
private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {
Graphics g = canvas1.getGraphics();
g.drawRect(10, 10, 100, 100);
}
Thanks in advance.
First of all, you shouldn't put AWT components inside Swing components. Use JComponent or JPanel instead of Canvas.
Second, no, it shouldn't repaint itself. When the button is clicked, you should simply store what should be painted in some variable, and the paintComponent() method should be overridden in order to paint what is stored in this variable. This way, every time the component is repainted, it will repaint what has been stored last in this variable.
For example:
public class RectangleComponent extends JComponent {
private boolean shouldPaintRectangle = false;
public void setShouldPaintRectangle(boolean b) {
this.shouldPaintRectangle = b;
}
#Override
public void paintComponent(Graphics g) {
super.paintComponent(g);
if (shouldPaintRectangle) {
g.drawRect(10, 10, 100, 100);
}
}
}
In general, you should never ask the Graphics of a component and paint on it. Instead, you should override paintComponent() and paint the component using the Graphics passed as argument.