Develop Reference

Drawing many actors takes long time in scene2d

I have a problem with drawing many actors as it takes long time when testing with desktop project and not working on my android device.
I have a play button that when clicked should show 100 level for player to choose from.
Here is my code:
stage = new Stage(new ScalingViewport(Scaling.fill, 800, 1280));
Gdx.input.setInputProcessor(stage);
skin = new Skin(Gdx.files.internal("data/uiskin.json"));
Image play = new Image(new Texture(Gdx.files.internal("play.png")));
stage.addActor(play);
play.addListener(new ClickListener() {
#Override
public void clicked(InputEvent event, float x, float y) {
Table container = new Table();
stage.addActor(container);
container.setFillParent(true);
Table table = new Table();
Puzzle[] puzzles = new Puzzle[100];
for (int i=0; i<puzzles.length; i++) {
table.padTop(60);
table.padBottom(60);
puzzles[i] = new Puzzle(i, false);
if (i%6 == 0) table.row();
table.add(puzzles[i]).pad(5);
}
ScrollPane scroll = new ScrollPane(table, skin);
container.add(scroll).expand().fill().colspan(4);
}
});
Here is puzzle class which simply shows a rectangle with puzzle number and if it is solved its color should be blue and if not color should be white.
private class Puzzle extends Actor {
TextureRegion rect;
BitmapFont font;
float w,h;
boolean solved;
int drawNum;
public Puzzle(int number, boolean solved) {
rect = new TextureRegion(new Texture(Gdx.files.internal("rect.png")));
setSize(rect.getRegionWidth(), rect.getRegionHeight());
this.drawNum = number + 1;
this.solved = solved;
if (solved) font = HelpingMethods.createFont(38, Color.GOLD);
else font = HelpingMethods.createFont(38, Color.DARK_GRAY);
GlyphLayout layout = new GlyphLayout();
layout.setText(font, "" + this.drawNum);
w = layout.width;
h = layout.height;
}
#Override
public void draw(Batch batch, float parentAlpha) {
Color color = getColor();
if (!solved) batch.setColor(1, 1, 1, color.a * parentAlpha);
else batch.setColor(0, 0, 1, color.a * parentAlpha);
font.setColor(color.r, color.g, color.b, color.a * parentAlpha);
batch.draw(rect, getX(), getY());
font.draw(batch, "" + drawNum, getX() + getWidth()/2 - w/2,
getY() + h + getHeight()/2 - h/2);
}
}
Here is createFont() method:
public static BitmapFont createFont(int size, Color color) {
FreeTypeFontGenerator generator = new FreeTypeFontGenerator
(Gdx.files.internal("fonts/font.ttf"));
FreeTypeFontGenerator.FreeTypeFontParameter parameter =
new FreeTypeFontGenerator.FreeTypeFontParameter();
parameter.size = size;
parameter.color = color;
parameter.minFilter = Texture.TextureFilter.Linear;
parameter.magFilter = Texture.TextureFilter.Linear;
BitmapFont font = generator.generateFont(parameter);
return font;
}
Any Solutions ?

The problem is, that whenever the play is clicked, you create new 100 Puzzle objects. In Puzzle constructor you generate BitmapFont with FreeTypeFontGenerator, which is expensive operation. And you do that 100 times. Instead, you should generate your BitmapFont object once (for example, when you initialize your game), and pass a reference to it to every Puzzle object. Also reuse Talbe container and GlyphLayout objects.
In game development in general you should avoid creating new objects, when possible, and reuse them instead. And the reason is not only it can be slow, but also, as in your case, when you create new Puzzle objects instead of old ones, you create a lot of work for a garbage collector, which can cause stutters.
Don't forget to dispose the BitmapFont object, when it's not needed anymore.

LibGDX using Animations with a skin (for drag n' drop)

I have set up a game where Actor fireflies randomly fly across the screen, while glowing on and off — and a user can drag them into a mason jar. Pretty happy I've got this working, but I'd like to add a bit more detail. I'd like to add a two-step animation so that it looks like their wings are flapping.
I know how to do this with the Animation class, making use of TextureAtlas and TextureRegion. But that was prior to me heading in this Drag n Drop direction.
My issue, I think, is that I'm using skins, and they might not play nice with Animations.
///////////////////
Portions of my code.
///////////////////
Some of the items I declare up top:
private TextureAtlas textureAtlas;
private Texture texture;
private TextureRegion[] regions = new TextureRegion[3];
private Animation ffFlapping;
Setting up my TextureAtlas:
textureAtlas = new TextureAtlas(Gdx.files.internal("Player Animation/player_animation.png.atlas"));
texture = new Texture(Gdx.files.internal("Player Animation/player_animation.png.png"));
Setting up the skin:
final Skin skin = new Skin();
skin.addRegions(textureAtlas);
Doing the animation:
TextureRegion[] ffAnimation = new TextureRegion[2];
ffAnimation[0] = (textureAtlas.findRegion("firefly-0"));
ffAnimation[1] = (textureAtlas.findRegion("firefly-1"));
ffFlapping = new Animation(0.01f, ffAnimation);
For loop to create all my fireflies:
// ********************************************
// iterate through the number of fireflies
// we want to draw out using fireflyCount
// ********************************************
for (int fireflyIndex = 0; fireflyIndex < fireflyCount; fireflyIndex++) {
// YELLOW FIREFLY HERE
String fireflyName = "firefly" + fireflyIndex;
// if I replace ffFlapping below with object, I get no errors,
// but also no animation
skin.add(fireflyName, ffFlapping);
final Firefly ff = new Firefly(skin, fireflyName);
System.out.println("Fireflies objects:" + fireflyIndex);
// Not sure this affected the color, but it starts the alpha at 0
ff.setColor(150, 150, 150, 0);
ff.setOrigin(ff.getWidth()/2, ff.getHeight()/2);
stage.addActor(ff);
// This was set up in the attempt to continue movement if user misses target
final MoveToAction actionRight = new MoveToAction();
final MoveToAction actionLeft = new MoveToAction();
// setting up right and left targets, with a random Y position
float toRight = Gdx.graphics.getWidth() + 60;
float toLeft = (Gdx.graphics.getWidth() -Gdx.graphics.getWidth())-60f;
// sets up speed of glow, and the random time firefly is off, and also on
float glow = MathUtils.random(.5f, 1f);
float delayRandomOff = MathUtils.random(2.3f, 4.5f);
float delayRandomOn = MathUtils.random(.5f, .9f);
// sets up first variable to randomly choose between toRight and toLeft
// assigns direction to that value
float randomDirection = MathUtils.random.nextBoolean() ? toRight : toLeft;
float direction = randomDirection;
SequenceAction sequence = new SequenceAction();
AlphaAction aa = new AlphaAction();
Action alphaStartOn = Actions.delay(delayRandomOn, Actions.fadeOut(glow));
Action alphaStartOff = Actions.delay(delayRandomOff, Actions.fadeIn(glow));
// toRight is the x value ... it goes (x, y, duration)
Action startRight = Actions.moveTo(toRight, MathUtils.random(50, Gdx.graphics.getHeight() - 40), MathUtils.random(10f, 45f));
// toLeft is the x value ... it goes (x, y, duration)
// 170 makes sure they don't fly on top of mason jar
Action startLeft = Actions.moveTo(toLeft, MathUtils.random(170, Gdx.graphics.getHeight() - 40), MathUtils.random(10f, 45f));
Action faceOpposite = Actions.rotateBy(180f);
Action faceOpposite2 = Actions.rotateBy(180f);
// THIS ENDLESSLY LOOPS THEM ON THE SCREEN
Action loopRight = Actions.forever(Actions.sequence(faceOpposite, startRight, faceOpposite2, startLeft));
Action loopLeft = Actions.forever(Actions.sequence(startLeft, faceOpposite, startRight, faceOpposite2));
Action loopGlow1 = Actions.forever(Actions.sequence(alphaStartOn, alphaStartOff));
Action loopGlow2 = Actions.forever(Actions.sequence(alphaStartOff, alphaStartOn));
// THIS IS DEFINITELY TRIGGERING THE MOVEMENT
if(direction == toRight) {
ff.addAction(loopRight);
ff.addAction(loopGlow1);
} else {
ff.addAction(loopLeft);
ff.addAction(loopGlow2);
}
// MAKE EACH FIREFLY DRAGGABLE, and SET LARGER SIZE as you drag
dragAndDrop.addSource(new DragAndDrop.Source(ff) {
public DragAndDrop.Payload dragStart (InputEvent event, float x, float y, int pointer) {
DragAndDrop.Payload payload = new DragAndDrop.Payload();
payload.setObject("Firefly captured");
payload.setDragActor(ff);
ff.clearActions();
getActor().setSize(80, 80);
// Firefly freezes on drag, and enlarges ... disappears if dropped in jar
// Does not visually drag with cursor since it was part of animation.
return payload;
}
// IF YOU DON'T DROP FIREFLY ON TARGET, MAKE SURE IT STAYS ON STAGE
// AND GOES BACK TO THE NORMAL SIZE
#Override
public void dragStop(InputEvent event, float x, float y, int pointer, DragAndDrop.Payload payload, DragAndDrop.Target target) {
if(target == null)
stage.addActor(ff);
ff.addAction(actionLeft);
getActor().setSize(50, 50);
}
});
// MAKE EACH FIREFLY DRAGGABLE, and SET LARGER SIZE as you drag
dragAndDrop.addSource(new DragAndDrop.Source(ff) {
public DragAndDrop.Payload dragStart (InputEvent event, float x, float y, int pointer) {
DragAndDrop.Payload payload = new DragAndDrop.Payload();
payload.setObject("Firefly captured");
payload.setDragActor(ff);
ff.clearActions();
getActor().setSize(80, 80);
// Firefly freezes on drag, and enlarges ... disappears if dropped in jar
// Does not visually drag with cursor since it was part of animation.
return payload;
}
// IF YOU DON'T DROP FIREFLY ON TARGET, MAKE SURE IT STAYS ON STAGE
// AND GOES BACK TO THE NORMAL SIZE
#Override
public void dragStop(InputEvent event, float x, float y, int pointer, DragAndDrop.Payload payload, DragAndDrop.Target target) {
if(target == null)
stage.addActor(ff);
ff.addAction(actionLeft);
getActor().setSize(50, 50);
}
});
} // ***** END OF FOR LOOP ***********
And here's my Firefly code:
public class Firefly extends Image {
private float x = MathUtils.random(20, Gdx.graphics.getWidth() -40);
private float y = MathUtils.random(200, Gdx.graphics.getHeight() - 40);
private float width = 70;
private float height = 70;
public Firefly(Skin skin, String drawableName) {
super(skin, drawableName);
this.setBounds(x, y, width, height);
}
} // firefly
The error I'm getting is:
com.badlogic.gdx.utils.GdxRuntimeException: No Drawable, NinePatch, TextureRegion, Texture, or Sprite registered with name: firefly-2
///////////////////////////////
Any tips are very much appreciated.
In the meantime, I'm creating a new feature branch and keeping at it.
My guess is that I need to somehow make my two-step animation into some kind of Drawable.
Thanks!
— Bill

Android - Draw an inverted circle that moves along with the player

I am building an Android game where a ball is controlled and moved using the motion sensor.
There are some posts on how to draw an inverted circle like this one, but it is unusable as Android does not support BufferedImage.
I created the player using the codes below
public class Player extends Task {
private final static float MAX_SPEED = 20;
private final static float SIZE = 16;
private Circle _cir = null;
private Paint _paint = new Paint();
private Vec _vec = new Vec();
private Vec _sensorVec = new Vec();
public Player(){
_cir = new Circle( 15, 15, SIZE ); //15,15 is the initial x,y coordinates
}
public final Circle getPt(){
return _cir;
}
private void setVec(){
float x = -AcSensor.Inst().getX()*2;
float y = AcSensor.Inst().getY()*2;
_sensorVec._x = x < 0 ? -x*x : x*x;
_sensorVec._y = y < 0 ? -y*y : y*y;
_sensorVec.setLengthCap(MAX_SPEED);
_vec.blend( _sensorVec, 0.05f );
}
private void Move(){
_cir._x += _vec._x;
_cir._y += _vec._y;
}
#Override
public boolean onUpdate(){
setVec();
Move();
return true;
}
#Override
public void onDraw( Canvas c ){
c.drawCircle(_cir._x, _cir._y, _cir._r, _paint);
}
}
Question is, how to create an inverted circle around the player so that the player only sees a limited distance while the outer part is filled with black color? For example, something like this:
.

Andengine - Shooting bullets in front of a rotating sprite (Turret / Ship)

I'm making a game with Andengine and i'm stuck for 2 days on shooting from a rotating sprite. I'm not a hero at geometry and already ask a teacher but he could also not provide me the correct answer. So who is a mathematics hero and help me out :).
The problem is that i cannot figure out where the bullet has to spawn in front of the turret. Rotating and finding the destination where the bullet has to go is no problem. It only about the spawn point.
I removed a lot of not-interesting-code for this question.
Okay so here is the rotating code from the turret-rotation:
public class AlienShip extends Ship {
public static final float BASE_ROTATION_SPEED = 0.25f;
public static final int DEFAULT_IMAGE_ROTATION = 90; //90 degrees
protected PlayerShip ship;
public AlienShip(float pX, float pY, TextureRegion pTextureRegion,
VertexBufferObjectManager pVertexBufferObject,FixedStepPhysicsWorld pw, int baseDurability) {
super(pX, pY, pTextureRegion, pVertexBufferObject, pw, baseDurability);
}
public void rotateToPlayer()
{
if (ship != null) {
float dX = this.getX() - ship.getX();
float dY = this.getY() - ship.getY();
float angle = (float) Math.atan2(-dY, dX);
float rotation = MathUtils.radToDeg(angle) + DEFAULT_IMAGE_ROTATION;
RotationModifier rotMod = new RotationModifier(BASE_ROTATION_SPEED, this.getRotation(), rotation);
this.registerEntityModifier(rotMod);
}
}
public void rotateToInitPos() {
RotationModifier rotMod = new RotationModifier(BASE_ROTATION_SPEED, this.getRotation(), 0);
this.registerEntityModifier(rotMod);
}
}
The code above is working fine.
Here is the code from the laser that the ship is shooting.
Read the comments to find out witch part is not working.
public class GameScene extends Scene {
protected PlayerShip playerShip;
private SpawnCallback createShootCallback(boolean player) {
return new SpawnCallback() {
#Override
public void spawn(SpawnTimer spawnTimer) {
PhysicsSprite laser = null;
AlienShip alienShip = (AlienShip) spawnTimer.getPhysicsSprite();
// laser = alienMissilePool.getMissileFromPool(x,y)
//spawn the laser in front of the rotating ship [Not working :( ]
laser = alienMissilePool.getMissileFromPool( ( alienShip.getX() * FloatMath.cos(MathUtils.degToRad(rotation)) - ((1280 - alienShip.getY() - alienShip.getY()/2) * FloatMath.sin(MathUtils.degToRad(rotation)) ) ) ,
( alienShip.getX() * FloatMath.sin(MathUtils.degToRad(rotation)) + ((1280 - alienShip.getY() - alienShip.getY()/2) * FloatMath.cos(MathUtils.degToRad(rotation)) ) ) );
//Set the rotation from the laser same to the ship rotation [Is working perfectly].
float rotation = alienShip.getRotation();
laser.setRotation(rotation);
//Set laser speed and direction [Is working perfectly]
float pX = 0.01f * (playerShip.getX() - laser.getX());
float pY = 0.01f * (playerShip.getY() - laser.getY());
laser.getSpriteBody().setLinearVelocity(pX, pY);
spawnPhysicsSprite(laser);
}
};
}
}
Here is a link to a drawing that shows the x-axis and y-axis values.
http://s24.postimg.org/citz29339/gamescene.png
Thank you!

Instead of getting into maths, why don't you put an object (Entity) positioned on the place of the turret and use it's position as the spawn point for the laser ?
so your turret would have an Entity attached to it on the place of the gun.
tell me if you need an example code

How can I to render a 2D graph/figure using OpenGL on Android?

I'm making a simple fractal viewing app for Android, just for fun. I'm also using it as an oppotunity to learn OpenGL since I've never worked with it before. Using the Android port of the NeHe tutorials as a starting point, my approach is to have one class (FractalModel) which does all the math to create the fractal, and FractalView which does all the rendering.
The difficulty I'm having is in getting the rendering to work. Since I'm essentially plotting a graph of points of different colors where each point should correspond to 1 pixel, I thought I'd handle this by rendering 1x1 rectangles over the entire screen, using the dimensions to calculate the offsets so that there's a 1:1 correspondence between the rectangles and the physical pixels. Since the color of each pixel will be calculated independently, I can re-use the same rendering code to render different parts of the fractal (I want to add panning and zooming later on).
Here is the view class I wrote:
public class FractalView extends GLSurfaceView implements Renderer {
private float[] mVertices;
private FloatBuffer[][] mVBuffer;
private ByteBuffer[][] mBuffer;
private int mScreenWidth;
private int mScreenHeight;
private float mXOffset;
private float mYOffset;
private int mNumPixels;
//references to current vertex coordinates
private float xTL;
private float yTL;
private float xBL;
private float yBL;
private float xBR;
private float yBR;
private float xTR;
private float yTR;
public FractalView(Context context, int w, int h){
super(context);
setEGLContextClientVersion(1);
mScreenWidth = w;
mScreenHeight = h;
mNumPixels = mScreenWidth * mScreenHeight;
mXOffset = (float)1.0/mScreenWidth;
mYOffset = (float)1.0/mScreenHeight;
mVertices = new float[12];
mVBuffer = new FloatBuffer[mScreenHeight][mScreenWidth];
mBuffer = new ByteBuffer[mScreenHeight][mScreenWidth];
}
public void onDrawFrame(GL10 gl){
int i,j;
gl.glClear(GL10.GL_COLOR_BUFFER_BIT | GL10.GL_DEPTH_BUFFER_BIT);
gl.glLoadIdentity();
mapVertices();
gl.glColor4f(0.0f,1.0f, 0.0f,.5f);
for(i = 0; i < mScreenHeight; i++){
for(j = 0; j < mScreenWidth; j++){
gl.glFrontFace(GL10.GL_CW);
gl.glVertexPointer(3, GL10.GL_FLOAT, 0, mVBuffer[i][j]);
gl.glEnableClientState(GL10.GL_VERTEX_ARRAY);
gl.glDrawArrays(GL10.GL_TRIANGLE_STRIP, 0, mVertices.length / 3);
gl.glDisableClientState(GL10.GL_VERTEX_ARRAY);
}
}
}
public void onSurfaceChanged(GL10 gl, int w, int h){
if(h == 0) { //Prevent A Divide By Zero By
h = 1; //Making Height Equal One
}
gl.glViewport(0, 0, w, h); //Reset The Current Viewport
gl.glMatrixMode(GL10.GL_PROJECTION); //Select The Projection Matrix
gl.glLoadIdentity(); //Reset The Projection Matrix
//Calculate The Aspect Ratio Of The Window
GLU.gluPerspective(gl, 45.0f, (float)w / (float)h, 0.1f, 100.0f);
gl.glMatrixMode(GL10.GL_MODELVIEW); //Select The Modelview Matrix
gl.glLoadIdentity();
}
public void onSurfaceCreated(GL10 gl, EGLConfig config){
gl.glShadeModel(GL10.GL_SMOOTH); //Enable Smooth Shading
gl.glClearColor(0.0f, 0.0f, 0.0f, 0.5f); //Black Background
gl.glClearDepthf(1.0f); //Depth Buffer Setup
gl.glEnable(GL10.GL_DEPTH_TEST); //Enables Depth Testing
gl.glDepthFunc(GL10.GL_LEQUAL); //The Type Of Depth Testing To Do
//Really Nice Perspective Calculations
gl.glHint(GL10.GL_PERSPECTIVE_CORRECTION_HINT, GL10.GL_NICEST);
}
private void mapVertices(){
int i,j;
xTL = -1;
yTL = 1;
xTR = -1 + mXOffset;
yTR = 1;
xBL = -1;
yBL = 1 - mYOffset;
xBR = -1 + mXOffset;
yBR = 1 - mYOffset;
for(i = 0; i < mScreenHeight; i++){
for (j = 0; j < mScreenWidth; j++){
//assign coords to vertex array
mVertices[0] = xBL;
mVertices[1] = yBL;
mVertices[2] = 0f;
mVertices[3] = xBR;
mVertices[4] = xBR;
mVertices[5] = 0f;
mVertices[6] = xTL;
mVertices[7] = yTL;
mVertices[8] = 0f;
mVertices[9] = xTR;
mVertices[10] = yTR;
mVertices[11] = 0f;
//add doubleBuffer
mBuffer[i][j] = ByteBuffer.allocateDirect(mVertices.length * 4);
mBuffer[i][j].order(ByteOrder.nativeOrder());
mVBuffer[i][j] = mBuffer[i][j].asFloatBuffer();
mVBuffer[i][j].put(mVertices);
mVBuffer[i][j].position(0);
//transform right
transformRight();
}
//transform down
transformDown();
//reset x
xTL = -1;
xTR = -1 + mXOffset;
xBL = -1;
xBR = -1 + mXOffset;
}
}
//transform all the coordinates 1 "pixel" to the right
private void transformRight(){
xTL = xTL + mXOffset; //TL
xBL = xBL + mXOffset; //BL
xBR = xBR + mXOffset; //BR
xTR = xTR + mXOffset; //TR;
}
//transform all of the coordinates 1 pixel down;
private void transformDown(){
yTL = yTL - mYOffset;
yBL = yBL - mYOffset;
yBR = yBR - mYOffset;
yTR = yTR - mYOffset;
}
}
Basically I'm trying to do it the same way as this (the square in lesson 2) but with far more objects. I'm assuming 1 and -1 roughly correspond to screen edges, (I know this isn't totally true, but I don't really understand how to use projection matrices and want to keep this as simple as possible unless there's a good resource out there I can learn from) but I understand that OpenGL's coordinates are separate from real screen coordinates. When I run my code I just get a black screen (it should be green) but LogCat shows the garbage collector working away so I know something is happening. I'm not sure if it's just a bug caused by my just not doing something right, or if it's just REALLY slow. In either case, what should I do differently? I feel like I may be going about this all wrong. I've looked around and most of the tutorials and examples are based on the link above.
Edit: I know I could go about this by generating a texture that fills up the entire screen and just drawing that, though the link I read which mentioned it said it would be slower since you're not supposed to redraw a texture every frame. That said, I only really need to redraw the texture when the perspective changes, so I could write my code to take this into account. The main difficulty I'm having currently is drawing the bitmap, and getting it to display correctly.

I would imagine that the blank screen is due to the fact that you are swapping buffers so many times, and also the fact that you are generating all your vertex buffers every frame. Thousands of buffer swaps AND thousands of buffer creations in a single frame would be INCREDIBLY slow.
One thing to mention is that Android devices have limited memory, so the garbage collector working away is probably an indication that your buffer creation code is eating up a lot of the available memory and the device is trying to free up some for the creation of new buffers.
I would suggest creating a texture that you fill with your pixel data each frame and then render to a single square that fills the screen. This will increase your speed by a huge amount, and also make your program more flexible.
Edit:
Look at the tutorial here : http://www.nullterminator.net/gltexture.html to get an idea on how to create textures and load them. You will basically need to fill BYTE* data with your own data.
If you are changing the data dynamically, you will need to update the texture data. Use the information here : http://www.opengl.org/wiki/Texture : in the section about Texture image modification.