Develop Reference

SurfaceView Vertical Line Drawing too Slowly across Screen

I have been experimenting with squeezing as much performance out of SurfaceView as possible. Currently, I'm subclassing it and implementing a runnable interface on it instead of a callback. I understand there is no hardware acceleration on it.
Still, if I either draw a canvas primitive vertical line scrolling across the screen or a bitmap vertical line, both run slower and slower after each pass. This felt to me like a memory leak, or is it just Android itself? Is OpenGL or another library really my last resort?
I've drawn plenty of scrolling backgrounds before at decent speeds (I think around 5 pixels per tick, this I'm aiming around 20-50 pixels a tick which if anything would be less stops along the way to render).
EDIT: Here is the SurfaceView extended, the thread it makes, the drawing method, and the initialization of it. Basically, this is in a slightly bigger class that just holds this screen's data. The drawXYZ() methods simply use the canvas primitives or a bitmap to paint mainly as the background, which is a solid background color with some vertical and horizontal lines on it like a music staff, little calculating is involved.
The drawCursor is what makes the scrolling vertical line and when I just let it loop the scrolling from left to right, it eventually lags much slower than the first scroll.
public class MySurfaceView extends SurfaceView implements Runnable
{
Thread renderThread = null;
SurfaceHolder holder;
volatile boolean running = false;
public MySurfaceView() {
super(mainActivity);
this.holder = getHolder();
holder.setFixedSize(screenW, screenH);
}
public void resume() {
running = true;
renderThread = new Thread(this);
renderThread.start();
}
#Override
public void run() {
while (running) {
if (!holder.getSurface().isValid()) {
continue;
}
Canvas canvas = holder.lockCanvas();
if(canvas != null) {
doDraw(canvas);
holder.unlockCanvasAndPost(canvas);
}
}
}
public void pause() {
running = false;
while (true) {
try {
renderThread.join();
break;
} catch (InterruptedException e) {
// retry
}
}
}
protected void doDraw(Canvas canvas)
{
canvas.drawColor(Color.rgb(56, 56, 62));
lastNotePlayed = OptionsContainer.getNotePlaying();
//Draw contours (rows).
paint.setColor(Color.rgb(0, 255, 255));
paint.setStrokeWidth(3);
paint.setTextSize(35);
drawContours(canvas, paint);
//Beats per measure (BPM).
paint.setColor(Color.rgb(233, 232, 232));
paint.setStrokeWidth(1);
paint.setStyle(Paint.Style.STROKE);
paint.setPathEffect(bpmLines);
drawBPM(canvas, paint);
paint.setPathEffect(null);
//Draw measures.
paint.setStrokeWidth(5);
drawMeasures(canvas, paint);
//Draw note node inputs.
paint.setColor(Color.rgb(76, 255, 0));
for (int i = 0; i < OptionsContainer.noteList.length; i++) {
if (OptionsContainer.noteList[i].getContour() != 0) {
if (OptionsContainer.noteList[i].getContour() > (OptionsContainer.contour / 2)) {
//Staff on left side, below note.
canvas.drawBitmap(lowerStaffBmp, OptionsContainer.noteList[i].getX(), OptionsContainer.noteList[i].getY(), null);
} else {
canvas.drawBitmap(higherStaffBmp, OptionsContainer.noteList[i].getX(), OptionsContainer.noteList[i].getY() - 40, null);
}
}
}
//Draw cursor.
paint.setStrokeWidth(2);
paint.setColor(Color.WHITE);
drawCursor(canvas, paint);
if (OptionsContainer.isRest)
canvas.drawBitmap(restBmp, (OptionsContainer.screenWidth / 2), (screenHeight - 100) / 2, null);
}
}
#Override
public void init() {
surfaceView = new MySurfaceView();
surfaceView.setLayoutParams(layoutParams);
surfaceView.setOnTouchListener(new View.OnTouchListener() {
#Override
public boolean onTouch(View v, MotionEvent event) {
if (event.getAction() == MotionEvent.ACTION_UP) {
// Normalize x,y between 0 and 1
float x = event.getX();
float y = event.getY();
if (x < (OptionsContainer.screenWidth) && y < screenH) {
NoteNode note = new NoteNode(x, y, MainActivity.options);
if (note.getContour() == OptionsContainer.noteList[note.getBeat() - 1].getContour()) {
OptionsContainer.noteList[note.getBeat() - 1] = new NoteNode(x, screenHeight + 200, MainActivity.options);
} else {
OptionsContainer.noteList[note.getBeat() - 1] = note;
}
}
}
return true;
}
});
mainActivity.addContentView(surfaceView, layoutParams);
surfaceView.resume();
}
EDIT #2: Final Answer
Add Path.reset() after the path is drawn in drawBPM(). I'd imagine that stops a memory leak of that path which is trying to keep track of ALL the paths it has been writing and overwriting, little to our knowledge just looking at the lines on the screen. There was a similar Stack Overflow question but fadden's debugging tips below were very helpful for initially trying to figure out what and where it was going wrong.

"Squeezing performance" and Canvas-rendering don't really go together on a SurfaceView, but you can do okay on many devices.
Grafika's "multi-surface test" Activity features a bouncing circle, rendered in software. I haven't noticed it get slower over time, so I suspect something is wrong in your code. Note Grafika does not subclass SurfaceView, and I generally recommend against doing so -- it's too easy to do the wrong thing. The only valid reason to subclass SurfaceView is if you want to draw on both the Surface and the View, e.g. for some sort of mask effect.
You didn't show any code, so there's not much more we can tell you.
I don't see anything blatantly wrong in the code; seems pretty straightforward. I'd check to make sure OptionsContainer.noteList.length isn't growing without bound. Next step would be to use traceview to figure out which part of the rendering is slow, or just spread System.nanoTime() calls around to identify which part is getting progressively slower. If everything in the method shown is executing at a consistent speed except drawCursor(), move the time-check calls into there, narrowing it down until you find what's draining your performance.
If something is consuming memory quickly enough to cause heap issues, you should see a great deal of GC activity in the logcat output. The DDMS allocation tracker tool can help with that.

Drawing 200 textures in LibGdx based Android game

When I draw more around 100-200 textures all in the same screen, the device becomes very slow and the app crashes without any exceptions. Could you please let me know any best way to have 100 textures without compromising the performance.
I am using the TextureRegion from TextureAtlas.
MainGame
public void render(SpriteBatch sb) {
// TODO Auto-generated method stub
// System.out.println("BallPoolGame Screen - render");
batch = sb;
sb.setProjectionMatrix(camera.combined);
sb.begin();
sb.draw(BACKGROUND_BALL_POOL, 0, 0, SCREEN_WIDTH, SCREEN_HEIGHT);
cellManager.draw(sb);
ballManager.draw(sb);
sb.end();
}
private void setGameTextures() {
gameScreenAtlas = new TextureAtlas("data/texturetutorialpack.pack");
RED_BALL = gameScreenAtlas.findRegion("redball");
// RED_BALL.getTexture().setFilter(TextureFilter.Linear, TextureFilter.Linear);
BLUE_BALL = gameScreenAtlas.findRegion("blueball");
// BLUE_BALL.getTexture().setFilter(TextureFilter.Linear, TextureFilter.Linear);
GREEN_BALL = gameScreenAtlas.findRegion("greenball");
// GREEN_BALL.getTexture().setFilter(TextureFilter.Linear, TextureFilter.Linear);
}
CellManager
public void draw(SpriteBatch sb){
batch=sb;
showImageTexture(MODEL1,207,1);
if(showSelectedCell){
if(allPossiblePathSize>0)
setupBoardCellTexture();
showImage(CELL_SELECTED, rowCoordinate[cellRow], colCoordinate[cellCol]);
}
}
private void setupBoardCellTexture(){
for(CellGrid c : masterGrid){
if(cellTextureIndicator[c.getRow()][c.getCol()]==1){
showImage(CELL_ALL_PATH_TEXTURE,c.getRowCoordinate() ,c.getColCoordinate() );
}
}
}
private void showImage(TextureRegion tr, float rowCoordinate, float colCoordinate) {
batch.draw(tr, colCoordinate,rowCoordinate);
}
BallManager
public void draw(SpriteBatch sb) {
batch = sb;
setupBoardBallTexture();
if (moveTheBall) {
updateBallPosition();
showImage(ball.getTextureRegion(), moveRow + 6, moveCol + 6);
}
squeezeBalls.draw(sb);
}

You are missing some essential data about your app to answer than question:
How big is one texture on average (Size: widthxheight)
On which device is this error occuring (some devices might have less fillrate than others)
What texture filter does the TextureAtlas use (LINEAR, NEAREST, ...)
I guess that you are trying to draw many textures event if they are out of sight. If that is the case you have to implement a check if the cell is visible to the camera.
Another guess would be that you are trying to draw too many elements with the LINEAR TextureFilter. When using linear as a texture filter the gpu needs to sample way more points then with nearest (i think it was 4 times the samples; so in theory your gpu draws 400-800 textures; depending on images size that are too much for mobile gpu fillrates)
Try to describe more circumstances then i can give probably more insight in your problem.

How to find out if game sprite is moving smoothly?

I'm making a simple jumping game for android using libgdx and box2d and I cannot figure out how to make sprites move really smooth. I have checked several articles regarding timestep fixing and synchronizing renderer and physics emulation, but none of the suggested ways really helped (http://gafferongames.com/game-physics/fix-your-timestep/).
Finally I decided to run the most simple test setting box2d world step equal to the framerate (which in case of stable fps should provide the best performance), but still movement is not totally smooth. I have tested on PC and on Android device, with stable 60-61 FPS. Here is pseudocode:
In render:
world.step(Gdx.graphics.getDeltaTime(), 6, 2);
stage.act();
stage.draw();
Stage basically has just one actor with act and draw overriden:
#Override
public void draw(Batch batch, float arg1) {
float x = this.getX() - width/2;
float y = this.getY() - height/2;
batch.draw(sprite, x, y, width, height);
}
#Override
public void act (float delta) {
...
//get body position
position = body.getPosition();
this.setPosition(position.x, position.y);
}
Actor has box2d body attached to it, there is no gravity and body's velocity is set constant:
BodyDef bodyDef = new BodyDef();
bodyDef.type = BodyType.DynamicBody;
bodyDef.position.set(world_position);
bodyDef.linearDamping = 0f;
bodyDef.angularDamping = 0f;
bodyDef.fixedRotation = true;
bodyDef.gravityScale = 0f;
...fixure added to the body
body.setLinearVelocity(0, -2f);
Camera is not moving, the case seems to be dead simple and yet sprite does not move exactly perfect. (Though it still looks smoother then when using time accumulator and interpolation)
Is it possible to achive absolutely smooth movement at all? Is there some mistake in my approach?
I have checked some similar games on the same android device - it seems that objects are moving absolutely smooth, but maybe it just seems so, because too many things happen on the screen and I don't have time to notice.
Any advice would be appreciated.

After further testing and researched I have figured out the problem - it was related not to FPS, but to pixel rounding. Box2d bodies have float coordinates - after converting them to round pixel values animation bemace much smoother.

How about to use CCPhysicsSprite instead of change position of sprite by time? You can use a batch, too. Just
sprite = [CCPhysicsSprite spriteWithTexture:batch.texture];
[batch addChild:sprite];
CCPhysicsSprite class
Example:
#import "CCPhysicsSprite.h"
CCPhysicsSprite *sprite = [CCPhysicsSprite spriteWithFile:#"sprite.png"];
[self addChild:sprite];
b2BodyDef bodyDef;
bodyDef.type = b2_dynamicBody;
bodyDef.position.Set(300/PTM_RATIO, 200/PTM_RATIO);
body = world->CreateBody(&bodyDef);
b2CircleShape circleShape;
circleShape.m_radius = 0.3;
b2FixtureDef fixtureDef;
fixtureDef.shape = &circleShape;
fixtureDef.density = 1;
fixtureDef.friction = 0.3f;
body->CreateFixture(&fixtureDef);
[sprite setPTMRatio:PTM_RATIO];
[sprite setB2Body:body];
[sprite setPosition: ccp(300, 200)];

9patch looks pixeled when setSize is called too many times

I have a sprite that is supposed to act like a loadbar. I have tried this by using an example image that has been created like a 9patch-type (http://cdn.dibbus.com/wp-content/uploads/2011/03/btn_black.9.png). It seems okay in the start, but as the width of the sprite increases the sprite starts to look pixeled. Anyone know what the problem could be, or have any solution? The code is shown below.
public Sprite loaded;
public void init()
{
atlas = new TextureAtlas(Gdx.files.
internal("data/misc/menu_button.pack"));
loaded = atlas.createSprite("loadbar");
loaded.setPosition((Misc.WIDTH/2) - unloaded.getWidth()/2,
Misc.HEIGTH - unloaded.getHeight());
}
public void draw_load_bar() //render function
{
if(loaded.getWidth() < 600)
{
loaded.setSize(loaded.getWidth()+ 0.5f, loaded.getHeight());
}
loaded.draw(batch);
}

Dont use a Sprite to stretch it. I'd recommend a real Ninepatch from libgdx for it.
public NinePatch loaded;
private float posX, posY, width, height;
public void init()
{
loaded = new NinePatch(the Texture here,10, 10, 10, 10); //bounds outside
//set right pos here...
}
public void draw_load_bar(SpriteBatch batch) //render function
{
if(loaded.getWidth() < 600)
{
//update the size of it here (guess pos is static)
width++;
}
//need to parse the batch and the right sizes.
loaded.draw(batch, posx, posy, width, height);
}
after that you can handle it like a Sprite or Texture but it does stratch right without issues. If you want to the full Picture to be Stretched simply do net set any bounds at the creation new NinePatch(texture, 0,0,0,0)

Drawing a transparent shape in libGDX as an Actor?

I'm trying to draw a simple rect on the screen in a class and using it as an actor.
But whatever I do, it seems that there is no option to draw it transparent. Does anyone know how to do this?
Thanks in advance!
public class AreaColorRect extends Actor {
public float opacity = 0.0f;
private Color shapeFillColor = new Color();
public Rectangle area;
public ShapeRenderer shapeRen;
public AreaColorRect(float x, float y, float w, float h) {
shapeRen = new ShapeRenderer();
this.area = new Rectangle(x, y, w, h);
}
#Override
public void draw(SpriteBatch batch, float parentAlpha) {
shapeRen.begin(ShapeType.Filled);
shapeRen.setColor(new Color(shapeFillColor.r, shapeFillColor.g, shapeFillColor.b,
0.0f));
shapeRen.rect(area.x, area.y, area.width, area.height);
shapeRen.end();
}
public void setShapeFillColor(float r, float g, float b) {
this.shapeFillColor = new Color(r, g, b, 1);
}
}

You're mixing contexts. End your SpriteBatch before starting the ShapeRenderer. See libgdx - ShapeRenderer in Group.draw renders in wrong colour. This might not be the problem, though.
You also need to turn on blending. You can just do this once globally, or enable it as necessary (and disable it). It should be enabled by the SpriteBatch context, but I don't think its enabled for the ShapeRenderer.
Gdx.graphics.getGL10().glEnable(GL10.GL_BLEND); // Or GL20
The order you render your background and Actors also makes a difference for transparency.
Finally, you've set the opacity to 0, so the object will be completely invisible. That generally doesn't do anything at all. (I assume you're just trying to get a change from the current 100% visible?)

Sorry for digging this up. Since you are tagging Android, though, I thought I would just chip in my experiences.
I recently spent almost 4 hours on a problem, where alpha blending just wasn't working, as it isn't for you.
Turned out that libgdx' AndroidApplicationConfiguration uses 0 bit for alpha channel as default.
If this is the case for you, too, it might be worth changing that to something more sensible before you initialize() your app.

I just decided to use Scene2d for my game and reached the same question: how to use a rectangle as an actor and draw it on the screen?
Then i found this piece of documentation on the libgdx wiki
(By default the Scene2d has a SpriteBatch that handles drawing of the actors)
If an actor needs to perform drawing differently, such as with a
ShapeRenderer, the Batch should be ended and then begun again at the
end of the method. Of course, this causes the batch to be flushed, so
should be used judiciously. The transformation and projection matrices
from the Batch can be used:
private ShapeRenderer renderer = new ShapeRenderer();
public void draw (Batch batch, float parentAlpha) {
batch.end();
renderer.setProjectionMatrix(batch.getProjectionMatrix());
renderer.setTransformMatrix(batch.getTransformMatrix());
renderer.translate(getX(), getY(), 0);
renderer.begin(ShapeType.Filled);
renderer.setColor(Color.BLUE);
renderer.rect(0, 0, getWidth(), getHeight());
renderer.end();
batch.begin();
}