Android Live Wallpaper - why so slow - how to improve speed?
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06-07-2021 - |
Question
I'm attempting to create my first Live Wallpaper. It works and everything would be just fine except of the speed problem. It slows down desktop - widgets and icons are scrolling noticeably slower than when using pro live wallpapers (I'm testing it on Samsung note so there shouldn't be a speed problem). I start thinking that I do it all wrong way- so take a look at my code please:
public class DemoWallpaperService extends WallpaperService {
@Override
public Engine onCreateEngine() {
return new DemoWallpaperEngine();
}
private class DemoWallpaperEngine extends Engine {
private boolean mVisible = false;
private final Handler mHandler = new Handler();
int x=0,y=0,a=255,i=-1, a1=255, i1=-1;
float r=0,rs=1;
float rx1=10, rxs=-1;
private Matrix mMatrix = new Matrix();
private Matrix mMatrix1 = new Matrix();
private Matrix mMatrixRotate1 = new Matrix();
private Matrix mMatrixRotate2 = new Matrix();
public Bitmap spaceShip = BitmapFactory.decodeResource(getResources(), R.drawable.spaceship);
public Bitmap background= BitmapFactory.decodeResource(getResources(), R.drawable.back2short2j);
public Bitmap wyspa= BitmapFactory.decodeResource(getResources(), R.drawable.wyspa22g);
public Bitmap ksiezyc = BitmapFactory.decodeResource(getResources(), R.drawable.ksiezyc);
public Bitmap reflektorfront= BitmapFactory.decodeResource(getResources(), R.drawable.reflektorwyspa);
private float mPixels;
private float mPixels1;
private final Runnable mUpdateDisplay = new Runnable() {
@Override
public void run() {
draw();
}};
private void draw() {
SurfaceHolder holder = getSurfaceHolder();
Canvas c = null;
Display d = ((WindowManager)getSystemService(Context.WINDOW_SERVICE)).getDefaultDisplay();
int wx= d.getWidth();
int wy= d.getHeight();
try {
Runtime.getRuntime().gc();
c = holder.lockCanvas();
c.save();
if (c != null) {
Paint paintMoon = new Paint();
if(a1<=15){
i1=1;
}
else if(a1>=255){
i1=-1;
}
a1+=5*i1;
paintMoon.setAlpha(a1);
c.translate((float)mPixels, 0f);
c.drawBitmap(background, mMatrix, null);
c.drawBitmap(ksiezyc, 1027*wx/480,15*wy/800, paintMoon);
if(rx1<=-15){
rxs=1;
}
else if(rx1>=15){
rxs=-1;
}
rx1+=rxs*0.7;
c.translate((float)mPixels1, 0f);
//reflektor wyspa back
mMatrixRotate2.setTranslate(340*wx/480,300*wy/800);
mMatrixRotate2.preRotate(rx1,reflektorfront.getWidth()/2,20);
c.drawBitmap(reflektorfront, mMatrixRotate2, null);
c.drawBitmap(wyspa, mMatrix1, null);
if(r<=-15){
rs=1;
}
else if(r>=15){
rs=-1;
}
r+=rs*0.5;
mMatrixRotate1.setTranslate(160*wx/480,380*wy/800);
mMatrixRotate1.preRotate(r,reflektorfront.getWidth()/2,20);
c.drawBitmap(reflektorfront, mMatrixRotate1, null);
if(x<c.getWidth()){
x+=3;}
else{x=0;}
if(y<c.getHeight()){
y+=3;}
else{y=0;}
Paint paint = new Paint();
if(a<=5){
i=1;
}
else if(a>=255){
i=-1;
}
a+=10*i;
paint.setAlpha(a);
c.drawBitmap(spaceShip,x,y,paint);
c.restore();
}
} finally {
if (c != null)
holder.unlockCanvasAndPost(c);
}
mHandler.removeCallbacks(mUpdateDisplay);
if (mVisible) {
mHandler.postDelayed(mUpdateDisplay, 10);
}
}
@Override
public void onOffsetsChanged(float xOffset, float yOffset,
float xStep, float yStep, int xPixels, int yPixels){
super.onOffsetsChanged(xOffset, yOffset, xStep, yStep, xPixels, yPixels);
mPixels = xPixels*7/4;
mPixels1 = 500+xPixels;
draw();
}
@Override
public void onVisibilityChanged(boolean visible) {
mVisible = visible;
if (visible) {
draw();
} else {
mHandler.removeCallbacks(mUpdateDisplay);
}
}
@Override
public void onSurfaceChanged(SurfaceHolder holder, int format, int width, int height) {
super.onSurfaceChanged(holder, format, width, height);
float w = background.getWidth();
float h = background.getHeight();
float s = height / (float)h;
float z = height / (float)h;
mMatrix.reset();
mMatrix1.reset();
mMatrixRotate1.reset();
mMatrixRotate2.reset();
mMatrix.setScale(s, s);
mMatrix1.setScale(z, z);
mMatrixRotate1.setScale(s, s);
draw();
}
@Override
public void onSurfaceDestroyed(SurfaceHolder holder) {
super.onSurfaceDestroyed(holder);
mVisible = false;
mHandler.removeCallbacks(mUpdateDisplay);
}
@Override
public void onCreate(SurfaceHolder surfaceHolder) {
super.onCreate(surfaceHolder);
setTouchEventsEnabled(false);
}
@Override
public void onDestroy() {
super.onDestroy();
mVisible = false;
mHandler.removeCallbacks(mUpdateDisplay);
}
}
Basically its a bitmap at background (850x480jpg 70kb), that scrolls slower, bitmap at front (350x400 transparent gif 100 kb) that scrolls faster (to achieve parallax effect) and some smaller png bitmaps (3x 10-20 kb 50x50) that are rotating and moving at the foreground (lights and space ships).
My question is - am I missing the point - I'm animating it by refreshing draw() function with a delay set to 10. (that's the only way I know - should I animate it some other way? Are the bitmaps too big? Or why is it so slow? Should I use sprites to animate front small effects to make it faster? Are there other ways of animating life wallpaper? I went through many tutorials and I've come so far but now I have to ask for help.
Solution
I'm not sure it is the complete answer... But it is worth attempting this. Rather than referencing the bitmap using Bitmap.decodeResources() method, try this:
pic1 = Bitmap.createScaledBitmap(background, (int)background.getWidth(), (int)background.getHeight(), true);
I've been building parallax wallpapers for a while and have found that the slowness normally is due to how many bitmaps are drawn on the screen.