Great news! I really want to give the user the option to see the circles, and it sounds like upgrading to 4.0 will allow this. I'll wait for said upgrade before implementing it rather than use a software layer, as the speed loss when rendering in software is just too great.
To answer the other question as to how many times I could get it to redraw before it ran out of memory, on the Galaxy Tab 10.1 it worked three times, then failed on the fourth and subsequent times. Anyway, good to hear that this is fixed in 4.0. Thanks again. On Dec 15, 8:52 pm, Romain Guy <[email protected]> wrote: > Circles are currently drawn as texture, so every time you create > acircle with a different radius, the OpenGL pipeline generates a > newtexture. It should however not run out of memory since the > circlestextures are kept in a fixed size cache. You should > callsetLayerType(View.LAYER_TYPE_SOFTWARE, null) on your View to > workaround this problem. > > Update: I checked and this out of memory error is a bug in 3.2 that we > fixed in 4.0. > On Thu, Dec 15, 2011 at 4:31 PM, Christopher Van Kirk > > > > > > > > > > <[email protected]> wrote: > > How many times is 'a few'? > > > On 12/15/2011 12:45 AM, Christopher Golden wrote: > > >> In the course of developing an Android application, I'm finding a need > >> to draw several unfilled concentric circles centered on an arbitrary > >> point, enough that some of them are only partly visible on the > >> display. However, this does not appear to work with hardware > >> acceleration. My test rig is a stock Samsung Galaxy Tab 10.1 running > >> Android 3.2. > > >> The following code comes from a test subclass of View I wrote to > >> isolate the issue: > > >> private Paint paint = new Paint(); > > >> private int count = 0; > > >> private static final int[] COLORS = { 0xffff0000, 0xff00ff00, > >> 0xff0000ff, 0xffff00ff }; > > >> public TestCircles(Context context) { > >> super(context); > >> paint.setStrokeWidth(1.0f); > >> paint.setStyle(Paint.Style.STROKE); > >> } > > >> public TestCircles(Context context, AttributeSet attributes) { > >> super(context, attributes); > >> paint.setStrokeWidth(1.0f); > >> paint.setStyle(Paint.Style.STROKE); > >> } > > >> public boolean onTouchEvent(MotionEvent e) { > >> if (e.getAction() == MotionEvent.ACTION_DOWN) > >> invalidate(); > >> return true; > >> } > > >> protected void onDraw(Canvas canvas) { > > >> // Pick the color to use, cycling through the colors list > >> repeatedly, so that we can > >> // see the different redraws. > >> paint.setColor(COLORS[count++]); > >> count %= COLORS.length; > > >> // Set up the parameters for the circles; they will be centered at > >> the center of the > >> // canvas and have a maximum radius equal to the distance between > >> a canvas corner > >> // point and its center. > >> final float x = canvas.getWidth() / 2f; > >> final float y = canvas.getHeight() / 2f; > >> final float maxRadius = (float) Math.sqrt((x * x) + (y * y)); > > >> // Paint the rings until the rings are too large to see. > >> for (float radius = 20; radius< maxRadius; > >> radius += 20) > >> canvas.drawCircle(x, y, radius, paint); > >> } > > >> I am running TestCircles as the only View in an Activity, laying it > >> out to fill the available width and height (i.e. it is nearly full- > >> screen). I can tap on the display (triggering redraws) only a few > >> times before the redraws no longer occur (i.e. the circles' color > >> doesn't change). Actually, the onDraw() code is still running in > >> response to each tap -- as proven with diagnostic messages -- but > >> nothing changes onscreen. > > >> When onDraw() first starts to fail to redraw, the debug log includes > >> the following entry, once for every call to onDraw(): > > >> E/OpenGLRenderer(21867): OpenGLRenderer is out of memory! > > >> If I turn off hardware acceleration in the manifest, these problems go > >> away -- not surprising since clearly OpenGL is having problems -- and > >> actually it is a good deal faster than the few times it actually works > >> under hardware acceleration. > > >> My questions are: > > >> First, am I misusing Canvas, or is this a bug, or both? Is Android > >> allocating large bitmaps under the hood to draw these circles? It > >> doesn't seem like this should be this challenging to OpenGL, but I'm > >> new to hardware accelerated app development. > > >> Second, what's a good alternative way to draw large unfilled circles > >> that have portions extending out of the clipping region of the Canvas? > >> Losing hardware acceleration is not an option. > > >> Thanks in advance... > > > -- > > You received this message because you are subscribed to the Google > > Groups "Android Developers" group. > > To post to this group, send email to [email protected] > > To unsubscribe from this group, send email to > > [email protected] > > For more options, visit this group at > >http://groups.google.com/group/android-developers?hl=en > > -- > Romain Guy > Android framework engineer > [email protected] -- You received this message because you are subscribed to the Google Groups "Android Developers" group. 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