porter-duff

I am doing a small project for college and wondering if someone can tell me how I would go about doing a scratch card app. This app should have one image overlaying another. The one on top should allow the user to remove the image depending on where they rub on the image and thus part of the image that was removed revealing the image underneath. Pretty much like a scratch card. Any help would be great! This is the code im using at the moment . public class workinggraphics extends Activity { /** Called when the activity is first created. */ @Override public void onCreate(Bundle

I'm trying to mask a FrameLayout with a mask defined as a nine patch. However, although it works fine on 5.0+ on older versions (such as 4.4.4), the patch leaves an opaque black background. Is there anything that can be done to avoid this other than drawing to an off screen bitmap before rendering to the screen or reverting to software layers? public class MaskedLayout extends FrameLayout { private final static PorterDuffXfermode DST_IN = new PorterDuffXfermode(PorterDuff.Mode.DST_IN); private final Paint mPaint = new Paint(Paint.ANTI_ALIAS_FLAG); private NinePatchDrawable mMask; private

I am working on a picture editing tool in which I need to merge two images. Most of the image editing tools like gimp use PorterDuff modes for merging or blending images. I am also using the same approach in android. As android provides limited number of PorterDuff modes, I am not able to achieve the desired result. So, I am thinking of implementing PorterDuff modes(Overlapping, Hard-Light, Soft-Light, Color-burn, Color-dodge) which are not included in android. The problem is I don't know where to start. So, any reference or guidance in this regard will be highly appreciated. This is how you

I am trying to do something very simple (see above). I want all of the pixels of a canvas to be a solid color, except for the the pixels that fill a centered circle. I have read hundreds stack overflow post on this subject and have tried hundreds of things including setting the PorterDuff.Mode. Here is my current onDraw() of MyView extends View: protected void onDraw(Canvas canvas) { int w = canvas.getWidth(); int h = canvas.getHeight(); Paint framePaint = new Paint(); framePaint.setStyle(Paint.Style.FILL); framePaint.setColor(Color.BLUE); canvas.drawRect(0, 0, w, h, framePaint); Paint

I have a view which does some basic drawing. After this I want to draw a rectangle with a hole punched in so that only a region of the previous drawing is visible. And I'd like to do this with hardware acceleration enabled for my view for best performance. Currently I have two methods that work, but only works when disabled hardware acceleration and the other is too slow. Method 1: SW Acceleration (Slow) final int saveCount = canvas.save(); // Clip out a circle. circle.reset(); circle.addCircle(cx, cy, radius, Path.Direction.CW); circle.close(); canvas.clipPath(circle, Region.Op.DIFFERENCE); /

Okay so i've been trying to do this for a couple of days and i am getting no where. So i have the following two images: The First is a RPM Gauge The Second image is a full white graphic representing rpm gauge being full: I want to do the following: ask the user for an RPM input, if for example they enter 1.2 the gauge will fill up as follows: I have the user input working i need help with the animation. Here is what i have tried: I have tried using PorterDuff but it also clips the gauge in the background not just the white bar I've tried splitting the image into little bitmaps and store them

I'm trying to create the following design in my app. Design Mockup Its an overlay on top of the main UI. Trying to create this using a layout on top of the main UI with its background as a translucent shape created in XML. However, even after reading multiple posts, I'm not able to figure it out. I tried the following approach, but it didn't work. Created a ring shape with 200dp stroke and set it as source for a imageview and then set the scaletype to centerCrop but the shape does not scale as a bitmap does. Shape XML : <?xml version="1.0" encoding="utf-8"?> <shape xmlns:android="http:/