Using Bitmap as Canvas material for Android Images

Using Bitmap as Canvas material for Android Images
Overview

When Bitmap is used as the canvas material, the following pattern can be drawn:

Demo

/*** Image Processing: Painting on Bitmap */public class MyBitMapViewSec extends View {private int width; private int height; private Paint mPaintCircle; private Paint mPaintRect; private Bitmap mBitmap; private Canvas mCanvasBm; public MyBitMapViewSec (Context context) {super (context);} public MyBitMapViewSec (Context context, AttributeSet attrs) {super (context, attrs ); mPaintCircle = new Paint (); mPaintCircle. setColor (Color. YELLOW); mPaintRect = new Paint (); mPaintRect. setColor (Color. GREEN); // XOR: overlapping and overlapped parts are not displayed; DST_OVER: overlapping parts are not displayed; SRC_OVER overlapping parts are only shown as porterduxfermode mode = new porterduxfermode (PorterDuff. mode. XOR); mPaintRect. setXfermode (mode) ;}@ Override protected void onMeasure (int widthMeasureSpec, int heightMeasureSpec) {super. onMeasure (widthMeasureSpec, heightMeasureSpec); width = getDefaultSize (rows (), widthMeasureSpec); height = getDefaultSize (rows (), heightMeasureSpec); trim (width, height); // parameter: canvas width, length, and format: mBitmap = Bitmap. createBitmap (width, height, Bitmap. config. ARGB_8888); mCanvasBm = new Canvas (mBitmap); // customize a Canvas. The canvas material is a Bitmap object.} @ Override protected void onDraw (Canvas) {super. onDraw (canvas); canvas. drawColor (Color. RED); // first draw mCanvasBm on bitmap. drawCircle (width/2, height/2, width/2, mPaintCircle); mCanvasBm. drawRect (0, 0, width/2, width/2, mPaintRect); // draw the bitmap canvas. drawBitmap (mBitmap, 0, 0, null); // this step is required }}

Result demonstration:
Porterduxfermode mode = new porterduduxfermode (parameter );
When the parameter is PorterDuff. Mode. DST_OVEL:

When the parameter is PorterDuff. Mode. XOR: