[ANDROID] 터치에 비트 맵의 ​​특정 영역을 투명하게

터치에 비트 맵의 ​​특정 영역을 투명하게

해결법

1. ---

   1.

   import android.app.Activity;
   import android.content.Context;
   import android.graphics.Bitmap;
   import android.graphics.Bitmap.Config;
   import android.graphics.BlurMaskFilter.Blur;
   import android.graphics.BitmapFactory;
   import android.graphics.BlurMaskFilter;
   import android.graphics.Canvas;
   import android.graphics.Color;
   import android.graphics.Paint;
   import android.graphics.PorterDuff.Mode;
   import android.graphics.PorterDuffXfermode;
   import android.os.Bundle;
   import android.view.MotionEvent;
   import android.view.View;
   
   public class StartActivity extends Activity {
   
       @Override
       public void onCreate(Bundle savedInstanceState) {
           super.onCreate(savedInstanceState);
           setContentView(new TouchView(this));
   
   
       }
   
       class TouchView extends View{
           Bitmap bgr;
           Bitmap overlayDefault;
           Bitmap overlay;
           Paint pTouch;
           int X = -100;
           int Y = -100;
           Canvas c2;
   
           public TouchView(Context context) {
               super(context);
   
               bgr = BitmapFactory.decodeResource(getResources(),R.drawable.bgr);
               overlayDefault = BitmapFactory.decodeResource(getResources(),R.drawable.over);
               overlay = BitmapFactory.decodeResource(getResources(),R.drawable.over).copy(Config.ARGB_8888, true);  
               c2 = new Canvas(overlay);
   
               pTouch = new Paint(Paint.ANTI_ALIAS_FLAG);         
               pTouch.setXfermode(new PorterDuffXfermode(Mode.SRC_OUT)); 
               pTouch.setColor(Color.TRANSPARENT);
               pTouch.setMaskFilter(new BlurMaskFilter(15, Blur.NORMAL));
   
   
           }
   
           @Override
           public boolean onTouchEvent(MotionEvent ev) {
   
               switch (ev.getAction()) {
   
                   case MotionEvent.ACTION_DOWN: {
   
                       X = (int) ev.getX();
                       Y = (int) ev.getY();
                       invalidate();
   
                       break;
                   }
   
                   case MotionEvent.ACTION_MOVE: {
   
                           X = (int) ev.getX();
                           Y = (int) ev.getY();
                           invalidate();
                           break;
   
                   }           
   
                   case MotionEvent.ACTION_UP:
   
                       break;
   
               }
               return true;
           }
   
   
           @Override
           public void onDraw(Canvas canvas){
               super.onDraw(canvas);
   
               //draw background
               canvas.drawBitmap(bgr, 0, 0, null);
               //copy the default overlay into temporary overlay and punch a hole in it                          
               c2.drawBitmap(overlayDefault, 0, 0, null); //exclude this line to show all as you draw
               c2.drawCircle(X, Y, 80, pTouch);
               //draw the overlay over the background  
               canvas.drawBitmap(overlay, 0, 0, null);
   
           }
   
   
       }
   
   
   }
   

2. ---

   2.훗, 당신은 당신의 포스트 안에 응답 권리가있어!

   훗, 당신은 당신의 포스트 안에 응답 권리가있어!

   기본적으로 뭔가를 시도 :

   public void onDraw(Canvas canvas) {    
       if (myPaintFlag) {
           canvas.drawBitmap(bmp1, new Matrix(), null);
           canvas.drawBitmap(bmp2, new Matrix(), mPaint);
       }
       else {
           canvas.drawBitmap(bmp1, new Matrix(), mPaint);
           canvas.drawBitmap(bmp2, new Matrix(), null);
       }   
   }
   

from https://stackoverflow.com/questions/5368774/make-certain-area-of-bitmap-transparent-on-touch by cc-by-sa and MIT license