Uczyń pewien obszar bitmapy przezroczystym na dotyku
Mój pomysł polega na nakładaniu się na siebie dwóch obrazów i na onTouch, górny obraz powinien być przezroczysty na tym dotkniętym promieniu, odsłaniając w ten sposób dolny obraz.
Oto jak nakładam 2 obrazki:
Bitmap bmOverlay = Bitmap.createBitmap(bmp1.getWidth(), bmp1.getHeight(), bmp1.getConfig());
Canvas canvas = new Canvas(bmOverlay);
canvas.drawBitmap(bmp1, new Matrix(), null);
canvas.drawBitmap(bmp2, new Matrix(), null);
Zajrzałam do tego posta i mam taką farbę jak poniżej aby była przezroczysta:
mPaint = new Paint();
mPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC));
mPaint.setColor(Color.TRANSPARENT);
mPaint.setAntiAlias(true);
public void onDraw(Canvas canvas) {
canvas.drawCircle(40, 40, 30, mPaint); //hardcode to test
}
Problem w tym, że myślę, że okrąg od razu sprawia, że 2 obrazy są przezroczyste na zdefiniowanym promieniu, Jak mogę zrobić tylko górną bitmapę przezroczystą?
20
2 answers
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);
}
}
}
36
Author: Lumis,
Warning: date(): Invalid date.timezone value 'Europe/Kyiv', we selected the timezone 'UTC' for now. in /var/www/agent_stack/data/www/doraprojects.net/template/agent.layouts/content.php on line 54
2011-04-22 12:57:47
Warning: date(): Invalid date.timezone value 'Europe/Kyiv', we selected the timezone 'UTC' for now. in /var/www/agent_stack/data/www/doraprojects.net/template/agent.layouts/content.php on line 54
2011-04-22 12:57:47
Heh, masz odpowiedź w swoim poście!
W zasadzie Spróbuj czegoś takiego:
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);
}
}
0
Author: user432209,
Warning: date(): Invalid date.timezone value 'Europe/Kyiv', we selected the timezone 'UTC' for now. in /var/www/agent_stack/data/www/doraprojects.net/template/agent.layouts/content.php on line 54
2011-03-20 13:56:45
Warning: date(): Invalid date.timezone value 'Europe/Kyiv', we selected the timezone 'UTC' for now. in /var/www/agent_stack/data/www/doraprojects.net/template/agent.layouts/content.php on line 54
2011-03-20 13:56:45