ShaderEffect.java

package canvas.test;


import android.app.Activity;
import android.os.Bundle;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.PorterDuff;
import android.graphics.PorterDuff.Mode;
import android.graphics.PorterDuffXfermode;
import android.graphics.Rect;
import android.graphics.RectF;
import android.graphics.drawable.Drawable;
import android.view.View;
public class ShaderEffect extends Activity {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(new ImageEffect(this));
    }
    class ImageEffect extends View{
        Paint paint; 
        public ImageEffect (Context context){
            super(context);
            paint = new Paint();//��ʼ�����ʣ�Ϊ������ӰЧ��ʹ�á�
            paint.setAntiAlias(true);//ȥ����ݡ�
            paint.setShadowLayer(5f, 5.0f, 5.0f, Color.BLACK);//������Ӱ�㣬���ǹؼ���
            paint.setXfermode(new PorterDuffXfermode(Mode.SRC_IN));
        }
        @Override
        public void onDraw(Canvas canvas){
            super.onDraw(canvas);
            int posX = 20;
            int posY = 50;
            int PicWidth,PicHegiht; 
            
            Drawable drawable = getResources().getDrawable(R.drawable.button);
            Drawable dbe = getResources().getDrawable(R.drawable.button).mutate();//���������mutate��������ԭͼҲ�ᱻ�ı䣬��Ϊ���õ���Դ��ͬһ�������ж����ǹ���״̬�ġ�
            Drawable drawTest = getResources().getDrawable(R.drawable.button);
            Bitmap bmp = BitmapFactory.decodeResource(getResources(), R.drawable.button);
            
            PicWidth = drawable.getIntrinsicWidth();
            PicHegiht = drawable.getIntrinsicHeight();
            
            drawTest.setBounds(posX, (2 * posY) + PicHegiht, posX + PicWidth, (2 * posY) + 2 * PicHegiht );
            drawable.setBounds(posX,posY,posX+PicWidth,posY+PicHegiht);
            dbe.setBounds(0, 0, PicWidth, PicHegiht);
            
            canvas.drawColor(Color.WHITE);//���û�����ɫ
            canvas.save(Canvas.MATRIX_SAVE_FLAG);
            dbe.setColorFilter(0x7f000000,PorterDuff.Mode.SRC_IN);
            canvas.translate(posX + (int)(0.9 * PicWidth/2), posY + PicHegiht/2);//ͼ��ƽ��Ϊ�˸պ���ԭͼ���γ�Ӱ��Ч����
            canvas.skew(-0.9F, 0.0F);//ͼ����бЧ����
            canvas.scale(1.0f, 0.5f);//ͼ����ʵ�ǻ��������ţ�Y������СΪ1/2��
            dbe.draw(canvas);//�˴�Ϊ��ԭͼ��Ӱ��Ч��ͼ����ԭͼ�Ȼ���������²㡣
            drawable.clearColorFilter();
            canvas.restore();
            
            canvas.save(Canvas.MATRIX_SAVE_FLAG);
            drawable.draw(canvas);//�˴�Ϊ��ԭͼ������canvas�в��Ч������˻����Ӱ��֮�ϡ�
            canvas.restore();
            
            //Ĭ����Ч��ԭͼ
            canvas.save(Canvas.MATRIX_SAVE_FLAG);
            drawTest.draw(canvas);
            canvas.restore();
            
            //ͼƬ��ӰЧ��
            canvas.save(Canvas.MATRIX_SAVE_FLAG);
            //Rect rect = new Rect(2*posX + PicWidth, 2*posY + PicHegiht, 2*posX + 2*PicWidth, 2*posY + 2*PicHegiht);//��Ϊ�����ϵ���Ӱͼ����
            Rect rect = new Rect(2*posX + PicWidth + 3, 2*posY + PicHegiht + 3, 2*posX + 2*PicWidth - 2, 2*posY + 2*PicHegiht - 2);
            //����ͼƬ��ʵ�ʳߴ����ʾ������ͼ��Ҫ��һЩ�������Ҫ�ʵ������´�С���Դﵽ�Ϻõ�Ч��
            
            RectF rectF = new RectF(rect);
            canvas.drawRoundRect(rectF, 10f, 10f, paint);//��ԭ�о��λ����ϣ�����Բ�Ǿ��Σ�ͬʱ������Ӱ�㡣
            canvas.drawBitmap(bmp, 2*posX + PicWidth, 2*posY + PicHegiht, null);//����ԭͼ��
            canvas.restore();
        }
    }
}