高斯模糊效果

Posted 2020-09-17 骑猪撞交警

• 需要实现的效果

视觉设计师都是参照ios的效果设计的,毕竟人家的效果是业内标杆;而android要完全实现这种高斯模糊(也叫毛玻璃)效果,资源消耗巨大不说,效果也不是很理想.

• 效果分析

• 随着侧边栏划出,模糊的宽度也逐渐增加,直到侧边栏完全展开

• 模糊图片根据底层背景模糊的,根据底层背景图片动态改变

• 黑色背景显示在最上面

• 如何实现?

　　直接创建一个半透明的模糊层盖在上面?这种方式估计是最好的(不用考虑性能),还不知道UI设计师能不能提供,而且效果很一般.

　　使用DrawerLayout实现Material Design风格的侧滑,监听滑动距离,根据滑动距离切割底层背景,动态截图,根据截图生成模糊图片盖在上面;这种方式,想想就好了,我试过,还没拉出来就崩溃了,资源消耗和cpu占用过高;

　　实在不行,我只能退而求其次了,完全展开的时候截图并据此生成一张模糊图片,滑动的时候背景设置为透明,同时回收图片资源;上代码吧.

xml布局:

<?xml version="1.0" encoding="utf-8"?>
<android.support.v4.widget.DrawerLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/main_drawerlayout"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="com.google.lrcdemo.MainActivity">
    <!--内容区域-->
    <RelativeLayout
        android:id="@+id/main_content"
        android:layout_width="match_parent"
        android:layout_height="match_parent">



        <ImageView
            android:id="@+id/blurView"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:background="#3f000000"
            android:scaleType="centerCrop" />
        <LinearLayout
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:padding="10dp"
            android:orientation="horizontal">

            <Button
                android:id="@+id/btn_prev"
                android:background="@null"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="上一首" />

            <Button
                android:id="@+id/btn_next"
                android:background="@null"
                android:layout_marginLeft="10dp"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="下一首" />

            <TextView
                android:layout_marginLeft="50dp"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="收藏" />

            <CheckBox
                android:background="@null"
                android:id="@+id/btn_lyrics"
                android:layout_marginLeft="10dp"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="歌词" />
        </LinearLayout>

        <com.google.lrcdemo.Image3DSwitchView
            android:id="@+id/image_switch_view"
            android:layout_width="630dp"
            android:layout_height="300dp"
            android:layout_centerInParent="true">

            <com.google.lrcdemo.Image3DView
                android:id="@+id/image1"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:clickable="true"
                android:scaleType="fitXY"
                android:src="@drawable/image1" />

            <com.google.lrcdemo.Image3DView
                android:id="@+id/image2"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:clickable="true"
                android:scaleType="fitXY"
                android:src="@drawable/image2" />

            <com.google.lrcdemo.Image3DView
                android:id="@+id/image3"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:clickable="true"
                android:scaleType="fitXY"
                android:src="@drawable/image3" />

            <com.google.lrcdemo.Image3DView
                android:id="@+id/image4"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:clickable="true"
                android:scaleType="fitXY"
                android:src="@drawable/image4" />

            <com.google.lrcdemo.Image3DView
                android:id="@+id/image5"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:clickable="true"
                android:scaleType="fitXY"
                android:src="@drawable/image5" />

            <com.google.lrcdemo.Image3DView
                android:id="@+id/image6"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:clickable="true"
                android:scaleType="fitXY"
                android:src="@drawable/image6" />

            <com.google.lrcdemo.Image3DView
                android:id="@+id/image7"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:clickable="true"
                android:scaleType="fitXY"
                android:src="@drawable/image7" />
        </com.google.lrcdemo.Image3DSwitchView>
    </RelativeLayout>

    <!--左侧菜单区域-->
    <LinearLayout
        android:id="@+id/fg_left"
        android:layout_width="360dp"
        android:layout_height="match_parent"
        android:layout_gravity="left"
        android:orientation="vertical">

        <ImageView
            android:id="@+id/iv_blurry"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:src="#33000000" />
    </LinearLayout>


</android.support.v4.widget.DrawerLayout>

　　代码中:

 mDrawlayout = (DrawerLayout) findViewById(R.id.main_drawerlayout);
        main_content = (RelativeLayout) findViewById(R.id.main_content);
        fg_left = (LinearLayout) findViewById(R.id.fg_left);
        //得到开关额的对象
        mToggle = new ActionBarDrawerToggle(this, mDrawlayout, R.string.open, R.string.close) {
            /**
             * 当抽屉滑动状态改变的时候被调用
             * 状态值是STATE_IDLE（闲置--0）, STATE_DRAGGING（拖拽的--1）, STATE_SETTLING（固定--2）中之一。
             * 抽屉打开的时候，点击抽屉，drawer的状态就会变成STATE_DRAGGING，然后变成STATE_IDLE
             */
            @Override
            public void onDrawerStateChanged(int arg0) {
                Log.i("drawer的状态", "" + arg0);
            }

            /**
             * 当抽屉被滑动的时候调用此方法
             * arg1 表示 滑动的幅度（0-1）
             */
            @Override
            public void onDrawerSlide(View arg0, float arg1) {
                if (arg1 < 1) {
                    fg_left.setBackgroundColor(Color.TRANSPARENT);
                }
            }

            /**
             * 当一个抽屉被完全打开的时候被调用
             */
            @Override
            public void onDrawerOpened(View arg0) {
                Log.i("drawer", "抽屉被完全打开了！");
                blur(main_content, fg_left, 2, 8);
            }

            /**
             * 当一个抽屉完全关闭的时候调用此方法
             */

            @Override
            public void onDrawerClosed(View arg0) {
                Log.i("drawer", "抽屉被完全关闭了！");
            }
        };
        //同步状态默认回退的方法
        mToggle.syncState();
        //设置drawerLayout的监听
        mDrawlayout.setScrimColor(Color.TRANSPARENT);
        mDrawlayout.addDrawerListener(mToggle);
    }

高斯模糊的工具类:

/**
 * 设置高斯模糊的工具类
 * Created by zsl on 15/5/9.
 */
public class Fglass {

    /**
     * 设置高斯模糊
     * <p>
     * ps:
     * 设置高斯模糊是依靠scaleFactor和radius配合使用的，比如这里默认设置是：scaleFactor = 8;radius = 2; 模糊效果和scaleFactor = 1;radius = 20;是一样的，而且效率高
     *
     * @param fromView    从某个View获取截图
     * @param toView      高斯模糊设置到某个View上
     * @param radius      模糊度
     * @param scaleFactor 缩放比例
     */
    @TargetApi(Build.VERSION_CODES.JELLY_BEAN)
    public static void blur(View fromView, View toView, float radius, float scaleFactor) {

        //获取View的截图
        fromView.buildDrawingCache();
        fromView.setDrawingCacheEnabled(true);
        Bitmap bkg = fromView.getDrawingCache();

        if (radius < 1 || radius > 26) {
            scaleFactor = 8;
            radius = 2;
        }

        Bitmap overlay = Bitmap.createBitmap((int) (toView.getMeasuredWidth() / scaleFactor),
                (int) (toView.getMeasuredHeight() / scaleFactor), Bitmap.Config.ARGB_8888);
        Canvas canvas = new Canvas(overlay);
        canvas.translate(-toView.getLeft() / scaleFactor, -toView.getTop() / scaleFactor);
        canvas.scale(1 / scaleFactor, 1 / scaleFactor);
        Paint paint = new Paint();
        paint.setFlags(Paint.FILTER_BITMAP_FLAG);
        canvas.drawBitmap(bkg, 0, 0, paint);

        overlay = Fglass.doBlur(overlay, (int) radius, true);
        toView.setBackground(new BitmapDrawable(overlay));
        fromView.setDrawingCacheEnabled(false);
    }

    /**
     * 高斯模糊操作
     *
     * @param sentBitmap
     * @param radius
     * @param canReuseInBitmap
     * @return
     */
    private static Bitmap doBlur(Bitmap sentBitmap, int radius, boolean canReuseInBitmap) {

        Bitmap bitmap;
        if (canReuseInBitmap) {
            bitmap = sentBitmap;
        } else {
            bitmap = sentBitmap.copy(sentBitmap.getConfig(), true);
        }

        if (radius < 1) {
            return (null);
        }

        int w = bitmap.getWidth();
        int h = bitmap.getHeight();

        int[] pix = new int[w * h];
        bitmap.getPixels(pix, 0, w, 0, 0, w, h);

        int wm = w - 1;
        int hm = h - 1;
        int wh = w * h;
        int div = radius + radius + 1;

        int r[] = new int[wh];
        int g[] = new int[wh];
        int b[] = new int[wh];
        int rsum, gsum, bsum, x, y, i, p, yp, yi, yw;
        int vmin[] = new int[Math.max(w, h)];

        int divsum = (div + 1) >> 1;
        divsum *= divsum;
        int dv[] = new int[256 * divsum];
        for (i = 0; i < 256 * divsum; i++) {
            dv[i] = (i / divsum);
        }

        yw = yi = 0;

        int[][] stack = new int[div][3];
        int stackpointer;
        int stackstart;
        int[] sir;
        int rbs;
        int r1 = radius + 1;
        int routsum, goutsum, boutsum;
        int rinsum, ginsum, binsum;

        for (y = 0; y < h; y++) {
            rinsum = ginsum = binsum = routsum = goutsum = boutsum = rsum = gsum = bsum = 0;
            for (i = -radius; i <= radius; i++) {
                p = pix[yi + Math.min(wm, Math.max(i, 0))];
                sir = stack[i + radius];
                sir[0] = (p & 0xff0000) >> 16;
                sir[1] = (p & 0x00ff00) >> 8;
                sir[2] = (p & 0x0000ff);
                rbs = r1 - Math.abs(i);
                rsum += sir[0] * rbs;
                gsum += sir[1] * rbs;
                bsum += sir[2] * rbs;
                if (i > 0) {
                    rinsum += sir[0];
                    ginsum += sir[1];
                    binsum += sir[2];
                } else {
                    routsum += sir[0];
                    goutsum += sir[1];
                    boutsum += sir[2];
                }
            }
            stackpointer = radius;

            for (x = 0; x < w; x++) {

                r[yi] = dv[rsum];
                g[yi] = dv[gsum];
                b[yi] = dv[bsum];

                rsum -= routsum;
                gsum -= goutsum;
                bsum -= boutsum;

                stackstart = stackpointer - radius + div;
                sir = stack[stackstart % div];

                routsum -= sir[0];
                goutsum -= sir[1];
                boutsum -= sir[2];

                if (y == 0) {
                    vmin[x] = Math.min(x + radius + 1, wm);
                }
                p = pix[yw + vmin[x]];

                sir[0] = (p & 0xff0000) >> 16;
                sir[1] = (p & 0x00ff00) >> 8;
                sir[2] = (p & 0x0000ff);

                rinsum += sir[0];
                ginsum += sir[1];
                binsum += sir[2];

                rsum += rinsum;
                gsum += ginsum;
                bsum += binsum;

                stackpointer = (stackpointer + 1) % div;
                sir = stack[(stackpointer) % div];

                routsum += sir[0];
                goutsum += sir[1];
                boutsum += sir[2];

                rinsum -= sir[0];
                ginsum -= sir[1];
                binsum -= sir[2];

                yi++;
            }
            yw += w;
        }
        for (x = 0; x < w; x++) {
            rinsum = ginsum = binsum = routsum = goutsum = boutsum = rsum = gsum = bsum = 0;
            yp = -radius * w;
            for (i = -radius; i <= radius; i++) {
                yi = Math.max(0, yp) + x;

                sir = stack[i + radius];

                sir[0] = r[yi];
                sir[1] = g[yi];
                sir[2] = b[yi];

                rbs = r1 - Math.abs(i);

                rsum += r[yi] * rbs;
                gsum += g[yi] * rbs;
                bsum += b[yi] * rbs;

                if (i > 0) {
                    rinsum += sir[0];
                    ginsum += sir[1];
                    binsum += sir[2];
                } else {
                    routsum += sir[0];
                    goutsum += sir[1];
                    boutsum += sir[2];
                }

                if (i < hm) {
                    yp += w;
                }
            }
            yi = x;
            stackpointer = radius;
            for (y = 0; y < h; y++) {
                // Preserve alpha channel: ( 0xff000000 & pix[yi] )
                pix[yi] = (0xff000000 & pix[yi]) | (dv[rsum] << 16) | (dv[gsum] << 8) | dv[bsum];

                rsum -= routsum;
                gsum -= goutsum;
                bsum -= boutsum;

                stackstart = stackpointer - radius + div;
                sir = stack[stackstart % div];

                routsum -= sir[0];
                goutsum -= sir[1];
                boutsum -= sir[2];

                if (x == 0) {
                    vmin[y] = Math.min(y + r1, hm) * w;
                }
                p = x + vmin[y];

                sir[0] = r[p];
                sir[1] = g[p];
                sir[2] = b[p];

                rinsum += sir[0];
                ginsum += sir[1];
                binsum += sir[2];

                rsum += rinsum;
                gsum += ginsum;
                bsum += binsum;

                stackpointer = (stackpointer + 1) % div;
                sir = stack[stackpointer];

                routsum += sir[0];
                goutsum += sir[1];
                boutsum += sir[2];

                rinsum -= sir[0];
                ginsum -= sir[1];
                binsum -= sir[2];

                yi += w;
            }
        }

        bitmap.setPixels(pix, 0, w, 0, 0, w, h);

        return (bitmap);
    }
}

最终效果:

　　

　这个图片边缘是图片3d倾斜前的轮廓,不要在意这些细节.