Ответ 1
Это было на мой взгляд в течение некоторого времени, и я только что реализовал его благодаря вашему вопросу.
Чтобы это сделать, нам нужно нарисовать макет, который находится ниже нашего размытия, в растровое изображение. Затем, используя алгоритм размытия, мы должны размыть это растровое изображение и, наконец, нарисовать размытое растровое изображение в качестве нашего макета размытия.
К счастью, андроид имеет механизм кэширования чертежа, поэтому первая часть проста. Мы можем просто включить кешированный чертеж для нашего макета и использовать getDrawingCache() для получения растрового изображения из него.
Теперь нам нужен быстрый алгоритм размытия. Я использовал этот fooobar.com/questions/37704/...
Вот он.
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.ColorFilter;
import android.graphics.Paint;
import android.graphics.PixelFormat;
import android.graphics.drawable.Drawable;
import android.util.Log;
import android.view.View;
import java.lang.ref.WeakReference;
import java.util.InputMismatchException;
/**
* A drawable that draws the target view as blurred using fast blur
* <p/>
* <p/>
* TODO:we might use setBounds() to draw only part a of the target view
* <p/>
* Created by 10uR on 24.5.2014.
*/
public class BlurDrawable extends Drawable {
private WeakReference<View> targetRef;
private Bitmap blurred;
private Paint paint;
private int radius;
public BlurDrawable(View target) {
this(target, 10);
}
public BlurDrawable(View target, int radius) {
this.targetRef = new WeakReference<View>(target);
setRadius(radius);
target.setDrawingCacheEnabled(true);
target.setDrawingCacheQuality(View.DRAWING_CACHE_QUALITY_AUTO);
paint = new Paint();
paint.setAntiAlias(true);
paint.setFilterBitmap(true);
}
@Override
public void draw(Canvas canvas) {
if (blurred == null) {
View target = targetRef.get();
if (target != null) {
Bitmap bitmap = target.getDrawingCache(true);
if (bitmap == null) return;
blurred = fastBlur(bitmap, radius);
}
}
if (blurred != null && !blurred.isRecycled())
canvas.drawBitmap(blurred, 0, 0, paint);
}
/**
* Set the bluring radius that will be applied to target view bitmap
*
* @param radius should be 0-100
*/
public void setRadius(int radius) {
if (radius < 0 || radius > 100)
throw new InputMismatchException("Radius must be 0 <= radius <= 100 !");
this.radius = radius;
if (blurred != null) {
blurred.recycle();
blurred = null;
}
invalidateSelf();
}
public int getRadius() {
return radius;
}
@Override
public void setAlpha(int alpha) {
}
@Override
public void setColorFilter(ColorFilter cf) {
}
@Override
public int getOpacity() {
return PixelFormat.TRANSLUCENT;
}
/**
* from /questions/37704/fast-bitmap-blur-for-android-sdk/274214#274214
* <p/>
* <p/>
* <p/>
* Stack Blur v1.0 from
* http://www.quasimondo.com/StackBlurForCanvas/StackBlurDemo.html
* <p/>
* Java Author: Mario Klingemann <mario at quasimondo.com>
* http://incubator.quasimondo.com
* created Feburary 29, 2004
* Android port : Yahel Bouaziz <yahel at kayenko.com>
* http://www.kayenko.com
* ported april 5th, 2012
* <p/>
* This is a compromise between Gaussian Blur and Box blur
* It creates much better looking blurs than Box Blur, but is
* 7x faster than my Gaussian Blur implementation.
* <p/>
* I called it Stack Blur because this describes best how this
* filter works internally: it creates a kind of moving stack
* of colors whilst scanning through the image. Thereby it
* just has to add one new block of color to the right side
* of the stack and remove the leftmost color. The remaining
* colors on the topmost layer of the stack are either added on
* or reduced by one, depending on if they are on the right or
* on the left side of the stack.
* <p/>
* If you are using this algorithm in your code please add
* the following line:
* <p/>
* Stack Blur Algorithm by Mario Klingemann <[email protected]>
*/
private static Bitmap fastBlur(Bitmap sentBitmap, int radius) {
Bitmap 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];
Log.e("pix", w + " " + h + " " + pix.length);
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);
}
}
Использование:
View beneathView = //the view that beneath blur view
View blurView= //blur View
BlurDrawable blurDrawable = new BlurDrawable(beneathView, radius);
blurView.setBackgroundDrawable(blurDrawable);
И как мое тестовое приложение выглядело следующим образом:
Я решил не использовать это, потому что он слишком хакерский и не выглядит таким крутым, как я думал, что это будет на первом месте.
