package com.kunfei.bookshelf.help; import android.annotation.TargetApi; import android.content.Context; import android.graphics.Bitmap; import android.os.Build; import android.renderscript.Allocation; import android.renderscript.Element; import android.renderscript.RenderScript; import android.renderscript.ScriptIntrinsicBlur; import androidx.annotation.NonNull; import com.bumptech.glide.load.engine.bitmap_recycle.BitmapPool; import com.bumptech.glide.load.resource.bitmap.BitmapTransformation; import java.security.MessageDigest; public class BlurTransformation extends BitmapTransformation { private RenderScript rs; private int radius; public BlurTransformation(Context context, int radius) { super(); rs = RenderScript.create(context); this.radius = radius; } @TargetApi(Build.VERSION_CODES.JELLY_BEAN_MR1) @Override protected Bitmap transform(@NonNull BitmapPool pool, @NonNull Bitmap toTransform, int outWidth, int outHeight) { Bitmap blurredBitmap = toTransform.copy(Bitmap.Config.ARGB_8888, true); // Allocate memory for Renderscript to work with //分配用于渲染脚本的内存 Allocation input = Allocation.createFromBitmap(rs, blurredBitmap, Allocation.MipmapControl.MIPMAP_FULL, Allocation.USAGE_SHARED); Allocation output = Allocation.createTyped(rs, input.getType()); // Load up an instance of the specific script that we want to use. //加载我们想要使用的特定脚本的实例。 ScriptIntrinsicBlur script = ScriptIntrinsicBlur.create(rs, Element.U8_4(rs)); script.setInput(input); // Set the blur radius //设置模糊半径 script.setRadius(radius); // Start the ScriptIntrinsicBlur //启动 ScriptIntrinsicBlur, script.forEach(output); // Copy the output to the blurred bitmap //将输出复制到模糊的位图 output.copyTo(blurredBitmap); return blurredBitmap; } @Override public void updateDiskCacheKey(@NonNull MessageDigest messageDigest) { messageDigest.update("blur transformation".getBytes()); } }