pull/36/head
kunfei
5 years ago
parent
b2ac302c45
commit
bced8f3837
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package io.legado.app.utils |
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import android.content.Context |
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import android.graphics.Bitmap |
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import android.graphics.Bitmap.Config |
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import android.graphics.BitmapFactory |
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import android.graphics.Canvas |
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import android.renderscript.Allocation |
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import android.renderscript.Element |
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import android.renderscript.RenderScript |
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import android.renderscript.ScriptIntrinsicBlur |
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import android.view.View |
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import io.legado.app.App |
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import java.io.IOException |
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import kotlin.math.ceil |
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@SuppressWarnings("unused", "WeakerAccess") |
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object BitmapUtil { |
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/** |
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* 从path中获取图片信息,在通过BitmapFactory.decodeFile(String path)方法将突破转成Bitmap时， |
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* 遇到大一些的图片，我们经常会遇到OOM(Out Of Memory)的问题。所以用到了我们上面提到的BitmapFactory.Options这个类。 |
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* |
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* @param path 文件路径 |
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* @param width 想要显示的图片的宽度 |
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* @param height 想要显示的图片的高度 |
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* @return |
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*/ |
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fun decodeBitmap(path: String, width: Int, height: Int): Bitmap { |
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val op = BitmapFactory.Options() |
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// inJustDecodeBounds如果设置为true,仅仅返回图片实际的宽和高,宽和高是赋值给opts.outWidth,opts.outHeight; |
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op.inJustDecodeBounds = true |
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BitmapFactory.decodeFile(path, op) //获取尺寸信息 |
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//获取比例大小 |
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val wRatio = ceil((op.outWidth / width).toDouble()).toInt() |
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val hRatio = ceil((op.outHeight / height).toDouble()).toInt() |
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//如果超出指定大小，则缩小相应的比例 |
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if (wRatio > 1 && hRatio > 1) { |
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if (wRatio > hRatio) { |
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op.inSampleSize = wRatio |
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} else { |
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op.inSampleSize = hRatio |
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} |
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} |
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op.inJustDecodeBounds = false |
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return BitmapFactory.decodeFile(path, op) |
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} |
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/** 从path中获取Bitmap图片 |
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* @param path 图片路径 |
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* @return |
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*/ |
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fun decodeBitmap(path: String): Bitmap { |
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val opts = BitmapFactory.Options() |
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opts.inJustDecodeBounds = true |
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BitmapFactory.decodeFile(path, opts) |
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opts.inSampleSize = computeSampleSize(opts, -1, 128 * 128) |
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opts.inJustDecodeBounds = false |
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return BitmapFactory.decodeFile(path, opts) |
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} |
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/** |
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* 以最省内存的方式读取本地资源的图片 |
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* @param context 设备上下文 |
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* @param resId 资源ID |
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* @return |
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*/ |
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fun decodeBitmap(context: Context, resId: Int): Bitmap? { |
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val opt = BitmapFactory.Options() |
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opt.inPreferredConfig = Config.RGB_565 |
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//获取资源图片 |
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val `is` = context.resources.openRawResource(resId) |
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return BitmapFactory.decodeStream(`is`, null, opt) |
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} |
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/** |
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* @param context 设备上下文 |
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* @param resId 资源ID |
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* @param width |
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* @param height |
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* @return |
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*/ |
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fun decodeBitmap(context: Context, resId: Int, width: Int, height: Int): Bitmap? { |
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var inputStream = context.resources.openRawResource(resId) |
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val op = BitmapFactory.Options() |
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// inJustDecodeBounds如果设置为true,仅仅返回图片实际的宽和高,宽和高是赋值给opts.outWidth,opts.outHeight; |
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op.inJustDecodeBounds = true |
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BitmapFactory.decodeStream(inputStream, null, op) //获取尺寸信息 |
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//获取比例大小 |
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val wRatio = ceil((op.outWidth / width).toDouble()).toInt() |
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val hRatio = ceil((op.outHeight / height).toDouble()).toInt() |
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//如果超出指定大小，则缩小相应的比例 |
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if (wRatio > 1 && hRatio > 1) { |
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if (wRatio > hRatio) { |
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op.inSampleSize = wRatio |
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} else { |
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op.inSampleSize = hRatio |
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} |
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} |
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inputStream = context.resources.openRawResource(resId) |
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op.inJustDecodeBounds = false |
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return BitmapFactory.decodeStream(inputStream, null, op) |
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} |
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/** |
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* @param context 设备上下文 |
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* @param fileNameInAssets Assets里面文件的名称 |
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* @param width 图片的宽度 |
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* @param height 图片的高度 |
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* @return Bitmap |
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* @throws IOException |
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*/ |
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@Throws(IOException::class) |
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fun decodeBitmap(context: Context, fileNameInAssets: String, width: Int, height: Int): Bitmap? { |
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var inputStream = context.assets.open(fileNameInAssets) |
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val op = BitmapFactory.Options() |
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// inJustDecodeBounds如果设置为true,仅仅返回图片实际的宽和高,宽和高是赋值给opts.outWidth,opts.outHeight; |
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op.inJustDecodeBounds = true |
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BitmapFactory.decodeStream(inputStream, null, op) //获取尺寸信息 |
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//获取比例大小 |
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val wRatio = ceil((op.outWidth / width).toDouble()).toInt() |
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val hRatio = ceil((op.outHeight / height).toDouble()).toInt() |
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//如果超出指定大小，则缩小相应的比例 |
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if (wRatio > 1 && hRatio > 1) { |
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if (wRatio > hRatio) { |
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op.inSampleSize = wRatio |
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} else { |
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op.inSampleSize = hRatio |
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} |
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} |
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inputStream = context.assets.open(fileNameInAssets) |
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op.inJustDecodeBounds = false |
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return BitmapFactory.decodeStream(inputStream, null, op) |
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} |
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//图片不被压缩 |
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fun convertViewToBitmap(view: View, bitmapWidth: Int, bitmapHeight: Int): Bitmap { |
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val bitmap = Bitmap.createBitmap(bitmapWidth, bitmapHeight, Bitmap.Config.ARGB_8888) |
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view.draw(Canvas(bitmap)) |
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return bitmap |
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} |
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/** |
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* @param options |
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* @param minSideLength |
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* @param maxNumOfPixels |
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* @return |
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* 设置恰当的inSampleSize是解决该问题的关键之一。BitmapFactory.Options提供了另一个成员inJustDecodeBounds。 |
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* 设置inJustDecodeBounds为true后，decodeFile并不分配空间，但可计算出原始图片的长度和宽度，即opts.width和opts.height。 |
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* 有了这两个参数，再通过一定的算法，即可得到一个恰当的inSampleSize。 |
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* 查看Android源码，Android提供了下面这种动态计算的方法。 |
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*/ |
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fun computeSampleSize( |
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options: BitmapFactory.Options, |
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minSideLength: Int, |
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maxNumOfPixels: Int |
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): Int { |
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val initialSize = computeInitialSampleSize(options, minSideLength, maxNumOfPixels) |
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var roundedSize: Int |
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if (initialSize <= 8) { |
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roundedSize = 1 |
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while (roundedSize < initialSize) { |
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roundedSize = roundedSize shl 1 |
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} |
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} else { |
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roundedSize = (initialSize + 7) / 8 * 8 |
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} |
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return roundedSize |
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} |
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private fun computeInitialSampleSize( |
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options: BitmapFactory.Options, |
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minSideLength: Int, |
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maxNumOfPixels: Int |
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): Int { |
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val w = options.outWidth.toDouble() |
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val h = options.outHeight.toDouble() |
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val lowerBound = if (maxNumOfPixels == -1) |
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1 |
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else |
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Math.ceil(Math.sqrt(w * h / maxNumOfPixels)).toInt() |
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val upperBound = if (minSideLength == -1) 128 else Math.min( |
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Math.floor(w / minSideLength), |
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Math.floor(h / minSideLength) |
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).toInt() |
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if (upperBound < lowerBound) { |
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// return the larger one when there is no overlapping zone. |
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return lowerBound |
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} |
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return if (maxNumOfPixels == -1 && minSideLength == -1) { |
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1 |
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} else if (minSideLength == -1) { |
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lowerBound |
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} else { |
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upperBound |
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} |
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} |
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/** |
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* 高斯模糊 |
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*/ |
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fun stackBlur(srcBitmap: Bitmap?): Bitmap? { |
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if (srcBitmap == null) return null |
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val rs = RenderScript.create(App.INSTANCE) |
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val blurredBitmap = srcBitmap.copy(Config.ARGB_8888, true) |
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//分配用于渲染脚本的内存 |
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val input = Allocation.createFromBitmap( |
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rs, |
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blurredBitmap, |
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Allocation.MipmapControl.MIPMAP_FULL, |
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Allocation.USAGE_SHARED |
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) |
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val output = Allocation.createTyped(rs, input.type) |
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//加载我们想要使用的特定脚本的实例。 |
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val script = ScriptIntrinsicBlur.create(rs, Element.U8_4(rs)) |
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script.setInput(input) |
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//设置模糊半径 |
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script.setRadius(8f) |
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//启动 ScriptIntrinsicBlur |
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script.forEach(output) |
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//将输出复制到模糊的位图 |
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output.copyTo(blurredBitmap) |
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return blurredBitmap |
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} |
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} |
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