用于不规则按钮区域增加高斯模糊处理，实现原理就是截取控件在整个背景图像位置的图像，做高斯模糊处理之后，使用自定义的Path区域去裁剪绘制不规则区域的高斯模糊效果。
一、控件Kotlin实现代码
import android.content.Context
import android.graphics.*
import android.renderscript.Allocation
import android.renderscript.Element
import android.renderscript.RenderScript
import android.renderscript.ScriptIntrinsicBlur
import android.util.AttributeSet
import androidx.appcompat.widget.AppCompatImageView
import java.util.concurrent.Executors
import java.util.concurrent.atomic.AtomicBoolean
/**
* 航前检查区域高斯模糊处理View
*/
class IrregularBlurView @JvmOverloads constructor(
context: Context,
attrs: AttributeSet? = null,
defStyleAttr: Int = 0
) : AppCompatImageView(context, attrs, defStyleAttr) {
private val blurPath = Path()
private var blurredBackground: Bitmap? = null
private var triangleCutSize: Float = 32f
private var blurRadius: Float = 15f
private var lastSourceBitmap: Bitmap? = null
// 性能优化相关
private val blurExecutor = Executors.newSingleThreadExecutor()
private val isBlurInProgress = AtomicBoolean(false)
private var rs: RenderScript? = null
private var blurScript: ScriptIntrinsicBlur? = null
private var allocationIn: Allocation? = null
private var allocationOut: Allocation? = null
// 防抖参数
private var lastUpdateTime: Long = 0
private val UPDATE_THRESHOLD = 33L // 30fps，约33ms
// 缩放参数
private val SCALE_FACTOR = 0.25f // 缩小4倍进行模糊，大幅提升性能
init {
setBackgroundColor(Color.TRANSPARENT)
val typedArray = context.obtainStyledAttributes(attrs, R.styleable.IrregularBlurView)
triangleCutSize = typedArray.getDimension(
R.styleable.IrregularBlurView_triangleCutSize, 32f
)
blurRadius = typedArray.getFloat(
R.styleable.IrregularBlurView_blurRadius, 15f
)
typedArray.recycle()
// 预初始化RenderScript资源
initializeRenderScript()
}
private fun initializeRenderScript() {
try {
rs = RenderScript.create(context)
blurScript = ScriptIntrinsicBlur.create(rs, Element.U8_4(rs))
} catch (e: Exception) {
}
}
override fun onDetachedFromWindow() {
super.onDetachedFromWindow()
cleanup()
}
private fun cleanup() {
// 取消正在进行的模糊任务
isBlurInProgress.set(false)
// 释放RenderScript资源
blurScript?.destroy()
allocationIn?.destroy()
allocationOut?.destroy()
rs?.destroy()
blurredBackground?.recycle()
blurredBackground = null
}
fun setSourceBitmap(bitmap: Bitmap) {
if (bitmap.isRecycled) {
return
}
// 防抖检查
val currentTime = System.currentTimeMillis()
if (currentTime - lastUpdateTime < UPDATE_THRESHOLD) {
return
}
lastUpdateTime = currentTime
lastSourceBitmap = bitmap
if (width == 0 || height == 0) {
return
}
// 使用后台线程进行模糊处理
processBlurAsync(bitmap)
}
private fun getLocationOnScreen(): IntArray {
val location = IntArray(2)
getLocationOnScreen(location)
return location
}
private fun processBlurAsync(bitmap: Bitmap) {
if (isBlurInProgress.getAndSet(true)) {
return // 已有任务在进行中
}
blurExecutor.execute {
try {
val result = performBlurOperation(bitmap)
post {
isBlurInProgress.set(false)
result?.let {
updateBlurredBackground(it)
}
}
} catch (e: Exception) {
isBlurInProgress.set(false)
}
}
}
private fun performBlurOperation(bitmap: Bitmap): Bitmap? {
return try {
val location = getLocationOnScreen()
val x = location[0]
val y = location[1]
// 安全的裁剪区域计算
val safeLeft = x.coerceIn(0, bitmap.width - 1)
val safeTop = y.coerceIn(0, bitmap.height - 1)
val safeWidth = width.coerceAtMost(bitmap.width - safeLeft)
val safeHeight = height.coerceAtMost(bitmap.height - safeTop)
if (safeWidth <= 0 || safeHeight <= 0) {
return null
}
// 裁剪源区域
val croppedBitmap = Bitmap.createBitmap(
bitmap, safeLeft, safeTop, safeWidth, safeHeight
)
// 优化后的模糊处理
val blurred = optimizedSafeBlur(croppedBitmap)
croppedBitmap.recycle()
blurred
} catch (e: Exception) {
null
}
}
private fun updateBlurredBackground(bitmap: Bitmap) {
blurredBackground?.recycle()
blurredBackground = bitmap
invalidate()
}
/**
* 优化后的安全模糊方法
*/
private fun optimizedSafeBlur(image: Bitmap): Bitmap {
// 1. 大幅缩小图片尺寸进行模糊
val scaledWidth = (image.width * SCALE_FACTOR).toInt().coerceAtLeast(1)
val scaledHeight = (image.height * SCALE_FACTOR).toInt().coerceAtLeast(1)
val inputBitmap = Bitmap.createScaledBitmap(image, scaledWidth, scaledHeight, true)
// 2. 使用预分配的RenderScript资源
val result = try {
renderScriptBlur(inputBitmap)
} catch (e: Exception) {
fastJavaBlur(inputBitmap)
}
// 3. 模糊后放大到原始尺寸
val finalResult = Bitmap.createScaledBitmap(result, image.width, image.height, true)
// 回收临时bitmap
inputBitmap.recycle()
if (result != finalResult) {
result.recycle()
}
return finalResult
}
/**
* 使用预分配资源的RenderScript模糊
*/
private fun renderScriptBlur(input: Bitmap): Bitmap {
val rs = this.rs ?: throw IllegalStateException("RenderScript not initialized")
val blurScript = this.blurScript ?: throw IllegalStateException("Blur script not initialized")
// 重用或重新创建Allocation
if (allocationIn == null || allocationIn!!.type.element != Element.U8_4(rs)) {
allocationIn?.destroy()
allocationIn = Allocation.createFromBitmap(rs, input)
} else {
allocationIn!!.copyFrom(input)
}
if (allocationOut == null || allocationOut!!.type.element != Element.U8_4(rs)) {
allocationOut?.destroy()
allocationOut = Allocation.createTyped(rs, allocationIn!!.type)
}
val outputBitmap = Bitmap.createBitmap(input.width, input.height, Bitmap.Config.ARGB_8888)
blurScript.setRadius(blurRadius.coerceIn(0.1f, 25f))
blurScript.setInput(allocationIn)
blurScript.forEach(allocationOut)
allocationOut!!.copyTo(outputBitmap)
return outputBitmap
}
/**
* 快速Java模糊实现（备选方案）
*/
private fun fastJavaBlur(src: Bitmap): Bitmap {
val radius = 5 // 固定小半径，保证性能
val w = src.width
val h = src.height
val output = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888)
val srcPixels = IntArray(w * h)
val dstPixels = IntArray(w * h)
src.getPixels(srcPixels, 0, w, 0, 0, w, h)
// 水平模糊
for (y in 0 until h) {
for (x in 0 until w) {
var a = 0
var r = 0
var g = 0
var b = 0
var count = 0
for (dx in -radius..radius) {
val nx = (x + dx).coerceIn(0, w - 1)
val pixel = srcPixels[y * w + nx]
a += Color.alpha(pixel)
r += Color.red(pixel)
g += Color.green(pixel)
b += Color.blue(pixel)
count++
}
dstPixels[y * w + x] = Color.argb(
a / count, r / count, g / count, b / count
)
}
}
// 垂直模糊
for (x in 0 until w) {
for (y in 0 until h) {
var a = 0
var r = 0
var g = 0
var b = 0
var count = 0
for (dy in -radius..radius) {
val ny = (y + dy).coerceIn(0, h - 1)
val pixel = dstPixels[ny * w + x]
a += Color.alpha(pixel)
r += Color.red(pixel)
g += Color.green(pixel)
b += Color.blue(pixel)
count++
}
srcPixels[y * w + x] = Color.argb(
a / count, r / count, g / count, b / count
)
}
}
output.setPixels(srcPixels, 0, w, 0, 0, w, h)
return output
}
override fun onSizeChanged(w: Int, h: Int, oldw: Int, oldh: Int) {
super.onSizeChanged(w, h, oldw, oldh)
updateBlurPath()
lastSourceBitmap?.let { setSourceBitmap(it) }
}
private fun updateBlurPath() {
blurPath.reset()
blurPath.apply {
moveTo(triangleCutSize, 0f)
lineTo(width.toFloat(), 0f)
lineTo(width.toFloat(), height.toFloat())
lineTo(0f, height.toFloat())
lineTo(0f, triangleCutSize)
close()
}
}
override fun onDraw(canvas: Canvas) {
blurredBackground?.let { bitmap ->
if (!bitmap.isRecycled) {
canvas.save()
canvas.clipPath(blurPath)
canvas.drawBitmap(bitmap, 0f, 0f, null)
canvas.restore()
}
}
super.onDraw(canvas)
}
companion object {
private const val TAG = "IrregularBlurView"
}
}其中 blurPath 为不规则区域的Path参数，上面控件中实现的是左上角缺失一个三角形的不规则区域图形，可以根据自己的需求自定义不规则图形区域。setSourceBitmap(bitmap: Bitmap) 设置值为整个背景的BItmap，控件内部根据当前控件所在区域截取Path区域的内容做高斯模糊处理。
样式配置如下：
<declare-styleable name="IrregularBlurView">
<attr name="triangleCutSize" format="reference" />
<attr name="blurRadius" format="reference" />
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