Code for RenderScript blur

BlurSurfaceView_04.kt

    private fun blurWithRenderScript() {
        val renderScript = RenderScript.create(context)
        val blurScript = ScriptIntrinsicBlur.create(renderScript, Element.U8_4(renderScript))

        val inAllocation = Allocation.createFromBitmap(renderScript, bitmap)
        val outAllocation = Allocation.createTyped(renderScript, inAllocation.type)
        blurScript.setRadius(20f)
        blurScript.setInput(inAllocation)

        blurScript.forEach(outAllocation)
        outAllocation.copyTo(bitmap)

        inAllocation.destroy()
    }
    
    fun getBackgroundAndDrawBehind(parent: ViewGroup) {
        ...
        ...
        canvas?.restore()
        if (::bitmap.isInitialized) { //Only execute after bitmap is initialized
            blurWithRenderScript()
        }
    }