package com.github.miao1007.animewallpaper.ui.widget.blur;
import android.annotation.TargetApi;
import android.app.Activity;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Path;
import android.graphics.RectF;
import android.graphics.drawable.ColorDrawable;
import android.os.Build;
import android.renderscript.Allocation;
import android.renderscript.Element;
import android.renderscript.RenderScript;
import android.renderscript.ScriptIntrinsicBlur;
import android.support.annotation.ColorInt;
import android.support.annotation.IntRange;
import android.support.annotation.NonNull;
import android.view.View;
import android.view.Window;
/**
* Created by leon on 2/8/16.
* port Blur from <a href="https://github.com/500px/500px-android-blur">500px-android-blur</a>
*
* Real time Blur
* API 17 and above: use blur
*
* API 17 lower:
* @see #setColor(int)
*/
public class BlurDrawable extends ColorDrawable {
private int mDownsampleFactor;
private final View mBlurredBgView;
private int mBlurredViewWidth, mBlurredViewHeight;
private boolean mDownsampleFactorChanged;
private Bitmap mBitmapToBlur, mBlurredBitmap;
private Canvas mBlurringCanvas;
private RenderScript mRenderScript;
private ScriptIntrinsicBlur mBlurScript;
private Allocation mBlurInput, mBlurOutput;
private float offsetX;
private float offsetY;
private static boolean enabled;
private int mOverlayColor = Color.argb(200, 0xec, 0xec, 0xec);
private float cornerRadius = 0;
private final Path path = new Path();
/**
* will only initial once when class loaded
*/
static {
enabled = (Build.VERSION.SDK_INT >= 19);
}
private final RectF rectF = new RectF();
public BlurDrawable(@NonNull View mBlurredBgView) {
this.mBlurredBgView = mBlurredBgView;
if (enabled) {
initializeRenderScript(mBlurredBgView.getContext());
}
setOverlayColor(mOverlayColor);
}
/**
* used for dialog/fragment/popWindow/dialog
*
* @param activity the blurredView attached
* @see #setDrawOffset
*/
public BlurDrawable(Activity activity) {
this(activity.getWindow());
}
/**
* Set for window
*
* @param blurredWindow another window,void draw self(may throw stackoverflow)
*/
public BlurDrawable(Window blurredWindow) {
this(blurredWindow.getDecorView());
}
@TargetApi(17) private void setBlurRadius(@IntRange(from = 0, to = 25) int radius) {
if (!enabled) {
return;
}
mBlurScript.setRadius(radius);
}
@TargetApi(17) public void setDownSampleFactor(@IntRange(from = 0) int factor) {
if (!enabled) {
return;
}
if (mDownsampleFactor != factor) {
mDownsampleFactor = factor;
mDownsampleFactorChanged = true;
}
}
public void setCornerRadius(float radius) {
this.cornerRadius = radius;
}
/**
* set both for blur and non-blur
*/
public void setOverlayColor(@ColorInt int color) {
mOverlayColor = color;
setColor(color);
}
@TargetApi(17) private void initializeRenderScript(Context context) {
mRenderScript = RenderScript.create(context);
mBlurScript = ScriptIntrinsicBlur.create(mRenderScript, Element.U8_4(mRenderScript));
//设置blur半径, iOS中默认为12px
setBlurRadius(12);
//图片缩放等级，缩放越大越节约性能，理论要在100px^2以内
setDownSampleFactor(8);
}
/**
* 相当于一个单例的初始化
*/
private boolean prepare() {
//assume a 1080 x 1920 RecyclerView
final int width = mBlurredBgView.getWidth();
final int height = mBlurredBgView.getHeight();
if (mBlurringCanvas == null
|| mDownsampleFactorChanged
|| mBlurredViewWidth != width
|| mBlurredViewHeight != height) {
mDownsampleFactorChanged = false;
mBlurredViewWidth = width;
mBlurredViewHeight = height;
int scaledWidth = width / mDownsampleFactor;
int scaledHeight = height / mDownsampleFactor;
// The following manipulation is to avoid some RenderScript artifacts at the edge.
// 136 x 244
scaledWidth = scaledWidth - scaledWidth % 4 + 4;
scaledHeight = scaledHeight - scaledHeight % 4 + 4;
if (mBlurredBitmap == null
|| mBlurredBitmap.getWidth() != scaledWidth
|| mBlurredBitmap.getHeight() != scaledHeight) {
mBitmapToBlur = Bitmap.createBitmap(scaledWidth, scaledHeight, Bitmap.Config.ARGB_8888);
if (mBitmapToBlur == null) {
return false;
}
mBlurredBitmap = Bitmap.createBitmap(scaledWidth, scaledHeight, Bitmap.Config.ARGB_8888);
if (mBlurredBitmap == null) {
return false;
}
}
//创建了一个136 x 244的画板
//当画板调用draw是，将画到mBitmapToBlur上
mBlurringCanvas = new Canvas(mBitmapToBlur);
mBlurringCanvas.scale(1f / mDownsampleFactor, 1f / mDownsampleFactor);
mBlurInput = Allocation.createFromBitmap(mRenderScript, mBitmapToBlur,
Allocation.MipmapControl.MIPMAP_NONE, Allocation.USAGE_SCRIPT);
mBlurOutput = Allocation.createTyped(mRenderScript, mBlurInput.getType());
}
return true;
}
/**
* 渲染任务，可以在16ms完成，可以调用多核
* 将mBitmapToBlur渲染为mBlurredBitmap输出
*/
@TargetApi(17) private void blur(Bitmap mBitmapToBlur, Bitmap mBlurredBitmap) {
if (!enabled) {
return;
}
//类似于c中的alloc，这里是栈内存，这样就把bitmap放入了c的栈中
mBlurInput.copyFrom(mBitmapToBlur);
//滤镜加入输入源
mBlurScript.setInput(mBlurInput);
//滤镜进行渲染并输出到output，类似于DSP
mBlurScript.forEach(mBlurOutput);
//将栈内存复制到bitmap
mBlurOutput.copyTo(mBlurredBitmap);
}
/**
* force enable blur, however it will only works on API 17 or higher
* if your want to support more, use Support RenderScript Pack
*/
public void setEnabled(boolean enabled) {
BlurDrawable.enabled = enabled && (Build.VERSION.SDK_INT >= 17);
}
@TargetApi(17)
public void onDestroy() {
if (!enabled) {
return;
}
if (mRenderScript != null) {
mRenderScript.destroy();
}
}
@Override public void draw(Canvas canvas) {
if (cornerRadius != 0){
path.reset();
rectF.set(0, 0, canvas.getWidth(), canvas.getHeight());
path.addRoundRect(rectF,cornerRadius, cornerRadius, Path.Direction.CCW);
canvas.clipPath(path);
}
if (enabled) {
drawBlur(canvas);
}
//draw overlayColor
super.draw(canvas);
}
@TargetApi(17) private void drawBlur(Canvas canvas) {
if (prepare()) {
//在1920x1080中，只画一个大小为 136 x 244 的RecyclerView，这个View绘制了两次
//类似于开发者选项中的多显示输出
//将bitmaptoblur进行赋值
mBlurredBgView.draw(mBlurringCanvas);
//进行模糊渲染，生成mBlurredBitmap
blur(mBitmapToBlur, mBlurredBitmap);
//
canvas.save();
//这里的是dx，正好与坐标是相反的
canvas.translate(mBlurredBgView.getX() - offsetX, mBlurredBgView.getY() - offsetY);
//实际输出的只有 136 x 244的像素，缩放后就和当前view一样大了
canvas.scale(mDownsampleFactor, mDownsampleFactor);
canvas.drawBitmap(mBlurredBitmap, 0, 0, null);
canvas.restore();
}
}
/**
* set the offset between top view and blurred view
*/
@TargetApi(17)
public void setDrawOffset(float x, float y) {
this.offsetX = x;
this.offsetY = y;
}
public View getmBlurredBgView() {
return mBlurredBgView;
}
}