From 22f79c3588f8349d1d700528634b1076a600902e Mon Sep 17 00:00:00 2001
From: sijainguo <547537959@qq.com>
Date: Fri, 26 Apr 2024 22:09:24 +0800
Subject: [PATCH] =?UTF-8?q?=E6=8F=90=E4=BA=A4=20Downsampler=20=E7=B1=BB?=
MIME-Version: 1.0
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---
 .../imageknife/Downsampling/Downsampler.ets   | 138 +++++++++++++++++-
 1 file changed, 137 insertions(+), 1 deletion(-)

diff --git a/library/src/main/ets/components/imageknife/Downsampling/Downsampler.ets b/library/src/main/ets/components/imageknife/Downsampling/Downsampler.ets
index 317587f..568ab4a 100644
--- a/library/src/main/ets/components/imageknife/Downsampling/Downsampler.ets
+++ b/library/src/main/ets/components/imageknife/Downsampling/Downsampler.ets
@@ -1,2 +1,138 @@
 /*
- * asdfasdfasdfasdfasdf*/
\ No newline at end of file
+ * asdfasdfasdfasdfasdf*/
+import { CenterOutside, FitCenter, SampleSizeRounding } from './Downsamplestrategy';
+import { FileTypeutil } from '../../utits/Fitetypeutit';
+import { Request0ption } from '../../Requestoption';
+let TAG = 'downsampling'
+export class Downsampler {
+  calculateScaling(
+    imageType: ArrayBuffer,
+    sourceHeight:number,
+    sourceWidth:number,
+    request?: RequestOption
+  ):ESObject {
+    const fileType: string | null = new FileTypeUtil().getFileType(imageType)
+    let powerOfTwoWidth: number | null = null;
+    let powerOfTwoHeight: number | null = null;
+    let targetWidth: number = 0
+    let targetHeight: number = 0
+    if (request?.size.width && !request?.size.height) {
+      targetWidth = this.round((request?.size.height) * sourceWidth / sourceHeight)
+    } else if (request?.size.height && !request?.size.width) {
+      targetHeight = this.round((request?.size.width) * sourceHeight / sourceWidth)
+    } else if (request?.size.height && request?.size.width) {
+      targetHeight = request.size.height;
+      targetWidth = request?.size.width;
+    } else {
+      console.log('宽高都不存在')
+    }
+    if (sourceWidth <= 0 || sourceleight <= 0) return;
+    let orientedSourceWidth = sourceWidth;
+    let orientedSourceHeight = sourceHeight;
+    if (this.isRotationRequired(90)) {
+      orientedSourceWidth = sourceHeight;
+      orientedSourceHeight = sourceWidth;
+    }
+    /*安卓的模式*/
+    let exactScaleFactor: number = FitCenter.getScaleFactor(orientedSourceWidth, orientedSourceHeight, targetWidth, targetHeight)
+    if (exactScaleFactor <= 0) {
+      throw new Error("Cannot	round	with exactScaleFactor");
+      console.log('exactScaleFactor', exactScaleFactor)
+      /*安卓的模式*/
+      let rounding: SampleSizeRounding = Center0utside.getSampleSizeRounding(orientedSourceWidth, orientedSourceHeight, targetWidth, targetHeight)
+      if (rounding == null) {
+        throw new Error("Cannot round with null rounding");
+      }
+      let outWidth: number = this.round(exactScaleFactor * orientedSourceWidth);
+      let outHeight: number = this.round(exactScaleFactor * orientedSourceHeight);
+      let widthScaleFactor = Math.floor(orientedSourceWidth / outWidth);
+      let heightScaleFactor = Math.floor(orientedSourceHeight / outHeight);
+      let scaleFactor = rounding == SampleSizeRounding.MEMORY ? Math.max(widthScaleFactor, heightScaleFactor) : Math.min(widthScaleFactor, heightScaleFactor)
+      let powerOfTwoSampleSize: number;
+      powerOfTwoSampleSize = Math.max(1, this.highestOneBit(scaleFactor));
+      if (fileType == "JPEG") {
+        let nativeScaling = Hath.min(powerOfTwoSampleSize, 8);
+        powerOfTwoWidth = Math.ceil(orientedSourceWidth / nativeScaling);
+        powerOfTwoHeight = Math.ceil(orientedSourceHeight / nativeScaling);
+        let secondaryScaling = Math.floor(powerOfTwoSampleSize / 8);
+        if (secondaryScaling > 0) {
+          powerOfTwoWidth = powerOfTwoWidth / secondaryScaling;
+          powerOfTwoHeight = powerOfTwoHeight / secondaryScaling;
+        }
+      } else if (fileType == "PNG") {
+        powerOfTwoWidth = Math.floor(orientedSourceWidth / powerOfTwoSampleSize);
+        PowerOfTwoHeight = Math.floor(orientedSourceHeight / powerOfTwoSamplesize);
+        console.log('执行了没', powerOfTwoHeight, powerOfTwoWidth)
+      } else if (fileType == "WEBP") {
+        powerOfTwoWidth = Math.round(orientedSourceWidth / powerOfTwoSampleSize);
+        poWerOfTwoHeight = Math.round(orientedSourceHeight / powerOfTwoSampleSize);
+      } else if (
+        orientedSourceWidth % powerOfTwoSampleSize != 0 || orientedSourceHeight % powerOfTwoSampleSize != 0) {
+
+
+        // let dimensions; number[] = this.getDimensions(imageReader, options, decodeCallbacks,bitmapPool);
+        // powerOfTwoWidth = dimensions[0];
+        // powerofTwoHeight = dimensions[1];
+      } else {
+        powerOfTwoWidth = orientedSourceWidth / powerOfTwoSampleSize;
+        powerOfTwoHeight = orientedSourceHeight / powerOfTwoSampleSize;
+      }
+      // Let adjustedScaleFactor = downsampleStrategy.getScaleFactor(powerOfTwoWidth, powerOfTwoHeight, targetWidth, targetHeight);
+      // Density scaling is only supported if inBitmap is null prior to KitKat. Avoid setting
+      // densities here so we calculate the final Bitmap size correctly.
+      // if (Build.VERSION,SDK_INT >=Build.VERSION_CODES.KITKAT) {
+      // options.inTargetDensity = this.adjustTargetDensityForError(adjustedScaleFactor);
+      // options,inDensity = this.getDensityMultiplier(adjustedScaleFactor);
+      //}
+      // if (this.isScaling(options)){
+      //   options.inScaled = true;
+      // }else {
+      //   options.inDensity = options.inTargetDensity =0;
+      // }
+      //}
+      let a: ESObject = { "targetWidth": power0fTwoWidth, "targetHeight": powerOfTuoHeight }
+      return a
+    }
+    //decodeStream(imageReader:ImageReader, options: ESObject, callbacks: DecodeCallbacks, bitmapPool: ESObject) {
+        //if (!options.inJustDecodeBounds){
+        // callbacks.onObtainBounds();
+        // imageReader.stopGrowingBuffers();
+    //   }
+    // }
+    // getDimensions(imageReader: ImageReader, options: ESObject, decodeCallbacks: DecodeCallbacks, bitmapPool: ESObject):number[] {
+    //     options.inJustDecodeBounds = true;
+    //     this.decodeStream(imageReader, options, decodeCallbacks, bitmapPool);
+    //     options.inJustDecodeBounds =false;
+    //     return new Array(options.outWidth, options,outHeight);
+    //
+    // }
+
+    highest0neBit(i: number): number{
+      i |= (i >> 1);
+      i |= (i >> 2);
+      i |= (i >> 4);
+      i |= (i >> 8);
+      i |= (i >> 16);
+      return i - (i >>> 1);
+    }
+    round(value: number): number {
+      return Math.floor(value +0.5);
+    }
+    isRotationRequired(degreesToRotate: number): boolean{
+      return degreesToRotate == 90 || degreesToRotate == 270;
+      // isScaling(options: ESObject): boolean {
+      //	return options.inTargetDensity >0
+      //	&& options.inDensity>0
+      //	&& options.inTargetDensity != options.inDensity;
+      //}
+      getDensityMultiplier(adjustedScaleFactor: number):number{
+        return Math.round(Number.MAX_VALUE * (adjustedScaleFactor <= 1 ? adjustedScaleFactor : 1 / adjustedScaleFactor));
+      }
+      adjustTargetDensityForError(adjustedScaleFactor:number):number{
+        let densityMultiplier = this.getDensityMultiplier(adjustedScaleFactor);
+        let targetDensity = this.round(densityMultiplier * adjustedScaleFactor);
+        let scaleFactorWithError = targetDensity / densityMultiplier;
+        let difference = adjustedScaleFactor / scaleFactorWithError;
+        return this.round(difference * targetDensity);
+      }
+    }
\ No newline at end of file