降采样优化

Signed-off-by: tsm <tianshuangming@h-partners.com>

library/src/main/ets/ImageKnifeDispatcher.ets

@@ -656,11 +656,11 @@ async function requestJob(request: RequestJobRequest, requestList?: List<ImageKn
       editable: true,
       desiredSize: defaultSize
     };
-    let imageInfo = await imageSource.getImageInfo()
+    // let imageInfo = await imageSource.getImageInfo()
     if ((request.downsampType !== DownsampleStrategy.NONE && request.downsampType !== undefined) &&
       request.requestSource == ImageKnifeRequestSource.SRC) {
       let reqSize =
-        new Downsampler().calculateScaling(typeValue, imageInfo.size.width, imageInfo.size.height, request.targetWidth,
+        new Downsampler().calculateScaling(typeValue, size.width, size.height, request.targetWidth,
           request.targetHeight, request.downsampType)
       opts = {
         editable: true,
@@ -682,12 +682,12 @@ async function requestJob(request: RequestJobRequest, requestList?: List<ImageKn
       type:typeValue
     };
   }
-
-  let imageInfo = await imageSource.getImageInfo()
+  let size = (await imageSource.getImageInfo()).size
+  // let imageInfo = await imageSource.getImageInfo()
   if ((request.downsampType !== undefined && request.downsampType !== DownsampleStrategy.NONE) &&
     request.requestSource == ImageKnifeRequestSource.SRC) {
     let reqSize =
-      new Downsampler().calculateScaling(typeValue, imageInfo.size.width, imageInfo.size.height, request.targetWidth,
+      new Downsampler().calculateScaling(typeValue, size.width, size.height, request.targetWidth,
         request.targetHeight, request.downsampType)
 
     decodingOptions = {
@@ -698,7 +698,7 @@ async function requestJob(request: RequestJobRequest, requestList?: List<ImageKn
       }
     }
   }
-  let size = (await imageSource.getImageInfo()).size
+
   await imageSource.createPixelMap(decodingOptions)
     .then((pixelmap: PixelMap) => {
       resPixelmap = pixelmap

library/src/main/ets/downsampling/DownsampleStartegy.ets

@@ -20,7 +20,7 @@ export class FitCenter implements BaseDownsampling {
     return "FitCenter"
   }
 
-  getScaleFactor(sourceWidth: number, sourceHeight: number, requestedWidth: number, requestedHeight: number,downsampType:DownsampleStrategy
+  getScaleFactor(sourceWidth: number, sourceHeight: number, requestedWidth: number, requestedHeight: number,downsampType:DownsampleStrategy |undefined
     ): number {
     if (downsampType===DownsampleStrategy.FIT_CENTER_MEMORY) {
       const widthPercentage = requestedWidth / sourceWidth
@@ -34,7 +34,7 @@ export class FitCenter implements BaseDownsampling {
   }
 
   //实现 getSampleSizeRounding 方法
-  getSampleSizeRounding(sourceWidth: number, sourceHeight: number, requestedWidth: number, requestedHeight: number,downsampType:DownsampleStrategy
+  getSampleSizeRounding(sourceWidth: number, sourceHeight: number, requestedWidth: number, requestedHeight: number,downsampType:DownsampleStrategy|undefined
     ): number {
     if (downsampType===DownsampleStrategy.FIT_CENTER_QUALITY) {
       return SampleSizeRounding.QUALITY;
@@ -121,7 +121,7 @@ export class CenterInside implements BaseDownsampling {
     return "CenterInside"
   }
 
-  getScaleFactor(sourceWidth: number, sourceHeight: number, requestedWidth: number, requestedHeight: number,downsampType:DownsampleStrategy
+  getScaleFactor(sourceWidth: number, sourceHeight: number, requestedWidth: number, requestedHeight: number,downsampType:DownsampleStrategy|undefined
     ): number {
     //获取 FIT_CENTER 的缩放因子
     const fitCenterScaleFactor: ESObject =
@@ -131,21 +131,20 @@ export class CenterInside implements BaseDownsampling {
 
   }
 
-  getScale(sourceWidth: number, sourceHeight: number, requestedWidth: number, requestedHeight: number,downsampType:DownsampleStrategy
-    ): number {
-    if (downsampType===DownsampleStrategy.FIT_CENTER_QUALITY) {
+  getScale(sourceWidth: number, sourceHeight: number, requestedWidth: number, requestedHeight: number,downsampType:DownsampleStrategy|undefined
+  ): number {
+    if (downsampType===DownsampleStrategy.FIT_CENTER_MEMORY) {
       const widthPercentage = requestedWidth / sourceWidth
       const heightPercentage = requestedHeight / sourceHeight
       return Math.min(widthPercentage, heightPercentage)
     } else {
-      //类似 AT_LEAST,但只要求一个维度或另一个维度大于等于请求的尺寸
       const maxIntegerFactor = Math.max(sourceHeight / requestedHeight, sourceWidth / requestedWidth);
-      return maxIntegerFactor === 0 ? 1 : 1 / highestOneBit(maxIntegerFactor);
-
+      const a = maxIntegerFactor === 0 ? 1 : 1 / highestOneBit(maxIntegerFactor)
+      return a;
     }
   }
 
-  getSampleSizeRounding(sourceWidth: number, sourceHeight: number, requestedWidth: number, requestedHeight: number,downsampType:DownsampleStrategy
+  getSampleSizeRounding(sourceWidth: number, sourceHeight: number, requestedWidth: number, requestedHeight: number,downsampType:DownsampleStrategy|undefined
     ): SampleSizeRounding {
     //如果缩放因子为 1，表示没有缩放，优先选择质量
     if (this.getScaleFactor(sourceWidth, sourceHeight, requestedWidth, requestedHeight, downsampType) === 1) {
@@ -155,7 +154,7 @@ export class CenterInside implements BaseDownsampling {
     return this.getSampleSize(sourceWidth, sourceHeight, requestedWidth, requestedHeight,downsampType);
   }
 
-  getSampleSize(sourceWidth: number, sourceHeight: number, requestedWidth: number, requestedHeight: number,downsampType:DownsampleStrategy
+  getSampleSize(sourceWidth: number, sourceHeight: number, requestedWidth: number, requestedHeight: number,downsampType:DownsampleStrategy|undefined
     ): SampleSizeRounding {
     if (downsampType===DownsampleStrategy.CENTER_INSIDE_MEMORY) {
       return SampleSizeRounding.MEMORY;

library/src/main/ets/downsampling/Downsampler.ets

@@ -30,82 +30,33 @@ export interface calculateScaleType {
 export class Downsampler {
   calculateScaling(
     typeValue: string | null,
-    sourceHeight: number, //原始宽高
+    // TODO 宽高调整
     sourceWidth: number | undefined, //原始宽高
-    requestHeight: number, //请求宽高
+    sourceHeight: number, //原始宽高
     requestWidth: number, //请求宽高
+    requestHeight: number, //请求宽高
     downsampType: DownsampleStrategy | undefined,
-
   ): calculateScaleType {
-    let degreesToRotate: ESObject = 90;
     const fileType = typeValue //获取图片类型
-    let powerOfTwoWidth: number | null = null;
-    let powerOfTwoHeight: number | null = null;
-    let targetWidth: number = 0
-    let targetHeight: number = 0
-
+    // TODO 命名修改 powerOfTwoWidth改为targetWidth
+    let targetWidth: number | null = null;
+    let targetHeight: number | null = null;
     if (sourceHeight <= 0 || sourceWidth == undefined || sourceWidth == null || sourceWidth <= 0) {
-      throw new Error("Cannot found width or height");
+      throw new Error("Cannot found width or height"); // TODO catch
     }
-    let orientedSourceWidth = sourceWidth;
-    let orientedSourceHeight = sourceHeight;
-    if (this.isRotationRequired(degreesToRotate)) {
-      orientedSourceWidth = sourceHeight;
-      orientedSourceHeight = sourceWidth;
-    }
-    if (requestWidth && !requestHeight) {
-      targetWidth = this.round((requestHeight) * orientedSourceWidth / orientedSourceHeight)
-    } else if (requestHeight && !requestWidth) {
-      targetHeight = this.round((requestWidth) * orientedSourceHeight / orientedSourceWidth)
-    } else if (requestHeight && requestWidth) {
-      targetWidth =
-        requestHeight == sourceWidth ? (this.isRotationRequired(degreesToRotate) ? sourceHeight : sourceWidth) :
-          requestWidth;
-      targetHeight =
-        requestHeight == sourceHeight ? (this.isRotationRequired(degreesToRotate) ? sourceWidth : sourceHeight) :
-          requestWidth;
-    } else {
-      throw new Error("Cannot found width or height");
-    }
-    let exactScaleFactor: number | undefined
-    let rounding: SampleSizeRounding | undefined
-    if(downsampType===DownsampleStrategy.FIT_CENTER_MEMORY || downsampType===DownsampleStrategy.FIT_CENTER_QUALITY){
-      exactScaleFactor = new FitCenter()
-        .getScaleFactor(orientedSourceWidth, orientedSourceHeight, targetWidth, targetHeight,downsampType)
-      rounding = new FitCenter()
-        .getSampleSizeRounding(orientedSourceWidth, orientedSourceHeight, targetWidth, targetHeight,downsampType)
-
-    }else if(downsampType===DownsampleStrategy.NONE){
-      exactScaleFactor = new None()
-        .getScaleFactor(orientedSourceWidth, orientedSourceHeight, targetWidth, targetHeight)
-      rounding = new None()
-        .getSampleSizeRounding(orientedSourceWidth, orientedSourceHeight, targetWidth, targetHeight)
-    }else if( downsampType===DownsampleStrategy.AT_MOST){
-      exactScaleFactor = new AtMost()
-        .getScaleFactor(orientedSourceWidth, orientedSourceHeight, targetWidth, targetHeight)
-      rounding = new AtMost()
-        .getSampleSizeRounding(orientedSourceWidth, orientedSourceHeight, targetWidth, targetHeight)
-    }else if(downsampType===DownsampleStrategy.CENTER_INSIDE_MEMORY || downsampType===DownsampleStrategy.CENTER_INSIDE_QUALITY){
-      exactScaleFactor = new CenterInside()
-        .getScaleFactor(orientedSourceWidth, orientedSourceHeight, targetWidth, targetHeight,downsampType)
-      rounding = new CenterInside()
-        .getSampleSizeRounding(orientedSourceWidth, orientedSourceHeight, targetWidth, targetHeight,downsampType)
-    }else if(downsampType===DownsampleStrategy.CENTER_OUTSIDE){
-      exactScaleFactor = new CenterOutside()
-        .getScaleFactor(orientedSourceWidth, orientedSourceHeight, targetWidth, targetHeight)
-      rounding = new CenterOutside()
-        .getSampleSizeRounding(orientedSourceWidth, orientedSourceHeight, targetWidth, targetHeight)
+    if(downsampType===undefined){
+      throw new Error("Cannot found downsampType");
     }
+    let downsampler = this.getDownsampler(downsampType);
+    let exactScaleFactor : number = downsampler.getScaleFactor(sourceWidth, sourceHeight, requestWidth, requestHeight, downsampType);
+    let rounding: SampleSizeRounding= downsampler.getSampleSizeRounding(sourceWidth, sourceHeight, requestWidth, requestHeight, downsampType);
     if (exactScaleFactor==undefined|| exactScaleFactor <= 0 ) {
       throw new Error("Cannot round with exactScaleFactor");
     }
-    if (rounding == undefined) {
-      throw new Error("Cannot round with null rounding");
-    }
-    let outWidth: number = this.round(exactScaleFactor * orientedSourceWidth);
-    let outHeight: number = this.round(exactScaleFactor * orientedSourceHeight);
-    let widthScaleFactor = orientedSourceWidth / outWidth;
-    let heightScaleFactor = orientedSourceHeight / outHeight;
+    let outWidth: number = this.round(exactScaleFactor * sourceWidth);
+    let outHeight: number = this.round(exactScaleFactor * sourceHeight);
+    let widthScaleFactor = sourceWidth / outWidth;
+    let heightScaleFactor = sourceHeight / outHeight;
     let scaleFactor = rounding ==SampleSizeRounding.QUALITY ? Math.max(widthScaleFactor, heightScaleFactor) :
     Math.min(widthScaleFactor, heightScaleFactor) //将整型的缩放因子转换为2的次幂采样大小
     let powerOfTwoSampleSize: number = scaleFactor;
@@ -115,27 +66,36 @@ export class Downsampler {
     }
     //基于上一步得出的采样大小，根据不同的图片类型，计算采样后的图片尺寸
     if (fileType === "png") {
-      powerOfTwoWidth = Math.floor(orientedSourceWidth / powerOfTwoSampleSize);
-      powerOfTwoHeight = Math.floor(orientedSourceHeight / powerOfTwoSampleSize);
+      targetWidth = Math.floor(sourceWidth / powerOfTwoSampleSize);
+      targetHeight = Math.floor(sourceHeight / powerOfTwoSampleSize);
     } else if (fileType === "webp") {
-      powerOfTwoWidth = Math.round(orientedSourceWidth / powerOfTwoSampleSize);
-      powerOfTwoHeight = Math.round(orientedSourceHeight / powerOfTwoSampleSize);
+      targetWidth = Math.round(sourceWidth / powerOfTwoSampleSize);
+      targetHeight = Math.round(sourceHeight / powerOfTwoSampleSize);
     } else {
-      powerOfTwoWidth = orientedSourceWidth / powerOfTwoSampleSize;
-      powerOfTwoHeight = orientedSourceHeight / powerOfTwoSampleSize;
+      targetWidth = sourceWidth / powerOfTwoSampleSize;
+      targetHeight = sourceHeight / powerOfTwoSampleSize;
+    }
+    return  { targetWidth, targetHeight }
+  }
+  getDownsampler(downsampType:DownsampleStrategy) {
+    switch (downsampType) {
+      case DownsampleStrategy.FIT_CENTER_MEMORY:
+      case DownsampleStrategy.FIT_CENTER_QUALITY:
+        return new FitCenter();
+      case DownsampleStrategy.NONE:
+        return new None();
+      case DownsampleStrategy.AT_MOST:
+        return new AtMost();
+      case DownsampleStrategy.CENTER_INSIDE_MEMORY:
+      case DownsampleStrategy.CENTER_INSIDE_QUALITY:
+        return new CenterInside();
+      case DownsampleStrategy.CENTER_OUTSIDE:
+        return new CenterOutside();
+      default:
+        throw new Error('Unsupported downsampling strategy');
     }
-    let a: calculateScaleType = {
-      "targetWidth": powerOfTwoWidth,
-      "targetHeight": powerOfTwoHeight
-    }
-    return a
   }
-
   round(value: number): number {
     return Math.floor(value + 0.5);
   }
-
-  isRotationRequired(degreesToRotate: number): boolean {
-    return degreesToRotate == 90 || degreesToRotate == 270;
-  }
 }