降采样适配SVG图片

library/src/main/ets/components/imageknife/Downsampling/Downsampler.ets

@@ -5,6 +5,7 @@ import { FileTypeUtil } from '../utils/FileTypeUtil';
 import { CenterOutside, FitCenter, SampleSizeRounding } from './DownsampleStartegy';
 
 let TAG = 'downsampling'
+
 export class Downsampler {
   calculateScaling(
     imageType: ArrayBuffer,
@@ -50,8 +51,12 @@ export class Downsampler {
     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)
+    // 将整型的缩放因子转换为2的次幂采样大小
     let powerOfTwoSampleSize: number;
-      powerOfTwoSampleSize = Math.max(1, this.highestOneBit(scaleFactor));
+    if (rounding == SampleSizeRounding.MEMORY && powerOfTwoSampleSize < (1 / exactScaleFactor)) {
+      powerOfTwoSampleSize = powerOfTwoSampleSize << 1;
+    }
+    // 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 == "JPEG") {
       let nativeScaling = Math.min(powerOfTwoSampleSize, 8);
       powerOfTwoWidth = Math.ceil(orientedSourceWidth / nativeScaling);
@@ -95,6 +100,7 @@ export class Downsampler {
     let a: ESObject = { "targetWidth": powerOfTwoWidth, "targetHeight": powerOfTwoHeight }
     return a
   }
+
   //decodeStream(imageReader:ImageReader, options: ESObject, callbacks: DecodeCallbacks, bitmapPool: ESObject) {
   //if (!options.inJustDecodeBounds){
   // callbacks.onObtainBounds();
@@ -117,12 +123,15 @@ export class Downsampler {
     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
@@ -131,6 +140,7 @@ export class Downsampler {
   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);

library/src/main/ets/components/imageknife/utils/ParseImageUtil.ets

@@ -20,7 +20,12 @@ import { RequestOption } from '../RequestOption';
 import { Downsampler } from '../Downsampling/Downsampler';
 
 export class ParseImageUtil implements IParseImage<PixelMap> {
-  parseImage(imageinfo: ArrayBuffer, onCompleteFunction: (value: PixelMap) => void | PromiseLike<PixelMap>, onErrorFunction: (reason?: BusinessError | string) => void,request?:RequestOption) {
+  parseImage(
+    imageinfo: ArrayBuffer,
+    onCompleteFunction: (value: PixelMap) => void | PromiseLike<PixelMap>,
+    onErrorFunction: (reason?: BusinessError | string) => void,
+    request?:RequestOption
+  ) {
     this.parseImageThumbnail(1, imageinfo, onCompleteFunction, onErrorFunction,request)
   }
 

library/src/main/ets/components/imageknife/utils/svg/SVGParseImpl.ets

@@ -34,6 +34,29 @@ export class SVGParseImpl implements IParseSvg {
       editable: true,
       desiredSize: defaultSize
     };
+    imageSource.getInageInfo().then((value) => {
+      let hValue = Math.round(value.size.height);
+      let wValue = Math.round(value.size.width);
+      let defaultSize: image.size = {
+        height: hValue,
+        width: wValue
+      };
+      let opts: image.DecodingOptions = {
+        editable: true,
+        desiredSize: defaultSize
+      };
+      if (option?.downsampType.getName() !== 'DownsampleNone') {
+        const b: ESObject = new Downsampler().calculateScaling(imageInfo, hValue, wValue, option)
+        console.log("bbb-----", JSON.stringify(b))
+        opts = {
+          editable: true,
+          desiredSize: {
+            width: b.targetWidth,
+            height: b.targetHeight
+          }
+        }
+      }
+    })
     imageSource.createPixelMap(opts).then((pixelMap: image.PixelMap) => {
       let imageKnifeData = ImageKnifeData.createImagePixelMap(ImageKnifeType.PIXELMAP, pixelMap)
       onComplete(imageKnifeData?.drawPixelMap?.imagePixelMap as PixelMap);