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ImageKnife
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降采样适配3.x 

Signed-off-by: tsm <2418639820@qq.com>
This commit is contained in:
tsm 2024-05-22 15:56:09 +08:00
parent 2ace95a345
commit 488619cd18
1 changed files with 5 additions and 51 deletions
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56
library/src/main/ets/downsampling/DownsampleStartegy.ets
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@ -14,13 +14,11 @@
*/
import { BaseDownsampling } from './BaseDownsampling';
import { highestOneBit,SampleSizeRounding } from './downsampleUtils';
//FitCenter类实现DownsampleStartegy
@Sendable
export class FitCenter implements BaseDownsampling {
getName() {
return "FitCenter"
}
//实现 getScaleFactor 方法
getScaleFactor(sourceWidth: number, sourceHeight: number, requestedWidth: number, requestedHeight: number,autoResize?:boolean): number {
const IS_BITMAP_FACTORY_SCALING_SUPPORTED = autoResize; //这里需要根据实际情况设置这个值
@ -43,22 +41,16 @@ export class FitCenter implements BaseDownsampling {
if (!IS_BITMAP_FACTORY_SCALING_SUPPORTED) {
return 0;
} else {
// TODO: 这个逻辑可能不正确，但是如果不这样做，我们可能会跳过一个采样尺寸，因为 QUALITY 更喜欢宽度和高度缩放因子中比较小的那个
// MEMORY 折中方案,他让我们更喜欢两者中较大的那个
return SampleSizeRounding.MEMORY;
}
}
}
//None 类实现 DownsampleStrategy 接口
@Sendable
export class None implements BaseDownsampling{
getName(): string{
return "DownsampleNone"
}
//实现 getScaleFactor 方法
public getScaleFactor(sourceWidth: number, sourceHeight: number, requestedWidth: number, requestedHeight: number): number {
//不进行任何下采样，缩放因子为 1
return 1;
@ -66,7 +58,6 @@ export class None implements BaseDownsampling{
//实现 getSampleSizeRounding 方法
public getSampleSizeRounding(sourceWidth: number, sourceHeight: number, requestedWidth: number, requestedHeight: number): SampleSizeRounding {
//总是返回 QUALITY
return SampleSizeRounding.QUALITY
}
@ -81,7 +72,6 @@ export class CenterOutside implements BaseDownsampling {
return "CenterOutside"
}
//实现 getScaleFactor 方法
getScaleFactor(sourceWidth: number, sourceHeight: number, requestedWidth: number, requestedHeight: number): number {
const widthPercentage = requestedWidth / sourceWidth;
const heightPercentage = requestedHeight / sourceHeight;
@ -89,7 +79,6 @@ export class CenterOutside implements BaseDownsampling {
return Math.max(widthPercentage, heightPercentage);
}
//实现 getSampleSizeRounding 方法
getSampleSizeRounding(sourceWidth: number, sourceHeight: number, requestedWidth: number, requestedHeight: number): SampleSizeRounding {
//根据 CenterOutside 的逻辑，总是返回 QUALITY
return SampleSizeRounding.QUALITY;
@ -99,11 +88,6 @@ export class CenterOutside implements BaseDownsampling {
/*请求尺寸大于实际尺寸不进行放大,按照原图展示*/
@Sendable
export class Atleast implements BaseDownsampling {
//构造函数
constructor(){
//TypeScript 默认构造函数不需要特殊标记
}
getName() {
return "AtLeast"
}
@ -115,7 +99,6 @@ export class Atleast implements BaseDownsampling {
//根据最小整数因子计算缩放因子
return minIntegerFactor === 0 ? 1 : 1 / highestOneBit(minIntegerFactor);
}
//实现 getSampleSizeRounding 方法
public getSampleSizeRounding(sourceWidth: number, sourceHeight: number, requestedWidth: number, requestedHeight: number): SampleSizeRounding {
//总是返回 QUALITY
return SampleSizeRounding.QUALITY
@ -134,24 +117,15 @@ export class AtMost implements BaseDownsampling {
const maxIntegerFactor = Math.ceil(Math.max(sourceHeight / requestedHeight, sourceWidth / requestedWidth));
let lesserOrEqualSampleSize = Math.max(1, highestOneBit(maxIntegerFactor));
let greaterOrEqualSampleSize = lesserOrEqualSampleSize
// if (lesserOrEqualSampleSize < maxIntegerFactor) {
// let greaterOrEqualSampleSize = lesserOrEqualSampleSize <<= 1; // lest shift by 1
// }
if (lesserOrEqualSampleSize < maxIntegerFactor) {
greaterOrEqualSampleSize = lesserOrEqualSampleSize <<= 1;
}
greaterOrEqualSampleSize = lesserOrEqualSampleSize << (lesserOrEqualSampleSize < maxIntegerFactor ? 1 : 0)
//返回缩放因子
return 1 / greaterOrEqualSampleSize
}
highestOneBit(i: number): number {
i |= (i >> 1);
i |= (i >> 2);
i |= (i >> 4);
i |= (i >> 8);
i |= (i >> 16);
return i - (i >>> 1);
}
//实现 getSampleSizeRounding 方法
getSampleSizeRounding(sourceWidth: number, sourceHeight: number, requestedWidth: number, requestHeight: number): SampleSizeRounding {
//根据 AtMost 的逻辑，总是返回 MEMORY
return SampleSizeRounding.MEMORY
@ -166,18 +140,16 @@ export class CenterInside implements BaseDownsampling {
return "CenterInside"
}
//实现 getScaleFactor 方法
getScaleFactor(sourceWidth: number, sourceHeight: number, requestedWidth: number, requestedHeight: number,autoResize?:boolean): number {
//获取 FIT_CENTER 的缩放因子
const fitCenterScaleFactor : ESObject = this.getScale(sourceWidth,sourceHeight,requestedWidth,requestedHeight,autoResize);
//实现 getScaleFactor 方法
//返回不超过 1 的缩放因子，即尽量缩小图像以适应目标尺寸，但不会放大
return Math.min(1,fitCenterScaleFactor);
}
getScale(sourceWidth: number, sourceHeight: number, requestedWidth: number, requestedHeight: number,autoResize?:boolean): number {
const IS_BITMAP_FACTORY_SCALING_SUPPORTED = autoResize; //这里需要根据实际情况设置这个值
const IS_BITMAP_FACTORY_SCALING_SUPPORTED = autoResize;
if (IS_BITMAP_FACTORY_SCALING_SUPPORTED) {
const widthPercentage = requestedWidth / sourceWidth
const heightPercentage = requestedHeight / sourceHeight
@ -190,9 +162,6 @@ export class CenterInside implements BaseDownsampling {
}
}
//实现 getSampleSizeRounding 方法
getSampleSizeRounding(sourceWidth: number, sourceHeight: number, requestedWidth: number, requestedHeight: number,autoResize?:boolean): 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,autoResize) === 1) {
@ -201,27 +170,12 @@ export class CenterInside implements BaseDownsampling {
//否则，使用 FIL_CENTER 的 SampleSizeRounding 值
return this.getSampleSize(sourceWidth,sourceHeight,requestedWidth,requestedHeight);
}
highestOneBit(i: number): number {
i |= (i >> 1);
i |= (i >> 2);
i |= (i >> 4);
i |= (i >> 8);
i |= (i >> 16);
return i - (i >>> 1);
}
//实现 getSampleSizeRounding 方法
getSampleSize(sourceWidth: number, sourceHeight: number, requestedWidth: number, requestedHeight: number,autoResize?:boolean): SampleSizeRounding {
const IS_BITMAP_FACTORY_SCALING_SUPPORTED = autoResize; //这里需要根据实际情况设置这个值
const IS_BITMAP_FACTORY_SCALING_SUPPORTED = autoResize;
if (IS_BITMAP_FACTORY_SCALING_SUPPORTED) {
return 0;
} else {
// TODO: 这个逻辑可能不正确，但是如果不这样做，我们可能会跳过一个采样尺寸，因为 QUALITY 更喜欢宽度和高度缩放因子中比较小的那个
// MEMORY 折中方案,他让我们更喜欢两者中较大的那个
//
// }
return SampleSizeRounding.MEMORY;
}
}