fix: 截图抗锯齿

src/sdk/cover/index.js

@@ -313,7 +313,7 @@ export const enter = (dom, isLocal) => {
         
         screenshot: (width, height, bgOpacity=1) => {
             //截图  
-            var {getImagePromise, finishPromise} =  viewer.startScreenshot({ type: 'default', useRenderTarget:true, bgOpacity }, width, height) 
+            var {getImagePromise, finishPromise} =  viewer.startScreenshot({ type: 'default', /* useRenderTarget:true,  */bgOpacity }, width, height) 
             var deferred = $.Deferred();
             finishPromise.done(({dataUrl}) => {
                deferred.resolve(dataUrl)