hu de yi

In modern page development, SPA requires the destruction of the Spreadsheet when routing switches. How do I destroy the Spreadsheet? ```js sp.dispose(); ? //or sp.destroy(); ```

 when page has scroll I have automatically scrolled to change the table. I want to disable the change operation, otherwise when I open the page, I will scroll to...

透明瓦片，而不是背景颜色是黑色的 - 默认的黑色瓦片会导致地形解码出问题   - 这个pr的目的让生成的瓦片默认透明  

vt的性能太差了

1

demo:http://examples.maptalks.com/examples/cn/vector/vtlayer/load-mapbox

https://github.com/pissang/geometry-extrude/blob/51e34cbd098d23425e9176ff5f98f9170aa4959b/src/main.js?_pjax=%23js-repo-pjax-container#L616 ```js const {indices, vertices, splittedMap, topVertices, holes, depth} = preparedData[p]; const bevelSize = Math.min(depth / 2, opts.bevelSize); const bevelSegments = !(bevelSize > 0) ? 0 : opts.bevelSegments; //hole is...

fix #2337

fix #1720

fix #1637