https://github.com/springmeyer/vt-overzooming-clipping-testcase
Testcase demonstrating a possible vt compositing bug in node-mapnik/mapnik-vt.
https://github.com/springmeyer/vt-overzooming-clipping-testcase
Last synced: 7 months ago
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Testcase demonstrating a possible vt compositing bug in node-mapnik/mapnik-vt.
- Host: GitHub
- URL: https://github.com/springmeyer/vt-overzooming-clipping-testcase
- Owner: springmeyer
- Created: 2017-04-04T21:28:13.000Z (about 9 years ago)
- Default Branch: master
- Last Pushed: 2017-05-03T22:15:40.000Z (about 9 years ago)
- Last Synced: 2024-12-28T18:28:04.953Z (over 1 year ago)
- Language: JavaScript
- Size: 3.91 KB
- Stars: 0
- Watchers: 1
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: readme.md
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README
Testcase visualizing vt compositing and overzooming in node-mapnik/mapnik-vt.
## Setup
Run:
```
npm install
npm install -g geojsonio-cli
```
## Details
This testcase generally:
- Creates source data on the fly that is "padded" (extends outside the extent of the tile being composited)
- Adds polygons representing the padded source data ("parent") and the exact tile extent ("child")
- Composites the tile to a new overzoomed tile
- Outputs the result (combined with the original geojson) to a final geojson that can be visualized in geojson.io
The idea is to make changes to the script, then re-run the result to quickly view the impact.
## Usage
Sample usage that renders a tile with a 256 px buffer (double the tile extent):
```
node overzoom.js --z 6 --x 11 --y 23 --buffer 256 | geojsonio
```
Note: http://www.maptiler.org/google-maps-coordinates-tile-bounds-projection/ is a good reference for trying different tiles