{"action":"opened","issue":{"url":"https://api.github.com/repos/rrag/react-stockcharts/issues/22","labels_url":"https://api.github.com/repos/rrag/react-stockcharts/issues/22/labels{/name}","comments_url":"https://api.github.com/repos/rrag/react-stockcharts/issues/22/comments","events_url":"https://api.github.com/repos/rrag/react-stockcharts/issues/22/events","html_url":"https://github.com/rrag/react-stockcharts/issues/22","id":110627974,"number":22,"title":"Improve canvas draw performance","user":{"login":"rrag","id":10691183,"avatar_url":"https://avatars.githubusercontent.com/u/10691183?v=3","gravatar_id":"","url":"https://api.github.com/users/rrag","html_url":"https://github.com/rrag","followers_url":"https://api.github.com/users/rrag/followers","following_url":"https://api.github.com/users/rrag/following{/other_user}","gists_url":"https://api.github.com/users/rrag/gists{/gist_id}","starred_url":"https://api.github.com/users/rrag/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/rrag/subscriptions","organizations_url":"https://api.github.com/users/rrag/orgs","repos_url":"https://api.github.com/users/rrag/repos","events_url":"https://api.github.com/users/rrag/events{/privacy}","received_events_url":"https://api.github.com/users/rrag/received_events","type":"User","site_admin":false},"labels":[],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":0,"created_at":"2015-10-09T10:06:29Z","updated_at":"2015-10-09T10:06:29Z","closed_at":null,"body":"Based on http://www.html5rocks.com/en/tutorials/canvas/performance/\r\n\r\n1. Avoid unnecessary canvas state changes, do not use `ctx.globalAlpha` to set opacity, use the rgba format for color. This avoids changing the state\r\n2. Avoid floating point coordinates, not sure if this one is still relavant, there is still some lag in pan actions when lot of data and multiple indicators are available. so experiment with this for atleast the `Line` to evaluate improvement"}}