{"action":"opened","issue":{"url":"https://api.github.com/repos/phetsims/scenery/issues/381","labels_url":"https://api.github.com/repos/phetsims/scenery/issues/381/labels{/name}","comments_url":"https://api.github.com/repos/phetsims/scenery/issues/381/comments","events_url":"https://api.github.com/repos/phetsims/scenery/issues/381/events","html_url":"https://github.com/phetsims/scenery/issues/381","id":57110356,"number":381,"title":"Do we need to webgl clear?","user":{"login":"samreid","id":679486,"avatar_url":"https://avatars.githubusercontent.com/u/679486?v=3","gravatar_id":"","url":"https://api.github.com/users/samreid","html_url":"https://github.com/samreid","followers_url":"https://api.github.com/users/samreid/followers","following_url":"https://api.github.com/users/samreid/following{/other_user}","gists_url":"https://api.github.com/users/samreid/gists{/gist_id}","starred_url":"https://api.github.com/users/samreid/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/samreid/subscriptions","organizations_url":"https://api.github.com/users/samreid/orgs","repos_url":"https://api.github.com/users/samreid/repos","events_url":"https://api.github.com/users/samreid/events{/privacy}","received_events_url":"https://api.github.com/users/samreid/received_events","type":"User","site_admin":false},"labels":[{"url":"https://api.github.com/repos/phetsims/scenery/labels/webgl","name":"webgl","color":"000000"}],"state":"open","locked":false,"assignee":{"login":"jonathanolson","id":480878,"avatar_url":"https://avatars.githubusercontent.com/u/480878?v=3","gravatar_id":"","url":"https://api.github.com/users/jonathanolson","html_url":"https://github.com/jonathanolson","followers_url":"https://api.github.com/users/jonathanolson/followers","following_url":"https://api.github.com/users/jonathanolson/following{/other_user}","gists_url":"https://api.github.com/users/jonathanolson/gists{/gist_id}","starred_url":"https://api.github.com/users/jonathanolson/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/jonathanolson/subscriptions","organizations_url":"https://api.github.com/users/jonathanolson/orgs","repos_url":"https://api.github.com/users/jonathanolson/repos","events_url":"https://api.github.com/users/jonathanolson/events{/privacy}","received_events_url":"https://api.github.com/users/jonathanolson/received_events","type":"User","site_admin":false},"milestone":null,"comments":0,"created_at":"2015-02-10T00:05:09Z","updated_at":"2015-02-10T00:05:09Z","closed_at":null,"body":"I noticed this line is taking up a relatively large amount of time in the profiler in webglnode.html:\r\n\r\n```js\r\ngl.clear( gl.COLOR_BUFFER_BIT | gl.DEPTH_BUFFER_BIT );\r\n```\r\n\r\nI tried commenting it out, rebuilding scenery and running again, and the profiler showed much faster timing, and the view looked the same.  Is that line necessary?  If it is not necessary now, when will it (or something like it) become necessary?"}}