{"action":"created","issue":{"url":"https://api.github.com/repos/phetsims/trig-tour/issues/62","labels_url":"https://api.github.com/repos/phetsims/trig-tour/issues/62/labels{/name}","comments_url":"https://api.github.com/repos/phetsims/trig-tour/issues/62/comments","events_url":"https://api.github.com/repos/phetsims/trig-tour/issues/62/events","html_url":"https://github.com/phetsims/trig-tour/issues/62","id":113918374,"number":62,"title":"Drawing the spiral shape performs poorly on iPad2","user":{"login":"jessegreenberg","id":6396244,"avatar_url":"https://avatars.githubusercontent.com/u/6396244?v=3","gravatar_id":"","url":"https://api.github.com/users/jessegreenberg","html_url":"https://github.com/jessegreenberg","followers_url":"https://api.github.com/users/jessegreenberg/followers","following_url":"https://api.github.com/users/jessegreenberg/following{/other_user}","gists_url":"https://api.github.com/users/jessegreenberg/gists{/gist_id}","starred_url":"https://api.github.com/users/jessegreenberg/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/jessegreenberg/subscriptions","organizations_url":"https://api.github.com/users/jessegreenberg/orgs","repos_url":"https://api.github.com/users/jessegreenberg/repos","events_url":"https://api.github.com/users/jessegreenberg/events{/privacy}","received_events_url":"https://api.github.com/users/jessegreenberg/received_events","type":"User","site_admin":false},"labels":[],"state":"open","locked":false,"assignee":{"login":"jessegreenberg","id":6396244,"avatar_url":"https://avatars.githubusercontent.com/u/6396244?v=3","gravatar_id":"","url":"https://api.github.com/users/jessegreenberg","html_url":"https://github.com/jessegreenberg","followers_url":"https://api.github.com/users/jessegreenberg/followers","following_url":"https://api.github.com/users/jessegreenberg/following{/other_user}","gists_url":"https://api.github.com/users/jessegreenberg/gists{/gist_id}","starred_url":"https://api.github.com/users/jessegreenberg/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/jessegreenberg/subscriptions","organizations_url":"https://api.github.com/users/jessegreenberg/orgs","repos_url":"https://api.github.com/users/jessegreenberg/repos","events_url":"https://api.github.com/users/jessegreenberg/events{/privacy}","received_events_url":"https://api.github.com/users/jessegreenberg/received_events","type":"User","site_admin":false},"milestone":null,"comments":10,"created_at":"2015-10-28T20:46:04Z","updated_at":"2015-12-14T22:15:53Z","closed_at":null,"body":"While playing with the spiral to reproduce issue #61, I became concerned about the performance of the spiral on iPad2.  After ~5 rotations, the drag behavior bogs down as the number of line segments in the shape grows.\r\n\r\nAs the spiral shape changes, it is unfortunate to redraw the whole thing.  The shape itself only changes by a single line segment every time the angle changes. For spiral consisting of 1200 line segments, 1199 of them are being redrawn, but do not need to change.\r\n\r\n@jonathanolson recommends two solutions that might perform better:\r\n\r\n1) A clipping region that grows with the spiral, the full spiral always exists on the unit circle.\r\n2) Maintaining individual 'circles' on the spiral so that only one circle needs to be redrawn as the angle changes.\r\n\r\nI will first try option 1 above, it seems the simplest and perhaps the most beneficial to performance."},"comment":{"url":"https://api.github.com/repos/phetsims/trig-tour/issues/comments/164577203","html_url":"https://github.com/phetsims/trig-tour/issues/62#issuecomment-164577203","issue_url":"https://api.github.com/repos/phetsims/trig-tour/issues/62","id":164577203,"user":{"login":"jessegreenberg","id":6396244,"avatar_url":"https://avatars.githubusercontent.com/u/6396244?v=3","gravatar_id":"","url":"https://api.github.com/users/jessegreenberg","html_url":"https://github.com/jessegreenberg","followers_url":"https://api.github.com/users/jessegreenberg/followers","following_url":"https://api.github.com/users/jessegreenberg/following{/other_user}","gists_url":"https://api.github.com/users/jessegreenberg/gists{/gist_id}","starred_url":"https://api.github.com/users/jessegreenberg/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/jessegreenberg/subscriptions","organizations_url":"https://api.github.com/users/jessegreenberg/orgs","repos_url":"https://api.github.com/users/jessegreenberg/repos","events_url":"https://api.github.com/users/jessegreenberg/events{/privacy}","received_events_url":"https://api.github.com/users/jessegreenberg/received_events","type":"User","site_admin":false},"created_at":"2015-12-14T22:15:53Z","updated_at":"2015-12-14T22:15:53Z","body":"Preventing block fitting seems to have little impact on performance in trig-tour.  Frame rate fluctuates between 8-14 fps, about the same as before."}}