From c56fce2be897a8c665ec367cf4f00cf78e7c310f Mon Sep 17 00:00:00 2001 From: Tim Schaub Date: Thu, 5 Jul 2012 21:45:16 -0600 Subject: [PATCH] Attempting to clarify. --- doc/ol3.md | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/doc/ol3.md b/doc/ol3.md index c2d1370456..a6b43e0ad4 100644 --- a/doc/ol3.md +++ b/doc/ol3.md @@ -201,6 +201,15 @@ Renderer Questions: - Store tile layer extent in TileLayer or in TileGrid? (not clear) + +Two concepts: tile coordinate system range and and available data extent. +TileGrid extent is range (or validity extent) of the tile coordinate system. +TileLayer extent is the available data extent. A particular TileGrid may range +from 0,0 to 10,10. My cache may conform to that grid but I may only have tiles +ranging from 2,2 to 8,8. When you need to wrap multiple worlds, you pay +attention to the TileGrid extent. When you need to decide whether or not to +bother requesting a tile, you pay attention to the TileLayer extent. + - Who determines "best" resolution? (static function?)