From b71c9ec7c9f510696668adab1331772ce48754f9 Mon Sep 17 00:00:00 2001 From: tschaub Date: Thu, 4 Apr 2013 08:20:36 -0700 Subject: [PATCH] Updated Use Cases (markdown) --- Use-Cases.md | 2 ++ 1 file changed, 2 insertions(+) diff --git a/Use-Cases.md b/Use-Cases.md index 11c0c7c..553e05a 100644 --- a/Use-Cases.md +++ b/Use-Cases.md @@ -38,6 +38,8 @@ _Questions/comments from Eric:_ How do we know that the transform's source projection is EPSG:4326? It's not specified anywhere in the application code. Maybe you assume that the user/external projection is EPSG:4326 by default? +**Answer from Tim**: GeoJSON describes the CRS. For formats that don't describe their CRS, the user would provide a projection property on the source. + You say that "This alternative can be implemented if the layer knows the map projection". Why? The layer renderer knows about the map/view projection, so I think it could be the one providing the projection (the transform's target projection). As I see it the transform operation would occur during the first `render` pass, the one occurring when the layer is added to the map. I've also been thinking about where to store the transformed data. But before that: in most cases, do we really want/need to store both the original data and the transformed data? I'd say no.