From: Gillian W. <gil...@at...> - 2004-07-05 00:42:42
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Hi, I'm not sure what "all those code" encompasses and haven't looked into this problem myself so I don't know if this is really an issue or not, but my concern here would be that changing the float 32's to float 64's for raster source tile loading could slow things down noticeably for large rasters or when many rasters are open, and cause caching problems earlier on (I'm thinking of those of us who routinely use large/many rasters and don't generally use int32 images here :-) ). Maybe this could be controlled through a #define on build for now, along the lines of Sylvain's #ifdef GV_USE_DOUBLE_PRECISION_COORDS for vectors (or just use the gvgeocoord type directly and use the same define), until any unexpected wrinkles have been ironed out and others have had a chance to test the change in the context of their applications? Unless the scope of these changes is smaller than I thought from the exchange below, in which case you can ignore this response. Gillian Andrey Kiselev wrote: >On Fri, Jul 02, 2004 at 11:50:27AM +0200, Julien Demaria wrote: > > >>>Could you change definition for value[] arry to double and replace >>>GDT_CFloat32 with the GDT_CFloat64 and test whether it helps for your >>>data? >>> >>> >>Yes, for my little tracktool problem change GDT_CFloat32 to >>GDT_CFloat64 works well ; >> >> > >Ok, I have commited that change. > > > >>but it seems OpenEV assigns to all rasters with a GDAL type different >>than GDT_Byte an internal GDAL type GDT_Float32 (see function >>gv_raster_new in gv_raster.c) and then always casts data to float. >> >>I'll try to change this and use directly the true GDAL type of the >>raster, but I believe there are some part of code which now only treat >>GDT_Byte and GDT_Float32 cases to update... (examples : functions >>gv_scale_tile_to_byte and gv_raster_layer_srctile_check_nodata in >>gvrastersource.c). >> >> > >I think we can try to convert all those code to GDT_Float64 type, if >nobody hasn't any objections. > > Andrey > > > |