Hi, Can you please send me any releavant links or sites.
Thanks in advance On Fri, Apr 24, 2009 at 6:15 PM, Wally <[email protected]> wrote: > > On Apr 24, 8:56 am, "Neil.Young" <[email protected]> wrote: > > return > > > Math.round(offset-radius*Math.log((1+Math.sin(y*Math.PI/180))/(1-Math.sin(y*Math.PI/180)))/2); > > ... > > z=Math.sqrt(((z*z)/(x*x+y*y))); > > z=Math.log(z)/Math.log(factor); > > ... > > Integer arithmetic? A couple of month ago I ported adjust.js to Python. > > Adjust.js is using the same kind of LtoXY things. Compared to > > "classical" solutions for converting a lat/lon to an image coordinate > > adjust.js was _dimensions_ slower... Didn't try this packer stuff in > > comparison to others, but - where is the super fast integer arithmetic > here? > > > > Wally schrieb: > > The LLToXY stuff is done once outside the main loop. The "log" stuff > is also done once outside the main loop. The "other" encoders > determine zoom levels with brute force comparison loops. Packer uses > built-in math functions without a loop. > > The essence of the Douglas-Peucker point reduction algorithm is > determining the height of triangles. Packer uses pixels which are > fixed point numbers. The "other" encoders use Lat/Lon coordinates > which are floating point numbers. Packer does it in-line without > function calls. The "other" encoders use several levels of nested > function calls. Packer splits each segment twice in a single pass. > The "other" encoders split each segment once per pass. Packer avoids > recursive function calls by expanding the stack in-line. Packer also > splits polygons into sensible polylines rather than blindly applying D- > P to the entire poly. > > Try both on complex polys. The "other" encoders frequently crap out > with a "script is running slowly" message. Packer can often handle > the same polys. > > > > --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "Google Maps API" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/Google-Maps-API?hl=en -~----------~----~----~----~------~----~------~--~---
