Paul Norman
aa302c237d
postgis-vt-util comes with a standard formula for zoom from scaleDenominator, and this is well tested. This also fixes the function throwing an error on NULL input.
13 lines
350 B
PL/PgSQL
13 lines
350 B
PL/PgSQL
CREATE OR REPLACE FUNCTION cartodb.CDB_ZoomFromScale(scaleDenominator numeric)
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RETURNS int
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LANGUAGE SQL
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IMMUTABLE
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AS $$
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SELECT
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CASE
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-- Don't bother if the scale is larger than ~zoom level 0
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WHEN scaleDenominator > 600000000 OR scaleDenominator = 0 THEN NULL
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ELSE CAST (ROUND(LOG(2, 559082264.028/scaleDenominator)) AS INTEGER)
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END;
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$$;
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