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Optimize overview pixel adjustment for integer-pixel cells

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This commit is contained in:
Javier Goizueta 2016-04-25 13:53:59 +02:00
parent 7b2100b51e
commit 3c12cf629f
1 changed files with 8 additions and 2 deletions
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10
scripts-available/CDB_Overviews.sql
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@ -703,8 +703,14 @@ AS $$
cell_y := Format('gy*%1$s + %2$s', grid_m, grid_m/2);
-- Displacement to the nearest pixel center:
offset_x := Format('%2$s/2 - MOD((%1$s)::numeric, (%2$s)::numeric)::float8', cell_x, pixel_m);
offset_y := Format('%2$s/2 - MOD((%1$s)::numeric, (%2$s)::numeric)::float8', cell_y, pixel_m);
IF MOD(grid_px::numeric, 1.0::numeric) = 0 THEN
offset_m := pixel_m/2 - MOD((grid_m/2)::numeric, pixel_m::numeric)::float8;
offset_x := Format('%s', offset_m);
offset_y := Format('%s', offset_m);
ELSE
offset_x := Format('%2$s/2 - MOD((%1$s)::numeric, (%2$s)::numeric)::float8', cell_x, pixel_m);
offset_y := Format('%2$s/2 - MOD((%1$s)::numeric, (%2$s)::numeric)::float8', cell_y, pixel_m);
END IF;
point_geom := Format('ST_SetSRID(ST_MakePoint(%1$s + %3$s, %2$s + %4$s), 3857)', cell_x, cell_y, offset_x, offset_y);