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-- Semantic of tolerance depends on the `toltype` argument, which can be:
-- 0: Tolerance is number of segments per quadrant
-- 1: Tolerance is max distance between curve and line
-- 2: Tolerance is max angle between radii defining line vertices
--
-- Supported flags:
-- 1: Symmetric output (result in same vertices when inverting the curve)
SELECT 'semicircle1', ST_AsText(ST_SnapToGrid(ST_CurveToLine(
'CIRCULARSTRING(0 0,100 -100,200 0)'::geometry,
3, -- Tolerance
0, -- Above is number of segments per quadrant
0 -- no flags
), 2));
SELECT 'semicircle2', ST_AsText(ST_SnapToGrid(ST_CurveToLine(
'CIRCULARSTRING(0 0,100 -100,200 0)'::geometry,
20, -- Tolerance
1, -- Above is max distance between curve and line
0 -- no flags
), 2));
SELECT 'semicircle2.sym', ST_AsText(ST_SnapToGrid(ST_CurveToLine(
'CIRCULARSTRING(0 0,100 -100,200 0)'::geometry,
20, -- Tolerance
1, -- Above is max distance between curve and line
1 -- Symmetric flag
), 2));
SELECT 'semicircle3', ST_AsText(ST_SnapToGrid(ST_CurveToLine(
'CIRCULARSTRING(0 0,100 -100,200 0)'::geometry,
radians(40), -- Tolerance
2, -- Above is max angle between generating radii
0 -- no flags
), 2));
SELECT 'semicircle3.sym', ST_AsText(ST_SnapToGrid(ST_CurveToLine(
'CIRCULARSTRING(0 0,100 -100,200 0)'::geometry,
radians(40), -- Tolerance
2, -- Above is max angle between generating radii
1 -- Symmetric flag
), 2));
SELECT 'semicircle3.sym.ret', ST_AsText(ST_SnapToGrid(ST_CurveToLine(
'CIRCULARSTRING(0 0,100 -100,200 0)'::geometry,
radians(40), -- Tolerance
2, -- Above is max angle between generating radii
3 -- Symmetric and RetainAngle flags
), 2));
SELECT 'multiarc1', ST_AsText(ST_SnapToGrid(ST_CurveToLine(
'CIRCULARSTRING(0 0,100 -100,200 0,400 200,600 0)'::geometry,
radians(45), -- Tolerance
2, -- Above is max angle between generating radii
3 -- Symmetric and RetainAngle flags
), 2));
SELECT 'multiarc1.maxerr20.sym', ST_AsText(ST_SnapToGrid(ST_CurveToLine(
'CIRCULARSTRING(0 0,100 -100,200 0,400 200,600 0)'::geometry,
20, -- Tolerance
1, -- Above is max distance between curve and line
1 -- Symmetric
), 2));
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