Class: QgsMapToPixelSimplifier¶
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class
qgis.core.
QgsMapToPixelSimplifier
(simplifyFlags: int, tolerance: float, simplifyAlgorithm: QgsMapToPixelSimplifier.SimplifyAlgorithm = QgsMapToPixelSimplifier.Distance)¶ Bases:
QgsAbstractGeometrySimplifier
Constructor
QgsMapToPixelSimplifier(
QgsMapToPixelSimplifier
)Implementation of GeometrySimplifier using the “MapToPixel” algorithm
Simplifies a geometry removing points within of the maximum distance difference that defines the MapToPixel info of a RenderContext request. This class enables simplify the geometries to be rendered in a MapCanvas target to speed up the vector drawing.
- Parameters
simplifyFlags (int) –
tolerance (float) –
simplifyAlgorithm –
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Distance
= 0¶
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NoFlags
= 0¶
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class
SimplifyAlgorithm
¶ Bases:
int
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SimplifyEnvelope
= 2¶
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class
SimplifyFlag
¶ Bases:
int
-
SimplifyGeometry
= 1¶
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SnapToGrid
= 1¶
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SnappedToGridGlobal
= 3¶
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Visvalingam
= 2¶
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calculateLengthSquared2D
(x1: float, y1: float, x2: float, y2: float) → float¶ Returns the squared 2D-distance of the vector defined by the two points specified
- Parameters
x1 (float) –
y1 (float) –
x2 (float) –
y2 (float) –
- Return type
float
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equalSnapToGrid
(x1: float, y1: float, x2: float, y2: float, gridOriginX: float, gridOriginY: float, gridInverseSizeXY: float) → bool¶ Returns whether the points belong to the same grid
- Parameters
x1 (float) –
y1 (float) –
x2 (float) –
y2 (float) –
gridOriginX (float) –
gridOriginY (float) –
gridInverseSizeXY (float) –
- Return type
bool
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isGeneralizableByMapBoundingBox
(envelope: QgsRectangle, map2pixelTol: float) → bool¶ Returns whether the envelope can be replaced by its BBOX when is applied the specified map2pixel context
isGeneralizableByMapBoundingBox(self, envelope:
QgsRectangle
) -> bool Returns whether the envelope can be replaced by its BBOX when is applied the specified map2pixel context- Parameters
envelope (QgsRectangle) –
map2pixelTol (float) –
- Return type
bool
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setSimplifyAlgorithm
(self, simplifyAlgorithm: QgsMapToPixelSimplifier.SimplifyAlgorithm)¶ Sets the local simplification algorithm of the vector layer managed
- Parameters
simplifyAlgorithm (QgsMapToPixelSimplifier.SimplifyAlgorithm) –
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setSimplifyFlags
(self, simplifyFlags: int)¶ Sets the simplification hints of the vector layer managed
- Parameters
simplifyFlags (int) –
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setTolerance
(self, value: float)¶ Sets the tolerance of the vector layer managed
- Parameters
value (float) –
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simplify
(self, geometry: QgsGeometry) → QgsGeometry¶ Returns a simplified version the specified geometry
- Parameters
geometry (QgsGeometry) –
- Return type
-
simplifyAlgorithm
(self) → QgsMapToPixelSimplifier.SimplifyAlgorithm¶ Gets the local simplification algorithm of the vector layer managed
- Return type
-
simplifyFlags
(self) → int¶ Gets the simplification hints of the vector layer managed
- Return type
int