a few functions useful in geometry calculations. More...

#include <algorithm>
#include <math.h>
#include <stdlib.h>
#include <math/box2.h>
#include <geometry/eda_angle.h>

Classes
class	DISABLE_ARC_RADIUS_CORRECTION
	When creating polygons to create a clearance polygonal area, the polygon must be same or bigger than the original shape. More...

Namespaces
namespace	KIGEOM

Functions
int	GetArcToSegmentCount (int aRadius, int aErrorMax, const EDA_ANGLE &aArcAngle)

int	CircleToEndSegmentDeltaRadius (int aInnerCircleRadius, int aSegCount)

int	GetCircleToPolyCorrection (int aMaxError)

template<typename T >
VECTOR2< T >	GetVectorSnapped45 (const VECTOR2< T > &aVec, bool only45=false)
	Snap a vector onto the nearest 0, 45 or 90 degree line.

template<typename in_type , typename ret_type = in_type, typename pad_type = unsigned int, typename = typename std::enable_if<std::is_unsigned<pad_type>::value>::type>
VECTOR2< ret_type >	GetClampedCoords (const VECTOR2< in_type > &aCoords, pad_type aPadding=1u)
	Clamps a vector to values that can be negated, respecting numeric limits of coordinates data type with specified padding.

template<typename T >
bool	IsVec2SafeXY (const VECTOR2< T > &aVec)
	Check if both coordinates of a vector are within the limits of the integer type.

bool	ClipLine (const BOX2I *aClipBox, int &x1, int &y1, int &x2, int &y2)
	Test if any part of a line falls within the bounds of a rectangle.

bool	KIGEOM::BoxHitTest (const VECTOR2I &aHitPoint, const BOX2I &aHittee, int aAccuracy)
	Perform a point-to-box hit test.

bool	KIGEOM::BoxHitTest (const BOX2I &aHitter, const BOX2I &aHittee, bool aHitteeContained, int aAccuracy)
	Perform a box-to-box hit test.

Detailed Description

a few functions useful in geometry calculations.

Definition in file geometry_utils.h.

Function Documentation

◆ CircleToEndSegmentDeltaRadius()

int CircleToEndSegmentDeltaRadius	(	int	aInnerCircleRadius,
		int	aSegCount
	)

Returns: the radius diffence of the circle defined by segments inside the circle and the radius of the circle tangent to the middle of segments (defined by segments outside this circle)

Parameters

aInnerCircleRadius	is the radius of the circle tangent to the middle of segments
aSegCount	is the seg count to approximate the circle

Definition at line 67 of file geometry_utils.cpp.

References std::abs(), delta, and KiROUND().

Referenced by ConvertArcToPolyline(), SHAPE_ARC::ConvertToPolyline(), CornerListToPolygon(), TransformCircleToPolygon(), and TransformOvalToPolygon().

◆ ClipLine()

bool ClipLine	(	const BOX2I *	aClipBox,
		int &	x1,
		int &	y1,
		int &	x2,
		int &	y2
	)

Test if any part of a line falls within the bounds of a rectangle.

Please note that this is only accurate for lines that are one pixel wide.

Parameters

aClipBox	- The rectangle to test.
x1	- X coordinate of one end of a line.
y1	- Y coordinate of one end of a line.
x2	- X coordinate of the other end of a line.
y2	- Y coordinate of the other end of a line.

Returns: - False if any part of the line lies within the rectangle.

Definition at line 137 of file geometry_utils.cpp.

References clipOutCode(), BOX2< Vec >::GetBottom(), BOX2< Vec >::GetRight(), BOX2< Vec >::GetX(), and BOX2< Vec >::GetY().

Referenced by KIGFX::DrawDashedLine(), STROKE_PARAMS::Stroke(), KIGFX::ORIGIN_VIEWITEM::ViewDraw(), and PCB_TRACK::ViewGetLOD().

◆ GetArcToSegmentCount()

int GetArcToSegmentCount	(	int	aRadius,
		int	aErrorMax,
		const EDA_ANGLE &	aArcAngle
	)

Returns: the number of segments to approximate a arc by segments with a given max error (this number is >= 1)

Parameters

aRadius	is the radius od the circle or arc
aErrorMax	is the max error This is the max distance between the middle of a segment and the circle.
aArcAngleDegree	is the arc angle

Definition at line 42 of file geometry_utils.cpp.

References EDA_ANGLE::AsDegrees(), KiROUND(), and MIN_SEGCOUNT_FOR_CIRCLE.

Referenced by SHAPE_POLY_SET::chamferFilletPolygon(), ConvertArcToPolyline(), SHAPE_ARC::ConvertToPolyline(), CornerListToPolygon(), BOARD_ADAPTER::createTrackWithMargin(), KIGFX::OPENGL_GAL::DrawArcSegment(), EXPORTER_PCB_VRML::ExportVrmlPadHole(), EXPORTER_PCB_VRML::ExportVrmlViaHoles(), fillArcPOLY(), gen_arc(), BOARD_ADAPTER::GetCircleSegmentCount(), SHAPE_POLY_SET::Inflate(), PCB_IO_EAGLE::loadPlain(), PCB_IO_EAGLE::loadPolygon(), SHAPE_POLY_SET::OffsetLineChain(), PCB_IO_EAGLE::packageCircle(), PCB_IO_EAGLE::packagePolygon(), DIALOG_GLOBAL_EDIT_TEARDROPS::TransferDataFromWindow(), TransformCircleToPolygon(), and TransformOvalToPolygon().

◆ GetCircleToPolyCorrection()

int GetCircleToPolyCorrection ( int aMaxError )

Returns: the radius correction to approximate a circle.

Parameters

aMaxError is the same error value used to calculate the number of segments.

When creating a polygon from a circle, the polygon is inside the circle. Only corners are on the circle. This is incorrect when building clearance areas of circles, that need to build the equivalent polygon outside the circle.

Definition at line 106 of file geometry_utils.cpp.

References s_disable_arc_correction.

Referenced by CornerListToPolygon(), TransformCircleToPolygon(), and TransformOvalToPolygon().

◆ GetClampedCoords()

template<typename in_type , typename ret_type = in_type, typename pad_type = unsigned int, typename = typename std::enable_if<std::is_unsigned<pad_type>::value>::type>

VECTOR2< ret_type > GetClampedCoords	(	const VECTOR2< in_type > &	aCoords,
		pad_type	aPadding = `1u`
	)

Clamps a vector to values that can be negated, respecting numeric limits of coordinates data type with specified padding.

Numeric limits are (-2^31 + 1) to (2^31 - 1).

Takes care of rounding in case of floating point to integer conversion.

Parameters

aCoord	- vector to clamp.
aPadding	- padding from the limits. Must not be negative.

Returns: clamped vector.

Definition at line 144 of file geometry_utils.h.

References VECTOR2< T >::x, and VECTOR2< T >::y.

◆ GetVectorSnapped45()

template<typename T >

VECTOR2< T > GetVectorSnapped45	(	const VECTOR2< T > &	aVec,
		bool	only45 = `false`
	)

Snap a vector onto the nearest 0, 45 or 90 degree line.

The magnitude of the vector is NOT kept, instead the coordinates are set equal (and/or opposite) or to zero as needed. The effect of this is that if the starting vector is on a square grid, the resulting snapped vector will still be on the same grid.

Parameters