geometry_utils.cpp File Reference

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

#include <cstdint>
#include <algorithm>
#include <geometry/geometry_utils.h>
#include <math/util.h>

Go to the source code of this file.

Macros
#define	MIN_SEGCOUNT_FOR_CIRCLE   8

Functions
int	GetArcToSegmentCount (int aRadius, int aErrorMax, const EDA_ANGLE &aArcAngle)
int	CircleToEndSegmentDeltaRadius (int aRadius, int aSegCount)
int	GetCircleToPolyCorrection (int aMaxError)
int	clipOutCode (const BOX2I *aClipBox, int x, int y)
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.

Variables
static bool	s_disable_arc_correction = false

Detailed Description

a few functions useful in geometry calculations.

Definition in file geometry_utils.cpp.

Macro Definition Documentation

MIN_SEGCOUNT_FOR_CIRCLE

#define MIN_SEGCOUNT_FOR_CIRCLE   8

Definition at line 40 of file geometry_utils.cpp.

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().

clipOutCode()

int clipOutCode ( const BOX2I *  aClipBox, int  x, int  y  )

inline

Definition at line 117 of file geometry_utils.cpp.

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

Referenced by ClipLine().

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().

Variable Documentation

s_disable_arc_correction

bool s_disable_arc_correction = false

static

Definition at line 94 of file geometry_utils.cpp.

Referenced by DISABLE_ARC_RADIUS_CORRECTION::DISABLE_ARC_RADIUS_CORRECTION(), GetCircleToPolyCorrection(), and DISABLE_ARC_RADIUS_CORRECTION::~DISABLE_ARC_RADIUS_CORRECTION().