KiCad PCB EDA Suite
trigo.cpp File Reference

Trigonometric and geometric basic functions. More...

#include <limits>
#include <stdlib.h>
#include <type_traits>
#include <geometry/seg.h>
#include <math/util.h>
#include <math/vector2d.h>
#include <trigo.h>

Go to the source code of this file.

Functions

bool IsPointOnSegment (const wxPoint &aSegStart, const wxPoint &aSegEnd, const wxPoint &aTestPoint)
 Test if aTestPoint is on line defined by aSegStart and aSegEnd. More...
 
bool SegmentIntersectsSegment (const wxPoint &a_p1_l1, const wxPoint &a_p2_l1, const wxPoint &a_p1_l2, const wxPoint &a_p2_l2, wxPoint *aIntersectionPoint)
 Test if two lines intersect. More...
 
bool TestSegmentHit (const wxPoint &aRefPoint, wxPoint aStart, wxPoint aEnd, int aDist)
 Test if aRefPoint is with aDistance on the line defined by aStart and aEnd. More...
 
double ArcTangente (int dy, int dx)
 
void RotatePoint (int *pX, int *pY, double angle)
 
void RotatePoint (int *pX, int *pY, int cx, int cy, double angle)
 
void RotatePoint (wxPoint *point, const wxPoint &centre, double angle)
 
void RotatePoint (VECTOR2I &point, const VECTOR2I &centre, double angle)
 
void RotatePoint (double *pX, double *pY, double cx, double cy, double angle)
 
void RotatePoint (double *pX, double *pY, double angle)
 
const VECTOR2D GetArcCenter (const VECTOR2D &aStart, const VECTOR2D &aMid, const VECTOR2D &aEnd)
 
const VECTOR2I GetArcCenter (const VECTOR2I &aStart, const VECTOR2I &aMid, const VECTOR2I &aEnd)
 Determine the center of an arc or circle given three points on its circumference. More...
 
const wxPoint GetArcCenter (const wxPoint &aStart, const wxPoint &aMid, const wxPoint &aEnd)
 

Detailed Description

Trigonometric and geometric basic functions.

Definition in file trigo.cpp.

Function Documentation

◆ ArcTangente()

double ArcTangente ( int  dy,
int  dx 
)

Definition at line 162 of file trigo.cpp.

163 {
164 
165  /* gcc is surprisingly smart in optimizing these conditions in
166  a tree! */
167 
168  if( dx == 0 && dy == 0 )
169  return 0;
170 
171  if( dy == 0 )
172  {
173  if( dx >= 0 )
174  return 0;
175  else
176  return -1800;
177  }
178 
179  if( dx == 0 )
180  {
181  if( dy >= 0 )
182  return 900;
183  else
184  return -900;
185  }
186 
187  if( dx == dy )
188  {
189  if( dx >= 0 )
190  return 450;
191  else
192  return -1800 + 450;
193  }
194 
195  if( dx == -dy )
196  {
197  if( dx >= 0 )
198  return -450;
199  else
200  return 1800 - 450;
201  }
202 
203  // Of course dy and dx are treated as double
204  return RAD2DECIDEG( atan2( (double) dy, (double) dx ) );
205 }
double RAD2DECIDEG(double rad)
Definition: trigo.h:219

References RAD2DECIDEG().

Referenced by BuildCornersList_S_Shape(), LIB_ARC::CalcEdit(), LIB_ARC::CalcRadiusAngles(), AM_PRIMITIVE::ConvertShapeToPolygon(), AR_MATRIX::drawSegmentQcq(), fillArcPOLY(), ARC::GetAngle(), ARC::GetArcAngleEnd(), DRAWSEGMENT::GetArcAngleStart(), ARC::GetArcAngleStart(), GRCSegm(), DRAWSEGMENT::HitTest(), ARC::HitTest(), PCAD2KICAD::PCB_ARC::Parse(), BRDITEMS_PLOTTER::PlotDrawSegment(), BRDITEMS_PLOTTER::PlotFootprintGraphicItem(), PLOTTER::segmentAsOval(), AR_MATRIX::traceArc(), and TransformSegmentToPolygon().

◆ GetArcCenter() [1/3]

const VECTOR2D GetArcCenter ( const VECTOR2D aStart,
const VECTOR2D aMid,
const VECTOR2D aEnd 
)

Definition at line 341 of file trigo.cpp.

342 {
343  VECTOR2D center;
344  double yDelta_21 = aMid.y - aStart.y;
345  double xDelta_21 = aMid.x - aStart.x;
346  double yDelta_32 = aEnd.y - aMid.y;
347  double xDelta_32 = aEnd.x - aMid.x;
348 
349  // This is a special case for aMid as the half-way point when aSlope = 0 and bSlope = inf
350  // or the other way around. In that case, the center lies in a straight line between
351  // aStart and aEnd
352  if( ( ( xDelta_21 == 0.0 ) && ( yDelta_32 == 0.0 ) ) ||
353  ( ( yDelta_21 == 0.0 ) && ( xDelta_32 == 0.0 ) ) )
354  {
355  center.x = ( aStart.x + aEnd.x ) / 2.0;
356  center.y = ( aStart.y + aEnd.y ) / 2.0 ;
357  return center;
358  }
359 
360  // Prevent div=0 errors
361  if( xDelta_21 == 0.0 )
362  xDelta_21 = std::numeric_limits<double>::epsilon();
363 
364  if( xDelta_32 == 0.0 )
365  xDelta_32 = -std::numeric_limits<double>::epsilon();
366 
367  double aSlope = yDelta_21 / xDelta_21;
368  double bSlope = yDelta_32 / xDelta_32;
369 
370  // If the points are colinear, the center is at infinity, so offset
371  // the slope by a minimal amount
372  // Warning: This will induce a small error in the center location
373  if( yDelta_32 * xDelta_21 == yDelta_21 * xDelta_32 )
374  {
375  aSlope += std::numeric_limits<double>::epsilon();
376  bSlope -= std::numeric_limits<double>::epsilon();
377  }
378 
379  if( aSlope == 0.0 )
380  aSlope = std::numeric_limits<double>::epsilon();
381 
382  if( bSlope == 0.0 )
383  bSlope = -std::numeric_limits<double>::epsilon();
384 
385 
386  center.x = ( aSlope * bSlope * ( aStart.y - aEnd.y ) +
387  bSlope * ( aStart.x + aMid.x ) -
388  aSlope * ( aMid.x + aEnd.x ) ) / ( 2 * ( bSlope - aSlope ) );
389 
390  center.y = ( ( ( aStart.x + aMid.x ) / 2.0 - center.x ) / aSlope +
391  ( aStart.y + aMid.y ) / 2.0 );
392 
393  return center;
394 }
VECTOR2 defines a general 2D-vector/point.
Definition: vector2d.h:61

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

Referenced by GetArcCenter().

◆ GetArcCenter() [2/3]

const VECTOR2I GetArcCenter ( const VECTOR2I aStart,
const VECTOR2I aMid,
const VECTOR2I aEnd 
)

Determine the center of an arc or circle given three points on its circumference.

Parameters
aStartThe starting point of the circle (equivalent to aEnd)
aMidThe point on the arc, half-way between aStart and aEnd
aEndThe ending point of the circle (equivalent to aStart)
Returns
The center of the circle

Definition at line 397 of file trigo.cpp.

398 {
399  VECTOR2D dStart( static_cast<double>( aStart.x ), static_cast<double>( aStart.y ) );
400  VECTOR2D dMid( static_cast<double>( aMid.x ), static_cast<double>( aMid.y ) );
401  VECTOR2D dEnd( static_cast<double>( aEnd.x ), static_cast<double>( aEnd.y ) );
402  VECTOR2D dCenter = GetArcCenter( dStart, dMid, dEnd );
403 
404  VECTOR2I iCenter;
405 
406  iCenter.x = KiROUND( Clamp<double>( double( std::numeric_limits<int>::min() / 2.0 ),
407  dCenter.x,
408  double( std::numeric_limits<int>::max() / 2.0 ) ) );
409 
410  iCenter.y = KiROUND( Clamp<double>( double( std::numeric_limits<int>::min() / 2.0 ),
411  dCenter.y,
412  double( std::numeric_limits<int>::max() / 2.0 ) ) );
413 
414  return iCenter;
415 }
VECTOR2 defines a general 2D-vector/point.
Definition: vector2d.h:61
const VECTOR2D GetArcCenter(const VECTOR2D &aStart, const VECTOR2D &aMid, const VECTOR2D &aEnd)
Definition: trigo.cpp:341
constexpr ret_type KiROUND(fp_type v)
Round a floating point number to an integer using "round halfway cases away from zero".
Definition: util.h:61

References GetArcCenter(), KiROUND(), VECTOR2< T >::x, and VECTOR2< T >::y.

Referenced by ARC::GetPosition(), ARC::GetRadius(), SCH_SEXPR_PARSER::parseArc(), and POINT_EDITOR::updateItem().

◆ GetArcCenter() [3/3]

const wxPoint GetArcCenter ( const wxPoint aStart,
const wxPoint aMid,
const wxPoint aEnd 
)

Definition at line 418 of file trigo.cpp.

419 {
420  VECTOR2D dStart( static_cast<double>( aStart.x ), static_cast<double>( aStart.y ) );
421  VECTOR2D dMid( static_cast<double>( aMid.x ), static_cast<double>( aMid.y ) );
422  VECTOR2D dEnd( static_cast<double>( aEnd.x ), static_cast<double>( aEnd.y ) );
423  VECTOR2D dCenter = GetArcCenter( dStart, dMid, dEnd );
424 
425  wxPoint iCenter;
426 
427  iCenter.x = KiROUND( Clamp<double>( double( std::numeric_limits<int>::min() / 2.0 ),
428  dCenter.x,
429  double( std::numeric_limits<int>::max() / 2.0 ) ) );
430 
431  iCenter.y = KiROUND( Clamp<double>( double( std::numeric_limits<int>::min() / 2.0 ),
432  dCenter.y,
433  double( std::numeric_limits<int>::max() / 2.0 ) ) );
434 
435  return iCenter;
436 }
VECTOR2 defines a general 2D-vector/point.
Definition: vector2d.h:61
const VECTOR2D GetArcCenter(const VECTOR2D &aStart, const VECTOR2D &aMid, const VECTOR2D &aEnd)
Definition: trigo.cpp:341
constexpr ret_type KiROUND(fp_type v)
Round a floating point number to an integer using "round halfway cases away from zero".
Definition: util.h:61

References GetArcCenter(), KiROUND(), wxPoint::x, VECTOR2< T >::x, wxPoint::y, and VECTOR2< T >::y.

◆ IsPointOnSegment()

bool IsPointOnSegment ( const wxPoint aSegStart,
const wxPoint aSegEnd,
const wxPoint aTestPoint 
)

Test if aTestPoint is on line defined by aSegStart and aSegEnd.

This function is faster than TestSegmentHit() because aTestPoint should be exactly on the line. This works fine only for H, V and 45 degree line segments.

Parameters
aSegStartThe first point of the line segment.
aSegEndThe second point of the line segment.
aTestPointThe point to test.
Returns
true if the point is on the line segment.

Definition at line 42 of file trigo.cpp.

44 {
45  wxPoint vectSeg = aSegEnd - aSegStart; // Vector from S1 to S2
46  wxPoint vectPoint = aTestPoint - aSegStart; // Vector from S1 to P
47 
48  // Use long long here to avoid overflow in calculations
49  if( (long long) vectSeg.x * vectPoint.y - (long long) vectSeg.y * vectPoint.x )
50  return false; /* Cross product non-zero, vectors not parallel */
51 
52  if( ( (long long) vectSeg.x * vectPoint.x + (long long) vectSeg.y * vectPoint.y ) <
53  ( (long long) vectPoint.x * vectPoint.x + (long long) vectPoint.y * vectPoint.y ) )
54  return false; /* Point not on segment */
55 
56  return true;
57 }

References wxPoint::x, and wxPoint::y.

Referenced by SCH_LINE_WIRE_BUS_TOOL::AddJunctionsIfNeeded(), SCH_EDIT_FRAME::BreakSegment(), SCH_LINE_WIRE_BUS_TOOL::finishSegments(), NETLIST_OBJECT_LIST::segmentToPointConnect(), SCH_EDIT_FRAME::TrimWire(), SCH_BUS_WIRE_ENTRY::UpdateDanglingState(), and SCH_BUS_BUS_ENTRY::UpdateDanglingState().

◆ RotatePoint() [1/6]

void RotatePoint ( int *  pX,
int *  pY,
double  angle 
)

Definition at line 208 of file trigo.cpp.

209 {
210  int tmp;
211 
213 
214  // Cheap and dirty optimizations for 0, 90, 180, and 270 degrees.
215  if( angle == 0 )
216  return;
217 
218  if( angle == 900 ) /* sin = 1, cos = 0 */
219  {
220  tmp = *pX;
221  *pX = *pY;
222  *pY = -tmp;
223  }
224  else if( angle == 1800 ) /* sin = 0, cos = -1 */
225  {
226  *pX = -*pX;
227  *pY = -*pY;
228  }
229  else if( angle == 2700 ) /* sin = -1, cos = 0 */
230  {
231  tmp = *pX;
232  *pX = -*pY;
233  *pY = tmp;
234  }
235  else
236  {
237  double fangle = DECIDEG2RAD( angle );
238  double sinus = sin( fangle );
239  double cosinus = cos( fangle );
240  double fpx = (*pY * sinus ) + (*pX * cosinus );
241  double fpy = (*pY * cosinus ) - (*pX * sinus );
242  *pX = KiROUND( fpx );
243  *pY = KiROUND( fpy );
244  }
245 }
void NORMALIZE_ANGLE_POS(T &Angle)
Definition: trigo.h:257
static DIRECTION_45::AngleType angle(const VECTOR2I &a, const VECTOR2I &b)
double DECIDEG2RAD(double deg)
Definition: trigo.h:218
constexpr ret_type KiROUND(fp_type v)
Round a floating point number to an integer using "round halfway cases away from zero".
Definition: util.h:61

References PNS::angle(), DECIDEG2RAD(), KiROUND(), and NORMALIZE_ANGLE_POS().

Referenced by PCAD2KICAD::PCB_MODULE::AddToBoard(), PCAD2KICAD::PCB_PAD::AddToModule(), SVG_PLOTTER::Arc(), BuildConvexHull(), BuildCornersList_S_Shape(), D_PAD::BuildPadPolygon(), D_PAD::BuildSegmentFromOvalShape(), LIB_ARC::CalcEdit(), DRAWSEGMENT::computeArcBBox(), PSLIKE_PLOTTER::computeTextParameters(), convertOblong2Segment(), ConvertOutlineToPolygon(), AM_PRIMITIVE::ConvertShapeToPolygon(), D_CODE::ConvertShapeToPolygon(), PCAD2KICAD::CorrectTextPosition(), EXCELLON_WRITER::createDrillFile(), MICROWAVE_TOOL::createFootprint(), SCH_GLOBALLABEL::CreateGraphicShape(), BOARD_ADAPTER::createNewPadWithClearance(), AM_PRIMITIVE::DrawBasicShape(), AR_MATRIX::drawSegmentQcq(), GBR_TO_PCB_EXPORTER::export_segarc_copper_item(), export_vrml_module(), export_vrml_padshape(), fillArcPOLY(), HPGL_PLOTTER::FlashPadOval(), PSLIKE_PLOTTER::FlashPadOval(), HPGL_PLOTTER::FlashPadRect(), PSLIKE_PLOTTER::FlashPadRect(), DXF_PLOTTER::FlashPadRect(), HPGL_PLOTTER::FlashPadTrapez(), PSLIKE_PLOTTER::FlashPadTrapez(), GERBER_PLOTTER::FlashPadTrapez(), DXF_PLOTTER::FlashPadTrapez(), GERBER_PLOTTER::FlashRegularPolygon(), FootprintWriteShape(), geom_transf(), GERBER_DRAW_ITEM::GetABPosition(), CN_ITEM::GetAnchor(), DRAWSEGMENT::GetArcEnd(), DRAWSEGMENT::GetArcMid(), LIB_TEXT::GetBoundingBox(), SCH_FIELD::GetBoundingBox(), LIB_PIN::GetBoundingBox(), LIB_FIELD::GetBoundingBox(), DRAWSEGMENT::GetBoundingBox(), SCH_TEXT::GetBoundingBox(), SCH_LABEL::GetBoundingBox(), D_PAD::GetBoundingBox(), EDA_RECT::GetBoundingBoxRotated(), WS_DATA_ITEM_POLYGONS::GetCornerPosition(), EDA_TEXT::GetLinePositions(), D_PAD::GetOblongGeometry(), GetRoundRectCornerCenters(), ARRAY_CIRCULAR_OPTIONS::GetTransform(), GERBER_DRAW_ITEM::GetXYPosition(), GRArc(), GRCSegm(), GRFilledArc(), ALTIUM_PCB::HelperParseDimensions6Center(), ALTIUM_PCB::HelperParseDimensions6Leader(), D_PAD::HitTest(), idf_export_module(), C3D_RENDER_RAYTRACING::insert3DPadHole(), EDA_RECT::Intersects(), SCH_LEGACY_PLUGIN_CACHE::loadArc(), LEGACY_PLUGIN::loadPAD(), MODULE::MoveAnchorPosition(), OGL_draw_half_open_cylinder(), ALTIUM_PCB::ParseComponentsBodies6Data(), GPCB_FPL_CACHE::parseMODULE(), PCB_PARSER::parseMODULE_unchecked(), BRDITEMS_PLOTTER::PlotFootprintGraphicItem(), GERBER_PLOTTER::plotRoundRectAsRegion(), MARKER_PCB::Rotate(), SCH_JUNCTION::Rotate(), LIB_CIRCLE::Rotate(), LIB_RECTANGLE::Rotate(), SCH_MARKER::Rotate(), LIB_BEZIER::Rotate(), PCB_TARGET::Rotate(), SCH_NO_CONNECT::Rotate(), LIB_TEXT::Rotate(), TEXTE_PCB::Rotate(), LIB_ARC::Rotate(), SCH_BUS_ENTRY_BASE::Rotate(), LIB_POLYLINE::Rotate(), PAD_CS_PRIMITIVE::Rotate(), TRACK::Rotate(), SCH_BITMAP::Rotate(), TEXTE_MODULE::Rotate(), SCH_FIELD::Rotate(), SCH_LINE::Rotate(), SCH_SHEET_PIN::Rotate(), LIB_FIELD::Rotate(), DIMENSION::Rotate(), DRAWSEGMENT::Rotate(), MODULE::Rotate(), SCH_TEXT::Rotate(), ARC::Rotate(), ZONE_CONTAINER::Rotate(), LIB_PIN::Rotate(), SCH_SHEET::Rotate(), SCH_COMPONENT::Rotate(), D_PAD::Rotate(), SCH_LINE::RotateEnd(), RotatePoint(), SCH_LINE::RotateStart(), WS_DATA_ITEM_POLYGONS::SetBoundingBox(), EDGE_MODULE::SetDrawCoord(), TEXTE_MODULE::SetDrawCoord(), D_PAD::SetDrawCoord(), EDGE_MODULE::SetLocalCoord(), TEXTE_MODULE::SetLocalCoord(), D_PAD::SetLocalCoord(), D_PAD::ShapePos(), PLOTTER::sketchOval(), PNS_KICAD_IFACE_BASE::syncPad(), TEXTE_MODULE::TextHitTest(), EDA_TEXT::TextHitTest(), AR_MATRIX::TraceFilledRectangle(), DIALOG_PAD_PROPERTIES::TransferDataFromWindow(), EAGLE_PLUGIN::transferPad(), TransformArcToPolygon(), BOARD_ADAPTER::TransformArcToSegments(), EDA_TEXT::TransformBoundingBoxWithClearanceToPolygon(), TransformCircleToPolygon(), TransformOvalToPolygon(), TransformSegmentToPolygon(), DRAWSEGMENT::TransformShapeWithClearanceToPolygon(), and D_PAD::TransformShapeWithClearanceToPolygon().

◆ RotatePoint() [2/6]

void RotatePoint ( int *  pX,
int *  pY,
int  cx,
int  cy,
double  angle 
)

Definition at line 248 of file trigo.cpp.

249 {
250  int ox, oy;
251 
252  ox = *pX - cx;
253  oy = *pY - cy;
254 
255  RotatePoint( &ox, &oy, angle );
256 
257  *pX = ox + cx;
258  *pY = oy + cy;
259 }
void RotatePoint(int *pX, int *pY, double angle)
Definition: trigo.cpp:208
static DIRECTION_45::AngleType angle(const VECTOR2I &a, const VECTOR2I &b)

References PNS::angle(), and RotatePoint().

◆ RotatePoint() [3/6]

void RotatePoint ( wxPoint point,
const wxPoint centre,
double  angle 
)

Definition at line 262 of file trigo.cpp.

263 {
264  int ox, oy;
265 
266  ox = point->x - centre.x;
267  oy = point->y - centre.y;
268 
269  RotatePoint( &ox, &oy, angle );
270  point->x = ox + centre.x;
271  point->y = oy + centre.y;
272 }
void RotatePoint(int *pX, int *pY, double angle)
Definition: trigo.cpp:208
static DIRECTION_45::AngleType angle(const VECTOR2I &a, const VECTOR2I &b)

References PNS::angle(), RotatePoint(), wxPoint::x, and wxPoint::y.

◆ RotatePoint() [4/6]

void RotatePoint ( VECTOR2I point,
const VECTOR2I centre,
double  angle 
)

Definition at line 274 of file trigo.cpp.

275 {
276  wxPoint c( centre.x, centre.y );
277  wxPoint p( point.x, point.y );
278 
279  RotatePoint(&p, c, angle);
280 
281  point.x = p.x;
282  point.y = p.y;
283 }
void RotatePoint(int *pX, int *pY, double angle)
Definition: trigo.cpp:208
static DIRECTION_45::AngleType angle(const VECTOR2I &a, const VECTOR2I &b)

References PNS::angle(), RotatePoint(), wxPoint::x, VECTOR2< T >::x, wxPoint::y, and VECTOR2< T >::y.

◆ RotatePoint() [5/6]

void RotatePoint ( double *  pX,
double *  pY,
double  cx,
double  cy,
double  angle 
)

Definition at line 286 of file trigo.cpp.

287 {
288  double ox, oy;
289 
290  ox = *pX - cx;
291  oy = *pY - cy;
292 
293  RotatePoint( &ox, &oy, angle );
294 
295  *pX = ox + cx;
296  *pY = oy + cy;
297 }
void RotatePoint(int *pX, int *pY, double angle)
Definition: trigo.cpp:208
static DIRECTION_45::AngleType angle(const VECTOR2I &a, const VECTOR2I &b)

References PNS::angle(), and RotatePoint().

◆ RotatePoint() [6/6]

void RotatePoint ( double *  pX,
double *  pY,
double  angle 
)

Definition at line 300 of file trigo.cpp.

301 {
302  double tmp;
303 
305 
306  // Cheap and dirty optimizations for 0, 90, 180, and 270 degrees.
307  if( angle == 0 )
308  return;
309 
310  if( angle == 900 ) /* sin = 1, cos = 0 */
311  {
312  tmp = *pX;
313  *pX = *pY;
314  *pY = -tmp;
315  }
316  else if( angle == 1800 ) /* sin = 0, cos = -1 */
317  {
318  *pX = -*pX;
319  *pY = -*pY;
320  }
321  else if( angle == 2700 ) /* sin = -1, cos = 0 */
322  {
323  tmp = *pX;
324  *pX = -*pY;
325  *pY = tmp;
326  }
327  else
328  {
329  double fangle = DECIDEG2RAD( angle );
330  double sinus = sin( fangle );
331  double cosinus = cos( fangle );
332 
333  double fpx = (*pY * sinus ) + (*pX * cosinus );
334  double fpy = (*pY * cosinus ) - (*pX * sinus );
335  *pX = fpx;
336  *pY = fpy;
337  }
338 }
void NORMALIZE_ANGLE_POS(T &Angle)
Definition: trigo.h:257
static DIRECTION_45::AngleType angle(const VECTOR2I &a, const VECTOR2I &b)
double DECIDEG2RAD(double deg)
Definition: trigo.h:218

References PNS::angle(), DECIDEG2RAD(), and NORMALIZE_ANGLE_POS().

◆ SegmentIntersectsSegment()

bool SegmentIntersectsSegment ( const wxPoint a_p1_l1,
const wxPoint a_p2_l1,
const wxPoint a_p1_l2,
const wxPoint a_p2_l2,
wxPoint aIntersectionPoint = nullptr 
)

Test if two lines intersect.

Parameters
a_p1_l1The first point of the first line.
a_p2_l1The second point of the first line.
a_p1_l2The first point of the second line.
a_p2_l2The second point of the second line.
aIntersectionPointis filled with the intersection point if it exists
Returns
bool - true if the two segments defined by four points intersect. (i.e. if the 2 segments have at least a common point)

Definition at line 61 of file trigo.cpp.

64 {
65 
66  //We are forced to use 64bit ints because the internal units can overflow 32bit ints when
67  // multiplied with each other, the alternative would be to scale the units down (i.e. divide
68  // by a fixed number).
69  long long dX_a, dY_a, dX_b, dY_b, dX_ab, dY_ab;
70  long long num_a, num_b, den;
71 
72  //Test for intersection within the bounds of both line segments using line equations of the
73  // form:
74  // x_k(u_k) = u_k * dX_k + x_k(0)
75  // y_k(u_k) = u_k * dY_k + y_k(0)
76  // with 0 <= u_k <= 1 and k = [ a, b ]
77 
78  dX_a = a_p2_l1.x - a_p1_l1.x;
79  dY_a = a_p2_l1.y - a_p1_l1.y;
80  dX_b = a_p2_l2.x - a_p1_l2.x;
81  dY_b = a_p2_l2.y - a_p1_l2.y;
82  dX_ab = a_p1_l2.x - a_p1_l1.x;
83  dY_ab = a_p1_l2.y - a_p1_l1.y;
84 
85  den = dY_a * dX_b - dY_b * dX_a ;
86 
87  //Check if lines are parallel
88  if( den == 0 )
89  return false;
90 
91  num_a = dY_ab * dX_b - dY_b * dX_ab;
92  num_b = dY_ab * dX_a - dY_a * dX_ab;
93 
94  // Only compute the intersection point if requested
95  if( aIntersectionPoint )
96  {
97  *aIntersectionPoint = a_p1_l1;
98  aIntersectionPoint->x += KiROUND( dX_a * ( double )num_a / ( double )den );
99  aIntersectionPoint->y += KiROUND( dY_a * ( double )num_b / ( double )den );
100  }
101 
102  if( den < 0 )
103  {
104  den = -den;
105  num_a = -num_a;
106  num_b = -num_b;
107  }
108 
109  //Test sign( u_a ) and return false if negative
110  if( num_a < 0 )
111  return false;
112 
113  //Test sign( u_b ) and return false if negative
114  if( num_b < 0 )
115  return false;
116 
117  //Test to ensure (u_a <= 1)
118  if( num_a > den )
119  return false;
120 
121  //Test to ensure (u_b <= 1)
122  if( num_b > den )
123  return false;
124 
125  return true;
126 }
constexpr ret_type KiROUND(fp_type v)
Round a floating point number to an integer using "round halfway cases away from zero".
Definition: util.h:61

References KiROUND(), wxPoint::x, and wxPoint::y.

Referenced by EDA_RECT::Intersects().

◆ TestSegmentHit()

bool TestSegmentHit ( const wxPoint aRefPoint,
wxPoint  aStart,
wxPoint  aEnd,
int  aDist 
)

Test if aRefPoint is with aDistance on the line defined by aStart and aEnd.

Parameters
aRefPoint= reference point to test
aStartis the first end-point of the line segment
aEndis the second end-point of the line segment
aDist= maximum distance for hit

Definition at line 129 of file trigo.cpp.

130 {
131  int xmin = aStart.x;
132  int xmax = aEnd.x;
133  int ymin = aStart.y;
134  int ymax = aEnd.y;
135  wxPoint delta = aStart - aRefPoint;
136 
137  if( xmax < xmin )
138  std::swap( xmax, xmin );
139 
140  if( ymax < ymin )
141  std::swap( ymax, ymin );
142 
143  // First, check if we are outside of the bounding box
144  if( ( ymin - aRefPoint.y > aDist ) || ( aRefPoint.y - ymax > aDist ) )
145  return false;
146 
147  if( ( xmin - aRefPoint.x > aDist ) || ( aRefPoint.x - xmax > aDist ) )
148  return false;
149 
150  // Next, eliminate easy cases
151  if( aStart.x == aEnd.x && aRefPoint.y > ymin && aRefPoint.y < ymax )
152  return std::abs( delta.x ) <= aDist;
153 
154  if( aStart.y == aEnd.y && aRefPoint.x > xmin && aRefPoint.x < xmax )
155  return std::abs( delta.y ) <= aDist;
156 
157  SEG segment( aStart, aEnd );
158  return segment.PointCloserThan( aRefPoint, aDist + 1 );
159 }
Definition: seg.h:39

References SEG::PointCloserThan(), wxPoint::x, and wxPoint::y.

Referenced by SCH_EAGLE_PLUGIN::addBusEntries(), DRAWING_TOOL::DrawVia(), LIB_RECTANGLE::HitTest(), LIB_BEZIER::HitTest(), SCH_BUS_ENTRY_BASE::HitTest(), WS_DRAW_ITEM_LINE::HitTest(), TRACK::HitTest(), SCH_LINE::HitTest(), WS_DRAW_ITEM_RECT::HitTest(), DRAWSEGMENT::HitTest(), DIMENSION::HitTest(), GERBER_DRAW_ITEM::HitTest(), D_PAD::HitTest(), SCH_EAGLE_PLUGIN::moveLabels(), and SCH_TEXT::UpdateDanglingState().