kicad/polygon/math_for_graphics.cpp

1733 lines
39 KiB
C++

// math for graphics utility routines, from FreePCB
using namespace std;
#include <vector>
#include <math.h>
#include <float.h>
#include <limits.h>
#include "fctsys.h"
#include "PolyLine.h"
// function to find inflection-pont to create a "dogleg" of two straight-line segments
// where one segment is vertical or horizontal and the other is at 45 degrees or 90 degrees
// enter with:
// pi = start point
// pf = end point
// mode = IM_90_45 or IM_45_90 or IM_90
//
CPoint GetInflectionPoint( CPoint pi, CPoint pf, int mode )
{
CPoint p = pi;
if( mode == IM_NONE )
return p;
int dx = pf.x - pi.x;
int dy = pf.y - pi.y;
if( dx == 0 || dy == 0 || abs(dx) == abs(dy) )
{
// only one segment needed
}
else
{
if( abs(dy) > abs(dx) )
{
// vertical > horizontal
if( mode == IM_90 )
{
p.x = pi.x;
p.y = pf.y;
}
else if( mode == IM_45_90 || mode == IM_90_45 )
{
int vert; // length of vertical line needed
if( dy > 0 )
vert = dy - abs(dx); // positive
else
vert = dy + abs(dx); // negative
if( mode == IM_90_45 )
p.y = pi.y + vert;
else if( mode == IM_45_90 )
{
p.y = pf.y - vert;
p.x = pf.x;
}
}
else
wxASSERT(0);
}
else
{
// horizontal > vertical
if( mode == IM_90 )
{
p.x = pf.x;
p.y = pi.y;
}
else if( mode == IM_45_90 || mode == IM_90_45 )
{
int hor; // length of horizontal line needed
if( dx > 0 )
hor = dx - abs(dy); // positive
else
hor = dx + abs(dy); // negative
if( mode == IM_90_45 )
p.x = pi.x + hor;
else if( mode == IM_45_90 )
{
p.x = pf.x - hor;
p.y = pf.y;
}
}
else
wxASSERT(0);
}
}
return p;
}
//
// function to rotate a point clockwise about another point
// currently, angle must be 0, 90, 180 or 270
//
void RotatePoint( CPoint *p, int angle, CPoint org )
{
if( angle == 90 )
{
int tempy = org.y + (org.x - p->x);
p->x = org.x + (p->y - org.y);
p->y = tempy;
}
else if( angle > 90 )
{
for( int i=0; i<(angle/90); i++ )
RotatePoint( p, 90, org );
}
}
// function to rotate a rectangle clockwise about a point
// angle must be 0, 90, 180 or 270
// on exit, r->top > r.bottom, r.right > r.left
//
void RotateRect( CRect *r, int angle, CPoint org )
{
CRect tr;
if( angle == 90 )
{
tr.left = org.x + (r->bottom - org.y);
tr.right = org.x + (r->top - org.y);
tr.top = org.y + (org.x - r->right);
tr.bottom = org.y + (org.x - r->left);
if( tr.left > tr.right )
{
int temp = tr.right;
tr.left = tr.right;
tr.left = temp;
}
if( tr.left > tr.right )
{
int temp = tr.right;
tr.left = tr.right;
tr.left = temp;
}
if( tr.bottom > tr.top )
{
int temp = tr.bottom;
tr.bottom = tr.top;
tr.top = temp;
}
}
else if( angle > 90 )
{
tr = *r;
for( int i=0; i<(angle/90); i++ )
RotateRect( &tr, 90, org );
}
*r = tr;
}
// test for hit on line segment
// i.e. cursor within a given distance from segment
// enter with: x,y = cursor coords
// (xi,yi) and (xf,yf) are the end-points of the line segment
// dist = maximum distance for hit
//
int TestLineHit( int xi, int yi, int xf, int yf, int x, int y, double dist )
{
double dd;
// test for vertical or horizontal segment
if( xf==xi )
{
// vertical segment
dd = fabs( (double)(x-xi) );
if( dd<dist && ( (yf>yi && y<yf && y>yi) || (yf<yi && y>yf && y<yi) ) )
return 1;
}
else if( yf==yi )
{
// horizontal segment
dd = fabs( (double)(y-yi) );
if( dd<dist && ( (xf>xi && x<xf && x>xi) || (xf<xi && x>xf && x<xi) ) )
return 1;
}
else
{
// oblique segment
// find a,b such that (xi,yi) and (xf,yf) lie on y = a + bx
double b = (double)(yf-yi)/(xf-xi);
double a = (double)yi-b*xi;
// find c,d such that (x,y) lies on y = c + dx where d=(-1/b)
double d = -1.0/b;
double c = (double)y-d*x;
// find nearest point to (x,y) on line segment (xi,yi) to (xf,yf)
double xp = (a-c)/(d-b);
double yp = a + b*xp;
// find distance
dd = sqrt((x-xp)*(x-xp)+(y-yp)*(y-yp));
if( fabs(b)>0.7 )
{
// line segment more vertical than horizontal
if( dd<dist && ( (yf>yi && yp<yf && yp>yi) || (yf<yi && yp>yf && yp<yi) ) )
return 1;
}
else
{
// line segment more horizontal than vertical
if( dd<dist && ( (xf>xi && xp<xf && xp>xi) || (xf<xi && xp>xf && xp<xi) ) )
return 1;
}
}
return 0; // no hit
}
// find intersection between y = a + bx and y = c + dx;
//
int FindLineIntersection( double a, double b, double c, double d, double * x, double * y )
{
*x = (c-a)/(b-d);
*y = a + b*(*x);
return 0;
}
// set EllipseKH struct to describe the ellipse for an arc
//
int MakeEllipseFromArc( int xi, int yi, int xf, int yf, int style, EllipseKH * el )
{
// arc (quadrant of ellipse)
// convert to clockwise arc
int xxi, xxf, yyi, yyf;
if( style == CPolyLine::ARC_CCW )
{
xxi = xf;
xxf = xi;
yyi = yf;
yyf = yi;
}
else
{
xxi = xi;
xxf = xf;
yyi = yi;
yyf = yf;
}
// find center and radii of ellipse
double xo=0, yo=0;
if( xxf > xxi && yyf > yyi )
{
xo = xxf;
yo = yyi;
el->theta1 = M_PI;
el->theta2 = M_PI/2.0;
}
else if( xxf < xxi && yyf > yyi )
{
xo = xxi;
yo = yyf;
el->theta1 = -M_PI/2.0;
el->theta2 = -M_PI;
}
else if( xxf < xxi && yyf < yyi )
{
xo = xxf;
yo = yyi;
el->theta1 = 0.0;
el->theta2 = -M_PI/2.0;
}
else if( xxf > xxi && yyf < yyi )
{
xo = xxi;
yo = yyf;
el->theta1 = M_PI/2.0;
el->theta2 = 0.0;
}
el->Center.X = xo;
el->Center.Y = yo;
el->xrad = abs(xf-xi);
el->yrad = abs(yf-yi);
#if 0
el->Phi = 0.0;
el->MaxRad = el->xrad;
el->MinRad = el->yrad;
if( el->MaxRad < el->MinRad )
{
el->MaxRad = el->yrad;
el->MinRad = el->xrad;
el->Phi = M_PI/2.0;
}
#endif
return 0;
}
// find intersections between line segment (xi,yi) to (xf,yf)
// and line segment (xi2,yi2) to (xf2,yf2)
// the line segments may be arcs (i.e. quadrant of an ellipse) or straight
// returns number of intersections found (max of 2)
// returns coords of intersections in arrays x[2], y[2]
//
int FindSegmentIntersections( int xi, int yi, int xf, int yf, int style,
int xi2, int yi2, int xf2, int yf2, int style2,
double x[], double y[] )
{
double xr[12], yr[12];
int iret = 0;
if( max(xi,xf) < min(xi2,xf2)
|| min(xi,xf) > max(xi2,xf2)
|| max(yi,yf) < min(yi2,yf2)
|| min(yi,yf) > max(yi2,yf2) )
return 0;
if( style != CPolyLine::STRAIGHT && style2 != CPolyLine::STRAIGHT )
{
// two identical arcs intersect
if( style == style2 && xi == xi2 && yi == yi2 && xf == xf2 && yf == yf2 )
{
if( x && y )
{
x[0] = xi;
y[0] = yi;
}
return 1;
}
else if( style != style2 && xi == xf2 && yi == yf2 && xf == xi2 && yf == yi2 )
{
if( x && y )
{
x[0] = xi;
y[0] = yi;
}
return 1;
}
}
if( style == CPolyLine::STRAIGHT && style2 == CPolyLine::STRAIGHT )
{
// both straight-line segments
int x, y;
bool bYes = TestForIntersectionOfStraightLineSegments( xi, yi, xf, yf, xi2, yi2, xf2, yf2, &x, &y );
if( !bYes )
return 0;
xr[0] = x;
yr[0] = y;
iret = 1;
}
else if( style == CPolyLine::STRAIGHT )
{
// first segment is straight, second segment is an arc
int ret;
double x1r, y1r, x2r, y2r;
if( xf == xi )
{
// vertical first segment
double a = xi;
double b = DBL_MAX/2.0;
ret = FindLineSegmentIntersection( a, b, xi2, yi2, xf2, yf2, style2,
&x1r, &y1r, &x2r, &y2r );
}
else
{
double b = (double)(yf-yi)/(double)(xf-xi);
double a = yf - b*xf;
ret = FindLineSegmentIntersection( a, b, xi2, yi2, xf2, yf2, style2,
&x1r, &y1r, &x2r, &y2r );
}
if( ret == 0 )
return 0;
if( InRange( x1r, xi, xf ) && InRange( y1r, yi, yf ) )
{
xr[iret] = x1r;
yr[iret] = y1r;
iret++;
}
if( ret == 2 )
{
if( InRange( x2r, xi, xf ) && InRange( y2r, yi, yf ) )
{
xr[iret] = x2r;
yr[iret] = y2r;
iret++;
}
}
}
else if( style2 == CPolyLine::STRAIGHT )
{
// first segment is an arc, second segment is straight
int ret;
double x1r, y1r, x2r, y2r;
if( xf2 == xi2 )
{
// vertical second segment
double a = xi2;
double b = DBL_MAX/2.0;
ret = FindLineSegmentIntersection( a, b, xi, yi, xf, yf, style,
&x1r, &y1r, &x2r, &y2r );
}
else
{
double b = (double)(yf2-yi2)/(double)(xf2-xi2);
double a = yf2 - b*xf2;
ret = FindLineSegmentIntersection( a, b, xi, yi, xf, yf, style,
&x1r, &y1r, &x2r, &y2r );
}
if( ret == 0 )
return 0;
if( InRange( x1r, xi2, xf2 ) && InRange( y1r, yi2, yf2 ) )
{
xr[iret] = x1r;
yr[iret] = y1r;
iret++;
}
if( ret == 2 )
{
if( InRange( x2r, xi2, xf2 ) && InRange( y2r, yi2, yf2 ) )
{
xr[iret] = x2r;
yr[iret] = y2r;
iret++;
}
}
}
else
{
// both segments are arcs
EllipseKH el1;
EllipseKH el2;
MakeEllipseFromArc( xi, yi, xf, yf, style, &el1 );
MakeEllipseFromArc( xi2, yi2, xf2, yf2, style2, &el2 );
int n;
if( el1.xrad+el1.yrad > el2.xrad+el2.yrad )
n = GetArcIntersections( &el1, &el2 );
else
n = GetArcIntersections( &el2, &el1 );
iret = n;
}
if( x && y )
{
for( int i=0; i<iret; i++ )
{
x[i] = xr[i];
y[i] = yr[i];
}
}
return iret;
}
// find intersection between line y = a + bx and line segment (xi,yi) to (xf,yf)
// if b > DBL_MAX/10, assume vertical line at x = a
// the line segment may be an arc (i.e. quadrant of an ellipse)
// return 0 if no intersection
// returns 1 or 2 if intersections found
// sets coords of intersections in *x1, *y1, *x2, *y2
// if no intersection, returns min distance in dist
//
int FindLineSegmentIntersection( double a, double b, int xi, int yi, int xf, int yf, int style,
double * x1, double * y1, double * x2, double * y2,
double * dist )
{
double xx = 0, yy = 0; //Init made to avoid C compil "uninitialized" warning
bool bVert = false;
if( b > DBL_MAX/10.0 )
bVert = true;
if( xf != xi )
{
// non-vertical segment, get intersection
if( style == CPolyLine::STRAIGHT || yf == yi )
{
// horizontal or oblique straight segment
// put into form y = c + dx;
double d = (double)(yf-yi)/(double)(xf-xi);
double c = yf - d*xf;
if( bVert )
{
// if vertical line, easy
if( InRange( a, xi, xf ) )
{
*x1 = a;
*y1 = c + d*a;
return 1;
}
else
{
if( dist )
*dist = min( abs(a-xi), abs(a-xf) );
return 0;
}
}
if( fabs(b-d) < 1E-12 )
{
// parallel lines
if( dist )
{
*dist = GetPointToLineDistance( a, b, xi, xf );
}
return 0; // lines parallel
}
// calculate intersection
xx = (c-a)/(b-d);
yy = a + b*(xx);
// see if intersection is within the line segment
if( yf == yi )
{
// horizontal line
if( (xx>=xi && xx>xf) || (xx<=xi && xx<xf) )
return 0;
}
else
{
// oblique line
if( (xx>=xi && xx>xf) || (xx<=xi && xx<xf)
|| (yy>yi && yy>yf) || (yy<yi && yy<yf) )
return 0;
}
}
else if( style == CPolyLine::ARC_CW || style == CPolyLine::ARC_CCW )
{
// arc (quadrant of ellipse)
// convert to clockwise arc
int xxi, xxf, yyi, yyf;
if( style == CPolyLine::ARC_CCW )
{
xxi = xf;
xxf = xi;
yyi = yf;
yyf = yi;
}
else
{
xxi = xi;
xxf = xf;
yyi = yi;
yyf = yf;
}
// find center and radii of ellipse
double xo = xxf, yo = yyi, rx, ry; // Init made to avoid C compil warnings
if( xxf > xxi && yyf > yyi )
{
xo = xxf;
yo = yyi;
}
else if( xxf < xxi && yyf > yyi )
{
xo = xxi;
yo = yyf;
}
else if( xxf < xxi && yyf < yyi )
{
xo = xxf;
yo = yyi;
}
else if( xxf > xxi && yyf < yyi )
{
xo = xxi;
yo = yyf;
}
rx = fabs( (double)(xxi-xxf) );
ry = fabs( (double)(yyi-yyf) );
bool test;
double xx1, xx2, yy1, yy2, aa;
if( bVert )
{
// shift vertical line to coordinate system of ellipse
aa = a - xo;
test = FindVerticalLineEllipseIntersections( rx, ry, aa, &yy1, &yy2 );
if( !test )
return 0;
// shift back to PCB coordinates
yy1 += yo;
yy2 += yo;
xx1 = a;
xx2 = a;
}
else
{
// shift line to coordinate system of ellipse
aa = a + b*xo - yo;
test = FindLineEllipseIntersections( rx, ry, aa, b, &xx1, &xx2 );
if( !test )
return 0;
// shift back to PCB coordinates
yy1 = aa + b*xx1;
xx1 += xo;
yy1 += yo;
yy2 = aa + b*xx2;
xx2 += xo;
yy2 += yo;
}
int npts = 0;
if( (xxf>xxi && xx1<xxf && xx1>xxi) || (xxf<xxi && xx1<xxi && xx1>xxf) )
{
if( (yyf>yyi && yy1<yyf && yy1>yyi) || (yyf<yyi && yy1<yyi && yy1>yyf) )
{
*x1 = xx1;
*y1 = yy1;
npts = 1;
}
}
if( (xxf>xxi && xx2<xxf && xx2>xxi) || (xxf<xxi && xx2<xxi && xx2>xxf) )
{
if( (yyf>yyi && yy2<yyf && yy2>yyi) || (yyf<yyi && yy2<yyi && yy2>yyf) )
{
if( npts == 0 )
{
*x1 = xx2;
*y1 = yy2;
npts = 1;
}
else
{
*x2 = xx2;
*y2 = yy2;
npts = 2;
}
}
}
return npts;
}
else
wxASSERT(0);
}
else
{
// vertical line segment
if( bVert )
return 0;
xx = xi;
yy = a + b*xx;
if( (yy>=yi && yy>yf) || (yy<=yi && yy<yf) )
return 0;
}
*x1 = xx;
*y1 = yy;
return 1;
}
// Test for intersection of line segments
// If lines are parallel, returns false
// If true, returns intersection coords in x, y
// if false, returns min. distance in dist (may be 0.0 if parallel)
// and coords on nearest point in one of the segments in (x,y)
//
bool TestForIntersectionOfStraightLineSegments( int x1i, int y1i, int x1f, int y1f,
int x2i, int y2i, int x2f, int y2f,
int * x, int * y, double * d )
{
double a, b, dist;
// first, test for intersection
if( x1i == x1f && x2i == x2f )
{
// both segments are vertical, can't intersect
}
else if( y1i == y1f && y2i == y2f )
{
// both segments are horizontal, can't intersect
}
else if( x1i == x1f && y2i == y2f )
{
// first seg. vertical, second horizontal, see if they cross
if( InRange( x1i, x2i, x2f )
&& InRange( y2i, y1i, y1f ) )
{
if( x )
*x = x1i;
if( y )
*y = y2i;
if( d )
*d = 0.0;
return true;
}
}
else if( y1i == y1f && x2i == x2f )
{
// first seg. horizontal, second vertical, see if they cross
if( InRange( y1i, y2i, y2f )
&& InRange( x2i, x1i, x1f ) )
{
if( x )
*x = x2i;
if( y )
*y = y1i;
if( d )
*d = 0.0;
return true;
}
}
else if( x1i == x1f )
{
// first segment vertical, second oblique
// get a and b for second line segment, so that y = a + bx;
b = (double)(y2f-y2i)/(x2f-x2i);
a = (double)y2i - b*x2i;
double x1, y1, x2, y2;
int test = FindLineSegmentIntersection( a, b, x1i, y1i, x1f, y1f, CPolyLine::STRAIGHT,
&x1, &y1, &x2, &y2 );
if( test )
{
if( InRange( y1, y1i, y1f ) && InRange( x1, x2i, x2f ) && InRange( y1, y2i, y2f ) )
{
if( x )
*x = (int) x1;
if( y )
*y = (int) y1;
if( d )
*d = 0.0;
return true;
}
}
}
else if( y1i == y1f )
{
// first segment horizontal, second oblique
// get a and b for second line segment, so that y = a + bx;
b = (double)(y2f-y2i)/(x2f-x2i);
a = (double)y2i - b*x2i;
double x1, y1, x2, y2;
int test = FindLineSegmentIntersection( a, b, x1i, y1i, x1f, y1f, CPolyLine::STRAIGHT,
&x1, &y1, &x2, &y2 );
if( test )
{
if( InRange( x1, x1i, x1f ) && InRange( x1, x2i, x2f ) && InRange( y1, y2i, y2f ) )
{
if( x )
*x = (int) x1;
if( y )
*y = (int) y1;
if( d )
*d = 0.0;
return true;
}
}
}
else if( x2i == x2f )
{
// second segment vertical, first oblique
// get a and b for first line segment, so that y = a + bx;
b = (double)(y1f-y1i)/(x1f-x1i);
a = (double)y1i - b*x1i;
double x1, y1, x2, y2;
int test = FindLineSegmentIntersection( a, b, x2i, y2i, x2f, y2f, CPolyLine::STRAIGHT,
&x1, &y1, &x2, &y2 );
if( test )
{
if( InRange( x1, x1i, x1f ) && InRange( y1, y1i, y1f ) && InRange( y1, y2i, y2f ) )
{
if( x )
*x = (int) x1;
if( y )
*y = (int) y1;
if( d )
*d = 0.0;
return true;
}
}
}
else if( y2i == y2f )
{
// second segment horizontal, first oblique
// get a and b for second line segment, so that y = a + bx;
b = (double)(y1f-y1i)/(x1f-x1i);
a = (double)y1i - b*x1i;
double x1, y1, x2, y2;
int test = FindLineSegmentIntersection( a, b, x2i, y2i, x2f, y2f, CPolyLine::STRAIGHT,
&x1, &y1, &x2, &y2 );
if( test )
{
if( InRange( x1, x1i, x1f ) && InRange( y1, y1i, y1f ) )
{
if( x )
*x = (int) x1;
if( y )
*y = (int) y1;
if( d )
*d = 0.0;
return true;
}
}
}
else
{
// both segments oblique
if( (long)(y1f-y1i)*(x2f-x2i) != (long)(y2f-y2i)*(x1f-x1i) )
{
// not parallel, get a and b for first line segment, so that y = a + bx;
b = (double)(y1f-y1i)/(x1f-x1i);
a = (double)y1i - b*x1i;
double x1, y1, x2, y2;
int test = FindLineSegmentIntersection( a, b, x2i, y2i, x2f, y2f, CPolyLine::STRAIGHT,
&x1, &y1, &x2, &y2 );
// both segments oblique
if( test )
{
if( InRange( x1, x1i, x1f ) && InRange( y1, y1i, y1f ) )
{
if( x )
*x = (int) x1;
if( y )
*y = (int) y1;
if( d )
*d = 0.0;
return true;
}
}
}
}
// don't intersect, get shortest distance between each endpoint and the other line segment
dist = GetPointToLineSegmentDistance( x1i, y1i, x2i, y2i, x2f, y2f );
double xx = x1i;
double yy = y1i;
double dd = GetPointToLineSegmentDistance( x1f, y1f, x2i, y2i, x2f, y2f );
if( dd < dist )
{
dist = dd;
xx = x1f;
yy = y1f;
}
dd = GetPointToLineSegmentDistance( x2i, y2i, x1i, y1i, x1f, y1f );
if( dd < dist )
{
dist = dd;
xx = x2i;
yy = y2i;
}
dd = GetPointToLineSegmentDistance( x2f, y2f, x1i, y1i, x1f, y1f );
if( dd < dist )
{
dist = dd;
xx = x2f;
yy = y2f;
}
if( x )
*x = (int) xx;
if( y )
*y = (int) yy;
if( d )
*d = dist;
return false;
}
// quicksort algorithm
// sorts array numbers[], also moves elements of another array index[]
//
#define Q3WAY
void quickSort(int numbers[], int index[], int array_size)
{
#ifdef Q3WAY
q_sort_3way(numbers, index, 0, array_size - 1);
#else
q_sort(numbers, index, 0, array_size - 1);
#endif
}
// standard quicksort
//
void q_sort(int numbers[], int index[], int left, int right)
{
int pivot, pivot_index, l_hold, r_hold;
l_hold = left;
r_hold = right;
pivot = numbers[left];
pivot_index = index[left];
while (left < right)
{
while ((numbers[right] >= pivot) && (left < right))
right--;
if (left != right)
{
numbers[left] = numbers[right];
index[left] = index[right];
left++;
}
while ((numbers[left] <= pivot) && (left < right))
left++;
if (left != right)
{
numbers[right] = numbers[left];
index[right] = index[left];
right--;
}
}
numbers[left] = pivot;
index[left] = pivot_index;
pivot = left;
left = l_hold;
right = r_hold;
if (left < pivot)
q_sort(numbers, index, left, pivot-1);
if (right > pivot)
q_sort(numbers, index, pivot+1, right);
}
// 3-way quicksort...useful where there are duplicate values
//
void q_sort_3way( int a[], int b[], int l, int r )
{
#define EXCH(i,j) {int temp=a[i]; a[i]=a[j]; a[j]=temp; temp=b[i]; b[i]=b[j]; b[j]=temp;}
int i = l - 1;
int j = r;
int p = l - 1;
int q = r;
int v = a[r];
if( r <= l )
return;
for(;;)
{
while( a[++i] < v );
while( v < a[--j] )
if( j == 1 )
break;
if( i >= j )
break;
EXCH( i, j );
if( a[i] == v )
{
p++;
EXCH( p, i );
}
if( v == a[j] )
{
q--;
EXCH( j, q );
}
}
EXCH( i, r );
j = i - 1;
i = i + 1;
for( int k=l; k<p; k++, j-- )
EXCH( k, j );
for( int k=r-1; k>q; k--, i++ )
EXCH( i, k );
q_sort_3way( a, b, l, j );
q_sort_3way( a, b, i, r );
}
// solves quadratic equation
// i.e. ax**2 + bx + c = 0
// returns true if solution exist, with solutions in x1 and x2
// else returns false
//
bool Quadratic( double a, double b, double c, double *x1, double *x2 )
{
double root = b*b - 4.0*a*c;
if( root < 0.0 )
return false;
root = sqrt( root );
*x1 = (-b+root)/(2.0*a);
*x2 = (-b-root)/(2.0*a);
return true;
}
// finds intersections of vertical line at x
// with ellipse defined by (x^2)/(a^2) + (y^2)/(b^2) = 1;
// returns true if solution exist, with solutions in y1 and y2
// else returns false
//
bool FindVerticalLineEllipseIntersections( double a, double b, double x, double *y1, double *y2 )
{
double y_sqr = (1.0-(x*x)/(a*a))*b*b;
if( y_sqr < 0.0 )
return false;
*y1 = sqrt(y_sqr);
*y2 = -*y1;
return true;
}
// finds intersections of straight line y = c + dx
// with ellipse defined by (x^2)/(a^2) + (y^2)/(b^2) = 1;
// returns true if solution exist, with solutions in x1 and x2
// else returns false
//
bool FindLineEllipseIntersections( double a, double b, double c, double d, double *x1, double *x2 )
{
// quadratic terms
double A = d*d+b*b/(a*a);
double B = 2.0*c*d;
double C = c*c-b*b;
return Quadratic( A, B, C, x1, x2 );
}
#if 0
// draw a straight line or an arc between xi,yi and xf,yf
//
void DrawArc( CDC * pDC, int shape, int xxi, int yyi, int xxf, int yyf, bool bMeta )
{
int xi, yi, xf, yf;
if( shape == DL_LINE || xxi == xxf || yyi == yyf )
{
// draw straight line
pDC->MoveTo( xxi, yyi );
pDC->LineTo( xxf, yyf );
}
else if( shape == DL_ARC_CCW || shape == DL_ARC_CW )
{
// set endpoints so we can always draw counter-clockwise arc
if( shape == DL_ARC_CW )
{
xi = xxf;
yi = yyf;
xf = xxi;
yf = yyi;
}
else
{
xi = xxi;
yi = yyi;
xf = xxf;
yf = yyf;
}
pDC->MoveTo( xi, yi );
if( xf > xi && yf > yi )
{
// quadrant 1
int w = (xf-xi)*2;
int h = (yf-yi)*2;
if( !bMeta )
pDC->Arc( xf-w, yi+h, xf, yi,
xi, yi, xf, yf );
else
pDC->Arc( xf-w, yi, xf, yi+h,
xf, yf, xi, yi );
}
else if( xf < xi && yf > yi )
{
// quadrant 2
int w = -(xf-xi)*2;
int h = (yf-yi)*2;
if( !bMeta )
pDC->Arc( xi-w, yf, xi, yf-h,
xi, yi, xf, yf );
else
pDC->Arc( xi-w, yf-h, xi, yf,
xf, yf, xi, yi );
}
else if( xf < xi && yf < yi )
{
// quadrant 3
int w = -(xf-xi)*2;
int h = -(yf-yi)*2;
if( !bMeta )
pDC->Arc( xf, yi, xf+w, yi-h,
xi, yi, xf, yf );
else
pDC->Arc( xf, yi-h, xf+w, yi,
xf, yf, xi, yi );
}
else if( xf > xi && yf < yi )
{
// quadrant 4
int w = (xf-xi)*2;
int h = -(yf-yi)*2;
if( !bMeta )
pDC->Arc( xi, yf+h, xi+w, yf,
xi, yi, xf, yf );
else
pDC->Arc( xi, yf, xi+w, yf+h,
xf, yf, xi, yi );
}
pDC->MoveTo( xxf, yyf );
}
else
wxASSERT(0); // oops
}
#endif
// Get arrays of circles, rects and line segments to represent pad
// for purposes of drawing pad or calculating clearances
// margins of circles and line segments represent pad outline
// circles and rects are used to find points inside pad
//
void GetPadElements( int type, int x, int y, int wid, int len, int radius, int angle,
int * nr, my_rect r[], int * nc, my_circle c[], int * ns, my_seg s[] )
{
*nc = 0;
*nr = 0;
*ns = 0;
if( type == PAD_ROUND )
{
*nc = 1;
c[0] = my_circle(x,y,wid/2);
return;
}
if( type == PAD_SQUARE )
{
*nr = 1;
r[0] = my_rect(x-wid/2, y-wid/2,x+wid/2, y+wid/2);
*ns = 4;
s[0] = my_seg(x-wid/2, y+wid/2,x+wid/2, y+wid/2); // top
s[1] = my_seg(x-wid/2, y-wid/2,x+wid/2, y-wid/2); // bottom
s[2] = my_seg(x-wid/2, y-wid/2,x-wid/2, y+wid/2); // left
s[3] = my_seg(x+wid/2, y-wid/2,x+wid/2, y+wid/2); // right
return;
}
if( type == PAD_OCTAGON )
{
const double pi = 3.14159265359;
*nc = 1; // circle represents inside of polygon
c[0] = my_circle(x, y, wid/2);
*ns = 8; // now create sides of polygon
double theta = pi/8.0;
double radius = 0.5*(double)wid/cos(theta);
double last_x = x + radius*cos(theta);
double last_y = y + radius*sin(theta);
for( int is=0; is<8; is++ )
{
theta += pi/4.0;
double dx = x + radius*cos(theta);
double dy = y + radius*sin(theta);
s[is] = my_seg((int) last_x, (int) last_y, x, y);
last_x = dx;
last_y = dy;
}
return;
}
//
int h;
int v;
if( angle == 90 || angle == 270 )
{
h = wid;
v = len;
}
else
{
v = wid;
h = len;
}
if( type == PAD_RECT )
{
*nr = 1;
r[0] = my_rect(x-h/2, y-v/2, x+h/2, y+v/2);
*ns = 4;
s[0] = my_seg(x-h/2, y+v/2,x+h/2, y+v/2); // top
s[1] = my_seg(x-h/2, y-v/2,x+h/2, y-v/2); // bottom
s[2] = my_seg(x-h/2, y-v/2,x-h/2, y+v/2); // left
s[3] = my_seg(x+h/2, y-v/2,x+h/2, y+v/2); // right
return;
}
if( type == PAD_RRECT )
{
*nc = 4;
c[0] = my_circle(x-h/2+radius, y-v/2+radius, radius); // bottom left circle
c[1] = my_circle(x+h/2-radius, y-v/2+radius, radius); // bottom right circle
c[2] = my_circle(x-h/2+radius, y+v/2-radius, radius); // top left circle
c[3] = my_circle(x+h/2-radius, y+v/2-radius, radius); // top right circle
*ns = 4;
s[0] = my_seg(x-h/2+radius, y+v/2, x+h/2-radius, y+v/2); // top
s[1] = my_seg(x-h/2+radius, y-v/2, x+h/2-radius, y+v/2); // bottom
s[2] = my_seg(x-h/2, y-v/2+radius, x-h/2, y+v/2-radius); // left
s[3] = my_seg(x+h/2, y-v/2+radius, x+h/2, y+v/2-radius); // right
return;
}
if( type == PAD_OVAL )
{
if( h > v )
{
// horizontal
*nc = 2;
c[0] = my_circle(x-h/2+v/2, y, v/2); // left circle
c[1] = my_circle(x+h/2-v/2, y, v/2); // right circle
*nr = 1;
r[0] = my_rect(x-h/2+v/2, y-v/2, x+h/2-v/2, y+v/2);
*ns = 2;
s[0] = my_seg(x-h/2+v/2, y+v/2, x+h/2-v/2, y+v/2); // top
s[1] = my_seg(x-h/2+v/2, y-v/2, x+h/2-v/2, y-v/2); // bottom
}
else
{
// vertical
*nc = 2;
c[0] = my_circle(x, y+v/2-h/2, h/2); // top circle
c[1] = my_circle(x, y-v/2+h/2, h/2); // bottom circle
*nr = 1;
r[0] = my_rect(x-h/2, y-v/2+h/2, x+h/2, y+v/2-h/2);
*ns = 2;
s[0] = my_seg(x-h/2, y-v/2+h/2, x-h/2, y+v/2-h/2); // left
s[1] = my_seg(x+h/2, y-v/2+h/2, x+h/2, y+v/2-h/2); // left
}
return;
}
wxASSERT(0);
}
// Find distance from a staright line segment to a pad
//
int GetClearanceBetweenSegmentAndPad( int x1, int y1, int x2, int y2, int w,
int type, int x, int y, int wid, int len, int radius, int angle )
{
if( type == PAD_NONE )
return INT_MAX;
else
{
int nc, nr, ns;
my_circle c[4];
my_rect r[2];
my_seg s[8];
GetPadElements( type, x, y, wid, len, radius, angle,
&nr, r, &nc, c, &ns, s );
// first test for endpoints of line segment in rectangle
for( int ir=0; ir<nr; ir++ )
{
if( x1 >= r[ir].xlo && x1 <= r[ir].xhi && y1 >= r[ir].ylo && y1 <= r[ir].yhi )
return 0;
if( x2 >= r[ir].xlo && x2 <= r[ir].xhi && y2 >= r[ir].ylo && y2 <= r[ir].yhi )
return 0;
}
// now get distance from elements of pad outline
int dist = INT_MAX;
for( int ic=0; ic<nc; ic++ )
{
int d = (int)GetPointToLineSegmentDistance( c[ic].x, c[ic].y, x1, y1, x2, y2 ) - c[ic].r - w/2;
dist = min(dist,d);
}
for( int is=0; is<ns; is++ )
{
double d;
TestForIntersectionOfStraightLineSegments( s[is].xi, s[is].yi, s[is].xf, s[is].yf,
x1, y1, x2, y2, NULL, NULL, &d );
dist = min(dist, (int)d - w/2);
}
return max(0,dist);
}
}
// Get clearance between 2 segments
// Returns point in segment closest to other segment in x, y
// in clearance > max_cl, just returns max_cl and doesn't return x,y
//
int GetClearanceBetweenSegments( int x1i, int y1i, int x1f, int y1f, int style1, int w1,
int x2i, int y2i, int x2f, int y2f, int style2, int w2,
int max_cl, int * x, int * y )
{
// check clearance between bounding rectangles
int test = max_cl + w1/2 + w2/2;
if( min(x1i,x1f)-max(x2i,x2f) > test )
return max_cl;
if( min(x2i,x2f)-max(x1i,x1f) > test )
return max_cl;
if( min(y1i,y1f)-max(y2i,y2f) > test )
return max_cl;
if( min(y2i,y2f)-max(y1i,y1f) > test )
return max_cl;
if( style1 == CPolyLine::STRAIGHT && style1 == CPolyLine::STRAIGHT )
{
// both segments are straight lines
int xx, yy;
double dd;
TestForIntersectionOfStraightLineSegments( x1i, y1i, x1f, y1f,
x2i, y2i, x2f, y2f, &xx, &yy, &dd );
int d = max( 0, (int)dd - w1/2 - w2/2 );
if( x )
*x = xx;
if( y )
*y = yy;
return d;
}
// not both straight-line segments
// see if segments intersect
double xr[2];
double yr[2];
test = FindSegmentIntersections( x1i, y1i, x1f, y1f, style1, x2i, y2i, x2f, y2f, style2, xr, yr );
if( test )
{
if( x )
*x = (int) xr[0];
if( y )
*y = (int) yr[0];
return 0;
}
// at least one segment is an arc
EllipseKH el1;
EllipseKH el2;
bool bArcs;
int xi=0, yi=0, xf=0, yf=0;
if( style2 == CPolyLine::STRAIGHT )
{
// style1 = arc, style2 = straight
MakeEllipseFromArc( x1i, y1i, x1f, y1f, style1, &el1 );
xi = x2i;
yi = y2i;
xf = x2f;
yf = y2f;
bArcs = false;
}
else if( style1 == CPolyLine::STRAIGHT )
{
// style2 = arc, style1 = straight
xi = x1i;
yi = y1i;
xf = x1f;
yf = y1f;
MakeEllipseFromArc( x2i, y2i, x2f, y2f, style2, &el1 );
bArcs = false;
}
else
{
// style1 = arc, style2 = arc
MakeEllipseFromArc( x1i, y1i, x1f, y1f, style1, &el1 );
MakeEllipseFromArc( x2i, y2i, x2f, y2f, style2, &el2 );
bArcs = true;
}
const int NSTEPS = 32;
if( el1.theta2 > el1.theta1 )
wxASSERT(0);
if( bArcs && el2.theta2 > el2.theta1 )
wxASSERT(0);
// test multiple points in both segments
double th1;
double th2;
double len2;
if( bArcs )
{
th1 = el2.theta1;
th2 = el2.theta2;
len2 = max(el2.xrad, el2.yrad);
}
else
{
th1 = 1.0;
th2 = 0.0;
len2 = abs(xf-xi)+abs(yf-yi);
}
double s_start = el1.theta1;
double s_end = el1.theta2;
double s_start2 = th1;
double s_end2 = th2;
double dmin = DBL_MAX;
double xmin = 0, ymin = 0, smin = 0, smin2 = 0; // Init made to avoid C compil warnings
int nsteps = NSTEPS;
int nsteps2 = NSTEPS;
double step = (s_start-s_end)/(nsteps-1);
double step2 = (s_start2-s_end2)/(nsteps2-1);
while( (step * max(el1.xrad, el1.yrad)) > 0.1*NM_PER_MIL
&& (step2 * len2) > 0.1*NM_PER_MIL )
{
step = (s_start-s_end)/(nsteps-1);
for( int i=0; i<nsteps; i++ )
{
double s;
if( i < nsteps-1 )
s = s_start - i*step;
else
s = s_end;
double x = el1.Center.X + el1.xrad*cos(s);
double y = el1.Center.Y + el1.yrad*sin(s);
// if not an arc, use s2 as fractional distance along line
step2 = (s_start2-s_end2)/(nsteps2-1);
for( int i2=0; i2<nsteps2; i2++ )
{
double s2;
if( i2 < nsteps2-1 )
s2 = s_start2 - i2*step2;
else
s2 = s_end2;
double x2, y2;
if( !bArcs )
{
x2 = xi + (xf-xi)*s2;
y2 = yi + (yf-yi)*s2;
}
else
{
x2 = el2.Center.X + el2.xrad*cos(s2);
y2 = el2.Center.Y + el2.yrad*sin(s2);
}
double d = Distance( (int) x, (int) y, (int) x2, (int) y2 );
if( d < dmin )
{
dmin = d;
xmin = x;
ymin = y;
smin = s;
smin2 = s2;
}
}
}
if( step > step2 )
{
s_start = min(el1.theta1, smin + step);
s_end = max(el1.theta2, smin - step);
step = (s_start - s_end)/nsteps;
}
else
{
s_start2 = min(th1, smin2 + step2);
s_end2 = max(th2, smin2 - step2);
step2 = (s_start2 - s_end2)/nsteps2;
}
}
if( x )
*x = (int) xmin;
if( y )
*y = (int) ymin;
return max(0, (int)dmin-w1/2-w2/2); // allow for widths
}
// Find clearance between pads
// For each pad:
// type = PAD_ROUND, PAD_SQUARE, etc.
// x, y = center position
// w, l = width and length
// r = corner radius
// angle = 0 or 90 (if 0, pad length is along x-axis)
//
int GetClearanceBetweenPads( int type1, int x1, int y1, int w1, int l1, int r1, int angle1,
int type2, int x2, int y2, int w2, int l2, int r2, int angle2 )
{
if( type1 == PAD_NONE )
return INT_MAX;
if( type2 == PAD_NONE )
return INT_MAX;
int dist = INT_MAX;
int nr, nc, ns, nrr, ncc, nss;
my_rect r[2], rr[2];
my_circle c[4], cc[4];
my_seg s[8], ss[8];
GetPadElements( type1, x1, y1, w1, l1, r1, angle1,
&nr, r, &nc, c, &ns, s );
GetPadElements( type2, x2, y2, w2, l2, r2, angle2,
&nrr, rr, &ncc, cc, &nss, ss );
// now find distance from every element of pad1 to every element of pad2
for( int ic=0; ic<nc; ic++ )
{
for( int icc=0; icc<ncc; icc++ )
{
int d = (int) Distance( c[ic].x, c[ic].y, cc[icc].x, cc[icc].y )
- c[ic].r - cc[icc].r;
dist = min(dist,d);
}
for( int iss=0; iss<nss; iss++ )
{
int d = (int) GetPointToLineSegmentDistance( c[ic].x, c[ic].y,
ss[iss].xi, ss[iss].yi, ss[iss].xf, ss[iss].yf ) - c[ic].r;
dist = min(dist,d);
}
}
for( int is=0; is<ns; is++ )
{
for( int icc=0; icc<ncc; icc++ )
{
int d = (int) GetPointToLineSegmentDistance( cc[icc].x, cc[icc].y,
s[is].xi, s[is].yi, s[is].xf, s[is].yf ) - cc[icc].r;
dist = min(dist,d);
}
for( int iss=0; iss<nss; iss++ )
{
double d;
TestForIntersectionOfStraightLineSegments( s[is].xi, s[is].yi, s[is].xf, s[is].yf,
ss[iss].xi, ss[iss].yi, ss[iss].xf, ss[iss].yf, NULL, NULL, &d );
dist = min(dist, (int)d);
}
}
return max(dist,0);
}
// Get min. distance from (x,y) to line y = a + bx
// if b > DBL_MAX/10, assume vertical line at x = a
// returns closest point on line in xp, yp
//
double GetPointToLineDistance( double a, double b, int x, int y, double * xpp, double * ypp )
{
if( b > DBL_MAX/10 )
{
// vertical line
if( xpp && ypp )
{
*xpp = a;
*ypp = y;
}
return abs(a-x);
}
// find c,d such that (x,y) lies on y = c + dx where d=(-1/b)
double d = -1.0/b;
double c = (double)y-d*x;
// find nearest point to (x,y) on line through (xi,yi) to (xf,yf)
double xp = (a-c)/(d-b);
double yp = a + b*xp;
if( xpp && ypp )
{
*xpp = xp;
*ypp = yp;
}
// find distance
return Distance( x, y, (int) xp, (int) yp );
}
/***********************************************************************************/
double GetPointToLineSegmentDistance( int x, int y, int xi, int yi, int xf, int yf )
/***********************************************************************************/
/** Function GetPointToLineSegmentDistance
* Get distance between line segment and point
* @param x,y = point
* @param xi,yi and xf,yf = the end-points of the line segment
* @return the distance
*/
{
// test for vertical or horizontal segment
if( xf==xi )
{
// vertical line segment
if( InRange( y, yi, yf ) )
return abs( x - xi );
else
return min( Distance( x, y, xi, yi ), Distance( x, y, xf, yf ) );
}
else if( yf==yi )
{
// horizontal line segment
if( InRange( x, xi, xf ) )
return abs( y - yi );
else
return min( Distance( x, y, xi, yi ), Distance( x, y, xf, yf ) );
}
else
{
// oblique segment
// find a,b such that (xi,yi) and (xf,yf) lie on y = a + bx
double b = (double)(yf-yi)/(xf-xi);
double a = (double)yi-b*xi;
// find c,d such that (x,y) lies on y = c + dx where d=(-1/b)
double d = -1.0/b;
double c = (double)y-d*x;
// find nearest point to (x,y) on line through (xi,yi) to (xf,yf)
double xp = (a-c)/(d-b);
double yp = a + b*xp;
// find distance
if( InRange( xp, xi, xf ) && InRange( yp, yi, yf ) )
return Distance( x, y, (int) xp, (int) yp );
else
return min( Distance( x, y, xi, yi ), Distance( x, y, xf, yf ) );
}
}
// test for value within range
//
bool InRange( double x, double xi, double xf )
{
if( xf>xi )
{
if( x >= xi && x <= xf )
return true;
}
else
{
if( x >= xf && x <= xi )
return true;
}
return false;
}
// Get distance between 2 points
//
double Distance( int x1, int y1, int x2, int y2 )
{
double d;
d = sqrt( (double)(x1-x2)*(x1-x2) + (double)(y1-y2)*(y1-y2) );
if( d > INT_MAX || d < INT_MIN )
wxASSERT(0);
return (int)d;
}
// this finds approximate solutions
// note: this works best if el2 is smaller than el1
//
int GetArcIntersections( EllipseKH * el1, EllipseKH * el2,
double * x1, double * y1, double * x2, double * y2 )
{
if( el1->theta2 > el1->theta1 )
wxASSERT(0);
if( el2->theta2 > el2->theta1 )
wxASSERT(0);
const int NSTEPS = 32;
double xret[2], yret[2];
double xscale = 1.0/el1->xrad;
double yscale = 1.0/el1->yrad;
// now transform params of second ellipse into reference frame
// with origin at center if first ellipse,
// scaled so the first ellipse is a circle of radius = 1.0
double xo = (el2->Center.X - el1->Center.X)*xscale;
double yo = (el2->Center.Y - el1->Center.Y)*yscale;
double xr = el2->xrad*xscale;
double yr = el2->yrad*yscale;
// now test NSTEPS positions in arc, moving clockwise (ie. decreasing theta)
double step = M_PI/((NSTEPS-1)*2.0);
double d_prev=0, th_prev;
double th_interp;
double th1;
int n = 0;
for( int i=0; i<NSTEPS; i++ )
{
double theta;
if( i < NSTEPS-1 )
theta = el2->theta1 - i*step;
else
theta = el2->theta2;
double x = xo + xr*cos(theta);
double y = yo + yr*sin(theta);
double d = 1.0 - sqrt(x*x + y*y);
if( i>0 )
{
bool bInt = false;
if( d >= 0.0 && d_prev <= 0.0 )
{
th_interp = theta + (step*(-d_prev))/(d-d_prev);
bInt = true;
}
else if( d <= 0.0 && d_prev >= 0.0 )
{
th_interp = theta + (step*d_prev)/(d_prev-d);
bInt = true;
}
if( bInt )
{
x = xo + xr*cos(th_interp);
y = yo + yr*sin(th_interp);
th1 = atan2( y, x );
if( th1 <= el1->theta1 && th1 >= el1->theta2 )
{
xret[n] = x*el1->xrad + el1->Center.X;
yret[n] = y*el1->yrad + el1->Center.Y;
n++;
if( n > 2 )
wxASSERT(0);
}
}
}
d_prev = d;
th_prev = theta;
}
if( x1 )
*x1 = xret[0];
if( y1 )
*y1 = yret[0];
if( x2 )
*x2 = xret[1];
if( y2 )
*y2 = yret[1];
return n;
}
// this finds approximate solution
//
//double GetSegmentClearance( EllipseKH * el1, EllipseKH * el2,
double GetArcClearance( EllipseKH * el1, EllipseKH * el2,
double * x1, double * y1 )
{
const int NSTEPS = 32;
if( el1->theta2 > el1->theta1 )
wxASSERT(0);
if( el2->theta2 > el2->theta1 )
wxASSERT(0);
// test multiple positions in both arcs, moving clockwise (ie. decreasing theta)
double th_start = el1->theta1;
double th_end = el1->theta2;
double th_start2 = el2->theta1;
double th_end2 = el2->theta2;
double dmin = DBL_MAX;
double xmin=0, ymin=0, thmin=0, thmin2=0;
int nsteps = NSTEPS;
int nsteps2 = NSTEPS;
double step = (th_start-th_end)/(nsteps-1);
double step2 = (th_start2-th_end2)/(nsteps2-1);
while( (step * max(el1->xrad, el1->yrad)) > 1.0*NM_PER_MIL
&& (step2 * max(el2->xrad, el2->yrad)) > 1.0*NM_PER_MIL )
{
step = (th_start-th_end)/(nsteps-1);
for( int i=0; i<nsteps; i++ )
{
double theta;
if( i < nsteps-1 )
theta = th_start - i*step;
else
theta = th_end;
double x = el1->Center.X + el1->xrad*cos(theta);
double y = el1->Center.Y + el1->yrad*sin(theta);
step2 = (th_start2-th_end2)/(nsteps2-1);
for( int i2=0; i2<nsteps2; i2++ )
{
double theta2;
if( i2 < nsteps2-1 )
theta2 = th_start2 - i2*step2;
else
theta2 = th_end2;
double x2 = el2->Center.X + el2->xrad*cos(theta2);
double y2 = el2->Center.Y + el2->yrad*sin(theta2);
double d = Distance( (int) x, (int) y, (int) x2, (int) y2 );
if( d < dmin )
{
dmin = d;
xmin = x;
ymin = y;
thmin = theta;
thmin2 = theta2;
}
}
}
if( step > step2 )
{
th_start = min(el1->theta1, thmin + step);
th_end = max(el1->theta2, thmin - step);
step = (th_start - th_end)/nsteps;
}
else
{
th_start2 = min(el2->theta1, thmin2 + step2);
th_end2 = max(el2->theta2, thmin2 - step2);
step2 = (th_start2 - th_end2)/nsteps2;
}
}
if( x1 )
*x1 = xmin;
if( y1 )
*y1 = ymin;
return dmin;
}