/*
* $Header: /home/dmarkle/xtrkcad-fork-cvs/xtrkcad/app/bin/utility.c,v 1.2 2009-05-25 18:11:03 m_fischer Exp $
*/
/* XTrkCad - Model Railroad CAD
* Copyright (C) 2005 Dave Bullis
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
#include <stdlib.h>
#include <stdio.h>
#ifndef WINDOWS
#include <unistd.h>
#endif
#include <math.h>
#include "common.h"
#include "utility.h"
/*****************************************************************************
*
* VARIABLES
*
*/
double radiusGranularity = 1.0/8.0;
DEBUGF_T debugIntersection = 0;
#define CLOSE (1.0)
/*****************************************************************************
*
* UTLITY FUNCTIONS
*
*/
#ifndef min
double max( double a, double b )
{
if (a>b) return a;
return b;
}
double min( double a, double b )
{
if (a<b) return a;
return b;
}
#endif
double FindDistance( coOrd p0, coOrd p1 )
{
double dx = p1.x-p0.x, dy = p1.y-p0.y;
return sqrt( dx*dx + dy*dy );
}
double NormalizeAngle( double a )
{
while (a<0.0) a += 360.0;
while (a>=360.0) a -= 360.0;
if ( a > 360.0-EPSILON ) a = 0.0;
return a;
}
double DifferenceBetweenAngles(double a, double b) {
double difference = b - a;
while (difference < -180) difference += 360;
while (difference > 180) difference -= 360;
return difference;
}
int AngleInRange(double a, double start, double size) {
if (DifferenceBetweenAngles(start+size,a)<=0.0) {
if (DifferenceBetweenAngles(start,a)>=0.0)
return 0;
else return 1;
}
return -1;
}
int IsAligned( double a1, double a2 )
{
a1 = NormalizeAngle( a1 - a2 + 90.0 );
return ( a1 < 180 );
}
double D2R( double D )
{
D = NormalizeAngle(D);
if (D >= 180.0) D = D - 360.0;
return D * (M_PI*2) / 360.0;
}
double R2D( double R )
{
return NormalizeAngle( R * 360.0 / (M_PI*2) );
}
void Rotate( coOrd *p, coOrd orig, double angle )
{
double x=p->x,y=p->y;
x -= orig.x;
y -= orig.y;
p->x = (POS_T)(x * cos(D2R(angle)) + y * sin(D2R(angle)));
p->y = (POS_T)(y * cos(D2R(angle)) - x * sin(D2R(angle)));
p->x += orig.x;
p->y += orig.y;
}
/**
* Translate coordinates.
*
* \param res OUT new (translated) position
* \param orig IN old position
* \param a IN angle
* \param d IN distance
*/
void Translate( coOrd *res, coOrd orig, double a, double d )
{
res->x = orig.x + (POS_T)(d * sin( D2R(a)) );
res->y = orig.y + (POS_T)(d * cos( D2R(a)) );
}
double FindAngle( coOrd p0, coOrd p1 )
{
double dx = p1.x-p0.x, dy = p1.y-p0.y;
if (small(dx)) {
if (dy >=0) return 0.0;
else return 180.0;
}
if (small(dy)) {
if (dx >=0) return 90.0;
else return 270.0;
}
return R2D(atan2( dx,dy ));
}
BOOL_T PointOnCircle( coOrd * resP, coOrd center, double radius, double angle )
{
double r;
r = sin(D2R(angle));
r = radius * r;
resP->x = center.x + (POS_T)(radius * sin(D2R(angle)));
resP->y = center.y + (POS_T)(radius * cos(D2R(angle)));
return 1;
}
double ConstrainR( double r )
{
double ret;
ret = r / radiusGranularity;
ret = floor( ret + 0.5 );
ret = ret * radiusGranularity;
return ret;
}
void FindPos( coOrd * res, double * beyond, coOrd pos, coOrd orig, double angle, double length )
{
double a0, a1;
double d;
#ifdef __linux
static volatile double x;
#else
double x;
#endif
a0 = FindAngle( orig, pos );
a1 = NormalizeAngle( a0 - angle );
d = FindDistance( orig, pos );
x = d * cos( D2R( a1 ) );
if ( x < 0.0 ) {
res->x = (POS_T)0.0;
} else if (x > length) {
res->x = (POS_T)length;
} else {
res->x = (POS_T)x;
}
if (beyond) *beyond = x - res->x;
res->y = (POS_T)(d * sin( D2R( a1 )) );
}
/* Find intersection:
Given 2 lines each described by a point and angle (P0,A0) (P1,A1)
there exists a common point PC.
d0x = sin(A0)
d0y = cos(A0)
d1x = sin(A1)
d1y = cos(A1)
Pc.x = P0.x + N0 * d0x
Pc.y = P0.y + N0 * d0y
Pc.x = P1.x + N1 * d1x
Pc.y = P1.y + N1 * d1y
Combining:
(1) Pc.x = P0.x + N0 * d0x = P1.x + N1 * d1y
(2) Pc.y = P0.y + N0 * d0y = P1.y + N1 * d1y
Solve Pc.y for N0:
P0.y + N0 * d0y = P1.y + N1 * d1y
N0 * d0y = P1.y + N1 * d1y - P0.y
N0 = (P1.y + N1 * d1y - P0.y) / d0y
(3) N0 = (P1.y - P0.y + N1 * d1y) / d0y
Solve Pc.x for N1:
P0.x + N0 * d0x = P1.x + N1 * d1x
P0.x + N0 * d0x - P1.x = N1 * d1x
(P0.x + N0 * d0x - P1.x) / d1x = N1
(4) (P0.x - P1.x + N0 * d0x) / d1x = N1
Substitute (3) into (4):
(P0.x - P1.x + [(P1.y - P0.y + N1 * d1y) / d0y ] * d0x)
N1 = -----------------------------------------------------------
d1x
Regroup:
(P0.x - P1.x + [(P1.y - P0.y)/d0y] * d0x [ N1 * d1y / d0y ] * d0x
N1 = -------------------------------------------- + ------------------------
d1x d1x
(P0.x - P1.x + [(P1.y - P0.y)/d0y] * d0x N1 * (d1y * d0x / d0y)
N1 = -------------------------------------------- + ------------------------
d1x d1x
(P0.x - P1.x + [(P1.y - P0.y)/d0y] * d0x (d1y * d0x / d0y)
N1 = -------------------------------------------- + N1 * --------------------
d1x d1x
(d1y * d0x / d0y) (P0.x - P1.x + [(P1.y - P0.y)/d0y] * d0x
N1 * ( 1 - ----------------- ) = --------------------------------------------
d1x d1x
(P0.x - P1.x + [(P1.y - P0.y)/d0y] * d0x
--------------------------------------------
d1x
N1 = ============================================
d1y * d0x / d0y
1 - ---------------
d1x
(P0.x - P1.x + [(P1.y - P0.y)/d0y] * d0x
--------------------------------------------
d1x
N1 = ============================================
d1x - d1y * d0x / d0y
---------------------
d1x
d1x cancel
(P0.x - P1.x + [(P1.y - P0.y)/d0y] * d0x
N1 = ============================================
d1x - d1y * d0x / d0y
(P0.x - P1.x + [(P1.y - P0.y)/d0y] * d0x
N1 = ============================================
d1x*d0y - d1y*d0x
-------------------
d0y
Bring up d0y:
{ ((P0.x - P1.x + [(P1.y - P0.y)/d0y] * d0x } * d0y
N1 = =======================================================
d1x*d0y - d1y*d0x
Distribute and cancel:
(P0.x - P1.x) * d0y + (P1.y - P0.y) * d0x
N1 = =============================================
d1x*d0y - d1y*d0x
if (d1x*d0y - d1y*d0x) = 0 then lines are parallel
*/
BOOL_T FindIntersection( coOrd *Pc, coOrd P0, double A0, coOrd P1, double A1 )
{
double dx0, dy0, dx1, dy1, N1;
double d;
#ifndef WINDOWS
if (debugIntersection >= 3)
printf("FindIntersection( [%0.3f %0.3f] A%0.3f [%0.3f %0.3f] A%0.3f\n",
P0.x, P0.y, A0, P1.x, P1.y, A1 );
#endif
dx0 = sin( D2R( A0 ) );
dy0 = cos( D2R( A0 ) );
dx1 = sin( D2R( A1 ) );
dy1 = cos( D2R( A1 ) );
d = dx1 * dy0 - dx0 * dy1;
if (d < EPSILON && d > -EPSILON) {
#ifndef WINDOWS
if (debugIntersection >=3 ) printf("dx1 * dy0 - dx0 * dy1 = %0.3f\n", d );
#endif
return FALSE;
}
/*
* (P0.x - P1.x) * d0y + (P1.y - P0.y) * d0x
* N1 = =============================================
* d1x*d0y - d1y*d0x
*/
N1 = dy0 * (P0.x - P1.x) + dx0 * (P1.y - P0.y );
N1 = N1 / d;
Pc->x = P1.x + (POS_T)(N1*dx1);
Pc->y = P1.y + (POS_T)(N1*dy1);
#ifndef WINDOWS
if (debugIntersection >=3 ) printf( " [%0.3f,%0.3f]\n", Pc->x, Pc->y );
#endif
return TRUE;
}
EPINX_T PickArcEndPt( coOrd pc, coOrd p0, coOrd p1 )
{
double a;
a = NormalizeAngle( FindAngle( pc, p1 ) - FindAngle( pc, p0 ) );
if (a > 180.0)
return 0;
else
return 1;
}
EPINX_T PickLineEndPt( coOrd p0, double a0, coOrd p1 )
{
double a;
a = NormalizeAngle( FindAngle( p0, p1 ) - a0 );
if (a < 90.0 || a > 270 )
return 0;
else
return 1;
}
double LineDistance( coOrd *p, coOrd p0, coOrd p1 )
{
double d, a;
coOrd pp, zero;
zero.x = zero.y = (POS_T)0.0;
d = FindDistance( p0, p1 );
a = FindAngle( p0, p1 );
pp.x = p->x-p0.x;
pp.y = p->y-p0.y;
Rotate( &pp, zero, -a );
if (pp.y < 0.0-EPSILON) {
d = FindDistance( p0, *p );
*p = p0;
return d;
} else if (pp.y > d+EPSILON ) {
d = FindDistance( p1, *p );
*p = p1;
return d;
} else {
p->x = p0.x + (POS_T)(pp.y*sin(D2R(a)));
p->y = p0.y + (POS_T)(pp.y*cos(D2R(a)));
return pp.x>=0? pp.x : -pp.x;
}
}
double CircleDistance( coOrd *p, coOrd c, double r, double a0, double a1 )
{
double d;
double a,aa;
coOrd pEnd;
d = FindDistance( c, *p );
a = FindAngle( c, *p );
aa = NormalizeAngle( a - a0 );
if (a1 >= 360.0 || aa <= a1) {
d = fabs(d-r);
PointOnCircle( p, c, r, a );
} else {
if ( aa < a1+(360.0-a1)/2.0 ) {
PointOnCircle( &pEnd, c, r, a0+a1 );
} else {
PointOnCircle( &pEnd, c, r, a0 );
}
d = FindDistance( *p, pEnd );
*p = pEnd;
}
return d;
}
coOrd AddCoOrd( coOrd p0, coOrd p1, double a )
{
coOrd res, zero;
zero.x = zero.y = (POS_T)0.0;
Rotate(&p1, zero, a );
res.x = p0.x + p1.x;
res.y = p0.y + p1.y;
return res;
}
BOOL_T InRect( coOrd pos, coOrd rect )
{
if (pos.x >= 0.0 && pos.x <= rect.x && pos.y >= 0.0 && pos.y <= rect.y)
return 1;
else
return 0;
}
static BOOL_T IntersectLine( POS_T *fx0, POS_T *fy0, POS_T x1, POS_T y1, POS_T x, POS_T y )
{
POS_T x0=*fx0, y0=*fy0, dx, dy;
BOOL_T rc;
#ifdef TEST
printf(" IntersectLine( P0=[%0.2f %0.2f] P1=[%0.2f %0.2f] X=%0.2f Y=%0.2f\n",
x0, y0, x1, y1, x, y );
#endif
dx = x1-x0;
dy = y1-y0;
if (dy==0.0) {
if (y0 == y)
rc = TRUE;
else
rc = FALSE;
} else {
x0 += (y-y0) * dx/dy;
if (x0 < -EPSILON || x0 > x) {
rc = FALSE;
} else {
*fx0 = x0;
*fy0 = y;
rc = TRUE;
}
}
#ifdef TEST
if (rc)
printf(" = TRUE [%0.2f %0.2f]\n", *fx0, *fy0 );
else
printf(" = FALSE\n");
#endif
return rc;
}
/*
* intersectBox - find point on box boundary ([0,0],[size]) where
* line from p0 (interior) to p1 (exterior) intersects
*/
static void IntersectBox( coOrd *p1, coOrd p0, coOrd size, int x1, int y1 )
{
#ifdef TEST
printf(" IntersectBox( P1=[%0.2f %0.2f] P0=[%0.2f %0.2f] S=[%0.2f %0.2f] X1=%d Y1=%d\n",
p1->x, p1->y, p0.x, p0.y, size.x, size.y, x1, y1 );
#endif
if ( y1!=0 &&
IntersectLine( &p1->x, &p1->y, p0.x, p0.y, size.x, (y1==-1?(POS_T)0.0:size.y) ))
return;
else if ( x1!=0 &&
IntersectLine( &p1->y, &p1->x, p0.y, p0.x, size.y, (x1==-1?(POS_T)0.0:size.x) ))
return;
#ifndef WINDOWS
else
fprintf(stderr, "intersectBox bogus\n" );
#endif
}
BOOL_T ClipLine( coOrd *fp0, coOrd *fp1, coOrd orig, double angle, coOrd size )
{
coOrd p0 = *fp0, p1 = * fp1;
int x0, y0, x1, y1;
#ifdef TEST
printf("ClipLine( P0=[%0.2f %0.2f] P1=[%0.2f %0.2f] O=[%0.2f %0.2f] A=%0.2f S=[%0.2f %0.2f]\n",
p0.x, p0.y, p1.x, p1.y, orig.x, orig.y, angle, size.x, size.y );
#endif
Rotate( &p0, orig, -angle );
Rotate( &p1, orig, -angle );
p0.x -= orig.x; p0.y -= orig.y;
p1.x -= orig.x; p1.y -= orig.y;
/* categorize point as to sector:
-1,1 | 0,1 | 1,1
------------+-------------S----------
-1,0 | 0,0 | 1,0
------------O-------------+----------
-1,-1 | 0,-1 + 1,-1
*/
if ( p0.x < 0.0-EPSILON ) x0 = -1;
else if ( p0.x > size.x+EPSILON ) x0 = 1;
else x0 = 0;
if ( p0.y < 0.0-EPSILON ) y0 = -1;
else if ( p0.y > size.y+EPSILON ) y0 = 1;
else y0 = 0;
if ( p1.x < 0.0-EPSILON ) x1 = -1;
else if ( p1.x > size.x+EPSILON ) x1 = 1;
else x1 = 0;
if ( p1.y < 0.0-EPSILON ) y1 = -1;
else if ( p1.y > size.y+EPSILON ) y1 = 1;
else y1 = 0;
#ifdef TEST
printf(" X0=%d Y0=%d X1=%d Y1=%d\n", x0, y0, x1, y1 );
#endif
/* simple cases: one or both points within box */
if ( x0==0 && y0==0 ) {
if ( x1==0 && y1==0 ) {
/* both within box */
return 1;
}
/* p0 within, p1 without */
IntersectBox( &p1, p0, size, x1, y1 );
p1.x += orig.x; p1.y += orig.y;
Rotate( &p1, orig, angle );
*fp1 = p1;
return 1;
}
if ( x1==0 && y1==0 ) {
/* p1 within, p0 without */
IntersectBox( &p0, p1, size, x0, y0 );
p0.x += orig.x; p0.y += orig.y;
Rotate( &p0, orig, angle );
*fp0 = p0;
return 1;
}
/* both points without box and cannot intersect */
if ( (x0==x1 && y0==y1) || /* within same sector (but not the middle one) */
(x0!=0 && x0==x1) || /* both right or left */
(y0!=0 && y0==y1) ) /* both above or below */
return 0;
#ifdef TEST
printf(" complex intersection\n");
#endif
/* possible intersection */
if ( y0!=0 &&
IntersectLine( &p0.x, &p0.y, p1.x, p1.y, size.x, (y0==-1?(POS_T)0.0:size.y) ))
IntersectBox( &p1, p0, size, x1, y1 );
else if ( y1!=0 &&
IntersectLine( &p1.x, &p1.y, p0.x, p0.y, size.x, (y1==-1?(POS_T)0.0:size.y) ))
IntersectBox( &p0, p1, size, x0, y0 );
else if ( x0!=0 &&
IntersectLine( &p0.y, &p0.x, p1.y, p1.x, size.y, (x0==-1?(POS_T)0.0:size.x) ))
IntersectBox( &p1, p0, size, x1, y1 );
else if ( x1!=0 &&
IntersectLine( &p1.y, &p1.x, p0.y, p0.x, size.y, (x1==-1?(POS_T)0.0:size.x) ))
IntersectBox( &p0, p1, size, x0, y0 );
else {
return 0;
}
p0.x += orig.x; p0.y += orig.y;
p1.x += orig.x; p1.y += orig.y;
Rotate( &p0, orig, angle );
Rotate( &p1, orig, angle );
*fp0 = p0;
*fp1 = p1;
return 1;
}
#ifdef LATER
BOOL_T ClipArc( double a0, double a1, coOrd pos, double radius, coOrd orig, double angle, double size )
{
i = -1;
state = unknown;
if (pos.y + radius < 0.0 ||
pos.y - radius > size.y ||
pos.x + radius < 0.0 ||
pos.x - radius > size.x )
return 0;
if (pos.y + radius <= size.y ||
pos.y - radius >= 0.0 ||
pos.x + radius <= size.x ||
pos.x - radius >= 0.0 )
return 1;
if (pos.y + radius > size.y) {
a = R2D(acos( (size.y-pos.y) / radius ) ));
if (pos.x + radius*cos(R2D(a)) > size.x) {
state = outside;
} else {
state = inside;
i++;
aa[i].a0 = a;
}
} else {
state = inside;
i++;
aa[i].a0 = 0;
}
}
#endif
#ifdef TEST
void Test( double p0x, double p0y, double p1x, double p1y, double origx, double origy, double angle, double sizex, double sizey )
{
coOrd p0, p1, orig, size, p0a, p1a;
BOOL_T rc;
p0.x = p0x; p0.y = p0y; p1.x = p1x; p1.y = p1y;
orig.x = origx; orig.y = origy;
size.x = sizex; size.y = sizey;
p0a = p0; p1a = p1;
rc = ClipLine( &p0, &p1, orig, angle, size );
printf("clipLine=%d P0=[%0.3f %0.3f] P1=[%0.3f %0.3f]\n", rc,
p0.x, p0.y, p1.x, p1.y );
}
INT_T Main( INT_T argc, char *argv[] )
{
double a[9];
int i;
if (argc != 10) {
printf("usage: a x0 y0 x1 y1 xo yo a xs ys\n");
Exit(1);
}
argv++;
for (i=0;i<9;i++)
a[i] = atof( *argv++ );
Test( a[0], a[1], a[2], a[3], a[4], a[5], a[6], a[7], a[8] );
}
#endif