source: cpp/frams/util/3d.cpp @ 1103

// This file is a part of Framsticks SDK.  http://www.framsticks.com/
// Copyright (C) 1999-2020  Maciej Komosinski and Szymon Ulatowski.
// See LICENSE.txt for details.

#include <common/nonstd_math.h>
#include <common/log.h>
#include "3d.h"
#include <algorithm> // std::min(), std::max()

Pt3D operator+(const Pt3D &p1, const Pt3D &p2) { return Pt3D(p1.x + p2.x, p1.y + p2.y, p1.z + p2.z); }
Pt3D operator-(const Pt3D &p1, const Pt3D &p2) { return Pt3D(p1.x - p2.x, p1.y - p2.y, p1.z - p2.z); }

Pt3D Pt3D_0(0, 0, 0);

bool Pt3D::report_errors = true;

double Pt3D::operator()() const
{
        double q = x * x + y * y + z * z;
        if (q < 0) { if (report_errors) logPrintf("Pt3D", "operator()", LOG_ERROR, "sqrt(%g): domain error", q); return 0; }
        return sqrt(q);
}

bool Pt3D::normalize()
{
        double len = length();
        if (fabs(len) < 1e-50) { if (report_errors) logPrintf("Pt3D", "normalize()", LOG_WARN, "vector[%g,%g,%g] too small", x, y, z); x = 1; y = 0; z = 0; return false; }
        operator/=(len);
        return true;
}

double Pt3D::distanceTo(const Pt3D& p) const
{
        double dx = x - p.x;
        double dy = y - p.y;
        double dz = z - p.z;
        return sqrt(dx * dx + dy * dy + dz * dz);
}

double Pt3D::manhattanDistanceTo(const Pt3D& p) const
{
        return fabs(x - p.x) + fabs(y - p.y) + fabs(z - p.z);
}

Orient Orient_1(Pt3D(1, 0, 0), Pt3D(0, 1, 0), Pt3D(0, 0, 1));

// simple rotation
void rotate2D(double k, double &x, double &y)
{
        double s = sin(k), c = cos(k);
        double t = c * x - s * y;
        y = s * x + c * y;
        x = t;
}

void rotate2D(double s, double c, double &x, double &y)
{
        double t = c * x - s * y;
        y = s * x + c * y;
        x = t;
}

double Pt3D::getAngle(double dx, double dy)
{
        if (dx == 0 && dy == 0)
        {
                if (report_errors) logPrintf("Pt3D", "getAngle()", LOG_WARN, "atan2(%g,%g)", dy, dx);
                return 0; // incorrect result, but there is no correct one
        }
        return atan2(dy, dx);
}

void Pt3D::getAngles(const Pt3D& X, const Pt3D& dir)
{
        Pt3D t1(X), t2(dir);
        if (fabs(t1.x) > 1e-50 || fabs(t1.y) > 1e-50) // non-vertical
        {
                z = atan2(t1.y, t1.x);
                rotate2D(-z, t1.x, t1.y);
                rotate2D(-z, t2.x, t2.y);
                y = getAngle(t1.x, t1.z);
        }
        else // vertical
        {
                z = 0;
                if (t1.z < 0)
                        y = -M_PI_2; // down
                else
                        y = M_PI_2; // up
        }
        rotate2D(-y, t2.x, t2.z);
        x = getAngle(t2.z, -t2.y);
}

void Pt3D::getMin(const Pt3D& p)
{
        if (p.x < x) x = p.x;
        if (p.y < y) y = p.y;
        if (p.z < z) z = p.z;
}
void Pt3D::getMax(const Pt3D& p)
{
        if (p.x > x) x = p.x;
        if (p.y > y) y = p.y;
        if (p.z > z) z = p.z;
}

double Pt3D::minComponentValue() const
{
        return std::min(x, std::min(y, z));
}

double Pt3D::maxComponentValue() const
{
        return std::max(x, std::max(y, z));
}

void Pt3D::vectorProduct(const Pt3D& a, const Pt3D& b)
{
        x = a.y * b.z - a.z * b.y;
        y = a.z * b.x - a.x * b.z;
        z = a.x * b.y - a.y * b.x;
}

void Orient::lookAt(const Pt3D& X, const Pt3D& dir)
{
        x = X; x.normalize();
        y.vectorProduct(dir, x);
        z.vectorProduct(x, y);
        if ((!y.normalize()) || (!z.normalize()))
                lookAt(X);// dir was (nearly?) parallel, there is no good solution, use the x-only variant
}

void Orient::lookAt(const Pt3D& X)
{
        x = X; x.normalize();
        // "invent" y vector, not parallel to x
        double ax = fabs(x.x), ay = fabs(x.y), az = fabs(x.z);
        // find the smallest component
        if ((ax <= ay) && (ax <= az)) // x
        {
                y.x = 0; y.y = -x.z; y.z = x.y; // (0,-z,y)
        }
        if ((ay <= ax) && (ay <= az)) // y
        {
                y.x = -x.z; y.y = 0; y.z = x.x; // (-z,0,x)
        }
        else // z
        {
                y.x = -x.y; y.y = x.x; y.z = 0; // (-y,x,0)
        }
        y.normalize();
        z.vectorProduct(x, y);
}

// 2D distance
double d2(double x, double y)
{
        double q = x * x + y * y;
        if (q < 0) { if (Pt3D::report_errors) logPrintf("", "d2()", LOG_ERROR, "sqrt(%g): domain error", q); return 0; }
        return sqrt(q);
}

Orient::Orient(const Matrix44& m)
{
        x.x = m[0];  x.y = m[1];  x.z = m[2];
        y.x = m[4];  y.y = m[5];  y.z = m[6];
        z.x = m[8];  z.y = m[9];  z.z = m[10];
}

void Orient::operator=(const Pt3D &rot)
{
        *this = Orient_1;
        rotate(rot);
}

void Orient::rotate(const Pt3D &v)
{
        double s, c;
        if (v.x != 0)
        {
                s = sin(v.x); c = cos(v.x);
                rotate2D(s, c, x.y, x.z);
                rotate2D(s, c, y.y, y.z);
                rotate2D(s, c, z.y, z.z);
        }
        if (v.y != 0)
        {
                s = sin(v.y); c = cos(v.y);
                rotate2D(s, c, x.x, x.z);
                rotate2D(s, c, y.x, y.z);
                rotate2D(s, c, z.x, z.z);
        }
        if (v.z != 0)
        {
                s = sin(v.z); c = cos(v.z);
                rotate2D(s, c, x.x, x.y);
                rotate2D(s, c, y.x, y.y);
                rotate2D(s, c, z.x, z.y);
        }
}

void Orient::transform(Pt3D& target, const Pt3D &s) const
{
        target.x = s.x * x.x + s.y * y.x + s.z * z.x;
        target.y = s.x * x.y + s.y * y.y + s.z * z.y;
        target.z = s.x * x.z + s.y * y.z + s.z * z.z;
}

void Orient::revTransform(Pt3D& target, const Pt3D &s) const
{
        target.x = s.x * x.x + s.y * x.y + s.z * x.z;
        target.y = s.x * y.x + s.y * y.y + s.z * y.z;
        target.z = s.x * z.x + s.y * z.y + s.z * z.z;
}

void Orient::transform(Orient& target, const Orient& src) const
{
        transform(target.x, src.x);
        transform(target.y, src.y);
        transform(target.z, src.z);
}

void Orient::revTransform(Orient& target, const Orient& src) const
{
        revTransform(target.x, src.x);
        revTransform(target.y, src.y);
        revTransform(target.z, src.z);
}

void Orient::getAngles(Pt3D &angles) const
{
        angles.getAngles(x, z);
}

bool Orient::normalize()
{
        bool ret = 1;
        y.vectorProduct(z, x);
        z.vectorProduct(x, y);
        if (!x.normalize()) ret = 0;
        if (!z.normalize()) ret = 0;
        if (!y.normalize()) ret = 0;
        return ret;
}

Matrix44::Matrix44(const Orient &rot)
{
        m[0] = rot.x.x;  m[1] = rot.x.y;  m[2] = rot.x.z;  m[3] = 0;
        m[4] = rot.y.x;  m[5] = rot.y.y;  m[6] = rot.y.z;  m[7] = 0;
        m[8] = rot.z.x;  m[9] = rot.z.y;  m[10] = rot.z.z; m[11] = 0;
        m[12] = 0;       m[13] = 0;       m[14] = 0;       m[15] = 1;
}

void Matrix44::operator+=(const Pt3D &)
{

}

void Matrix44::operator*=(const Pt3D &)
{
}

void Matrix44::operator*=(double sc)
{
}