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AI_Line.h

Go to the documentation of this file.

#ifndef AI_LINE_H
#define AI_LINE_H
//-------------------------------------------------------------------
#include "AI_Vector.h"

class AI_Line2 {
public:
    AI_Vector2 b;
    AI_Vector2 m;

    AI_Line2() {};
    AI_Line2(const AI_Vector2& v0, const AI_Vector2& v1) : b(v0), m(v1-v0) {};
    AI_Line2(const AI_Line2& l) : b(l.b), m(l.m) {};

    //--- minimal distance of point to line -------------------------
    float distance(const AI_Vector2& p)
    {
        AI_Vector2 diff(p-b);
        float l = (m % m);
        if (l > 0.0f) {
            float t = (m % diff) / l;
            return (diff - m*t).len();
        } else {
            // line is really a point...
            return (p-b).len();
        }
    };
    //--- minimal distance of point to line segment -----------------
    float distance(const AI_Vector2& p, const float t0, const float t1)
    {
        AI_Vector2 diff(p-b);
        float l = (m % m);
        if (l > 0.0f) 
        {
            float t = (m % diff) / l;

            if (t<t0)
                return (diff - m*t0).len();
            else if (t>t1)
                return (diff - m*t1).len();
            else 
                return (diff - m*t).len();
        } 
        else 
        {
            // line is really a point...
            return (p-b).len();
        }
    };
    void set (const AI_Vector2& v0, const AI_Vector2& v1)
    {
        b.set(v0);
        m.set(v1-v0);
    };
    const AI_Vector2& start(void) const
    {
        return b;
    };
    AI_Vector2 end(void) const
    {
        return (b+m);
    };
    float len(void) const
    {
        return m.len();
    };
    //--- get 2d point on line given t ------------------------------
    AI_Vector2 ipol(const float t) const
    {
        return AI_Vector2(b + m*t);
    };
    bool intersection(const AI_Line2 &other, float tol) const
    {
        AI_Vector2 params;
        if (intersection(other, params, tol))
        {
            float min = -tol;
            float max = 1.0f+tol;
            if (params.x >= min && params.x <= max &&
                params.y >= min && params.y <= max)
                return true;
        }
        return false;
    };
    bool intersection(const AI_Line2 &other, AI_Vector2 &params, float tol) const
    {
        float D = other.m.x * m.y - m.x * other.m.y;
        if ( ai_fequal(D, 0.0f, tol) )
            return false;
        
        float del1 = other.b.x - b.x;
        float del2 = other.b.y - b.y;

        float D1 = other.m.x * del2 - del1 * other.m.y;
        float D2 = m.x * del2 - del1 * m.y;

        params.x = D1 / D;
        params.y = D2 / D;

        return true;
    }

};

//-------------------------------------------------------------------
class AI_Line3 {
public:
    AI_Vector3 b;
    AI_Vector3 m;

    AI_Line3() {};
    AI_Line3(const AI_Vector3& v0, const AI_Vector3& v1) : b(v0), m(v1-v0) {};
    AI_Line3(const AI_Line3& l) : b(l.b), m(l.m) {};

    void set(const AI_Vector3& v0, const AI_Vector3& v1)
    {
        b = v0;
        m = v1-v0;
    };
    const AI_Vector3& start(void) const
    {
        return b;
    };
    AI_Vector3 end(void) const
    {
        return (b+m);
    };
    float len(void) const
    {
        return m.len();
    };
    float len_squared(void) const
    {
        return m.lensquared();
    }
    //--- minimal distance of point to line -------------------------
    float distance(const AI_Vector3& p) {
        AI_Vector3 diff(p-b);
        float l = (m % m);
        if (l > 0.0f) {
            float t = (m % diff) / l;
            diff = diff - m*t;
            return diff.len();
        } else {
            // line is really a point...
            AI_Vector3 v(p-b);
            return v.len();
        }
    };

    //--- get 3d point on line given t ------------------------------
    AI_Vector3 ipol(const float t) const
    {
        return AI_Vector3(b + m*t);
    };
};

//-------------------------------------------------------------------
#endif

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InExIn documentation generated by doxygen at Tue Dec 18 12:55:27 2007