GeoObjects.h

//derived geometric objects.  This is not yet officially part of MPMA, due to the fact that what's here is just random scattered stuff I found useful.
//Luke Lenhart (2005-2008)
//See /docs/License.txt for details on how this code may be used.

#pragma once

#include "Geo.h"

namespace GEO
{
    // -- 3D

    //A line or ray.
    struct Line
    {
        Vector3 pos; //position of a point on the line
        Vector3 dir; //direction of the line

        //
        inline Line() {}
        inline Line(const Vector3 &inPos, const Vector3 &inDir)
            { pos=inPos; dir=inDir; }
    };

    //A plane.
    struct Plane
    {
        float c0,c1,c2,c3; //plane coeffecients

        //
        inline Plane() {}
        //from a position and a normal
        inline Plane(const Vector3 &inPos, const Vector3 &inNormal)
        {
            Normal()=inNormal;
            Renormalize();
            c3=-VecDot(inPos,Normal());
        }
        //from the 4 coeffecients
        inline Plane(float inC0,float inC1,float inC2,float inC3): c0(inC0), c1(inC1), c2(inC2), c3(inC3)
            { Renormalize(); }

        //gets normal of plane
        inline Vector3& Normal() const { return *((Vector3*)this); }

        //normalizes normal of plane
        inline void Renormalize() { Normal().Normalize(); }
    };

    //A sphere.
    struct Sphere
    {
        Vector3 pos;
        float radius;

        //
        inline Sphere() {}
        inline Sphere(const Vector3 &p, float r)
        { pos=p; radius=r; }
    };

    //Axis-aligned 3d rectangle.
    struct AARectoid
    {
        Vector3 center;
        float xradius;
        float yradius;
        float zradius;

        //
        inline AARectoid() {}
        inline AARectoid(Vector3 c, float x, float y, float z)
        { center=c; xradius=x; yradius=y; zradius=z; }
    };

    //A an unbounded cylendar aligned along the x axis.
    struct XAlignedUnboundedCylinder: Line
    {
        float y;
        float z;
        float radius;

        //
        inline XAlignedUnboundedCylinder() {}
        inline XAlignedUnboundedCylinder(float ypos, float zpos, float rad)
        { y=ypos; z=zpos; radius=rad; }
    };

    //An ellipsoid whose stretch is aligned along the y axis
    struct YAlignedEllipsoid: Sphere
    {
        float ymultiplier;

        //
        inline YAlignedEllipsoid() {}
        inline YAlignedEllipsoid(const Vector3 &p, float r, float ymod)
        { pos=p; radius=r; ymultiplier=ymod; }
    };

    // -- 2D

    //a circle
    struct Circle
    {
        Vector2 pos;
        float radius;

        inline Circle() {}
        inline Circle(GEO::Vector2 position, float rad)
        { pos=position; radius=rad; }
    };

    //an ellipse aligned to the x and y axis
    struct AxisAlignedEllipse
    {
        Vector2 pos;
        float radius;
        float xmod;
        float ymod;

        inline AxisAlignedEllipse() {}
        inline AxisAlignedEllipse(Vector2 position, float rad, float xax, float yax)
        { pos=position; radius=rad; xmod=xax; ymod=yax; }
    };

}; //namespace GEO