stim/math/quad.h

#ifndef RTS_QUAD_H
#define RTS_QUAD_H
//enable CUDA_CALLABLE macro
#include <stim/cuda/callable.h>
#include <stim/math/vector.h>
#include <stim/math/triangle.h>
#include <stim/math/quaternion.h>
#include <iostream>
#include <iomanip>
#include <algorithm>
namespace stim{
//template for a quadangle class in ND space
template <class T, int N = 3>
struct quad
{
	/*
		B------------------>C
		^                   ^
		|                   |
		Y                   |
		|                   |
		|                   |
		A---------X-------->O
	*/
	/*T A[N];
	T B[N];
	T C[N];*/
	rts::vec<T, N> A;
	rts::vec<T, N> X;
	rts::vec<T, N> Y;
	CUDA_CALLABLE quad()
	{
	}
	CUDA_CALLABLE quad(vec<T, N> a, vec<T, N> b, vec<T, N> c)
	{
		A = a;		
		Y = b - a;
		X = c - a - Y;
	}
	/*******************************************************************
	Constructor - create a quad from a position, normal, and rotation
	*******************************************************************/
	CUDA_CALLABLE quad(rts::vec<T, N> c, rts::vec<T, N> normal, T width, T height, T theta)
	{
        //compute the X direction - start along world-space X
        Y = rts::vec<T, N>(0, 1, 0);
        if(Y == normal)
            Y = rts::vec<T, N>(0, 0, 1);
        X = Y.cross(normal).norm();
        std::cout<<X<<std::endl;
        //rotate the X axis by theta radians
        rts::quaternion<T> q;
        q.CreateRotation(theta, normal);
        X = q.toMatrix3() * X;
        Y = normal.cross(X);
        //normalize everything
        X = X.norm();
        Y = Y.norm();
        //scale to match the quad width and height
        X = X * width;
        Y = Y * height;
        //set the corner of the plane
        A = c - X * 0.5f - Y * 0.5f;
        std::cout<<X<<std::endl;
	}
	//boolean comparison
	bool operator==(const quad<T, N> & rhs)
	{
		if(A == rhs.A && X == rhs.X && Y == rhs.Y)
			return true;
		else
			return false;
	}
	/*******************************************
	Return the normal for the quad
	*******************************************/
	CUDA_CALLABLE rts::vec<T, N> n()
	{
        return (X.cross(Y)).norm();
	}
	CUDA_CALLABLE rts::vec<T, N> p(T a, T b)
	{
		rts::vec<T, N> result;
		//given the two parameters a, b = [0 1], returns the position in world space
		result = A + X * a + Y * b;
		return result;
	}
	CUDA_CALLABLE rts::vec<T, N> operator()(T a, T b)
	{
		return p(a, b);
	}
	std::string str()
	{
		std::stringstream ss;
		ss<<std::left<<"B="<<setfill('-')<<setw(20)<<A + Y<<">"<<"C="<<A + Y + X<<std::endl;
		ss<<setfill(' ')<<setw(23)<<"|"<<"|"<<std::endl<<setw(23)<<"|"<<"|"<<std::endl;
		ss<<std::left<<"A="<<setfill('-')<<setw(20)<<A<<">"<<"D="<<A + X;
        return ss.str();
	}
	CUDA_CALLABLE quad<T, N> operator*(T rhs)
	{
		//scales the plane by a scalar value
		//compute the center point
		rts::vec<T, N> c = A + X*0.5f + Y*0.5f;
		//create the new quadangle
		quad<T, N> result;
		result.X = X * rhs;
		result.Y = Y * rhs;
		result.A = c - result.X*0.5f - result.Y*0.5f;
		return result;
	}
	CUDA_CALLABLE T dist(vec<T, N> p)
	{
        //compute the distance between a point and this quad
        //first break the quad up into two triangles
        triangle<T, N> T0(A, A+X, A+Y);
        triangle<T, N> T1(A+X+Y, A+X, A+Y);
        T d0 = T0.dist(p);
        T d1 = T1.dist(p);
        if(d0 < d1)
            return d0;
        else
            return d1;
	}
	CUDA_CALLABLE T dist_max(vec<T, N> p)
	{
        T da = (A - p).len();
        T db = (A+X - p).len();
        T dc = (A+Y - p).len();
        T dd = (A+X+Y - p).len();
        return std::max( da, std::max(db, std::max(dc, dd) ) );
	}
};
}	//end namespace rts
template <typename T, int N>
std::ostream& operator<<(std::ostream& os, rts::quad<T, N> R)
{
    os<<R.str();
    return os;
}
#endif