soft-3d-renderer/Source/Point.hpp

#pragma once

#include "Matrix.hpp"
#include "Vec.hpp"


class Point
{
public:
	Point()
		: x(0), y(0), z(0), w(1)
	{}

	Point(float x, float y, float z)
		: x(x), y(y), z(z), w(1)
	{}

	Point operator-() const
	{
		return Point(
			-x,
			-y,
			-z);
	}

	Vector operator-(Point const& rhs) const
	{
		return Vector(
			x - rhs.x,
			y - rhs.y,
			z - rhs.z);
	}

	Point operator*(Matrix const& rhs)
	{
		Point result;

		for (int col = 0; col < 4; ++col)
		{
			float sum = 0.0;

			for (int row = 0; row < 4; ++row)
			{
				sum += e[row] * rhs.e[row][col];
			}

			result.e[col] = sum;
		}

		return result;
	}

	Point& operator*=(Matrix const& rhs)
	{
		*this = *this * rhs;

		return *this;
	}

	Point operator/(float rhs) const
	{
		float inverse = 1.0f / rhs;

		return Point(
			x * inverse,
			y * inverse,
			z * inverse);
	}

	Point& operator/=(float rhs)
	{
		x /= rhs;
		y /= rhs;
		z /= rhs;

		return *this;
	}

	union
	{
		float e[4];

		struct
		{
			float x, y, z, w;
		};
	};
};