charcoal/archive/math/mat4x4.h

#pragma once

#include "vec4.h"

namespace egm
{

	template <typename T>
	struct tmat4x4
	{
		// Column Major
		tvec4<T> a;
		tvec4<T> b;
		tvec4<T> c;
		tvec4<T> d;

		//Identity Matrix
		tmat4x4() : a(1, 0, 0, 0), b(0, 1, 0, 0), c(0, 0, 1, 0), d(0, 0, 0, 1) {}

		//Sets column by column
		tmat4x4(const tvec4<T>& a, const tvec4<T>& b, const tvec4<T>& c, const tvec4<T>& d) : a(a), b(b), c(c), d(d) {}

		//Sets by value (letter = column, number = row)
		tmat4x4(
			const T& a1, const T& a2, const T& a3, const T& a4,
			const T& b1, const T& b2, const T& b3, const T& b4,
			const T& c1, const T& c2, const T& c3, const T& c4,
			const T& d1, const T& d2, const T& d3, const T& d4
		) :
			a(a1, a2, a3, a4),
			b(b1, b2, b3, b4),
			c(c1, c2, c3, c4),
			d(d1, d2, d3, d4)
		{}

		tvec4<T>& operator[](const unsigned int& index)
		{
			switch (index)
			{
			case 0:
				return a;
			case 1:
				return b;
			case 2:
				return c;
			case 3:
				return d;
			default:
				throw "Index Out Of Bounds";
			}
		}

		bool operator==(const tmat4x4<T>& o)
		{
			return (o.a == a && o.b == b && o.c == c && o.d == d);
		}

		tmat4x4<T>& operator=(const tmat4x4<T>& o)
		{
			a = o.a;
			b = o.b;
			c = o.c;
			d = o.d;
			return *this;
		}

		tmat4x4<T> operator+(const tmat4x4<T>& o) const
		{
			return {
				a + o.a,
				b + o.b,
				c + o.c,
				d + o.d
			};
		}

		tmat4x4<T>& operator+=(const tmat4x4<T>& o)
		{
			a += o.a;
			b += o.b;
			c += o.c;
			d += o.d;
			return *this;
		}

		tmat4x4<T> operator-(const tmat4x4<T>& o) const
		{
			return {
				a - o.a,
				b - o.b,
				c - o.c,
				d - o.d
			};
		}

		tmat4x4<T>& operator-=(const tmat4x4<T>& o)
		{
			a -= o.a;
			b -= o.b;
			c -= o.c;
			d -= o.d;
			return *this;
		}

		tvec4<T> operator*(const tvec4<T>& v) const
		{
			// Probably should make a commented out row major version
			return {
				a.x * v.x + a.y * v.y + a.z * v.z + a.w * v.w,
				b.x * v.x + b.y * v.y + b.z * v.z + b.w * v.w,
				c.x * v.x + c.y * v.y + c.z * v.z + c.w * v.w,
				d.x * v.x + d.y * v.y + d.z * v.z + d.w * v.w,
			};
		}

		tmat4x4<T> operator*(const tmat4x4<T>& m) const
		{
			/* Row Major
			return {
				m.a.x * a.x + m.b.x * a.y + m.c.x * a.z + m.d.x * a.w,
				m.a.y * a.x + m.b.y * a.y + m.c.y * a.z + m.d.y * a.w,
				m.a.z * a.x + m.b.z * a.y + m.c.z * a.z + m.d.z * a.w,
				m.a.w * a.x + m.b.w * a.y + m.c.w * a.z + m.d.w * a.w,

				m.a.x * b.x + m.b.x * b.y + m.c.x * b.z + m.d.x * b.w,
				m.a.y * b.x + m.b.y * b.y + m.c.y * b.z + m.d.y * b.w,
				m.a.z * b.x + m.b.z * b.y + m.c.z * b.z + m.d.z * b.w,
				m.a.w * b.x + m.b.w * b.y + m.c.w * b.z + m.d.w * b.w,

				m.a.x * c.x + m.b.x * c.y + m.c.x * c.z + m.d.x * c.w,
				m.a.y * c.x + m.b.y * c.y + m.c.y * c.z + m.d.y * c.w,
				m.a.z * c.x + m.b.z * c.y + m.c.z * c.z + m.d.z * c.w,
				m.a.w * c.x + m.b.w * c.y + m.c.w * c.z + m.d.w * c.w,

				m.a.x * d.x + m.b.x * d.y + m.c.x * d.z + m.d.x * d.w,
				m.a.y * d.x + m.b.y * d.y + m.c.y * d.z + m.d.y * d.w,
				m.a.z * d.x + m.b.z * d.y + m.c.z * d.z + m.d.z * d.w,
				m.a.w * d.x + m.b.w * d.y + m.c.w * d.z + m.d.w * d.w,
			};
			*/
			// Column Major
			// Something is wrong here......
			return {
				a.x * m.a.x + b.x * m.a.y + c.x * m.a.z + d.x * m.a.w,
				a.y * m.a.x + b.y * m.a.y + c.y * m.a.z + d.y * m.a.w,
				a.z * m.a.x + b.z * m.a.y + c.z * m.a.z + d.z * m.a.w,
				a.w * m.a.x + b.w * m.a.y + c.w * m.a.z + d.w * m.a.w,

				a.x * m.b.x + b.x * m.b.y + c.x * m.b.z + d.x * m.b.w,
				a.y * m.b.x + b.y * m.b.y + c.y * m.b.z + d.y * m.b.w,
				a.z * m.b.x + b.z * m.b.y + c.z * m.b.z + d.z * m.b.w,
				a.w * m.b.x + b.w * m.b.y + c.w * m.b.z + d.w * m.b.w,

				a.x * m.c.x + b.x * m.c.y + c.x * m.c.z + d.x * m.c.w,
				a.y * m.c.x + b.y * m.c.y + c.y * m.c.z + d.y * m.c.w,
				a.z * m.c.x + b.z * m.c.y + c.z * m.c.z + d.z * m.c.w,
				a.w * m.c.x + b.w * m.c.y + c.w * m.c.z + d.w * m.c.w,

				a.x * m.d.x + b.x * m.d.y + c.x * m.d.z + d.x * m.d.w,
				a.y * m.d.x + b.y * m.d.y + c.y * m.d.z + d.y * m.d.w,
				a.z * m.d.x + b.z * m.d.y + c.z * m.d.z + d.z * m.d.w,
				a.w * m.d.x + b.w * m.d.y + c.w * m.d.z + d.w * m.d.w,
			};
		}

		tmat4x4<T>& operator*=(const tmat4x4<T>& o)
		{
			return *this = *this * o;
		}

		tmat4x4<T> operator*(const T& scalar) const
		{
			return {
				a * scalar,
				b * scalar,
				c * scalar,
				d * scalar
			};
		}

		tmat4x4<T>& operator*=(const T& scalar)
		{
			a *= scalar;
			b *= scalar;
			c *= scalar;
			d *= scalar;
			return *this;
		}

		tmat4x4<T> operator/(const T& scalar) const
		{
			return {
				a / scalar,
				b / scalar,
				c / scalar,
				d / scalar
			};
		}

		tmat4x4<T>& operator/=(const T& scalar)
		{
			a /= scalar;
			b /= scalar;
			c /= scalar;
			d /= scalar;
			return *this;
		}

		const T* data() const
		{
			return &a.x;
		}

		void zero()
		{
			a.x = 0;
			a.y = 0;
			a.z = 0;
			a.w = 0;
			b.x = 0;
			b.y = 0;
			b.z = 0;
			b.w = 0;
			c.x = 0;
			c.y = 0;
			c.z = 0;
			c.w = 0;
			d.x = 0;
			d.y = 0;
			d.z = 0;
			d.w = 0;
		}

		void to_identity()
		{
			a.x = static_cast<T>(1);
			a.y = static_cast<T>(0);
			a.z = static_cast<T>(0);
			a.w = static_cast<T>(0);
			b.x = static_cast<T>(0);
			b.y = static_cast<T>(1);
			b.z = static_cast<T>(0);
			b.w = static_cast<T>(0);
			c.x = static_cast<T>(0);
			c.y = static_cast<T>(0);
			c.z = static_cast<T>(1);
			c.w = static_cast<T>(0);
			d.x = static_cast<T>(0);
			d.y = static_cast<T>(0);
			d.z = static_cast<T>(0);
			d.w = static_cast<T>(1);
		}
	};

	typedef tmat4x4<float>	mat4x4;
	typedef tmat4x4<double>	dmat4x4;
	typedef tmat4x4<int>	imat4x4;

	const mat4x4 IDENTITY_MATRIX(
		1.0f, 0.0f, 0.0f, 0.0f,
		0.0f, 1.0f, 0.0f, 0.0f,
		0.0f, 0.0f, 1.0f, 0.0f,
		0.0f, 0.0f, 0.0f, 1.0f
	);
}