// Copyright 2016 The SwiftShader Authors. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//    http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#include "Vector.hpp"

#include "Matrix.hpp"
#include "System/Math.hpp"

namespace sw {

Vector Vector::operator+() const
{
	return *this;
}

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

Vector &Vector::operator+=(const Vector &v)
{
	x += v.x;
	y += v.y;
	z += v.z;

	return *this;
}

Vector &Vector::operator-=(const Vector &v)
{
	x -= v.x;
	y -= v.y;
	z -= v.z;

	return *this;
}

Vector &Vector::operator*=(float s)
{
	x *= s;
	y *= s;
	z *= s;

	return *this;
}

Vector &Vector::operator/=(float s)
{
	float r = 1.0f / s;

	return *this *= r;
}

bool operator==(const Vector &U, const Vector &v)
{
	if(U.x == v.x && U.y == v.y && U.z == v.z)
		return true;
	else
		return false;
}

bool operator!=(const Vector &U, const Vector &v)
{
	if(U.x != v.x || U.y != v.y || U.z != v.z)
		return true;
	else
		return false;
}

bool operator>(const Vector &u, const Vector &v)
{
	if((u^2) > (v^2))
		return true;
	else
		return false;
}

bool operator<(const Vector &u, const Vector &v)
{
	if((u^2) < (v^2))
		return true;
	else
		return false;
}

Vector operator+(const Vector &u, const Vector &v)
{
	return Vector(u.x + v.x, u.y + v.y, u.z + v.z);
}

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

float operator*(const Vector &u, const Vector &v)
{
	return u.x * v.x + u.y * v.y + u.z * v.z;
}

Vector operator*(float s, const Vector &v)
{
	return Vector(s * v.x, s * v.y, s * v.z);
}

Vector operator*(const Vector &v, float s)
{
	return Vector(v.x * s, v.y * s, v.z * s);
}

Vector operator/(const Vector &v, float s)
{
	float r = 1.0f / s;

	return Vector(v.x * r, v.y * r, v.z * r);
}

float operator^(const Vector &u, const Vector &v)
{
	return acos(u / Vector::N(u) * v / Vector::N(v));
}

Vector operator%(const Vector &u, const Vector &v)
{
	return Vector(u.y * v.z - u.z * v.y, u.z * v.x - u.x * v.z, u.x * v.y - u.y * v.x);
}

Vector operator*(const Matrix &M, const Vector &v)
{
	return Vector(M(1, 1) * v.x + M(1, 2) * v.y + M(1, 3) * v.z,
	              M(2, 1) * v.x + M(2, 2) * v.y + M(2, 3) * v.z,
	              M(3, 1) * v.x + M(3, 2) * v.y + M(3, 3) * v.z);
}

Vector operator*(const Vector &v, const Matrix &M)
{
	return Vector(v.x * M(1, 1) + v.y * M(2, 1) + v.z * M(3, 1) + M(4, 1),
	              v.x * M(1, 2) + v.y * M(2, 2) + v.z * M(3, 2) + M(4, 2),
	              v.x * M(1, 3) + v.y * M(2, 3) + v.z * M(3, 3) + M(4, 3));
}

Vector &operator*=(Vector &v, const Matrix &M)
{
	return v = v * M;
}

float Vector::N(const Vector &v)
{
	return sqrt(v.x*v.x + v.y*v.y + v.z*v.z);
}

float Vector::N2(const Vector &v)
{
	return v.x*v.x + v.y*v.y + v.z*v.z;
}

Vector lerp(const Vector &u, const Vector &v, float t)
{
	return Vector(u.x + t * (v.x - u.x),
	              u.y + t * (v.y - u.y),
	              u.z + t * (v.z - u.z));
}

}  // namespace sw