/*
 * Planck.js
 *
 * Copyright (c) Ali Shakiba
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 */

/** @internal */ const math_sin = Math.sin;
/** @internal */ const math_cos = Math.cos;
/** @internal */ const math_sqrt = Math.sqrt;

import { RotValue } from "./Rot";
import { TransformValue } from "./Transform";
import { Vec2Value } from "./Vec2";
import { Vec3Value } from "./Vec3";

export function vec2(x: number, y: number): Vec2Value {
  return { x, y };
}

export function vec3(x: number, y: number, z: number): Vec3Value {
  return { x, y, z };
}

export function rotation(angle: number): RotValue {
  return { s: math_sin(angle), c: math_cos(angle) };
}

export function setVec2(out: Vec2Value, x: number, y: number): Vec2Value {
  out.x = x;
  out.y = y;
  return out;
}

export function copyVec2(out: Vec2Value, w: Vec2Value): Vec2Value {
  out.x = w.x;
  out.y = w.y;
  return out;
}

export function zeroVec2(out: Vec2Value): Vec2Value {
  out.x = 0;
  out.y = 0;
  return out;
}

export function negVec2(out: Vec2Value): Vec2Value {
  out.x = -out.x;
  out.y = -out.y;
  return out;
}

export function plusVec2(out: Vec2Value, w: Vec2Value): Vec2Value {
  out.x += w.x;
  out.y += w.y;
  return out;
}

export function addVec2(out: Vec2Value, v: Vec2Value, w: Vec2Value): Vec2Value {
  out.x = v.x + w.x;
  out.y = v.y + w.y;
  return out;
}

export function minusVec2(out: Vec2Value, w: Vec2Value): Vec2Value {
  out.x -= w.x;
  out.y -= w.y;
  return out;
}

export function subVec2(out: Vec2Value, v: Vec2Value, w: Vec2Value): Vec2Value {
  out.x = v.x - w.x;
  out.y = v.y - w.y;
  return out;
}

export function mulVec2(out: Vec2Value, m: number): Vec2Value {
  out.x *= m;
  out.y *= m;
  return out;
}

export function scaleVec2(out: Vec2Value, m: number, w: Vec2Value): Vec2Value {
  out.x = m * w.x;
  out.y = m * w.y;
  return out;
}

export function plusScaleVec2(out: Vec2Value, m: number, w: Vec2Value): Vec2Value {
  out.x += m * w.x;
  out.y += m * w.y;
  return out;
}

export function minusScaleVec2(out: Vec2Value, m: number, w: Vec2Value): Vec2Value {
  out.x -= m * w.x;
  out.y -= m * w.y;
  return out;
}

export function combine2Vec2(out: Vec2Value, am: number, a: Vec2Value, bm: number, b: Vec2Value): Vec2Value {
  out.x = am * a.x + bm * b.x;
  out.y = am * a.y + bm * b.y;
  return out;
}

export function combine3Vec2(
  out: Vec2Value,
  am: number,
  a: Vec2Value,
  bm: number,
  b: Vec2Value,
  cm: number,
  c: Vec2Value,
): Vec2Value {
  out.x = am * a.x + bm * b.x + cm * c.x;
  out.y = am * a.y + bm * b.y + cm * c.y;
  return out;
}

export function normalizeVec2Length(out: Vec2Value): number {
  const length = math_sqrt(out.x * out.x + out.y * out.y);
  if (length !== 0) {
    const invLength = 1 / length;
    out.x *= invLength;
    out.y *= invLength;
  }
  return length;
}

export function normalizeVec2(out: Vec2Value): Vec2Value {
  const length = math_sqrt(out.x * out.x + out.y * out.y);
  if (length > 0) {
    const invLength = 1 / length;
    out.x *= invLength;
    out.y *= invLength;
  }
  return out;
}

export function crossVec2Num(out: Vec2Value, v: Vec2Value, w: number): Vec2Value {
  const x = w * v.y;
  const y = -w * v.x;
  out.x = x;
  out.y = y;
  return out;
}

export function crossNumVec2(out: Vec2Value, w: number, v: Vec2Value): Vec2Value {
  const x = -w * v.y;
  const y = w * v.x;
  out.x = x;
  out.y = y;
  return out;
}

export function crossVec2Vec2(a: Vec2Value, b: Vec2Value): number {
  return a.x * b.y - a.y * b.x;
}

export function dotVec2(a: Vec2Value, b: Vec2Value): number {
  return a.x * b.x + a.y * b.y;
}

export function lengthVec2(a: Vec2Value): number {
  return math_sqrt(a.x * a.x + a.y * a.y);
}

export function lengthSqrVec2(a: Vec2Value): number {
  return a.x * a.x + a.y * a.y;
}

export function distVec2(a: Vec2Value, b: Vec2Value): number {
  const dx = a.x - b.x;
  const dy = a.y - b.y;
  return math_sqrt(dx * dx + dy * dy);
}

export function distSqrVec2(a: Vec2Value, b: Vec2Value): number {
  const dx = a.x - b.x;
  const dy = a.y - b.y;
  return dx * dx + dy * dy;
}

export function dotVec3(v: Vec3Value, w: Vec3Value): number {
  return v.x * w.x + v.y * w.y + v.z * w.z;
}

export function setRotAngle(out: RotValue, a: number): RotValue {
  out.c = math_cos(a);
  out.s = math_sin(a);
  return out;
}

export function rotVec2(out: Vec2Value, q: RotValue, v: Vec2Value): Vec2Value {
  out.x = q.c * v.x - q.s * v.y;
  out.y = q.s * v.x + q.c * v.y;
  return out;
}

export function derotVec2(out: Vec2Value, q: RotValue, v: Vec2Value): Vec2Value {
  const x = q.c * v.x + q.s * v.y;
  const y = -q.s * v.x + q.c * v.y;
  out.x = x;
  out.y = y;
  return out;
}

export function rerotVec2(out: Vec2Value, before: RotValue, after: RotValue, v: Vec2Value): Vec2Value {
  const x0 = before.c * v.x + before.s * v.y;
  const y0 = -before.s * v.x + before.c * v.y;
  const x = after.c * x0 - after.s * y0;
  const y = after.s * x0 + after.c * y0;
  out.x = x;
  out.y = y;
  return out;
}

export function transform(x: number, y: number, a: number): TransformValue {
  return { p: vec2(x, y), q: rotation(a) };
}

export function copyTransform(out: TransformValue, transform: TransformValue): TransformValue {
  out.p.x = transform.p.x;
  out.p.y = transform.p.y;
  out.q.s = transform.q.s;
  out.q.c = transform.q.c;
  return out;
}

export function transformVec2(out: Vec2Value, xf: TransformValue, v: Vec2Value): Vec2Value {
  const x = xf.q.c * v.x - xf.q.s * v.y + xf.p.x;
  const y = xf.q.s * v.x + xf.q.c * v.y + xf.p.y;
  out.x = x;
  out.y = y;
  return out;
}

export function detransformVec2(out: Vec2Value, xf: TransformValue, v: Vec2Value): Vec2Value {
  const px = v.x - xf.p.x;
  const py = v.y - xf.p.y;
  const x = xf.q.c * px + xf.q.s * py;
  const y = -xf.q.s * px + xf.q.c * py;
  out.x = x;
  out.y = y;
  return out;
}

export function retransformVec2(out: Vec2Value, from: TransformValue, to: TransformValue, v: Vec2Value): Vec2Value {
  const x0 = from.q.c * v.x - from.q.s * v.y + from.p.x;
  const y0 = from.q.s * v.x + from.q.c * v.y + from.p.y;
  const px = x0 - to.p.x;
  const py = y0 - to.p.y;
  const x = to.q.c * px + to.q.s * py;
  const y = -to.q.s * px + to.q.c * py;
  out.x = x;
  out.y = y;
  return out;
}

export function detransformTransform(out: TransformValue, a: TransformValue, b: TransformValue): TransformValue {
  const c = a.q.c * b.q.c + a.q.s * b.q.s;
  const s = a.q.c * b.q.s - a.q.s * b.q.c;
  const x = a.q.c * (b.p.x - a.p.x) + a.q.s * (b.p.y - a.p.y);
  const y = -a.q.s * (b.p.x - a.p.x) + a.q.c * (b.p.y - a.p.y);
  out.q.c = c;
  out.q.s = s;
  out.p.x = x;
  out.p.y = y;
  return out;
}