export class Mat4 {

    constructor() {
        this.data = [
            1, 0, 0, 0,
            0, 1, 0, 0,
            0, 0, 1, 0,
            0, 0, 0, 1
        ]
    }

    set(m00, m01, m02, m03, m10, m11, m12, m13, m20, m21, m22, m23, m30, m31, m32, m33) {
        const d = this.data
        d[0] = m00; d[1] = m01; d[2] = m02; d[3] = m03;
        d[4] = m10; d[5] = m11; d[6] = m12; d[7] = m13;
        d[8] = m20; d[9] = m21; d[10] = m22; d[11] = m23;
        d[12] = m30; d[13] = m31; d[14] = m32; d[15] = m33;
        return this
    }

    clone() {
        return new Mat4().arr(this.da)
    }

    arr(arr, offset = 0) {
        for(let i = 0; i < 16; i++) {
            this.data[i] = arr[i + offset]
        }
        return this
    }

    identity() {
        this.set(
            1, 0, 0, 0,
            0, 1, 0, 0,
            0, 0, 1, 0,
            0, 0, 0, 1
        )
        return this
    }

    copy(m) {
        const d = this.data
        const o = m.data
        d[0] = o[0]; d[1] = o[1]; d[2] = o[2]; d[3] = o[3];
        d[4] = o[4]; d[5] = o[5]; d[6] = o[6]; d[7] = o[7];
        d[8] = o[8]; d[9] = o[9]; d[10] = o[10]; d[11] = o[11];
        d[12] = o[12]; d[13] = o[13]; d[14] = o[14]; d[15] = o[15];
        return this
    }

    mult(v) {
        return this.multmat(this.clone(), v)
    }

    premult(v) {
        return this.multmat(v, this.clone())
    }

    multmat(ma, mb) {
        const a = ma.data;
		const b = mb.data
        const d = this.data;

        const a00 = a[0],  a01 = a[1],  a02 = a[2],  a03 = a[3];
		const a10 = a[4],  a11 = a[5],  a12 = a[6],  a13 = a[7];
		const a20 = a[8],  a21 = a[9],  a22 = a[10], a23 = a[11];
		const a30 = a[12], a31 = a[13], a32 = a[14], a33 = a[15];

		const b00 = b[0],  b01 = b[1],  b02 = b[2],  b03 = a[3];
		const b10 = b[4],  b11 = b[5],  b12 = b[6],  b13 = a[7];
		const b20 = b[8],  b21 = b[9],  b22 = b[10], b23 = a[11];
		const b30 = b[12], b31 = b[13], b32 = b[14], b33 = a[15];

		d[0]  = a00 * b00 + a01 * b10 + a02 * b20 + a03 * b30;
		d[1]  = a00 * b01 + a01 * b11 + a02 * b21 + a03 * b31;
		d[2]  = a00 * b02 + a01 * b12 + a02 * b22 + a03 * b32;
		d[3] = a00 * b03 + a01 * b13 + a02 * b23 + a03 * b33;

		d[4] = a10 * b00 + a11 * b10 + a12 * b20 + a13 * b30;
		d[5] = a10 * b01 + a11 * b11 + a12 * b21 + a13 * b31;
		d[6] = a10 * b02 + a11 * b12 + a12 * b22 + a13 * b32;
		d[7] = a10 * b03 + a11 * b13 + a12 * b23 + a13 * b33;

		d[8]  = a20 * b00 + a21 * b10 + a22 * b20 + a23 * b30;
		d[9]  = a20 * b01 + a21 * b11 + a22 * b21 + a23 * b31;
		d[10] = a20 * b02 + a21 * b12 + a22 * b22 + a23 * b32;
		d[11] = a20 * b03 + a21 * b13 + a22 * b23 + a23 * b33;

		d[12] = a30 * b00 + a31 * b10 + a32 * b20 + a33 * b30;
		d[13] = a30 * b01 + a31 * b11 + a32 * b21 + a33 * b31;
		d[14] = a30 * b02 + a31 * b12 + a32 * b22 + a33 * b32;
		d[15] = a30 * b03 + a31 * b13 + a32 * b23 + a33 * b33;

		return this;
    }

    pos(v) {
        const d = this.data

        const m30 = d[0] * v.x + d[4] * v.y + d[8] * v.z;
        const m31 = d[1] * v.x + d[5] * v.y + d[9] * v.z;
        const m32 = d[2] * v.x + d[6] * v.y + d[10] * v.z;
        const m33 = d[3] * v.x + d[7] * v.y + d[11] * v.z; 

		d[3] += m30;
        d[7] += m31;
        d[11] += m32;
        d[15] += m33;
		return this;
	}

    rot(v) {
        const da = this.data;
		const c3 = Math.cos(v.z)
        const s3 = Math.sin(v.z)
		const c2 = Math.cos(v.x)
        const s2 = Math.sin(v.x)
		const c1 = Math.cos(v.y)
        const s1 = Math.sin(v.y)

        da[0] = c1 * c3 + s1 * s2 * s3
        da[4] = c2 * s3
        da[8] = c1 * s2 * s3 - c3 * s1

        da[1] = c3 * s1 * s2 - c1 * s3
        da[5] = c2 * c3
        da[9] = c1 * c3 * s2 + s1 * s3

        da[2] = c2 * s1
        da[6] = -s2
        da[10] = c1 * c2

        return this
    }

    scale( v ) {
		const d = this.data;

		d[0] *= v.x; d[1] *= v.y; d[2] *= v.z;
		d[4] *= v.x; d[5] *= v.y; d[6] *= v.z;
		d[8] *= v.x; d[9] *= v.y; d[10] *= v.z;
		d[12] *= v.x; d[13] *= v.y; d[14] *= v.z;

		return this;
	}

    get() {
        const d = this.data
        return [
            d[0], d[4], d[8], d[12],
            d[1], d[5], d[9], d[13],
            d[2], d[6], d[10], d[14],
            d[3], d[7], d[11], d[15] 
        ]
    }
}