Base types

FileMagic string

With some exceptions, all asset files have a FileMagic at the start of the file. It can be one of "ubi/b0-l" and "ubi/b0-b", which indicate whether the file is little- or big-endian respectively. However, only "ubi/b0-l", the little-endian variant, has ever been observed in the wild.

BasicString structure

The basic UTF-16 string used all over the place. Sometimes referred to as ubistring.

Name	Type	Description
len	uint32	Length of the string.
s	char[len]	The string.

BasicWString structure

Same as BasicString, except with UTF-16 encoding.

Name	Type	Description
len	uint32	Length of the string.
s	wchar_t[len]	The string.

EncryptedString structure

Same as BasicString, except all chars are "swizzled".

Name	Type	Description
len	uint32	Length of the string.
s	char[len]	The string.

Swizzle/unswizzle:

void EncryptedString::Swizzle() {
    for (int i = 0; i < this->len; i++) {
        byte b = this->s[i];
        this->s[i] = (b & 0xAA) >> 1 | (b & 0x55) << 1;
    }
    return;
}

Vector2 structure

Sometimes referred to as vec2.

Name	Type	Description
x	float32
y	float32

Vector3 structure

Sometimes referred to as vec3.

Name	Type	Description
x	float32
y	float32
z	float32

Vector4 / Quaternion structure

Sometimes referred to as vec4 or quat respectively.

Name	Type	Description
x	float32
y	float32
z	float32
w	float32

Matrix22 structure

Name	Type	Description
x	Vector2
y	Vector2

Matrix33 structure

Name	Type	Description
x	Vector3
y	Vector3
z	Vector3

Matrix44 structure

Name	Type	Description
x	Vector4
y	Vector4
z	Vector4
w	Vector4

Color structure

Name	Type	Description
r	float32	Red.
g	float32	Green.
b	float32	Blue.
a	float32	Alpha.

Box structure

Name	Type	Description
pMin	Vector3
pMax	Vector3

Array<Type> structure

Name	Type	Description
len	uint32	Length of the array.
elements	Type[len]	Elements of the array.

PairArray<Key, Value> structure

Name	Type	Description
len	uint32	Length of the array.
elements	Pair<Key, Value>[len]	Elements of the array.

Pair<Key, Value> structure

Name	Type	Description
k	Key	Key.
v	Value	Value.

CompressedQuaternion3U16 structure

Name	Type	Description
x	uint16
y	uint16
z	uint16

Compression/decompression:

void CompressedQuaternion3U16::Compress(Quaternion *src) {
    if (src->w < 0.0) {
        this->x = (uint16)((1.0 - src->x) * 32767.0);
        this->y = (uint16)((1.0 - src->y) * 32767.0);
        this->z = (uint16)((1.0 - src->z) * 32767.0);
    } else {
        this->x = (uint16)((1.0 + src->x) * 32767.0);
        this->y = (uint16)((1.0 + src->y) * 32767.0);
        this->z = (uint16)((1.0 + src->z) * 32767.0);
    }
    return;
}

void CompressedQuaternion3U16::Decompress(Quaternion *dst) {
    float w;

    dst->x = (float32)this->x*(1.0/32767.0) - 1.0;
    dst->y = (float32)this->y*(1.0/32767.0) - 1.0;
    dst->z = (float32)this->z*(1.0/32767.0) - 1.0;
    w = ((1.0 - dst->x*dst->x) - dst->y*dst->y) - dst->z*dst->z;
    if (w > 0.0) {
        dst->w = sqrt(w);
    } else {
        dst->w = 0.0;
    }
    return;
}

CompressedQuaternionU32 type

• Type: uint32
• Bits: xxaaaaaa aaaabbbb bbbbbbcc cccccccc
  • xx: greatest quat element (0 = x, 1 = y, 2 = z, 3 = w).
  • aaaaaaaaaa/bbbbbbbbbb/cccccccccc: other three elements.

Compression/decompression:

const float32 oneOverRootTwo  = sqrt(2.0) /     2.0;
const float32 scaleRange10Bit = sqrt(2.0) / pow(2.0, 10);

static uint32 CompressedQuaternionU32::CompressElement(float32 elem) {
    return min((uint32)((elem + oneOverRootTwo) * (1.0/scaleRange10Bit) + 0.000025), 0x3FF);
}

void CompressedQuaternionU32::Compress(Quaternion *src) {
    uint32 a, b, c, x;
    float32 ax, ay, az, aw;
    Quaternion q;

    q = *src;
    q.Normalize();

    ax = abs(q.x);
    ay = abs(q.y);
    az = abs(q.z);
    aw = abs(q.w);

    if (ax > ay && ax > az && ax > aw) {
        // x is greatest element.
        if (q.x < 0.0) q.Negate();
        a = CompressElement(q.y);
        b = CompressElement(q.z);
        c = CompressElement(q.w);
        x = 0;
    } else if (ay > az && ay > aw) {
        // y is greatest element.
        if (q.y < 0.0) q.Negate();
        a = CompressElement(q.x);
        b = CompressElement(q.z);
        c = CompressElement(q.w);
        x = 1;
    } else if (az > aw) {
        // z is greatest element.
        if (q.z < 0.0) q.Negate();
        a = CompressElement(q.x);
        b = CompressElement(q.y);
        c = CompressElement(q.w);
        x = 2;
    } else {
        // w is greatest element.
        if (q.w < 0.0) q.Negate();
        a = CompressElement(q.x);
        b = CompressElement(q.y);
        c = CompressElement(q.z);
        x = 3;
    }

    this->v = (x << 30) | (a << 20) | (b << 10) | a;
    return;
}

void CompressedQuaternionU32::Decompress(Quaternion *dst) {
    float32 a, b, c, s;

    a = (float32)(this->v >> 20 & 0x3FF) * scaleRange10Bit - oneOverRootTwo;
    b = (float32)(this->v >> 10 & 0x3FF) * scaleRange10Bit - oneOverRootTwo;
    c = (float32)(this->v >>  0 & 0x3FF) * scaleRange10Bit - oneOverRootTwo;
    s = sqrt(((1.0 - a*a) - b*b) - c*c);

    switch this->v >> 30 {
    case 0:
        dst->x = s;
        dst->y = a;
        dst->z = b;
        dst->w = c;
        break;
    case 1:
        dst->x = a;
        dst->y = s;
        dst->z = b;
        dst->w = c;
        break;
    case 2:
        dst->x = a;
        dst->y = b;
        dst->z = s;
        dst->w = c;
        break;
    case 3:
        dst->x = a;
        dst->y = b;
        dst->z = c;
        dst->w = s;
        break;
    }
    return;
}