GLKMatrix4Invert

static __inline__ GLKMatrix4 GLKMatrix4Invert(GLKMatrix4 matrix, bool *isInvertable) {
    
    float b00 = matrix.m[0] * matrix.m[5] - matrix.m[1] * matrix.m[4];
    float b01 = matrix.m[0] * matrix.m[6] - matrix.m[2] * matrix.m[4];
    float b02 = matrix.m[0] * matrix.m[7] - matrix.m[3] * matrix.m[4];
    float b03 = matrix.m[1] * matrix.m[6] - matrix.m[2] * matrix.m[5];
    float b04 = matrix.m[1] * matrix.m[7] - matrix.m[3] * matrix.m[5];
    float b05 = matrix.m[2] * matrix.m[7] - matrix.m[3] * matrix.m[6];
    float b06 = matrix.m[8] * matrix.m[13] - matrix.m[9] * matrix.m[12];
    float b07 = matrix.m[8] * matrix.m[14] - matrix.m[10] * matrix.m[12];
    float b08 = matrix.m[8] * matrix.m[15] - matrix.m[11] * matrix.m[12];
    float b09 = matrix.m[9] * matrix.m[14] - matrix.m[10] * matrix.m[13];
    float b10 = matrix.m[9] * matrix.m[15] - matrix.m[11] * matrix.m[13];
    float b11 = matrix.m[10] * matrix.m[15] - matrix.m[11] * matrix.m[14];
    
    // Calculate the determinant (inlined to avoid double-caching)
    float determinant = b00 * b11 - b01 * b10 + b02 * b09 + b03 * b08 - b04 * b07 + b05 * b06;
    if (isInvertable != NULL) {
        *isInvertable = determinant != 0;
    }
    
    if (determinant == 0) {
        return GLKMatrix4Identity;
    }
    
    float invDet = 1.0f / determinant;
    GLKMatrix4 m;
    
    m.m[0] = (matrix.m[5] * b11 - matrix.m[6] * b10 + matrix.m[7] * b09) * invDet;
    m.m[1] = (-matrix.m[1] * b11 + matrix.m[2] * b10 - matrix.m[3] * b09) * invDet;
    m.m[2] = (matrix.m[13] * b05 - matrix.m[14] * b04 + matrix.m[15] * b03) * invDet;
    m.m[3] = (-matrix.m[9] * b05 + matrix.m[10] * b04 - matrix.m[11] * b03) * invDet;
    m.m[4] = (-matrix.m[4] * b11 + matrix.m[6] * b08 - matrix.m[7] * b07) * invDet;
    m.m[5] = (matrix.m[0] * b11 - matrix.m[2] * b08 + matrix.m[3] * b07) * invDet;
    m.m[6] = (-matrix.m[12] * b05 + matrix.m[14] * b02 - matrix.m[15] * b01) * invDet;
    m.m[7] = (matrix.m[8] * b05 - matrix.m[10] * b02 + matrix.m[11] * b01) * invDet;
    m.m[8] = (matrix.m[4] * b10 - matrix.m[5] * b08 + matrix.m[7] * b06) * invDet;
    m.m[9] = (-matrix.m[0] * b10 + matrix.m[1] * b08 - matrix.m[3] * b06) * invDet;
    m.m[10] = (matrix.m[12] * b04 - matrix.m[13] * b02 + matrix.m[15] * b00) * invDet;
    m.m[11] = (-matrix.m[8] * b04 + matrix.m[9] * b02 - matrix.m[11] * b00) * invDet;
    m.m[12] = (-matrix.m[4] * b09 + matrix.m[5] * b07 - matrix.m[6] * b06) * invDet;
    m.m[13] = (matrix.m[0] * b09 - matrix.m[1] * b07 + matrix.m[2] * b06) * invDet;
    m.m[14] = (-matrix.m[12] * b03 + matrix.m[13] * b01 - matrix.m[14] * b00) * invDet;
    m.m[15] = (matrix.m[8] * b03 - matrix.m[9] * b01 + matrix.m[10] * b00) * invDet;
    
    return m;
}