1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157

use std::io::{Read, Result, Error, ErrorKind, Seek, SeekFrom};
use std::iter::repeat;
use std::mem::{forget, size_of, zeroed};

use bytepack::{LEUnpacker, Packed};

use flate2::{Decompress, Flush};

/// Represent a typed property of the FBX file format.
#[derive(Clone, Debug)]
pub enum Property {
    B(bool),
    I16(i16),
    I32(i32),
    I64(i64),
    F32(f32),
    F64(f64),
    RawArray(Vec<u8>),
    String(String),
    BArray(Vec<bool>),
    I8Array(Vec<i8>),
    I32Array(Vec<i32>),
    I64Array(Vec<i64>),
    F32Array(Vec<f32>),
    F64Array(Vec<f64>),
}

/// Represent a Node of the FBX file format. Each node has a `name` (or id) and is composed of a 
/// list of [`Property`](enum.Property.html) and a list of sub [`Node`](struct.Node.html).
#[derive(Clone, Debug)]
pub struct Node {
    /// Name of the node.
    pub name: String,
    /// List of properties of the node.
    pub properties: Vec<Property>,
    /// List of sub-nodes.
    pub subnodes: Vec<Node>,
}

/// Decode a `Property::RawArray`.
fn decode_raw_array<R: Read>(r : &mut R) -> Result<Vec<u8>> {
    let length = r.unpack::<u32>()? as usize;
    let mut array : Vec<u8> = repeat(0u8).take(length).collect();
    r.read_exact(&mut array[..])?;
    return Ok(array);
}

/// Decode a `Property::String`.
fn decode_string<R: Read>(r : &mut R) -> Result<String> {
    match String::from_utf8(decode_raw_array(r)?) {
        Ok(s) => Ok(s),
        Err(_) => Err(Error::new(ErrorKind::InvalidData, "Invalid UTF-8 characters in string"))
    }
}

/// Decode a `Property::*Array`.
fn decode_array<R: Read, T: Packed + Clone>(r : &mut R) -> Result<Vec<T>> {
    let length = r.unpack::<u32>()? as usize;
    let encoding = r.unpack::<u32>()?;
    let compressed_length = r.unpack::<u32>()? as usize;
    if encoding == 0 {
        let zero : T = unsafe { zeroed() };
        let mut array : Vec<T> = repeat(zero).take(length).collect();
        r.unpack_exact(&mut array[..])?;
        return Ok(array);
    }
    else if encoding == 1 {
        let mut compressed : Vec<u8> = repeat(0u8).take(compressed_length).collect();
        let mut decompressed : Vec<u8> = repeat(0u8).take(length * size_of::<T>()).collect();
        let mut deflater = Decompress::new(true);

        r.read_exact(&mut compressed)?;
        if let Err(_) = deflater.decompress(&compressed, &mut decompressed, Flush::Finish) {
            return Err(Error::new(ErrorKind::InvalidData, "Failed to deflate array"));
        }

        // Safe because we made sure the length and capacity of decompressed is length * size_of::<T>() 
        // and we properly forget decompressed
        decompressed.shrink_to_fit();
        unsafe {
            let converted = Vec::<T>::from_raw_parts(decompressed.as_mut_ptr() as *mut T, length, length);
            forget(decompressed);
            return Ok(converted);
        }
    }
    else {
        return Err(Error::new(ErrorKind::InvalidData, "Unknown array encoding"));
    }
}

/// Decode a [`Property`](enum.Property.html).
pub fn decode_property<R: Read>(r: &mut R) -> Result<Property> {
    match r.unpack()? {
        b'C' => Ok(Property::B(r.unpack::<u8>()? == 1)),
        b'Y' => Ok(Property::I16(r.unpack()?)),
        b'I' => Ok(Property::I32(r.unpack()?)),
        b'L' => Ok(Property::I64(r.unpack()?)),
        b'F' => Ok(Property::F32(r.unpack()?)),
        b'D' => Ok(Property::F64(r.unpack()?)),
        b'R' => Ok(Property::RawArray(decode_raw_array(r)?)),
        b'S' => Ok(Property::String(decode_string(r)?)),
        b'b' =>  Ok(Property::BArray(decode_array::<R, bool>(r)?)),
        b'c' =>  Ok(Property::I8Array(decode_array::<R, i8>(r)?)),
        b'i' =>  Ok(Property::I32Array(decode_array::<R, i32>(r)?)),
        b'l' =>  Ok(Property::I64Array(decode_array::<R, i64>(r)?)),
        b'f' =>  Ok(Property::F32Array(decode_array::<R, f32>(r)?)),
        b'd' =>  Ok(Property::F64Array(decode_array::<R, f64>(r)?)),
        _ => Err(Error::new(ErrorKind::InvalidData, "Invalid property type marker"))
    }
}

/// Decode a [`Node`](struct.Node.html).
pub fn decode_node<R: Read + Seek>(r: &mut R) -> Result<Option<Node>> {
    let end_offset = r.unpack::<u32>()? as u64;
    let property_number = r.unpack::<u32>()? as usize;
    let properties_size = r.unpack::<u32>()? as usize;
    let name_length = r.unpack::<u8>()? as usize;

    // NULL node, end of node list
    if end_offset == 0 && property_number == 0 && properties_size == 0 && name_length == 0 {
        return Ok(None);
    }

    let mut name_buffer : Vec<u8> = repeat(0u8).take(name_length).collect();
    r.read_exact(&mut name_buffer[..])?;
    let name = match String::from_utf8(name_buffer.clone()) {
        Ok(s) => s,
        Err(_) => {
            println!("Name Buffer: {:?}", name_buffer);
            return Err(Error::new(ErrorKind::InvalidData, "Invalid UTF-8 characters in node name"))
        }
    };

    let mut properties = Vec::<Property>::with_capacity(property_number);
    for _ in 0..property_number {
        properties.push(decode_property(r)?);
    }

    return Ok(Some(Node {
        name: name,
        properties: properties,
        subnodes: decode_node_list(r, end_offset)?
    }));
}

/// Decode a list of [`Node`](struct.Node.html).
pub fn decode_node_list<R: Read + Seek>(r: &mut R, end : u64) -> Result<Vec<Node>> {
    let mut nodes = Vec::<Node>::new();
    while let Some(node) = decode_node(r)? {
        nodes.push(node);
        let pos = r.seek(SeekFrom::Current(0))?;
        if pos >= end {
            break;
        }
    }
    return Ok(nodes);
}