//------------------------------------------------
//--- 010 Editor v12.0.1 Binary Template
//
//      File: dt_texture_compressed.dt
//   Authors: Lucas Schwiderski
//   Version: 
//   Purpose: 
//  Category: Darktide
// File Mask: 
//  ID Bytes: 
//   History: 
//------------------------------------------------

// The game does ship with two decompression options, but it I've only seen Oodle in the game files
// so far.
// I'd guess `0` is uncompressed, which would only happen in the dev releases, and likely be stripped by `#if`s.
// The compression method does not affect the rest of the data structure
typedef enum {
    Oodle = 1,
    Custom = 2,
} CompressionType;

CompressionType compression_type;

uint32 compressed_size;
uint32 uncompressed_size;

byte compressed_buffer[compressed_size] <format=hex, bgcolor=0x888545>;

// Skipped by the decompiled binary's code.
// Doesn't fit to be a length of a later data section. It doesn't match anything, and it's an uneven number.
uint32 unknown_1 <comment="Always 67 (0x43), so maybe a format/type specifier.">;
Assert(unknown_1 == 0x43);
    
typedef struct {
    uint32 offset;
    uint32 size;
} MipInfo;

typedef struct {
    // Checked bits:
    // >> 1: Some extra calculations are done with the next three fields around mipmaps
    //       Also determines if `unknown_2` is saved into `TextureImage`
    //       => Presumable means "has mipmaps" or VT2's "is streamable"
    // >> 2: So far, I haven't found a line of code that actually uses this bit.
    //       But there is a line that assigns `flags & 3`, indicating that this bit
    //       does get used somewhere else.
    // >> 8: TextureFormat.srgb, probably.
    uint32 flags <format=binary, comment="Some bitflags.">;

    // Does not match with the number of pairs in `mip_infos`.
    uint32 n_streamable_mips;
    uint32 width;
    uint32 height;

    // Offset and size of mip maps stored in the `.stream` file
    // Though it seems that they don't align with mipmaps properly.
    // The first size sometimes doesn't include enough data for a full texture
    // and it would end up with a black section.
    MipInfo mip_infos[16] <bgcolor=0x9b86d3, fgcolor=0xb2dbeb>;

    uint32 meta_size;
} TextureHeader;

TextureHeader texture_header;

// If there is an associated `.stream` file, its content is compressed with Oodle,
// and the numbers in `chunks` below specify the size of each chunk.
// I.e. the `comp_buf_size`, while the `raw_buf_size` is always `0x1000`.
if (texture_header.meta_size > 0) {
    uint32 num_chunks;
    Assert((num_chunks * 4) + 8 == texture_header.meta_size);

    uint16 unknown_6 <hidden=true>;
    Assert(unknown_6 == 0);

    // Always the same as `num_chunks`, but it's weird that this is a u16.
    // So probably a different meaning that just happens to be the same value in most/all cases.
    uint16 num_chunks_2 <hidden=true>;
    Assert(num_chunks == num_chunks_2);

    uint32 chunks[num_chunks];
}

// A key to look up a value in the engine's internal render quality settings.
// Specifically, a value that VT2 calls `mip_drop`.
// See `user_settings.conf` -> `texture_settings`
uint32 category <format=hex, comment="An IdString32">;

// Shortcuts to get to compile this:
// - `flags = 0` -> skips most of the mipmap stuff in the bundle file
// - `width = 0`, `height = 0` -> also skips some of the mipmap stuff
// - `n_streamable_mipmaps = 0` -> seems to be an intended value to only rely on DDS mipmaps
//                                 It does force `srgb` on through setting a special value for `flags`, though. So if that produces issues, I might
//                                 need to fake it s