wip: dynamic event size

Add an algorithm to generate a bot file from a set of timelines.

Reviewed-on: #3
Co-authored-by: Rhys Lloyd <krakow20@gmail.com>
Co-committed-by: Rhys Lloyd <krakow20@gmail.com>

Cargo.lock

@@ -10,9 +10,9 @@ checksum = "3d62b7694a562cdf5a74227903507c56ab2cc8bdd1f781ed5cb4cf9c9f810bfc"
 
 [[package]]
 name = "binrw"
-version = "0.14.1"
+version = "0.15.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7d4bca59c20d6f40c2cc0802afbe1e788b89096f61bdf7aeea6bf00f10c2909b"
+checksum = "81419ff39e6ed10a92a7f125290859776ced35d9a08a665ae40b23e7ca702f30"
 dependencies = [
  "array-init",
  "binrw_derive",
@@ -21,9 +21,9 @@ dependencies = [
 
 [[package]]
 name = "binrw_derive"
-version = "0.14.1"
+version = "0.15.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d8ba42866ce5bced2645bfa15e97eef2c62d2bdb530510538de8dd3d04efff3c"
+checksum = "376404e55ec40d0d6f8b4b7df3f87b87954bd987f0cf9a7207ea3b6ea5c9add4"
 dependencies = [
  "either",
  "owo-colors",
@@ -34,15 +34,15 @@ dependencies = [
 
 [[package]]
 name = "bitflags"
-version = "2.9.0"
+version = "2.10.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5c8214115b7bf84099f1309324e63141d4c5d7cc26862f97a0a857dbefe165bd"
+checksum = "812e12b5285cc515a9c72a5c1d3b6d46a19dac5acfef5265968c166106e31dd3"
 
 [[package]]
 name = "bytemuck"
-version = "1.22.0"
+version = "1.24.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b6b1fc10dbac614ebc03540c9dbd60e83887fda27794998c6528f1782047d540"
+checksum = "1fbdf580320f38b612e485521afda1ee26d10cc9884efaaa750d383e13e3c5f4"
 
 [[package]]
 name = "either"
@@ -51,42 +51,52 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "48c757948c5ede0e46177b7add2e67155f70e33c07fea8284df6576da70b3719"
 
 [[package]]
-name = "owo-colors"
-version = "3.5.0"
+name = "itertools"
+version = "0.14.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c1b04fb49957986fdce4d6ee7a65027d55d4b6d2265e5848bbb507b58ccfdb6f"
+checksum = "2b192c782037fadd9cfa75548310488aabdbf3d2da73885b31bd0abd03351285"
+dependencies = [
+ "either",
+]
+
+[[package]]
+name = "owo-colors"
+version = "4.2.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9c6901729fa79e91a0913333229e9ca5dc725089d1c363b2f4b4760709dc4a52"
 
 [[package]]
 name = "proc-macro2"
-version = "1.0.94"
+version = "1.0.103"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a31971752e70b8b2686d7e46ec17fb38dad4051d94024c88df49b667caea9c84"
+checksum = "5ee95bc4ef87b8d5ba32e8b7714ccc834865276eab0aed5c9958d00ec45f49e8"
 dependencies = [
  "unicode-ident",
 ]
 
 [[package]]
 name = "quote"
-version = "1.0.40"
+version = "1.0.42"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "1885c039570dc00dcb4ff087a89e185fd56bae234ddc7f056a945bf36467248d"
+checksum = "a338cc41d27e6cc6dce6cefc13a0729dfbb81c262b1f519331575dd80ef3067f"
 dependencies = [
  "proc-macro2",
 ]
 
 [[package]]
 name = "strafesnet_roblox_bot_file"
-version = "0.3.1"
+version = "0.8.1"
 dependencies = [
  "binrw",
  "bitflags",
+ "itertools",
 ]
 
 [[package]]
 name = "syn"
-version = "1.0.109"
+version = "2.0.111"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "72b64191b275b66ffe2469e8af2c1cfe3bafa67b529ead792a6d0160888b4237"
+checksum = "390cc9a294ab71bdb1aa2e99d13be9c753cd2d7bd6560c77118597410c4d2e87"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -95,6 +105,6 @@ dependencies = [
 
 [[package]]
 name = "unicode-ident"
-version = "1.0.18"
+version = "1.0.22"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5a5f39404a5da50712a4c1eecf25e90dd62b613502b7e925fd4e4d19b5c96512"
+checksum = "9312f7c4f6ff9069b165498234ce8be658059c6728633667c526e27dc2cf1df5"

Cargo.toml

@@ -1,8 +1,13 @@
 [package]
 name = "strafesnet_roblox_bot_file"
-version = "0.3.1"
-edition = "2021"
+version = "0.8.1"
+edition = "2024"
 
 [dependencies]
-binrw = "0.14.1"
+binrw = "0.15.0"
 bitflags = "2.6.0"
+itertools = { version = "0.14.0", optional = true }
+
+[features]
+default = ["itertools"]
+itertools = ["dep:itertools"]

README.md

@@ -3,30 +3,45 @@ Roblox Bhop/Surf Bot File Format
 
 ## Example
 
+Read the whole file and print each position:
 ```rust
-use strafesnet_roblox_bot_file::{File,TimedBlockId};
+use strafesnet_roblox_bot_file::v0::read_all_to_block;
 
-let file=std::fs::File::open("bot_file")?;
-let input=std::io::BufReader::new(file);
-let mut bot_file=File::new(input)?;
+let file=std::fs::read("bot_file")?;
+let mut input=std::io::Cursor::new(file);
 
-// read the whole file
-let block=bot_file.read_all()?;
+let block=read_all_to_block(&mut input)?;
 
-// or do data streaming block by block
-for &TimedBlockId{time,block_id} in &bot_file.header.offline_blocks_timeline{
-	// header is immutably borrowed
-	// while data is mutably borrowed
-	let block_info=bot_file.header.block_info(block_id)?;
-	let block=bot_file.data.read_block_info(block_info)?;
-	// offline blocks include the following event types:
-	// World, Gravity, Run, Camera, Setting
+for output_event in &block.output_events{
+	println!("{:?}",output_event.event.position);
 }
-for &TimedBlockId{time,block_id} in &bot_file.header.realtime_blocks_timeline{
-	let block_info=bot_file.header.block_info(block_id)?;
-	let block=bot_file.data.read_block_info(block_info)?;
-	// realtime blocks include the following event types:
-	// Input, Output, Sound
+```
+Or decode individual blocks using block location info:
+```rust
+use strafesnet_roblox_bot_file::v0::{Block,BlockTimelines,FileHeader};
+
+let file=std::fs::read("bot_file")?;
+let mut input=std::io::Cursor::new(file);
+
+// FileHeader is the first 16 bytes of the file.
+let header=FileHeader::from_reader(&mut input)?;
+// BlockTimelines is an index of the blocks within the file.
+let timelines=BlockTimelines::from_reader(&header,&mut input)?;
+
+// offline blocks include the following event types:
+// World, Gravity, Run, Camera, Setting
+for timed in timelines.offline_blocks(){
+	let block_info=timelines.block_info(timed.event)?;
+	let block_reader=block_info.take_seek(&mut input)?;
+	let block=Block::from_reader(block_reader)?;
+}
+
+// realtime blocks include the following event types:
+// Input, Output, Sound
+for timed in timelines.realtime_blocks(){
+	let block_info=timelines.block_info(timed.event)?;
+	let block_reader=block_info.take_seek(&mut input)?;
+	let block=Block::from_reader(block_reader)?;
 }
 ```
 

src/lib.rs

@@ -1,4 +1,7 @@
+pub use binrw::Error as BinrwError;
+
 pub mod v0;
+pub mod v1;
 
 #[cfg(test)]
 mod tests;

src/tests.rs

@@ -1,43 +1,41 @@
-use crate::v0::{Error,File,TimedBlockId};
+use crate::v0;
+use crate::v0::{Block,BlockTimelines,FileHeader};
 
 #[test]
-fn _1()->Result<(),Error>{
-	let file=std::fs::File::open("files/bhop_marble_7cf33a64-7120-4514-b9fa-4fe29d9523d").unwrap();
-	let input=std::io::BufReader::new(file);
-	let mut bot_file=File::new(input).unwrap();
-	println!("header={:?}",bot_file.header);
-	for &TimedBlockId{time,block_id} in &bot_file.header.offline_blocks_timeline{
-		println!("offline time={} block_id={:?}",time,block_id);
-		let block_info=bot_file.header.block_info(block_id)?;
-		let _block=bot_file.data.read_block_info(block_info)?;
-		// offline blocks include the following event types:
-		// World, Gravity, Run, Camera, Setting
+fn deserialize_manual()->Result<(),binrw::Error>{
+	let file=std::fs::read("files/bhop_marble_7cf33a64-7120-4514-b9fa-4fe29d9523d").unwrap();
+	let mut input=std::io::Cursor::new(file);
+	let header=FileHeader::from_reader(&mut input)?;
+	let timelines=BlockTimelines::from_reader(&header,&mut input)?;
+	for block in timelines.offline_blocks(){
+		let block_info=timelines.block_info(block.event).unwrap();
+		let block_reader=block_info.take_seek(&mut input)?;
+		let _block=Block::from_reader(block_reader)?;
 	}
-	for &TimedBlockId{time,block_id} in &bot_file.header.realtime_blocks_timeline{
-		println!("realtime time={} block_id={:?}",time,block_id);
-		let block_info=bot_file.header.block_info(block_id)?;
-		let _block=bot_file.data.read_block_info(block_info)?;
-		// realtime blocks include the following event types:
-		// Input, Output, Sound
+	for block in timelines.realtime_blocks(){
+		let block_info=timelines.block_info(block.event).unwrap();
+		let block_reader=block_info.take_seek(&mut input)?;
+		let _block=Block::from_reader(block_reader)?;
 	}
-
 	Ok(())
 }
 
 #[test]
-fn _2()->Result<(),Error>{
-	let file=std::fs::File::open("files/bhop_marble_7cf33a64-7120-4514-b9fa-4fe29d9523d").unwrap();
-	let input=std::io::BufReader::new(file);
-
-	let t0=std::time::Instant::now();
-
-	let mut bot_file=File::new(input).unwrap();
-
-	let _block=bot_file.read_all()?;
-
-	println!("{:?}",t0.elapsed());
-
+fn deserialize_all()->Result<(),v0::Error>{
+	let file=std::fs::read("files/bhop_marble_7cf33a64-7120-4514-b9fa-4fe29d9523d").unwrap();
+	let _block=v0::read_all_to_block(std::io::Cursor::new(file))?;
 	Ok(())
 }
 
-// TODO: file serialization test
+#[test]
+#[cfg(feature="itertools")]
+fn serialize_round_trip()->Result<(),binrw::Error>{
+	let file=std::fs::read("files/bhop_marble_7cf33a64-7120-4514-b9fa-4fe29d9523d").unwrap();
+	let block=v0::read_all_to_block(std::io::Cursor::new(file.as_slice())).unwrap();
+
+	let mut data=Vec::with_capacity(file.len());
+	v0::serialize(&block,&mut std::io::Cursor::new(&mut data))?;
+
+	// TODO: It encodes, but is it equal? Test something! PartialEq?
+	Ok(())
+}

src/v1.rs

@@ -0,0 +1,929 @@
+use std::io::{SeekFrom,Error as IoError};
+use binrw::binrw;
+use binrw::io::{TakeSeek,TakeSeekExt};
+use binrw::BinReaderExt;
+use crate::BinrwError;
+
+#[binrw]
+#[brw(little)]
+#[derive(Debug,Clone,Copy)]
+pub struct Time(u32);
+impl PartialEq for Time{
+	fn eq(&self,other:&Self)->bool{
+		self.0.eq(&other.0)
+	}
+}
+impl PartialOrd for Time{
+	fn partial_cmp(&self,other:&Self)->Option<core::cmp::Ordering>{
+		self.0.partial_cmp(&other.0)
+	}
+}
+
+#[binrw]
+#[brw(little)]
+#[derive(Debug,Clone)]
+pub struct Vector2{
+	pub x:f32,
+	pub y:f32,
+}
+#[binrw]
+#[brw(little)]
+#[derive(Debug,Clone)]
+pub struct Vector3{
+	pub x:f32,
+	pub y:f32,
+	pub z:f32,
+}
+
+bitflags::bitflags!{
+	#[derive(Debug,Clone,Copy,Hash,Eq,PartialEq)]
+	pub struct GameControls:u32{
+		const MoveForward=1<<0;
+		const MoveLeft=1<<1;
+		const MoveBack=1<<2;
+		const MoveRight=1<<3;
+		const MoveUp=1<<4;
+		const MoveDown=1<<5;
+		const LookUp=1<<6;
+		const LookLeft=1<<7;
+		const LookDown=1<<8;
+		const LookRight=1<<9;
+		const Jump=1<<10;
+		const Crouch=1<<11;
+		const Sprint=1<<12;
+		const Zoom=1<<13;
+		const Use=1<<14;
+		const Action1=1<<15;
+		const Action2=1<<16;
+	}
+}
+#[derive(Debug)]
+pub struct GameControlsError;
+impl std::fmt::Display for GameControlsError{
+	fn fmt(&self,f:&mut std::fmt::Formatter<'_>)->std::fmt::Result{
+		write!(f,"{self:?}")
+	}
+}
+impl std::error::Error for GameControlsError{}
+impl GameControls{
+	fn try_from_bits(bits:u32)->Result<Self,GameControlsError>{
+		Self::from_bits(bits).ok_or(GameControlsError)
+	}
+}
+
+// generic timed event
+#[binrw]
+#[brw(little)]
+#[derive(Debug,Clone)]
+pub struct Timed<E>
+	where
+		E:for<'a>binrw::BinRead<Args<'a>=()>,
+		E:for<'a>binrw::BinWrite<Args<'a>=()>,
+{
+	pub time:Time,
+	pub event:E,
+}
+
+impl<A,B> PartialEq<Timed<B>> for Timed<A>
+	where
+		A:for<'a>binrw::BinRead<Args<'a>=()>,
+		A:for<'a>binrw::BinWrite<Args<'a>=()>,
+		B:for<'a>binrw::BinRead<Args<'a>=()>,
+		B:for<'a>binrw::BinWrite<Args<'a>=()>,
+{
+	fn eq(&self,other:&Timed<B>)->bool{
+		self.time.eq(&other.time)
+	}
+}
+impl<A,B> PartialOrd<Timed<B>> for Timed<A>
+	where
+		A:for<'a>binrw::BinRead<Args<'a>=()>,
+		A:for<'a>binrw::BinWrite<Args<'a>=()>,
+		B:for<'a>binrw::BinRead<Args<'a>=()>,
+		B:for<'a>binrw::BinWrite<Args<'a>=()>,
+{
+	fn partial_cmp(&self,other:&Timed<B>)->Option<core::cmp::Ordering>{
+		self.time.partial_cmp(&other.time)
+	}
+}
+
+// input
+#[binrw]
+#[brw(little)]
+#[derive(Debug,Clone)]
+pub struct InputEvent{
+	#[br(try_map=GameControls::try_from_bits)]
+	#[bw(map=GameControls::bits)]
+	pub game_controls:GameControls,
+	pub mouse_pos:Vector2,
+}
+
+// output
+bitflags::bitflags!{
+	#[derive(Debug,Clone,Copy,Hash,Eq,PartialEq)]
+	pub struct TickInfo:u32{
+		const TickEnd=1<<0;
+		const Jump=1<<1;
+		const Strafe=1<<2;
+		const Touching=1<<3;
+	}
+}
+#[derive(Debug)]
+pub struct TickInfoError;
+impl std::fmt::Display for TickInfoError{
+	fn fmt(&self,f:&mut std::fmt::Formatter<'_>)->std::fmt::Result{
+		write!(f,"{self:?}")
+	}
+}
+impl std::error::Error for TickInfoError{}
+impl TickInfo{
+	fn try_from_bits(bits:u32)->Result<Self,TickInfoError>{
+		Self::from_bits(bits).ok_or(TickInfoError)
+	}
+}
+#[binrw]
+#[brw(little)]
+#[derive(Debug,Clone)]
+pub struct OutputEvent{
+	#[br(try_map=TickInfo::try_from_bits)]
+	#[bw(map=TickInfo::bits)]
+	pub tick_info:TickInfo,
+	pub angles:Vector3,
+	pub position:Vector3,
+	pub velocity:Vector3,
+	pub acceleration:Vector3,
+}
+
+// sound
+#[binrw]
+#[brw(little)]
+#[derive(Debug,Clone,Copy,Hash,Eq,PartialEq)]
+pub enum SoundType{
+	#[brw(magic=101u32)]
+	TrackGround,
+	#[brw(magic=102u32)]
+	TrackLadder,
+	#[brw(magic=103u32)]
+	TrackWater,
+	#[brw(magic=104u32)]
+	TrackAir,
+	#[brw(magic=201u32)]
+	JumpGround,
+	#[brw(magic=202u32)]
+	JumpLadder,
+	#[brw(magic=301u32)]
+	SmashGround,
+	#[brw(magic=302u32)]
+	SmashWall,
+}
+#[binrw]
+#[brw(little)]
+#[derive(Debug,Clone)]
+pub struct SoundEvent{
+	pub sound_type:SoundType,
+	/// Roblox enum
+	pub material:u32,
+}
+
+// world
+#[binrw]
+#[brw(little)]
+#[derive(Debug,Clone)]
+pub struct WorldEventReset{
+	pub position:Vector3,
+}
+#[binrw]
+#[brw(little)]
+#[derive(Debug,Clone)]
+pub struct WorldEventButton{
+	pub button_id:u32,
+}
+#[binrw]
+#[brw(little)]
+#[derive(Debug,Clone)]
+pub struct WorldEventSetTime{
+	pub time:Time,
+}
+#[binrw]
+#[brw(little)]
+#[derive(Debug,Clone)]
+pub struct WorldEventSetPaused{
+	#[br(map=|paused:u32|paused!=0)]
+	#[bw(map=|&paused:&bool|paused as u32)]
+	pub paused:bool,
+}
+#[binrw]
+#[brw(little)]
+#[derive(Debug,Clone)]
+pub enum WorldEvent{
+	#[brw(magic=0u32)]
+	Reset(WorldEventReset),
+	#[brw(magic=1u32)]
+	Button(WorldEventButton),
+	#[brw(magic=2u32)]
+	SetTime(WorldEventSetTime),
+	#[brw(magic=3u32)]
+	SetPaused(WorldEventSetPaused),
+}
+
+// gravity
+#[binrw]
+#[brw(little)]
+#[derive(Debug,Clone)]
+pub struct GravityEvent{
+	pub gravity:Vector3,
+}
+
+// run
+#[binrw]
+#[brw(little)]
+#[derive(Debug,Clone,Copy,Hash,Eq,PartialEq)]
+pub struct ModeID(pub u32);
+#[binrw]
+#[brw(little)]
+#[derive(Debug,Clone,Copy,Hash,Eq,PartialEq)]
+pub enum ModeSpec{
+	Exactly(ModeID),
+	#[brw(magic=-1i32)]
+	All,
+	#[brw(magic=-2i32)]
+	Invalid,
+	#[brw(magic=-3i32)]
+	InProgress,
+}
+#[binrw]
+#[brw(little)]
+#[derive(Debug,Clone,Copy,Hash,Eq,PartialEq)]
+pub enum Style{
+	#[brw(magic=1u32)]
+	Autohop,
+	#[brw(magic=2u32)]
+	Scroll,
+	#[brw(magic=3u32)]
+	Sideways,
+	#[brw(magic=4u32)]
+	HalfSideways,
+	#[brw(magic=5u32)]
+	WOnly,
+	#[brw(magic=6u32)]
+	AOnly,
+	#[brw(magic=7u32)]
+	Backwards,
+	#[brw(magic=8u32)]
+	Faste,
+	#[brw(magic=14u32)]
+	LowGravity,
+	#[brw(magic=501u32)]
+	Fly,
+	#[brw(magic=502u32)]
+	FlySustain,
+	#[brw(magic=503u32)]
+	Rocket,
+	#[brw(magic=504u32)]
+	Style3DStrafe,
+	#[brw(magic=505u32)]
+	RocketStrafe,
+}
+#[binrw]
+#[brw(little)]
+#[derive(Debug,Clone,Copy,Hash,Eq,PartialEq)]
+pub enum FlagReason{
+	#[brw(magic=0u32)]
+	Anticheat,
+	#[brw(magic=1u32)]
+	StyleChange,
+	#[brw(magic=2u32)]
+	Clock,
+	#[brw(magic=3u32)]
+	Pause,
+	#[brw(magic=4u32)]
+	Flying,
+	#[brw(magic=5u32)]
+	Gravity,
+	#[brw(magic=6u32)]
+	Timescale,
+	#[brw(magic=7u32)]
+	Timetravel,
+	#[brw(magic=8u32)]
+	Teleport,
+	#[brw(magic=9u32)]
+	Practice,
+}
+#[binrw]
+#[brw(little)]
+#[derive(Debug,Clone)]
+pub struct RunEventPrepare{
+	pub mode:ModeID,
+}
+#[binrw]
+#[brw(little)]
+#[derive(Debug,Clone)]
+pub struct RunEventZone{
+	pub mode:ModeID,
+}
+#[binrw]
+#[brw(little)]
+#[derive(Debug,Clone)]
+pub struct RunEventClear{
+	pub mode:ModeSpec,
+}
+#[binrw]
+#[brw(little)]
+#[derive(Debug,Clone)]
+pub struct RunEventFlag{
+	pub mode:ModeSpec,
+	pub flag_reason:FlagReason,
+}
+#[binrw]
+#[brw(little)]
+#[derive(Debug,Clone)]
+pub struct RunEventPractice{
+	pub mode:ModeSpec,
+	pub state_id:u32,
+}
+#[binrw]
+#[brw(little)]
+#[derive(Debug,Clone)]
+pub enum RunEvent{
+	#[brw(magic=0u32)]
+	Prepare(RunEventPrepare),
+	#[brw(magic=1u32)]
+	Start(RunEventZone),
+	#[brw(magic=2u32)]
+	Finish(RunEventZone),
+	#[brw(magic=3u32)]
+	Clear(RunEventClear),
+	#[brw(magic=4u32)]
+	Flag(RunEventFlag),
+	#[brw(magic=5u32)]
+	LoadState(RunEventPractice),
+	#[brw(magic=6u32)]
+	SaveState(RunEventPractice),
+}
+
+// camera
+#[binrw]
+#[brw(little)]
+#[derive(Debug,Clone,Copy,Hash,Eq,PartialEq)]
+pub enum CameraEventType{
+	#[brw(magic=0u32)]
+	CameraPunch,
+	#[brw(magic=1u32)]
+	Transform,
+}
+#[binrw]
+#[brw(little)]
+#[derive(Debug,Clone)]
+pub struct CameraEvent{
+	pub camera_event_type:CameraEventType,
+	pub value:Vector3,
+}
+
+// setting
+#[binrw]
+#[brw(little)]
+#[derive(Debug,Clone)]
+pub struct SettingEventFieldOfView{
+	pub fov:f64,
+}
+#[binrw]
+#[brw(little)]
+#[derive(Debug,Clone)]
+pub struct SettingEventSensitivity{
+	pub sensitivity_x:f64,
+	pub sensitivity_y:f64,
+}
+#[binrw]
+#[brw(little)]
+#[derive(Debug,Clone)]
+pub struct SettingEventTurnSpeed{
+	pub turn_speed:f64,
+}
+#[binrw]
+#[brw(little)]
+#[derive(Debug,Clone)]
+pub struct SettingEventStyle{
+	pub style:Style,
+}
+#[binrw]
+#[brw(little)]
+#[derive(Debug,Clone)]
+pub enum SettingEvent{
+	#[brw(magic=0u32)]
+	FieldOfView(SettingEventFieldOfView),
+	#[brw(magic=1u32)]
+	Sensitivity(SettingEventSensitivity),
+	#[brw(magic=2u32)]
+	TurnSpeed(SettingEventTurnSpeed),
+	#[brw(magic=3u32)]
+	Style(SettingEventStyle),
+}
+
+/// A segment of event timelines.
+/// Timelines are always be sorted.
+#[derive(Default)]
+pub struct Block{
+	pub input_events:Vec<Timed<InputEvent>>,
+	pub output_events:Vec<Timed<OutputEvent>>,
+	pub sound_events:Vec<Timed<SoundEvent>>,
+	pub world_events:Vec<Timed<WorldEvent>>,
+	pub gravity_events:Vec<Timed<GravityEvent>>,
+	pub run_events:Vec<Timed<RunEvent>>,
+	pub camera_events:Vec<Timed<CameraEvent>>,
+	pub setting_events:Vec<Timed<SettingEvent>>,
+}
+
+#[binrw]
+#[brw(little)]
+#[derive(Clone,Copy)]
+enum EventType{
+	#[brw(magic=1u32)]
+	Input,
+	#[brw(magic=2u32)]
+	Output,
+	#[brw(magic=3u32)]
+	Sound,
+	#[brw(magic=4u32)]
+	World,
+	#[brw(magic=5u32)]
+	Gravity,
+	#[brw(magic=6u32)]
+	Run,
+	#[brw(magic=7u32)]
+	Camera,
+	#[brw(magic=8u32)]
+	Setting,
+}
+#[binrw]
+#[brw(little)]
+struct BlockHeader{
+	num_input_events:u16,
+	num_output_events:u16,
+	num_sound_events:u16,
+	num_world_events:u16,
+	num_gravity_events:u16,
+	num_run_events:u16,
+	num_camera_events:u16,
+	num_setting_events:u16,
+}
+
+// binread args tech has been further refined
+fn read_data_into_events<R,T,F>(
+	data:&mut R,
+	events:&mut Vec<T>,
+	num_events:usize,
+	reserve_fn:F,
+)->Result<(),BinrwError>
+	where
+		R:BinReaderExt,
+		T:for<'a> binrw::BinRead<Args<'a>=()>,
+		F:Fn(&mut Vec<T>,usize),
+{
+	reserve_fn(events,num_events);
+	for _ in 0..num_events{
+		events.push(data.read_le()?);
+	}
+	Ok(())
+}
+
+impl Block{
+	pub fn from_reader<R:BinReaderExt>(data:R)->Result<Block,BinrwError>{
+		let mut block=Block::default();
+		// there is only supposed to be at most one of each type
+		// of event chunk per block, so allocate the size exactly.
+		block.extend_from_reader_exact(data)?;
+		Ok(block)
+	}
+	/// Read a complete data block and append the elements to the timelines in this block.
+	/// Reserves exactly enough information for the new data.
+	pub fn extend_from_reader_exact<R:BinReaderExt>(&mut self,mut data:R)->Result<(),BinrwError>{
+		let block_header:BlockHeader=data.read_le()?;
+		read_data_into_events(&mut data,&mut self.input_events,block_header.num_input_events as usize,Vec::reserve_exact)?;
+		read_data_into_events(&mut data,&mut self.output_events,block_header.num_output_events as usize,Vec::reserve_exact)?;
+		read_data_into_events(&mut data,&mut self.sound_events,block_header.num_sound_events as usize,Vec::reserve_exact)?;
+		read_data_into_events(&mut data,&mut self.world_events,block_header.num_world_events as usize,Vec::reserve_exact)?;
+		read_data_into_events(&mut data,&mut self.gravity_events,block_header.num_gravity_events as usize,Vec::reserve_exact)?;
+		read_data_into_events(&mut data,&mut self.run_events,block_header.num_run_events as usize,Vec::reserve_exact)?;
+		read_data_into_events(&mut data,&mut self.camera_events,block_header.num_camera_events as usize,Vec::reserve_exact)?;
+		read_data_into_events(&mut data,&mut self.setting_events,block_header.num_setting_events as usize,Vec::reserve_exact)?;
+		Ok(())
+	}
+	/// Read a complete data block and append the elements to the timelines in this block.
+	pub fn extend_from_reader<R:BinReaderExt>(&mut self,mut data:R)->Result<(),BinrwError>{
+		// sad code duplication
+		let block_header:BlockHeader=data.read_le()?;
+		read_data_into_events(&mut data,&mut self.input_events,block_header.num_input_events as usize,Vec::reserve)?;
+		read_data_into_events(&mut data,&mut self.output_events,block_header.num_output_events as usize,Vec::reserve)?;
+		read_data_into_events(&mut data,&mut self.sound_events,block_header.num_sound_events as usize,Vec::reserve)?;
+		read_data_into_events(&mut data,&mut self.world_events,block_header.num_world_events as usize,Vec::reserve)?;
+		read_data_into_events(&mut data,&mut self.gravity_events,block_header.num_gravity_events as usize,Vec::reserve)?;
+		read_data_into_events(&mut data,&mut self.run_events,block_header.num_run_events as usize,Vec::reserve)?;
+		read_data_into_events(&mut data,&mut self.camera_events,block_header.num_camera_events as usize,Vec::reserve)?;
+		read_data_into_events(&mut data,&mut self.setting_events,block_header.num_setting_events as usize,Vec::reserve)?;
+		Ok(())
+	}
+	fn extend_from_block_id_iter<'a,R:BinReaderExt>(&mut self,mut data:R,block_timelines:&BlockTimelines,blocks:impl IntoIterator<Item=&'a Timed<BlockId>>)->Result<(),Error>{
+		for timed in blocks{
+			let take_seek=block_timelines
+				.block_info(timed.event)?
+				.take_seek(&mut data)
+				.map_err(Error::Seek)?;
+			self.extend_from_reader(take_seek).map_err(Error::InvalidData)?;
+		}
+		Ok(())
+	}
+}
+
+#[derive(Debug)]
+pub enum Error{
+	InvalidBlockId(InvalidBlockId),
+	Seek(IoError),
+	InvalidData(BinrwError),
+}
+impl std::fmt::Display for Error{
+	fn fmt(&self,f:&mut std::fmt::Formatter<'_>)->std::fmt::Result{
+		write!(f,"{self:?}")
+	}
+}
+impl std::error::Error for Error{}
+
+#[binrw]
+#[brw(little)]
+#[derive(Debug,Clone,Copy)]
+pub struct BlockId(u32);
+#[binrw]
+#[brw(little)]
+#[derive(Debug,Clone)]
+struct BlockPosition(u32);
+
+#[derive(Debug)]
+pub struct InvalidBlockId(pub BlockId);
+impl std::fmt::Display for InvalidBlockId{
+	fn fmt(&self,f:&mut std::fmt::Formatter<'_>)->std::fmt::Result{
+		write!(f,"{self:?}")
+	}
+}
+impl std::error::Error for InvalidBlockId{}
+impl From<InvalidBlockId> for Error{
+	fn from(value:InvalidBlockId)->Self{
+		Self::InvalidBlockId(value)
+	}
+}
+
+/// The first 16 bytes of the file.
+#[binrw]
+#[brw(little)]
+#[brw(magic=b"qbot")]
+#[derive(Debug,Clone)]
+pub struct FileHeader{
+	file_version:u32,
+	num_offline_blocks:u32,
+	num_realtime_blocks:u32,
+}
+impl FileHeader{
+	pub fn from_reader<R:BinReaderExt>(mut data:R)->Result<Self,BinrwError>{
+		data.read_le()
+	}
+	fn block_position_count(&self)->u32{
+		self.num_offline_blocks+self.num_realtime_blocks+1
+	}
+	/// Get BlockInfo for the BlockTimelines.
+	/// BlockTimelines is not really a "Block" per se, but BlockInfo is just a byte range.
+	pub fn block_timelines_info(&self)->BlockInfo{
+		const BLOCK_POSITION_SIZE:u32=size_of::<BlockPosition>() as u32;
+		const TIMED_BLOCKID_SIZE:u32=8+4;
+		let size=BLOCK_POSITION_SIZE*self.block_position_count()
+			+TIMED_BLOCKID_SIZE*self.num_offline_blocks
+			+TIMED_BLOCKID_SIZE*self.num_realtime_blocks;
+		let start=16;
+		let end=start+size;
+		BlockInfo(start..end)
+	}
+}
+/// Information about "Blocks" of data.  Appears immediately after FileHeader.
+/// Contains all the information required to implement streaming download, decode, and playback.
+#[binrw]
+#[brw(little)]
+#[derive(Debug,Clone)]
+#[br(import_raw(header:&FileHeader))]
+pub struct BlockTimelines{
+	#[br(count=header.block_position_count())]
+	block_positions:Vec<BlockPosition>,
+	#[br(count=header.num_offline_blocks)]
+	offline_blocks_timeline:Vec<Timed<BlockId>>,
+	#[br(count=header.num_realtime_blocks)]
+	realtime_blocks_timeline:Vec<Timed<BlockId>>,
+}
+impl BlockTimelines{
+	pub fn from_reader<R:BinReaderExt>(header:&FileHeader,mut data:R)->Result<Self,BinrwError>{
+		data.read_le_args(header)
+	}
+	/// "Offline" blocks (containing World, Gravity, Run, Camera, and Setting events) in chronological order.
+	pub fn offline_blocks(&self)->&[Timed<BlockId>]{
+		&self.offline_blocks_timeline
+	}
+	/// "Realtime" blocks (containing Input, Output, and Sound events) in chronological order.
+	pub fn realtime_blocks(&self)->&[Timed<BlockId>]{
+		&self.realtime_blocks_timeline
+	}
+	/// Get BlockInfo for a specfic BlockId.
+	pub fn block_info(&self,block_id:BlockId)->Result<BlockInfo,InvalidBlockId>{
+		let BlockId(id)=block_id;
+		if self.block_positions.len() as u32<=id{
+			return Err(InvalidBlockId(block_id));
+		}
+		let BlockPosition(start)=self.block_positions[id as usize];
+		let BlockPosition(end)=self.block_positions[id as usize+1];
+		Ok(BlockInfo(start..end))
+	}
+}
+/// The range of data for a specific Block, relative to the start of the file.
+#[derive(Debug,Clone)]
+pub struct BlockInfo(core::ops::Range<u32>);
+impl BlockInfo{
+	/// Create an adapter which seeks to the block start and reads at most the block length.
+	pub fn take_seek<R:BinReaderExt>(&self,mut data:R)->Result<TakeSeek<R>,IoError>{
+		data.seek(SeekFrom::Start(self.start as u64))?;
+		Ok(data.take_seek(self.len() as u64))
+	}
+}
+impl core::ops::Deref for BlockInfo{
+	type Target=core::ops::Range<u32>;
+	fn deref(&self)->&Self::Target{
+		&self.0
+	}
+}
+
+/// Read offline blocks and combine the timelines into a single Block.
+/// Note that this reads the blocks in chronological order, not the order they appear in the file, so there is some seeking involved.
+pub fn read_offline_to_block<R:BinReaderExt>(mut data:R)->Result<Block,Error>{
+	let header=FileHeader::from_reader(&mut data).map_err(Error::InvalidData)?;
+	let block_timelines=BlockTimelines::from_reader(&header,&mut data).map_err(Error::InvalidData)?;
+	let mut block=Block::default();
+	block.extend_from_block_id_iter(data,&block_timelines,block_timelines.offline_blocks())?;
+	Ok(block)
+}
+
+/// Read realtime blocks and combine the timelines into a single Block.
+/// Note that this reads the blocks in chronological order, not the order they appear in the file, so there is some seeking involved.
+pub fn read_realtime_to_block<R:BinReaderExt>(mut data:R)->Result<Block,Error>{
+	let header=FileHeader::from_reader(&mut data).map_err(Error::InvalidData)?;
+	let block_timelines=BlockTimelines::from_reader(&header,&mut data).map_err(Error::InvalidData)?;
+	let mut block=Block::default();
+	block.extend_from_block_id_iter(data,&block_timelines,block_timelines.realtime_blocks())?;
+	Ok(block)
+}
+
+/// Read the entire file and combine the timelines into a single Block.
+/// Note that this reads the blocks in chronological order, not the order they appear in the file, so there is some seeking involved.
+pub fn read_all_to_block<R:BinReaderExt>(mut data:R)->Result<Block,Error>{
+	let header=FileHeader::from_reader(&mut data).map_err(Error::InvalidData)?;
+	let block_timelines=BlockTimelines::from_reader(&header,&mut data).map_err(Error::InvalidData)?;
+	let mut block=Block::default();
+	block.extend_from_block_id_iter(&mut data,&block_timelines,block_timelines.offline_blocks())?;
+	block.extend_from_block_id_iter(&mut data,&block_timelines,block_timelines.realtime_blocks())?;
+	Ok(block)
+}
+
+#[cfg(feature="itertools")]
+pub fn serialize<W:binrw::BinWriterExt>(block:&Block,writer:&mut W)->Result<(),BinrwError>{
+	use std::ops::Range;
+	const MAX_BLOCK_SIZE:usize=1<<18;
+	const FILE_VERSION:u32=0;
+	const EVENT_TYPES:[EventType;8]=[
+		EventType::Input,
+		EventType::Output,
+		EventType::Sound,
+		EventType::World,
+		EventType::Gravity,
+		EventType::Run,
+		EventType::Camera,
+		EventType::Setting,
+	];
+	const EVENT_SIZE:[usize;8]=[
+		8+4+2*4,	// Input
+		8+4+4*3*4,	// Output
+		8+4+4,		// Sound
+		8+4+12,		// World
+		8+3*4,		// Gravity
+		8+4+4+4,	// Run
+		8+4+3*4,	// Camera
+		8+4+8,		// Setting
+	];
+	#[derive(Clone,Default)]
+	struct Plan<T>([T;8]);
+	// A plan of how many events of each type to include in a data block.
+	impl Plan<usize>{
+		/// Predict the size increment from adding a new event.
+		fn size_increase(&self,event_type:EventType)->usize{
+			EVENT_SIZE[event_type as usize]
+		}
+		/// Add the new event.
+		fn accumulate(&mut self,event_type:EventType){
+			self.0[event_type as usize]+=1;
+		}
+		fn range(&self,end:&Plan<usize>)->Plan<Range<usize>>{
+			Plan(core::array::from_fn(|i|self.0[i]..end.0[i]))
+		}
+	}
+	// A plan of what range of events to include in a data block.
+	impl Plan<Range<usize>>{
+		/// Calculate the predicted size of the planned block.
+		fn size(&self)->usize{
+			self.0.iter()
+				.zip(EVENT_SIZE)
+				.map(|(range,event_size)|event_size*range.len())
+				.sum::<usize>()
+			+size_of::<BlockHeader>()
+		}
+		fn header(&self)->BlockHeader{
+			BlockHeader{
+				num_input_events:self.0[EventType::Input as usize].len() as u16,
+				num_output_events:self.0[EventType::Output as usize].len() as u16,
+				num_sound_events:self.0[EventType::Sound as usize].len() as u16,
+				num_world_events:self.0[EventType::World as usize].len() as u16,
+				num_gravity_events:self.0[EventType::Gravity as usize].len() as u16,
+				num_run_events:self.0[EventType::Run as usize].len() as u16,
+				num_camera_events:self.0[EventType::Camera as usize].len() as u16,
+				num_setting_events:self.0[EventType::Setting as usize].len() as u16,
+			}
+		}
+	}
+	// compare an event at the head of the plan to the best event collected so far.
+	fn collect_event<E>(
+		best:&mut Option<(Time,EventType)>,
+		list:&[Timed<E>],
+		plan:&Plan<usize>,
+		event_type:EventType,
+	)
+		where
+			E:for<'a>binrw::BinRead<Args<'a>=()>,
+			E:for<'a>binrw::BinWrite<Args<'a>=()>,
+	{
+		if let Some(event)=list.get(plan.0[event_type as usize])
+			&&best.is_none_or(|(time,_)|event.time<time)
+		{
+			*best=Some((event.time,event_type));
+		}
+	}
+	// plan a single block: collect events until the block is full
+	fn plan_block(plan:&mut Plan<usize>,next_event:impl Fn(&Plan<usize>)->Option<(Time,EventType)>)->Option<Time>{
+		let mut size=0;
+		let (start_time,first_event)=next_event(plan)?;
+
+		size+=plan.size_increase(first_event);
+		if MAX_BLOCK_SIZE<size{
+			return None;
+		}
+		plan.accumulate(first_event);
+
+		while let Some((_,event_type))=next_event(plan){
+			size+=plan.size_increase(event_type);
+			if MAX_BLOCK_SIZE<size{
+				break;
+			}
+			plan.accumulate(event_type);
+		}
+
+		Some(start_time)
+	}
+
+	struct PlannedBlock{
+		// index is not the same as BlockId.
+		// It is list-local for both plan_offline and plan_realtime.
+		index:usize,
+		time:Time,
+		plan:Plan<Range<usize>>,
+	}
+	fn plan_timeline<F>(next_event:F)->std::collections::VecDeque<PlannedBlock>
+		where
+			F:Copy,
+			F:Fn(&Plan<usize>)->Option<(Time,EventType)>
+	{
+		let mut timeline=std::collections::VecDeque::new();
+		let mut plan=Plan::default();
+		let mut last_plan=plan.clone();
+		let mut index=0;
+		while let Some(time)=plan_block(&mut plan,next_event){
+			timeline.push_back(PlannedBlock{
+				index,
+				time,
+				plan:last_plan.range(&plan),
+			});
+			last_plan=plan.clone();
+			index+=1;
+		}
+		timeline
+	}
+	// plan events into segments without spilling over max size threshold
+	// each plan describes the range of events included in the block.
+	let mut plan_offline=plan_timeline(|plan|{
+		let mut next_event=None;
+		collect_event(&mut next_event,&block.world_events,plan,EventType::World);
+		collect_event(&mut next_event,&block.gravity_events,plan,EventType::Gravity);
+		collect_event(&mut next_event,&block.run_events,plan,EventType::Run);
+		collect_event(&mut next_event,&block.camera_events,plan,EventType::Camera);
+		collect_event(&mut next_event,&block.setting_events,plan,EventType::Setting);
+		next_event
+	});
+	let mut plan_realtime=plan_timeline(|plan|{
+		let mut next_event=None;
+		collect_event(&mut next_event,&block.input_events,plan,EventType::Input);
+		collect_event(&mut next_event,&block.output_events,plan,EventType::Output);
+		collect_event(&mut next_event,&block.sound_events,plan,EventType::Sound);
+		next_event
+	});
+
+	let file_header=FileHeader{
+		file_version:FILE_VERSION,
+		num_offline_blocks:plan_offline.len() as u32,
+		num_realtime_blocks:plan_realtime.len() as u32,
+	};
+
+	let mut plan_order=Vec::with_capacity(plan_offline.len()+plan_realtime.len());
+	let mut block_positions=Vec::with_capacity(file_header.block_position_count() as usize);
+	// Fill the timelines with dummy values, we don't know the block ids yet.
+	// This can be done with Vec::spare_capacity_mut and unsafe, but whatever.
+	const DUMMY_BLOCK:Timed<BlockId>=Timed{time:Time(0),event:BlockId(0)};
+	let mut offline_blocks_timeline=vec![DUMMY_BLOCK;plan_offline.len()];
+	let mut realtime_blocks_timeline=vec![DUMMY_BLOCK;plan_realtime.len()];
+
+	{
+		// position starts after the *predicted* end of the BlockTimelines
+		let mut position=file_header.block_timelines_info().end;
+		let mut block_id=0;
+		let mut push_block=|timeline:&mut Vec<Timed<BlockId>>,planned:PlannedBlock|{
+			block_positions.push(BlockPosition(position));
+			position+=planned.plan.size() as u32;
+
+			// write the block id to the correct index
+			timeline[planned.index]=Timed{
+				time:planned.time,
+				event:BlockId(block_id),
+			};
+			block_id+=1;
+
+			plan_order.push(planned.plan);
+		};
+		// the first block in the file is an offline block to
+		// initialize the state of things like the current style
+		if let Some(plan)=plan_offline.pop_front(){
+			push_block(&mut offline_blocks_timeline,plan);
+		}
+		// the second block is the first realtime block which
+		// includes the starting position of the replay
+		if let Some(plan)=plan_realtime.pop_front(){
+			push_block(&mut realtime_blocks_timeline,plan);
+		}
+		// the third block is the last realtime block which
+		// is used by the game client to determine the duration
+		if let Some(plan)=plan_realtime.pop_back(){
+			push_block(&mut realtime_blocks_timeline,plan);
+		}
+		// push the remaining blocks in chronological order
+		for either_plan in itertools::merge_join_by(
+			plan_offline,
+			plan_realtime,
+			|offline,realtime|offline.time<=realtime.time,
+		){
+			match either_plan{
+				itertools::Either::Left(offline)=>push_block(&mut offline_blocks_timeline,offline),
+				itertools::Either::Right(realtime)=>push_block(&mut realtime_blocks_timeline,realtime),
+			}
+		}
+		// final position
+		block_positions.push(BlockPosition(position));
+	}
+
+	let block_timelines=BlockTimelines{
+		block_positions,
+		offline_blocks_timeline,
+		realtime_blocks_timeline,
+	};
+
+	use binrw::BinWrite;
+	file_header.write_le(writer)?;
+	block_timelines.write_le(writer)?;
+	for plan in plan_order{
+		let block_header=plan.header();
+		block_header.write_le(writer)?;
+		for (range,event_type) in plan.0.into_iter().zip(EVENT_TYPES){
+			let num_events=range.len();
+			if num_events==0{
+				continue;
+			}
+			match event_type{
+				EventType::Input=>block.input_events[range].write_le(writer)?,
+				EventType::Output=>block.output_events[range].write_le(writer)?,
+				EventType::Sound=>block.sound_events[range].write_le(writer)?,
+				EventType::World=>block.world_events[range].write_le(writer)?,
+				EventType::Gravity=>block.gravity_events[range].write_le(writer)?,
+				EventType::Run=>block.run_events[range].write_le(writer)?,
+				EventType::Camera=>block.camera_events[range].write_le(writer)?,
+				EventType::Setting=>block.setting_events[range].write_le(writer)?,
+			}
+		}
+	}
+
+	Ok(())
+}