yog_abi/

lib.rs

//! Yog stable C ABI — the ONLY types that cross the mod/runtime boundary.
//!
//! Rules this file must never break:
//!  - Every type is `#[repr(C)]`.
//!  - No Rust trait objects, no generics, no std types in public structs.
//!  - New fields are appended only at the END of structs; increment `ABI_MINOR`.
//!  - ABI_MAJOR bumps only when an existing field is removed or reordered.
//!
//! Mods and the runtime are compiled independently; the runtime loads a mod
//! only when its `ABI_VERSION` is exactly the runtime's.

use std::os::raw::c_void;

// ── Version ──────────────────────────────────────────────────────────────────

pub const ABI_MAJOR: u32 = 3;
pub const ABI_MINOR: u32 = 2;
/// `ABI_MAJOR * 10_000 + ABI_MINOR`.  Checked at mod load time.
pub const ABI_VERSION: u32 = ABI_MAJOR * 10_000 + ABI_MINOR;

// ── Primitive types ───────────────────────────────────────────────────────────

/// Borrowed UTF-8 byte slice passed to a function. NOT null-terminated.
/// Valid only for the duration of the call that provides it — never store.
#[repr(C)]
#[derive(Copy, Clone)]
pub struct YogStr {
    pub ptr: *const u8,
    pub len: u32,
}

impl YogStr {
    pub const EMPTY: Self = Self {
        ptr: std::ptr::null(),
        len: 0,
    };

    /// Borrow `s` — not `FromStr`, which can't return a borrowing value.
    #[allow(clippy::should_implement_trait)]
    #[inline]
    pub fn from_str(s: &str) -> Self {
        Self {
            ptr: s.as_ptr(),
            len: s.len() as u32,
        }
    }

    #[inline]
    pub fn is_empty(self) -> bool {
        self.len == 0 || self.ptr.is_null()
    }

    /// # Safety
    ///
    /// `ptr` must be valid UTF-8 of `len` bytes for at least the duration of
    /// the call that provided this `YogStr`.
    #[inline]
    pub unsafe fn as_str<'a>(self) -> &'a str {
        unsafe {
            if self.ptr.is_null() || self.len == 0 {
                return "";
            }
            std::str::from_utf8_unchecked(std::slice::from_raw_parts(self.ptr, self.len as usize))
        }
    }
}

/// Heap-allocated UTF-8 string owned by the RUNTIME.
/// `ptr == null` encodes `None` / "not found".
/// When `ptr` is non-null the caller MUST free it via `YogServer::free_str`.
#[repr(C)]
#[derive(Copy, Clone)]
pub struct YogOwnedStr {
    pub ptr: *mut u8,
    pub len: u32,
}

impl YogOwnedStr {
    pub const NONE: Self = Self {
        ptr: std::ptr::null_mut(),
        len: 0,
    };

    /// Allocate a new `YogOwnedStr` from a Rust `String`.
    pub fn from_string(s: String) -> Self {
        let len = s.len() as u32;
        let ptr = Box::into_raw(s.into_bytes().into_boxed_slice()) as *mut u8;
        Self { ptr, len }
    }

    #[inline]
    pub fn is_none(self) -> bool {
        self.ptr.is_null()
    }
}

/// Integer 3-D block position.
#[repr(C)]
#[derive(Copy, Clone)]
pub struct YogBlockPos {
    pub x: i32,
    pub y: i32,
    pub z: i32,
}

/// Float 3-D vector (position, velocity, …).
#[repr(C)]
#[derive(Copy, Clone)]
pub struct YogVec3 {
    pub x: f64,
    pub y: f64,
    pub z: f64,
}

// ── Event structs (Java → Rust) ───────────────────────────────────────────────

#[repr(C)]
pub struct YogBlockBreakEvent {
    pub player: YogStr,
    pub block: YogStr,
    pub pos: YogBlockPos,
    /// Dimension the block was broken in, e.g. `minecraft:overworld`.
    pub dimension: YogStr,
}

#[repr(C)]
pub struct YogChatEvent {
    pub player: YogStr,
    pub message: YogStr,
    pub dimension: YogStr,
}

/// Shared by player_join and player_leave.
#[repr(C)]
pub struct YogPlayerEvent {
    pub player: YogStr,
    pub uuid: YogStr,
    pub dimension: YogStr,
}

#[repr(C)]
pub struct YogUseItemEvent {
    pub player: YogStr,
    pub item: YogStr,
    /// ABI minor 25: whether the player was sneaking (shift) during use.
    pub sneaking: bool,
    pub dimension: YogStr,
}

#[repr(C)]
pub struct YogUseBlockEvent {
    pub player: YogStr,
    pub block: YogStr,
    pub pos: YogBlockPos,
    pub dimension: YogStr,
    /// Whether the player was sneaking (shift).
    pub sneaking: bool,
}

#[repr(C)]
pub struct YogAttackEntityEvent {
    pub player: YogStr,
    pub target_type: YogStr,
    pub target_uuid: YogStr,
    pub dimension: YogStr,
}

#[repr(C)]
pub struct YogEntityDamageEvent {
    pub entity_type: YogStr,
    pub uuid: YogStr,
    pub amount: f32,
    pub source: YogStr,
    pub dimension: YogStr,
}

#[repr(C)]
pub struct YogEntityDeathEvent {
    pub entity_type: YogStr,
    pub uuid: YogStr,
    pub source: YogStr,
    pub dimension: YogStr,
}

#[repr(C)]
pub struct YogEntitySpawnEvent {
    pub entity_type: YogStr,
    pub uuid: YogStr,
    pub dimension: YogStr,
}

/// Fired when a player dies (Pre: before death is processed; Post: after death).
/// Pre phase — return false to prevent death (keep entity alive at 0.5 HP).
#[repr(C)]
pub struct YogPlayerDeathEvent {
    pub player: YogStr,
    pub uuid: YogStr,
    /// Damage source identifier, e.g. `"player"`, `"fall"`.
    pub source: YogStr,
    pub dimension: YogStr,
}

/// Fired when a player respawns after death.
#[repr(C)]
pub struct YogPlayerRespawnEvent {
    pub player: YogStr,
    pub uuid: YogStr,
    /// True if respawning at a bed or anchor, false at world spawn.
    pub at_anchor: bool,
    /// Dimension respawned into (may differ from where the player died).
    pub dimension: YogStr,
}

/// Fired when a player earns an advancement (Post only).
#[repr(C)]
pub struct YogAdvancementEvent {
    pub player: YogStr,
    pub uuid: YogStr,
    /// Namespaced id, e.g. `"minecraft:story/mine_stone"`.
    pub advancement: YogStr,
    pub dimension: YogStr,
}

/// Fired when a player right-clicks (interacts with) an entity (Pre: before; Post: after).
/// Pre phase — return false to cancel the interaction.
#[repr(C)]
pub struct YogEntityInteractEvent {
    pub player: YogStr,
    pub player_uuid: YogStr,
    pub entity_type: YogStr,
    pub entity_uuid: YogStr,
    /// `"main_hand"` or `"off_hand"`.
    pub hand: YogStr,
    pub dimension: YogStr,
}

/// Fired when a player takes a crafted item from a crafting output slot (Post only).
#[repr(C)]
pub struct YogCraftEvent {
    pub player: YogStr,
    pub player_uuid: YogStr,
    pub result_item: YogStr,
    pub result_count: u32,
    pub dimension: YogStr,
}

/// A machine (an inventory's `.yui` `<RecipeArea>`) and the recipe its
/// slots make. Pre: whether it may — the result shows only if every
/// handler allows it (a workbench short of a resource says no); `player`
/// empty. Post: a player took the result — the mod takes its share (the
/// host takes the ingredients).
#[repr(C)]
pub struct YogMachineCraftEvent {
    /// The machine's inventory, e.g. `mymod:press`.
    pub machine: YogStr,
    /// The recipe's kind and id.
    pub kind: YogStr,
    pub recipe: YogStr,
    pub result_item: YogStr,
    pub result_count: u32,
    /// The recipe's values (`{ "energy": 4 }`), as JSON.
    pub values: YogStr,
    pub pos: YogBlockPos,
    pub dimension: YogStr,
    pub player: YogStr,
}

/// Fired when an explosion occurs in a world (Pre: before block destruction; Post: after).
/// Pre phase — return false to cancel the explosion (block and entity damage suppressed).
#[repr(C)]
pub struct YogExplosionEvent {
    pub dimension: YogStr,
    pub x: f64,
    pub y: f64,
    pub z: f64,
    pub power: f32,
    /// UUID of the entity that caused the explosion, or empty if world/tnt.
    pub cause_uuid: YogStr,
}

// ── ABI minor 9–10 event structs ──────────────────────────────────────────────

/// A hopper or dropper puts an item into a block that accepts items
/// (Pre: would it take it; Post: it takes it).
#[repr(C)]
pub struct YogItemInsertEvent {
    pub block: YogStr,
    pub pos: YogBlockPos,
    pub dimension: YogStr,
    pub item_id: YogStr,
    pub count: u32,
    /// The item's data as SNBT (`{}` for none).
    pub nbt: YogStr,
}

/// Fired when a player picks up an item entity (Pre: cancellable; Post: informational).
#[repr(C)]
pub struct YogItemPickupEvent {
    pub player: YogStr,
    pub player_uuid: YogStr,
    /// Registry id of the item, e.g. `"minecraft:diamond"`.
    pub item_id: YogStr,
    pub item_count: u32,
    /// UUID of the item entity that was picked up.
    pub entity_uuid: YogStr,
    pub dimension: YogStr,
}

/// Fired when a player sends a movement packet (Post only; very high frequency).
#[repr(C)]
pub struct YogPlayerMoveEvent {
    pub player: YogStr,
    pub player_uuid: YogStr,
    pub x: f64,
    pub y: f64,
    pub z: f64,
    pub yaw: f32,
    pub pitch: f32,
    pub dimension: YogStr,
}

/// Fired when a player opens a container screen (Pre: cancellable; Post: informational).
/// `container_type` is the screen handler registry id, e.g. `"minecraft:chest"`.
/// Empty string if the type is not in the registry (e.g. the player inventory).
#[repr(C)]
pub struct YogContainerOpenEvent {
    pub player: YogStr,
    pub player_uuid: YogStr,
    pub container_type: YogStr,
    pub dimension: YogStr,
}

/// Fired when a player closes a container screen (Post only).
#[repr(C)]
pub struct YogContainerCloseEvent {
    pub player: YogStr,
    pub player_uuid: YogStr,
    pub dimension: YogStr,
}

/// Fired when a persistent projectile (arrow, trident) hits a target (Pre: cancellable).
/// Pre phase — return false to cancel the hit (projectile passes through).
#[repr(C)]
pub struct YogProjectileHitEvent {
    /// Registry id of the projectile, e.g. `"minecraft:arrow"`.
    pub projectile_type: YogStr,
    pub projectile_uuid: YogStr,
    /// UUID of the entity that shot/threw this projectile, or empty.
    pub shooter_uuid: YogStr,
    /// `"block"` or `"entity"`.
    pub hit_type: YogStr,
    /// UUID of the entity that was hit (empty for block hits).
    pub hit_entity_uuid: YogStr,
    pub x: f64,
    pub y: f64,
    pub z: f64,
    pub dimension: YogStr,
}

/// Fired when a player places a block (Pre: before placement; Post: after).
#[repr(C)]
pub struct YogPlaceBlockEvent {
    pub player: YogStr,
    pub block: YogStr,
    pub pos: YogBlockPos,
    pub dimension: YogStr,
    /// Whether the player was sneaking (shift).
    pub sneaking: bool,
}

#[repr(C)]
pub struct YogPacketEvent {
    pub channel: YogStr,
    pub player: YogStr, // empty string on client-received packets
    pub payload: *const u8,
    pub payload_len: u32,
}

#[repr(C)]
pub struct YogCommandEvent {
    pub name: YogStr,
    pub args: YogStr,
    pub source: YogStr,
    pub uuid: YogStr,
    /// Empty for console-run commands (no world).
    pub dimension: YogStr,
}

// ── ABI minor 10 client event structs ─────────────────────────────────────────

/// Key press / release / repeat from the keyboard (client-side only).
#[repr(C)]
#[derive(Copy, Clone)]
pub struct YogKeyPressEvent {
    /// GLFW key code (e.g. `GLFW_KEY_E = 69`).
    pub key_code: i32,
    pub scan_code: i32,
    /// 0 = release, 1 = press, 2 = repeat.
    pub action: i32,
    /// Modifier bitmask: 1=shift, 2=ctrl, 4=alt, 8=super.
    pub modifiers: i32,
}

// ── Handler function-pointer types ────────────────────────────────────────────
//
// All event handlers receive a `phase: u8` argument:
//   0 = Pre  — fires before the action; return value matters (false = cancel).
//   1 = Post — fires after the action; return value is ignored.
//
// This unified signature lets one registered closure handle both phases.
//
// Client-side handlers (minor 10) do NOT receive a `YogServer*` — they run on
// the render thread and have no server context.

pub type YogBlockBreakFn =
    unsafe extern "C" fn(*mut c_void, *const YogServer, *const YogBlockBreakEvent, u8) -> bool;
pub type YogChatFn =
    unsafe extern "C" fn(*mut c_void, *const YogServer, *const YogChatEvent, u8) -> bool;
pub type YogPlayerFn =
    unsafe extern "C" fn(*mut c_void, *const YogServer, *const YogPlayerEvent, u8) -> bool;
pub type YogUseItemFn =
    unsafe extern "C" fn(*mut c_void, *const YogServer, *const YogUseItemEvent, u8) -> bool;
pub type YogUseBlockFn =
    unsafe extern "C" fn(*mut c_void, *const YogServer, *const YogUseBlockEvent, u8) -> bool;
pub type YogAttackEntityFn =
    unsafe extern "C" fn(*mut c_void, *const YogServer, *const YogAttackEntityEvent, u8) -> bool;
pub type YogEntityDamageFn =
    unsafe extern "C" fn(*mut c_void, *const YogServer, *const YogEntityDamageEvent, u8) -> bool;
pub type YogEntityDeathFn =
    unsafe extern "C" fn(*mut c_void, *const YogServer, *const YogEntityDeathEvent, u8) -> bool;
pub type YogEntitySpawnFn =
    unsafe extern "C" fn(*mut c_void, *const YogServer, *const YogEntitySpawnEvent, u8) -> bool;
pub type YogPlaceBlockFn =
    unsafe extern "C" fn(*mut c_void, *const YogServer, *const YogPlaceBlockEvent, u8) -> bool;
pub type YogPlayerDeathFn =
    unsafe extern "C" fn(*mut c_void, *const YogServer, *const YogPlayerDeathEvent, u8) -> bool;
pub type YogPlayerRespawnFn =
    unsafe extern "C" fn(*mut c_void, *const YogServer, *const YogPlayerRespawnEvent, u8) -> bool;
pub type YogAdvancementFn =
    unsafe extern "C" fn(*mut c_void, *const YogServer, *const YogAdvancementEvent, u8) -> bool;
pub type YogEntityInteractFn =
    unsafe extern "C" fn(*mut c_void, *const YogServer, *const YogEntityInteractEvent, u8) -> bool;
pub type YogCraftFn =
    unsafe extern "C" fn(*mut c_void, *const YogServer, *const YogCraftEvent, u8) -> bool;
pub type YogMachineCraftFn =
    unsafe extern "C" fn(*mut c_void, *const YogServer, *const YogMachineCraftEvent, u8) -> bool;
pub type YogExplosionFn =
    unsafe extern "C" fn(*mut c_void, *const YogServer, *const YogExplosionEvent, u8) -> bool;
pub type YogItemInsertFn =
    unsafe extern "C" fn(*mut c_void, *const YogServer, *const YogItemInsertEvent, u8) -> bool;
pub type YogItemPickupFn =
    unsafe extern "C" fn(*mut c_void, *const YogServer, *const YogItemPickupEvent, u8) -> bool;
pub type YogPlayerMoveFn =
    unsafe extern "C" fn(*mut c_void, *const YogServer, *const YogPlayerMoveEvent, u8) -> bool;
pub type YogContainerOpenFn =
    unsafe extern "C" fn(*mut c_void, *const YogServer, *const YogContainerOpenEvent, u8) -> bool;
pub type YogContainerCloseFn =
    unsafe extern "C" fn(*mut c_void, *const YogServer, *const YogContainerCloseEvent, u8) -> bool;
pub type YogProjectileHitFn =
    unsafe extern "C" fn(*mut c_void, *const YogServer, *const YogProjectileHitEvent, u8) -> bool;

/// Packet events — always Post, no phase.
pub type YogPacketFn = unsafe extern "C" fn(*mut c_void, *const YogServer, *const YogPacketEvent);
/// Server lifecycle / tick — no event struct, always fires.
pub type YogServerFn = unsafe extern "C" fn(*mut c_void, *const YogServer);
/// Command handler.
pub type YogCommandFn = unsafe extern "C" fn(
    ud: *mut c_void,
    srv: *const YogServer,
    ev: *const YogCommandEvent,
    reply_buf: *mut u8,
    reply_cap: u32,
    reply_len: *mut u32,
);
/// Scheduler handler (once or repeating).
pub type YogScheduledFn = unsafe extern "C" fn(*mut c_void, *const YogServer);

// ── ABI minor 10 — client-side function pointer types ────────────────────────

/// Client tick — no event, no server context.
pub type YogClientFn = unsafe extern "C" fn(ud: *mut c_void);
/// UI event for a `register_ui` screen. `event_id` is one of
/// `click:X:Y`, `drag:X:Y`, `release:X:Y`, `scroll:DY` and (ABI minor 33)
/// `key:KEY:MODS` — a GLFW key code pressed or repeating, with GLFW modifier
/// bits — and `char:CODEPOINT` — a typed character (Unicode scalar value).
/// Call `YogApi::ui_consume_event` while handling `key:`/`char:` to stop the
/// host's default handling of that key (Esc closing the screen, ...).
pub type YogUIEventFn = unsafe extern "C" fn(ud: *mut c_void, ui_id: YogStr, event_id: YogStr);
/// HUD render — `gfx` is the graphics context for this frame; only valid for
/// the call duration.  `draw2d_*` functions in `gfx` work here.
pub type YogHudRenderFn = unsafe extern "C" fn(ud: *mut c_void, gfx: *const YogGfxApi);
/// A book page's picture: `data`/`len` is the page's `data` (Yog Data,
/// binary), `x, y, w, h` its box in screen pixels; `gfx` is valid for the
/// call.
pub type YogPageDrawFn = unsafe extern "C" fn(
    ud: *mut c_void,
    gfx: *const YogGfxApi,
    data: *const u8,
    len: usize,
    x: f32,
    y: f32,
    w: f32,
    h: f32,
);
/// Whether a stack of `item` with custom data `snbt` gets a tooltip
/// picture; if so its size in GUI pixels goes to `w`, `h`.
pub type YogTooltipSizeFn =
    unsafe extern "C" fn(ud: *mut c_void, item: YogStr, snbt: YogStr, w: *mut f32, h: *mut f32) -> bool;
/// Draw the tooltip picture of a stack of `item` (custom data `snbt`) in
/// the box `x, y, w, h` (screen pixels); `gfx` is valid for the call.
pub type YogTooltipDrawFn = unsafe extern "C" fn(
    ud: *mut c_void,
    gfx: *const YogGfxApi,
    item: YogStr,
    snbt: YogStr,
    x: f32,
    y: f32,
    w: f32,
    h: f32,
);
/// Where a callback writes text it gives back: `write(sink, text)`, the
/// text copied by the caller during the call.
pub type YogTextSink = unsafe extern "C" fn(sink: *mut c_void, text: YogStr);
/// The name and tooltip lines of a stack of `item` with custom data
/// `snbt`: `false` for the item's own; else one `write` of the name (empty:
/// the item's own) and the lines that stand instead of its description,
/// separated by `\n`.
/// Takes bytes a handler writes (copies them; valid for the call).
pub type YogBytesSink = unsafe extern "C" fn(sink: *mut c_void, data: *const u8, len: usize);
/// A body frame (`yog_body::Frame`, its wire form): the handler writes its
/// ops (`yog_body::Ops`) to `sink`.
pub type YogBodyFn = unsafe extern "C" fn(ud: *mut c_void, frame: *const u8, len: usize, sink: *mut c_void, write: YogBytesSink);
/// The camera this frame; the handler changes `out` (each handler sees the
/// last one's result).
pub type YogCameraFn = unsafe extern "C" fn(ud: *mut c_void, frame: *const YogCameraFrame, out: *mut YogCameraOut);
/// The local player's travel step: `true` and `velocity` set replaces it.
pub type YogTravelFn = unsafe extern "C" fn(ud: *mut c_void, frame: *const YogTravelFrame, velocity: *mut [f32; 3]) -> bool;

/// See `yog_body::CameraFrame`.
#[repr(C)]
#[derive(Copy, Clone)]
pub struct YogCameraFrame {
    pub uuid: YogStr,
    pub partial: f32,
    pub pos: [f64; 3],
    pub yaw: f32,
    pub pitch: f32,
    pub detached: bool,
    pub flags: u32,
}

/// See `yog_body::CameraOut`.
#[repr(C)]
#[derive(Copy, Clone)]
pub struct YogCameraOut {
    pub local_offset: [f32; 3],
    pub world_offset: [f32; 3],
    pub yaw: f32,
    pub pitch: f32,
    pub roll: f32,
    pub fov: f32,
}

/// See `yog_body::TravelFrame`.
#[repr(C)]
#[derive(Copy, Clone)]
pub struct YogTravelFrame {
    pub uuid: YogStr,
    pub velocity: [f32; 3],
    pub look: [f32; 3],
    pub yaw: f32,
    pub pitch: f32,
    pub forward: f32,
    pub strafe: f32,
    pub jumping: bool,
    pub sneaking: bool,
    pub gravity: f32,
    pub flags: u32,
}

pub type YogItemTextFn =
    unsafe extern "C" fn(ud: *mut c_void, item: YogStr, snbt: YogStr, sink: *mut c_void, write: YogTextSink) -> bool;
/// World render — `gfx` contains `view_proj` and `camera_pos` for 3D rendering.
/// Valid only for the call duration.
pub type YogWorldRenderFn = unsafe extern "C" fn(ud: *mut c_void, gfx: *const YogGfxApi);
/// Key press — return `false` to cancel (prevent Minecraft from processing the key).
pub type YogKeyPressFn = unsafe extern "C" fn(ud: *mut c_void, ev: *const YogKeyPressEvent) -> bool;
/// Screen event — `screen_class` is the simple class name (e.g. `"InventoryScreen"`).
/// For `on_screen_open` return `false` to prevent the screen from opening.
pub type YogScreenFn = unsafe extern "C" fn(ud: *mut c_void, screen_class: YogStr) -> bool;

// ── ABI minor 14 — low-level GPU pipeline ────────────────────────────────────

/// Low-level GPU context passed to render handlers.
///
/// Provides direct access to the OpenGL pipeline: buffer objects, vertex arrays,
/// shader programs, textures, draw calls, and render state.
///
/// The per-frame fields (`screen_w/h`, `delta_tick`, `view_proj`, `camera_pos`)
/// are filled by the runtime before calling the handler; the function pointers
/// point to statically-allocated implementations.
///
/// Valid only for the duration of the render callback — never store the pointer.
/// GPU resource **handles** (`u32`) may be stored between frames.
///
/// Colors are `0xAARRGGBB` (Minecraft convention).
#[repr(C)]
#[derive(Copy, Clone)]
pub struct YogGfxApi {
    // ── Per-frame context ─────────────────────────────────────────────────────
    /// GUI-pixel screen width.
    pub screen_w: i32,
    /// GUI-pixel screen height.
    pub screen_h: i32,
    /// Partial-tick interpolation factor (0.0–1.0).
    pub delta_tick: f32,
    /// GUI scale factor: physical pixels per GUI pixel (e.g. 2.0 for 2× GUI scale).
    /// Useful for converting GUI-pixel coordinates to physical pixels for OpenGL calls.
    pub scale_factor: f32,
    /// View-projection matrix in camera-relative space (column-major, 16 × f32).
    /// All zeros during `on_hud_render`; filled during `on_world_render`.
    pub view_proj: [f32; 16],
    /// Camera world-space position.  All zeros during `on_hud_render`.
    pub camera_pos: [f32; 3],
    /// Local player world-space position (eye height).  All zeros during `on_hud_render`.
    /// Differs from `camera_pos` in third-person view.
    pub player_pos: [f32; 3],
    pub _pad1: f32,

    // ── GPU buffers ───────────────────────────────────────────────────────────
    /// Allocate a new GPU buffer (VBO / EBO). Returns 0 on failure.
    pub buf_create: unsafe extern "C" fn() -> u32,
    /// Delete a buffer created by `buf_create`.
    pub buf_delete: unsafe extern "C" fn(handle: u32),
    /// Upload `len` bytes from `bytes` into `handle`.
    /// `dynamic`: hints frequent updates (`GL_DYNAMIC_DRAW` vs `GL_STATIC_DRAW`).
    pub buf_data: unsafe extern "C" fn(handle: u32, bytes: *const u8, len: u32, dynamic: bool),
    /// Overwrite `len` bytes at `offset` in `handle`.
    pub buf_subdata: unsafe extern "C" fn(handle: u32, offset: u32, bytes: *const u8, len: u32),

    // ── Vertex arrays ─────────────────────────────────────────────────────────
    /// Create a vertex array object. Returns 0 on failure.
    pub vao_create: unsafe extern "C" fn() -> u32,
    /// Delete a VAO created by `vao_create`.
    pub vao_delete: unsafe extern "C" fn(handle: u32),
    /// Declare one vertex attribute in `vao`, sourced from `vbo`.
    /// `dtype`: 0=f32, 1=u8, 2=i32, 3=u32.
    pub vao_attrib: unsafe extern "C" fn(
        vao: u32,
        vbo: u32,
        index: u32,
        components: u8,
        dtype: u8,
        normalized: bool,
        stride: u32,
        offset: u32,
    ),
    /// Bind an index buffer (EBO) to `vao`.
    pub vao_set_ebo: unsafe extern "C" fn(vao: u32, ebo: u32),

    // ── Shader programs ───────────────────────────────────────────────────────
    /// Compile + link `vert_src` / `frag_src` (GLSL 150 core).
    /// Writes the program handle to `*out`. Returns false and logs on error.
    pub prog_create: unsafe extern "C" fn(vert: YogStr, frag: YogStr, out: *mut u32) -> bool,
    /// Delete a shader program.
    pub prog_delete: unsafe extern "C" fn(handle: u32),
    pub prog_uniform_1i: unsafe extern "C" fn(prog: u32, name: YogStr, v: i32),
    pub prog_uniform_1f: unsafe extern "C" fn(prog: u32, name: YogStr, v: f32),
    pub prog_uniform_2f: unsafe extern "C" fn(prog: u32, name: YogStr, x: f32, y: f32),
    pub prog_uniform_3f: unsafe extern "C" fn(prog: u32, name: YogStr, x: f32, y: f32, z: f32),
    pub prog_uniform_4f:
        unsafe extern "C" fn(prog: u32, name: YogStr, x: f32, y: f32, z: f32, w: f32),
    /// Set a mat4 uniform from 16 column-major floats.
    pub prog_uniform_mat4: unsafe extern "C" fn(prog: u32, name: YogStr, col_major: *const f32),

    // ── Textures ──────────────────────────────────────────────────────────────
    /// Upload RGBA8 pixel data as a new texture.
    /// `linear`: `GL_LINEAR` if true, `GL_NEAREST` if false.
    pub tex_create: unsafe extern "C" fn(w: u32, h: u32, rgba: *const u8, linear: bool) -> u32,
    /// Delete a texture created by `tex_create`.
    pub tex_delete: unsafe extern "C" fn(handle: u32),
    /// Bind `handle` to texture unit `unit` (0–7).
    pub tex_bind: unsafe extern "C" fn(unit: u32, handle: u32),
    /// Return the GL texture handle Minecraft uses for a namespaced resource
    /// (e.g. `"minecraft:textures/gui/icons.png"`). Returns 0 if not found.
    /// Do **not** delete handles obtained this way — Minecraft owns them.
    pub tex_from_mc: unsafe extern "C" fn(id: YogStr) -> u32,

    // ── Draw calls ────────────────────────────────────────────────────────────
    /// Draw `count` primitives from `vao`, using shader `prog`.
    /// `mode`: 0=Triangles, 1=Lines, 2=LineStrip, 3=TriangleStrip, 4=TriangleFan.
    pub draw_arrays: unsafe extern "C" fn(vao: u32, prog: u32, mode: u8, first: u32, count: u32),
    /// Draw indexed primitives.  `ebo` must be bound to `vao` via `vao_set_ebo`.
    /// `u32_idx`: `true` for `u32` indices, `false` for `u16` indices.
    pub draw_elements:
        unsafe extern "C" fn(vao: u32, ebo: u32, prog: u32, mode: u8, count: u32, u32_idx: bool),

    // ── Render state ──────────────────────────────────────────────────────────
    /// Enable/disable blending. `src`/`dst` are raw GL blend factor enum values.
    pub set_blend: unsafe extern "C" fn(enabled: bool, src: u32, dst: u32),
    /// Enable/disable depth testing and depth writes.
    pub set_depth: unsafe extern "C" fn(test: bool, write: bool),
    /// Enable the GL scissor: `x, y, w, h` in framebuffer pixels, from the
    /// bottom-left corner — for the GPU drawing here, not `draw2d_*` (the
    /// game batches 2D drawing; clip it by hand, as yog-ui does).
    pub set_scissor: unsafe extern "C" fn(x: i32, y: i32, w: i32, h: i32),
    /// Disable scissor clipping.
    pub clear_scissor: unsafe extern "C" fn(),
    /// Set the GL viewport (physical pixel coordinates).
    pub set_viewport: unsafe extern "C" fn(x: i32, y: i32, w: i32, h: i32),

    // ── 2D convenience (HUD-render only — uses MC's DrawContext) ─────────────
    /// Filled rectangle. Only valid during `on_hud_render`.
    pub draw2d_rect: unsafe extern "C" fn(x1: f32, y1: f32, x2: f32, y2: f32, color: u32),
    /// Vertical-gradient rectangle. Only valid during `on_hud_render`.
    pub draw2d_gradient:
        unsafe extern "C" fn(x1: f32, y1: f32, x2: f32, y2: f32, top: u32, bottom: u32),
    /// MC text renderer string. Only valid during `on_hud_render`.
    pub draw2d_text: unsafe extern "C" fn(text: YogStr, x: f32, y: f32, color: u32, shadow: bool),

    // ── appended in ABI minor 21 ──────────────────────────────────────────────
    /// Render an item stack (3D block models included) via MC's item renderer,
    /// like Patchouli's `renderItemStack`. `id` is a registry item id
    /// ("minecraft:crafting_table"); `size` is the on-screen size in GUI px
    /// (16 = inventory size). Only valid during `on_hud_render`.
    pub draw2d_item: unsafe extern "C" fn(id: YogStr, x: f32, y: f32, size: f32),

    // ── appended in ABI minor 33 ──────────────────────────────────────────────
    /// `draw2d_text` in the font `font` — a font id such as
    /// `"minecraft:default"`, `"minecraft:uniform"`, `"minecraft:alt"` or a
    /// resource-pack font (`"mymod:fancy"`); empty = the default font. Only
    /// valid during a render callback.
    pub draw2d_text_font:
        unsafe extern "C" fn(text: YogStr, font: YogStr, x: f32, y: f32, color: u32, shadow: bool),
    /// Width in GUI pixels of `text` drawn in `font` (empty = default), as the
    /// host's text renderer measures it. Callable from the render thread at
    /// any time (render callbacks and UI event handlers); the pointer stays
    /// valid for the life of the process.
    pub text_width: unsafe extern "C" fn(text: YogStr, font: YogStr) -> f32,

    // ── appended in ABI minor 34 ──────────────────────────────────────────────
    /// Draw the image `source` — a Yog image source (`item:apple`,
    /// `block:stone`, `sprite:button`, `mymod:gui/logo`, ...; see
    /// `yog_gfx::image`), resolved by the host for its Minecraft version —
    /// scaled into `(x, y, w, h)` (GUI pixels, nearest-neighbour). `(u, v,
    /// uw, vh)` is the part of the image to draw, in the image's own pixels;
    /// `uw <= 0` or `vh <= 0` = the whole image (items and sprites are
    /// always whole). `tint` multiplies the colors (`0xAARRGGBB`;
    /// `0xFFFFFFFF` = none; items ignore it). Only valid during a render
    /// callback.
    pub draw2d_image: unsafe extern "C" fn(
        source: YogStr,
        x: f32,
        y: f32,
        w: f32,
        h: f32,
        u: f32,
        v: f32,
        uw: f32,
        vh: f32,
        tint: u32,
    ),
    /// Natural size in GUI pixels of the image `source` (16×16 for items, a
    /// texture's pixel size, ...) into `*w`/`*h`. `false` (outputs untouched)
    /// when the source can't be resolved. Callable from the render thread at
    /// any time; the pointer stays valid for the life of the process.
    pub image_size: unsafe extern "C" fn(source: YogStr, w: *mut f32, h: *mut f32) -> bool,

    // ── ABI 1.4 ──────────────────────────────────────────────────────────────
    /// Draws the SVG document `data` scaled into `(x, y, w, h)` GUI pixels
    /// (rasterized by the host at the screen's resolution, cached).
    pub draw2d_svg: unsafe extern "C" fn(data: YogStr, x: f32, y: f32, w: f32, h: f32),
    /// Draws a living entity of type `entity` (`minecraft:zombie`) standing
    /// in `(x, y, w, h)` GUI pixels, as big as fits, turned `yaw` degrees
    /// (0 = facing the viewer) and tilted `pitch` degrees.
    pub draw2d_entity:
        unsafe extern "C" fn(entity: YogStr, x: f32, y: f32, w: f32, h: f32, yaw: f32, pitch: f32),

    // ── ABI 1.5 ──────────────────────────────────────────────────────────────
    /// Draws `text` in `font` (empty = default) at `(x, y)`, `scale` times
    /// its size.
    pub draw2d_text_scaled: unsafe extern "C" fn(
        text: YogStr,
        font: YogStr,
        x: f32,
        y: f32,
        scale: f32,
        color: u32,
        shadow: bool,
    ),
    /// Draws blocks in 3D, as big as fits in `(x, y, w, h)`: `blocks` is one
    /// `x y z state` line per block (`0 0 0 minecraft:furnace[facing=north]`),
    /// turned `yaw` degrees about the vertical and tilted `pitch` degrees.
    pub draw2d_blocks:
        unsafe extern "C" fn(blocks: YogStr, x: f32, y: f32, w: f32, h: f32, yaw: f32, pitch: f32),
}

unsafe impl Send for YogGfxApi {}
unsafe impl Sync for YogGfxApi {}

// ── Server action table (runtime → mod direction is wrong; it's mod → runtime) ─

/// All Minecraft-mutating calls available inside a handler.
///
/// `ctx` is an opaque pointer to the runtime's JNI state.  Every function takes
/// it as its first argument.  The pointer is valid for the lifetime of the process.
///
/// Strings **returned** by functions in this table are heap-allocated by the
/// runtime and must be freed with `free_str` after the caller has read them.
#[repr(C)]
pub struct YogServer {
    pub ctx: *mut c_void,
    pub abi_version: u32,
    /// `sizeof(YogServer)` at build time — allows mods compiled against an older
    /// table to detect and skip fields they don't know about.
    pub size: u32,

    /// Free a string returned by any function in this table.
    pub free_str: unsafe extern "C" fn(ptr: *mut u8, len: u32),

    // ── chat ─────────────────────────────────────────────────────────────────
    pub broadcast: unsafe extern "C" fn(ctx: *mut c_void, msg: YogStr),

    // ── world ────────────────────────────────────────────────────────────────
    pub get_block:
        unsafe extern "C" fn(ctx: *mut c_void, dim: YogStr, pos: YogBlockPos) -> YogOwnedStr,
    pub set_block: unsafe extern "C" fn(
        ctx: *mut c_void,
        dim: YogStr,
        pos: YogBlockPos,
        block: YogStr,
    ) -> bool,
    pub world_time: unsafe extern "C" fn(ctx: *mut c_void, dim: YogStr, out: *mut i64) -> bool,
    pub set_time: unsafe extern "C" fn(ctx: *mut c_void, dim: YogStr, time: i64) -> bool,
    pub is_raining: unsafe extern "C" fn(ctx: *mut c_void, dim: YogStr) -> bool,
    pub set_weather:
        unsafe extern "C" fn(ctx: *mut c_void, dim: YogStr, raining: bool, dur: i32) -> bool,

    // ── player ───────────────────────────────────────────────────────────────
    pub give_item:
        unsafe extern "C" fn(ctx: *mut c_void, player: YogStr, item: YogStr, count: u32) -> bool,
    pub player_teleport:
        unsafe extern "C" fn(ctx: *mut c_void, player: YogStr, pos: YogVec3) -> bool,
    pub send_to_player: unsafe extern "C" fn(
        ctx: *mut c_void,
        player: YogStr,
        channel: YogStr,
        data: *const u8,
        len: u32,
    ) -> bool,
    pub send_to_server:
        unsafe extern "C" fn(ctx: *mut c_void, channel: YogStr, data: *const u8, len: u32) -> bool,
    pub kick_player: unsafe extern "C" fn(ctx: *mut c_void, player: YogStr, reason: YogStr) -> bool,
    pub set_gamemode: unsafe extern "C" fn(ctx: *mut c_void, player: YogStr, mode: YogStr) -> bool,
    pub send_title: unsafe extern "C" fn(
        ctx: *mut c_void,
        player: YogStr,
        title: YogStr,
        sub: YogStr,
        fi: i32,
        stay: i32,
        fo: i32,
    ) -> bool,
    pub send_actionbar: unsafe extern "C" fn(ctx: *mut c_void, player: YogStr, msg: YogStr) -> bool,
    pub play_sound: unsafe extern "C" fn(
        ctx: *mut c_void,
        dim: YogStr,
        pos: YogVec3,
        sound: YogStr,
        vol: f32,
        pitch: f32,
    ) -> bool,
    pub play_sound_player: unsafe extern "C" fn(
        ctx: *mut c_void,
        player: YogStr,
        sound: YogStr,
        vol: f32,
        pitch: f32,
    ) -> bool,

    // ── entity ───────────────────────────────────────────────────────────────
    pub entity_teleport: unsafe extern "C" fn(ctx: *mut c_void, uuid: YogStr, pos: YogVec3) -> bool,
    pub entity_position:
        unsafe extern "C" fn(ctx: *mut c_void, uuid: YogStr, out: *mut YogVec3) -> bool,
    pub entity_health: unsafe extern "C" fn(ctx: *mut c_void, uuid: YogStr, out: *mut f32) -> bool,
    pub entity_set_health: unsafe extern "C" fn(ctx: *mut c_void, uuid: YogStr, hp: f32) -> bool,
    pub entity_kill: unsafe extern "C" fn(ctx: *mut c_void, uuid: YogStr) -> bool,
    pub spawn_entity: unsafe extern "C" fn(
        ctx: *mut c_void,
        type_id: YogStr,
        dim: YogStr,
        pos: YogVec3,
    ) -> YogOwnedStr,
    pub entity_add_effect: unsafe extern "C" fn(
        ctx: *mut c_void,
        uuid: YogStr,
        fx: YogStr,
        dur: i32,
        amp: u8,
        particles: bool,
    ) -> bool,
    pub entity_remove_effect:
        unsafe extern "C" fn(ctx: *mut c_void, uuid: YogStr, fx: YogStr) -> bool,
    pub entity_clear_effects: unsafe extern "C" fn(ctx: *mut c_void, uuid: YogStr) -> bool,
    pub entity_velocity:
        unsafe extern "C" fn(ctx: *mut c_void, uuid: YogStr, out: *mut YogVec3) -> bool,
    pub entity_set_velocity:
        unsafe extern "C" fn(ctx: *mut c_void, uuid: YogStr, vel: YogVec3) -> bool,
    pub entity_add_velocity:
        unsafe extern "C" fn(ctx: *mut c_void, uuid: YogStr, vel: YogVec3) -> bool,

    // ── tags & loot ──────────────────────────────────────────────────────────
    pub has_item_tag: unsafe extern "C" fn(ctx: *mut c_void, item: YogStr, tag: YogStr) -> bool,
    pub has_block_tag: unsafe extern "C" fn(ctx: *mut c_void, block: YogStr, tag: YogStr) -> bool,
    pub drop_loot:
        unsafe extern "C" fn(ctx: *mut c_void, table: YogStr, dim: YogStr, pos: YogVec3) -> bool,

    // ── scoreboard ───────────────────────────────────────────────────────────
    pub scoreboard_get:
        unsafe extern "C" fn(ctx: *mut c_void, obj: YogStr, player: YogStr, out: *mut i32) -> bool,
    pub scoreboard_set:
        unsafe extern "C" fn(ctx: *mut c_void, obj: YogStr, player: YogStr, score: i32) -> bool,
    pub scoreboard_add: unsafe extern "C" fn(
        ctx: *mut c_void,
        obj: YogStr,
        player: YogStr,
        delta: i32,
        out: *mut i32,
    ) -> bool,

    // ── boss bar ─────────────────────────────────────────────────────────────
    pub bossbar_create: unsafe extern "C" fn(
        ctx: *mut c_void,
        id: YogStr,
        title: YogStr,
        color: YogStr,
        style: YogStr,
    ) -> bool,
    pub bossbar_remove: unsafe extern "C" fn(ctx: *mut c_void, id: YogStr) -> bool,
    pub bossbar_set_title:
        unsafe extern "C" fn(ctx: *mut c_void, id: YogStr, title: YogStr) -> bool,
    pub bossbar_set_progress:
        unsafe extern "C" fn(ctx: *mut c_void, id: YogStr, progress: f32) -> bool,
    pub bossbar_set_color:
        unsafe extern "C" fn(ctx: *mut c_void, id: YogStr, color: YogStr) -> bool,
    pub bossbar_add_player:
        unsafe extern "C" fn(ctx: *mut c_void, id: YogStr, player: YogStr) -> bool,
    pub bossbar_remove_player:
        unsafe extern "C" fn(ctx: *mut c_void, id: YogStr, player: YogStr) -> bool,
    pub bossbar_set_visible:
        unsafe extern "C" fn(ctx: *mut c_void, id: YogStr, visible: bool) -> bool,

    // ── misc ─────────────────────────────────────────────────────────────────
    pub game_dir: unsafe extern "C" fn(ctx: *mut c_void) -> YogOwnedStr,

    // ── player query (ABI minor 4) ────────────────────────────────────────────
    /// Newline-separated list of online player names, or NONE if server not up.
    pub online_players: unsafe extern "C" fn(ctx: *mut c_void) -> YogOwnedStr,

    // ── block entity (NBT, ABI minor 3) ──────────────────────────────────────
    /// SNBT string of the block entity at `pos`, or NONE if there is none.
    pub get_block_nbt:
        unsafe extern "C" fn(ctx: *mut c_void, dim: YogStr, pos: YogBlockPos) -> YogOwnedStr,
    /// Write SNBT into the block entity at `pos`. Returns false if no block entity exists.
    pub set_block_nbt:
        unsafe extern "C" fn(ctx: *mut c_void, dim: YogStr, pos: YogBlockPos, snbt: YogStr) -> bool,

    // ── inventory (ABI minor 3) ───────────────────────────────────────────────
    /// Tab/newline-encoded inventory: one line per occupied slot, `slot\titem_id\tcount`.
    pub player_inventory: unsafe extern "C" fn(ctx: *mut c_void, player: YogStr) -> YogOwnedStr,
    /// Set (or clear when count==0) a specific inventory slot.
    pub player_set_slot: unsafe extern "C" fn(
        ctx: *mut c_void,
        player: YogStr,
        slot: u32,
        item_id: YogStr,
        count: u32,
    ) -> bool,

    // ── inventory-backed block slots (ABI minor 25, yog-inventory) ──────────
    /// `"item_id\tcount\tsnbt"` for the given slot of the block container
    /// at `pos`, or NONE if the slot is empty / there's no container there.
    pub get_inventory_slot: unsafe extern "C" fn(
        ctx: *mut c_void,
        dim: YogStr,
        pos: YogBlockPos,
        slot: u32,
    ) -> YogOwnedStr,
    /// Set (or clear when count==0) a slot of the block container at `pos`;
    /// `item_id` may carry the item's SNBT after a tab. Returns false if
    /// there's no container there.
    pub set_inventory_slot: unsafe extern "C" fn(
        ctx: *mut c_void,
        dim: YogStr,
        pos: YogBlockPos,
        slot: u32,
        item_id: YogStr,
        count: u32,
    ) -> bool,

    // ── cross-dimension teleport (ABI minor 3) ────────────────────────────────
    pub player_teleport_dim:
        unsafe extern "C" fn(ctx: *mut c_void, player: YogStr, dim: YogStr, pos: YogVec3) -> bool,
    pub entity_teleport_dim:
        unsafe extern "C" fn(ctx: *mut c_void, uuid: YogStr, dim: YogStr, pos: YogVec3) -> bool,

    // ── entity counting ───────────────────────────────────────────────────────
    /// Count loaded instances of `entity_type` in `dimension`. Returns -1 on error.
    pub world_entity_count:
        unsafe extern "C" fn(ctx: *mut c_void, dim: YogStr, entity_type: YogStr) -> i32,

    // ── entity NBT (ABI minor 6) ──────────────────────────────────────────────
    /// SNBT of the entity's persistent data, or NONE if entity not found.
    pub entity_get_nbt: unsafe extern "C" fn(ctx: *mut c_void, uuid: YogStr) -> YogOwnedStr,
    /// Merge SNBT data into the entity. Returns false if entity not found.
    pub entity_set_nbt: unsafe extern "C" fn(ctx: *mut c_void, uuid: YogStr, snbt: YogStr) -> bool,

    // ── particles (ABI minor 6) ───────────────────────────────────────────────
    /// Spawn `count` particles at `pos` in `dim`.
    /// `dx/dy/dz` control spread, `speed` controls particle speed.
    /// Returns false if the dimension or particle type is unknown.
    pub spawn_particles: unsafe extern "C" fn(
        ctx: *mut c_void,
        dim: YogStr,
        pos: YogVec3,
        particle_type: YogStr,
        count: i32,
        dx: f64,
        dy: f64,
        dz: f64,
        speed: f64,
    ) -> bool,

    // ── attributes (ABI minor 7) ──────────────────────────────────────────────
    /// Get the base value of an attribute on a living entity.
    /// `attribute_id` is a registry id, e.g. `"minecraft:generic.max_health"`.
    /// Returns `f64::NAN` if entity or attribute is not found.
    pub entity_attribute_get:
        unsafe extern "C" fn(ctx: *mut c_void, uuid: YogStr, attribute_id: YogStr) -> f64,
    /// Set the base value of an attribute. Returns false if entity or attribute is not found.
    pub entity_attribute_set: unsafe extern "C" fn(
        ctx: *mut c_void,
        uuid: YogStr,
        attribute_id: YogStr,
        value: f64,
    ) -> bool,

    // ── held item NBT (ABI minor 11) ─────────────────────────────────────────
    /// SNBT of the item currently held in the player's main hand.
    /// Returns NONE if the player is offline or holding air.
    pub get_held_item_nbt: unsafe extern "C" fn(ctx: *mut c_void, player: YogStr) -> YogOwnedStr,
    /// Merge `snbt` data into the NBT of the player's held main-hand item in-place.
    /// Returns false if the player is offline or holding air.
    pub set_held_item_nbt:
        unsafe extern "C" fn(ctx: *mut c_void, player: YogStr, snbt: YogStr) -> bool,

    // ── item stack query (ABI minor 12) ──────────────────────────────────────
    /// SNBT of the item in the player's off hand, or NONE if offline / holding air.
    pub get_offhand_item_nbt: unsafe extern "C" fn(ctx: *mut c_void, player: YogStr) -> YogOwnedStr,
    /// Merge `snbt` into the NBT of the player's off-hand item.
    /// Returns false if offline or holding air.
    pub set_offhand_item_nbt:
        unsafe extern "C" fn(ctx: *mut c_void, player: YogStr, snbt: YogStr) -> bool,
    /// Full item stack at inventory `slot`: tab-separated `item_id\tcount\tsnbt`.
    /// `snbt` is `{}` when the item has no NBT. Returns NONE if offline or slot empty.
    pub get_slot_item:
        unsafe extern "C" fn(ctx: *mut c_void, player: YogStr, slot: u32) -> YogOwnedStr,
    /// Replace inventory `slot` with an item stack. `snbt` may be empty to clear NBT.
    /// Pass `count == 0` to clear the slot (ignores `item_id` and `snbt`).
    pub set_slot_item: unsafe extern "C" fn(
        ctx: *mut c_void,
        player: YogStr,
        slot: u32,
        item_id: YogStr,
        count: u32,
        snbt: YogStr,
    ) -> bool,

    // ── entity rotation (ABI minor 25) ───────────────────────────────────────
    /// Yaw and pitch (degrees) of an entity by UUID. Returns false if the
    /// entity does not exist. `out` receives x=yaw, y=pitch, z=0.
    pub entity_rotation:
        unsafe extern "C" fn(ctx: *mut c_void, uuid: YogStr, out: *mut YogVec3) -> bool,

    // ── world queries & effects (ABI minor 1) ────────────────────────────────
    // Records come back as one tab-separated line; `yog_core`'s `EntityInfo`,
    // `BlockHit`, `BlockInfo` and `PlayerInfo` document and decode them.
    /// `EntityInfo` line of a loaded entity, or NONE.
    pub entity_info: unsafe extern "C" fn(ctx: *mut c_void, uuid: YogStr) -> YogOwnedStr,
    /// Newline-separated uuids of the entities touching the box.
    pub entities_in_box: unsafe extern "C" fn(
        ctx: *mut c_void,
        dim: YogStr,
        min: YogVec3,
        max: YogVec3,
    ) -> YogOwnedStr,
    /// `BlockHit` line of the first block on the segment, or NONE.
    pub raycast_block: unsafe extern "C" fn(
        ctx: *mut c_void,
        dim: YogStr,
        from: YogVec3,
        to: YogVec3,
    ) -> YogOwnedStr,
    /// Uuid of the nearest entity on the segment (not `exclude`), or NONE.
    pub raycast_entity: unsafe extern "C" fn(
        ctx: *mut c_void,
        dim: YogStr,
        from: YogVec3,
        to: YogVec3,
        exclude: YogStr,
    ) -> YogOwnedStr,
    /// `BlockInfo` line of the block at `pos`, or NONE.
    pub block_info:
        unsafe extern "C" fn(ctx: *mut c_void, dim: YogStr, pos: YogBlockPos) -> YogOwnedStr,
    pub break_block: unsafe extern "C" fn(
        ctx: *mut c_void,
        dim: YogStr,
        pos: YogBlockPos,
        drop: bool,
        breaker: YogStr,
    ) -> bool,
    pub place_block_from_slot: unsafe extern "C" fn(
        ctx: *mut c_void,
        player: YogStr,
        slot: u32,
        dim: YogStr,
        pos: YogBlockPos,
    ) -> bool,
    pub bonemeal: unsafe extern "C" fn(ctx: *mut c_void, dim: YogStr, pos: YogBlockPos) -> bool,
    pub explode: unsafe extern "C" fn(
        ctx: *mut c_void,
        dim: YogStr,
        pos: YogVec3,
        power: f32,
        fire: bool,
        source: YogStr,
    ) -> bool,
    /// `json` is a JSON text component (the `/tellraw` format).
    pub tellraw: unsafe extern "C" fn(ctx: *mut c_void, player: YogStr, json: YogStr) -> bool,
    pub entity_damage: unsafe extern "C" fn(
        ctx: *mut c_void,
        uuid: YogStr,
        amount: f32,
        damage_type: YogStr,
        attacker: YogStr,
    ) -> bool,
    pub entity_set_fire_ticks:
        unsafe extern "C" fn(ctx: *mut c_void, uuid: YogStr, ticks: i32) -> bool,
    pub player_add_xp: unsafe extern "C" fn(ctx: *mut c_void, player: YogStr, amount: i32) -> bool,
    pub player_set_may_fly:
        unsafe extern "C" fn(ctx: *mut c_void, player: YogStr, may_fly: bool) -> bool,
    /// `PlayerInfo` line of an online player, or NONE.
    pub player_info: unsafe extern "C" fn(ctx: *mut c_void, player: YogStr) -> YogOwnedStr,
    /// Uuid of the dropped item entity, or NONE.
    pub spawn_item: unsafe extern "C" fn(
        ctx: *mut c_void,
        dim: YogStr,
        pos: YogVec3,
        vel: YogVec3,
        item_id: YogStr,
        count: u32,
        snbt: YogStr,
    ) -> YogOwnedStr,
    /// `item_id\tcount\tsnbt` of a dropped item entity, or NONE.
    pub item_entity_stack: unsafe extern "C" fn(ctx: *mut c_void, uuid: YogStr) -> YogOwnedStr,
    pub item_entity_set_stack: unsafe extern "C" fn(
        ctx: *mut c_void,
        uuid: YogStr,
        item_id: YogStr,
        count: u32,
        snbt: YogStr,
    ) -> bool,
    // ── ABI minor 2 ──
    /// `json` is a JSON text component.
    pub actionbar_json:
        unsafe extern "C" fn(ctx: *mut c_void, player: YogStr, json: YogStr) -> bool,
    /// `face` is a `Direction` ordinal (down, up, north, south, west, east).
    pub use_item_on_block: unsafe extern "C" fn(
        ctx: *mut c_void,
        dim: YogStr,
        pos: YogBlockPos,
        face: u8,
        item_id: YogStr,
        player: YogStr,
    ) -> bool,
    pub pour_fluid: unsafe extern "C" fn(
        ctx: *mut c_void,
        dim: YogStr,
        pos: YogBlockPos,
        bucket_item_id: YogStr,
    ) -> bool,
    pub has_entity_tag:
        unsafe extern "C" fn(ctx: *mut c_void, entity_type: YogStr, tag_id: YogStr) -> bool,
    /// The block id a block item places, or NONE.
    pub item_block: unsafe extern "C" fn(ctx: *mut c_void, item_id: YogStr) -> YogOwnedStr,
    pub place_feature: unsafe extern "C" fn(
        ctx: *mut c_void,
        dim: YogStr,
        pos: YogBlockPos,
        feature_id: YogStr,
    ) -> bool,

    // ── ABI minor 3 ──────────────────────────────────────────────────────────
    pub set_item_cooldown:
        unsafe extern "C" fn(ctx: *mut c_void, player: YogStr, item_id: YogStr, ticks: i32) -> bool,
    /// The UUID of what an entity rides, or NONE.
    pub entity_vehicle: unsafe extern "C" fn(ctx: *mut c_void, uuid: YogStr) -> YogOwnedStr,
    /// The UUIDs of what rides an entity directly, one a line (empty: none).
    pub entity_passengers: unsafe extern "C" fn(ctx: *mut c_void, uuid: YogStr) -> YogOwnedStr,
    /// Seats `rider` on `vehicle`; `force`: even one that wouldn't take it.
    pub entity_mount:
        unsafe extern "C" fn(ctx: *mut c_void, rider: YogStr, vehicle: YogStr, force: bool) -> bool,
    /// Gets an entity off what it rides.
    pub entity_dismount: unsafe extern "C" fn(ctx: *mut c_void, uuid: YogStr) -> bool,
    /// Received redstone power 0–15, or -1 (no such dimension).
    pub redstone_power: unsafe extern "C" fn(ctx: *mut c_void, dim: YogStr, pos: YogBlockPos) -> i32,
    /// Sets how far an entity has fallen (fall damage counts it on landing).
    pub entity_set_fall_distance: unsafe extern "C" fn(ctx: *mut c_void, uuid: YogStr, distance: f32) -> bool,
    /// The strongest signal the block gives off 0–15, or -1 (not a source).
    pub redstone_signal: unsafe extern "C" fn(ctx: *mut c_void, dim: YogStr, pos: YogBlockPos) -> i32,
    pub set_redstone_output:
        unsafe extern "C" fn(ctx: *mut c_void, dim: YogStr, pos: YogBlockPos, level: i32) -> bool,
    /// `"ns:id[prop=value,...]"`, or NONE.
    pub get_block_state: unsafe extern "C" fn(ctx: *mut c_void, dim: YogStr, pos: YogBlockPos) -> YogOwnedStr,
    pub set_block_state:
        unsafe extern "C" fn(ctx: *mut c_void, dim: YogStr, pos: YogBlockPos, state: YogStr) -> bool,
    pub world_is_thundering: unsafe extern "C" fn(ctx: *mut c_void, dim: YogStr) -> bool,
    pub world_set_thunder:
        unsafe extern "C" fn(ctx: *mut c_void, dim: YogStr, thundering: bool, duration_ticks: i32) -> bool,
    /// Sets every block of the box `from..=to` to `state`; how many changed, or -1.
    pub fill_region: unsafe extern "C" fn(
        ctx: *mut c_void,
        dim: YogStr,
        from: YogBlockPos,
        to: YogBlockPos,
        state: YogStr,
    ) -> i32,
    /// The non-air blocks of the box `from..=to`: `"x y z state"` lines, or NONE.
    pub scan_region:
        unsafe extern "C" fn(ctx: *mut c_void, dim: YogStr, from: YogBlockPos, to: YogBlockPos) -> YogOwnedStr,

    // ── ABI 3.1 — entity dimensions ─────────────────────────────────────────
    /// An entity's own hitbox and eye height (blocks), or vanilla's again
    /// (`width` < 0); `false` if there's no such entity.
    pub entity_set_dimensions:
        unsafe extern "C" fn(ctx: *mut c_void, uuid: YogStr, width: f32, height: f32, eye: f32) -> bool,

    // ── ABI 3.2 — entity data ───────────────────────────────────────────────
    /// Sets (`flags` & 1) or removes a value an entity keeps under `key`;
    /// `flags` & 2 saves it with the entity. The players who see the entity
    /// get it. `false` for an empty uuid or key.
    pub entity_data_set:
        unsafe extern "C" fn(ctx: *mut c_void, uuid: YogStr, key: YogStr, data: *const u8, len: u32, flags: u32) -> bool,
    /// The value under `key`, written to `sink`; `false` if there's none.
    pub entity_data_get:
        unsafe extern "C" fn(ctx: *mut c_void, uuid: YogStr, key: YogStr, sink: *mut c_void, write: YogBytesSink) -> bool,
}

// ctx = *mut JavaVM which is global/stable. All fn ptrs are pure C-ABI.
unsafe impl Send for YogServer {}
unsafe impl Sync for YogServer {}

// ── Chunk generator callback (ABI minor 29) ───────────────────────────────────

/// Per-callback context handed to a registered chunk generator (see
/// `YogApi::register_chunk_generator`) — mirrors `YogGfxApi`'s pattern of
/// bundling per-call context with the function pointer(s) needed to act on
/// it. Valid only for the duration of the generator callback.
#[repr(C)]
#[derive(Copy, Clone)]
pub struct YogChunkWriterApi {
    /// Chunk X coordinate (in chunks, not blocks).
    pub chunk_x: i32,
    /// Chunk Z coordinate (in chunks, not blocks).
    pub chunk_z: i32,
    /// Minimum build height (world Y) for this dimension.
    pub min_y: i32,
    /// Total world height for this dimension.
    pub height: i32,
    /// Opaque host-side handle for the chunk currently being generated.
    pub ctx: *mut c_void,
    /// Set a block within this chunk column. `x`/`z` are local (0..16)
    /// chunk-relative coordinates; `y` is world-absolute.
    pub set_block:
        unsafe extern "C" fn(ctx: *mut c_void, x: i32, y: i32, z: i32, block_id: YogStr) -> bool,
}

unsafe impl Send for YogChunkWriterApi {}
unsafe impl Sync for YogChunkWriterApi {}

/// Called by the host once per chunk column that needs generating in the
/// registered dimension. `writer` is valid only for the duration of the call.
pub type YogChunkGeneratorFn =
    unsafe extern "C" fn(ud: *mut c_void, writer: *const YogChunkWriterApi);

// ── Registration table (passed to yog_mod_register) ──────────────────────────

/// Passed to `yog_mod_register`. Call the function pointers here to register
/// handlers, commands, content, and schedulers.
///
/// When mods compiled against ABI `N` load on a runtime with ABI `M > N`:
/// fields beyond `size` are not present in the mod's view — check `size` before
/// accessing fields added in later minor versions.
#[repr(C)]
pub struct YogApi {
    pub abi_version: u32,
    /// `sizeof(YogApi)` at the runtime's build time.
    pub size: u32,
    /// Opaque pointer to runtime handler storage.
    pub ctx: *mut c_void,
    /// Stable server action table — pass to handlers.
    pub server: *const YogServer,

    // ── events — all handlers receive (ud, srv, event, phase: u8) → bool ────────
    // phase 0 = Pre (return false to cancel), phase 1 = Post (return ignored).
    pub on_block_break: unsafe extern "C" fn(ctx: *mut c_void, ud: *mut c_void, h: YogBlockBreakFn),
    pub on_chat: unsafe extern "C" fn(ctx: *mut c_void, ud: *mut c_void, h: YogChatFn),
    pub on_player_join: unsafe extern "C" fn(ctx: *mut c_void, ud: *mut c_void, h: YogPlayerFn),
    pub on_player_leave: unsafe extern "C" fn(ctx: *mut c_void, ud: *mut c_void, h: YogPlayerFn),
    pub on_use_item: unsafe extern "C" fn(ctx: *mut c_void, ud: *mut c_void, h: YogUseItemFn),
    pub on_use_block: unsafe extern "C" fn(ctx: *mut c_void, ud: *mut c_void, h: YogUseBlockFn),
    pub on_attack_entity:
        unsafe extern "C" fn(ctx: *mut c_void, ud: *mut c_void, h: YogAttackEntityFn),
    pub on_entity_damage:
        unsafe extern "C" fn(ctx: *mut c_void, ud: *mut c_void, h: YogEntityDamageFn),
    pub on_entity_death:
        unsafe extern "C" fn(ctx: *mut c_void, ud: *mut c_void, h: YogEntityDeathFn),
    pub on_entity_spawn:
        unsafe extern "C" fn(ctx: *mut c_void, ud: *mut c_void, h: YogEntitySpawnFn),
    pub on_player_place_block:
        unsafe extern "C" fn(ctx: *mut c_void, ud: *mut c_void, h: YogPlaceBlockFn),
    pub on_player_death:
        unsafe extern "C" fn(ctx: *mut c_void, ud: *mut c_void, h: YogPlayerDeathFn),
    pub on_player_respawn:
        unsafe extern "C" fn(ctx: *mut c_void, ud: *mut c_void, h: YogPlayerRespawnFn),
    pub on_advancement:
        unsafe extern "C" fn(ctx: *mut c_void, ud: *mut c_void, h: YogAdvancementFn),
    // ── ABI minor 8 ──────────────────────────────────────────────────────────
    pub on_entity_interact:
        unsafe extern "C" fn(ctx: *mut c_void, ud: *mut c_void, h: YogEntityInteractFn),
    pub on_item_craft: unsafe extern "C" fn(ctx: *mut c_void, ud: *mut c_void, h: YogCraftFn),
    pub on_explosion: unsafe extern "C" fn(ctx: *mut c_void, ud: *mut c_void, h: YogExplosionFn),
    // ── ABI minor 9 ──────────────────────────────────────────────────────────
    pub on_item_pickup: unsafe extern "C" fn(ctx: *mut c_void, ud: *mut c_void, h: YogItemPickupFn),
    pub on_item_insert: unsafe extern "C" fn(ctx: *mut c_void, ud: *mut c_void, h: YogItemInsertFn),
    pub on_player_move: unsafe extern "C" fn(ctx: *mut c_void, ud: *mut c_void, h: YogPlayerMoveFn),
    pub on_container_open:
        unsafe extern "C" fn(ctx: *mut c_void, ud: *mut c_void, h: YogContainerOpenFn),
    pub on_container_close:
        unsafe extern "C" fn(ctx: *mut c_void, ud: *mut c_void, h: YogContainerCloseFn),
    pub on_projectile_hit:
        unsafe extern "C" fn(ctx: *mut c_void, ud: *mut c_void, h: YogProjectileHitFn),
    pub on_server_tick: unsafe extern "C" fn(ctx: *mut c_void, ud: *mut c_void, h: YogServerFn),
    pub on_server_started: unsafe extern "C" fn(ctx: *mut c_void, ud: *mut c_void, h: YogServerFn),
    pub on_server_stopping: unsafe extern "C" fn(ctx: *mut c_void, ud: *mut c_void, h: YogServerFn),

    // ── networking ───────────────────────────────────────────────────────────
    pub on_packet:
        unsafe extern "C" fn(ctx: *mut c_void, channel: YogStr, ud: *mut c_void, h: YogPacketFn),
    pub on_client_packet:
        unsafe extern "C" fn(ctx: *mut c_void, channel: YogStr, ud: *mut c_void, h: YogPacketFn),

    // ── commands ─────────────────────────────────────────────────────────────
    pub register_command:
        unsafe extern "C" fn(ctx: *mut c_void, name: YogStr, ud: *mut c_void, h: YogCommandFn),
    pub register_typed_command: unsafe extern "C" fn(
        ctx: *mut c_void,
        name: YogStr,
        schema: YogStr,
        ud: *mut c_void,
        h: YogCommandFn,
    ),

    // ── content ──────────────────────────────────────────────────────────────
    /// Register content of `kind` (`item`, `block`, `inventory`, `recipe`,
    /// `book`, `dimension`, `startup_grant`) named `id`: its definition as
    /// a Yog Data blob (`yog_data::binary`, `len` bytes at `data`), the
    /// shape of `yog_registry`'s / `yog_inventory`'s definitions, a recipe
    /// in Yog's format, a book, a dimension. One call for every kind of
    /// content — new kinds need no new ABI.
    pub register_content: unsafe extern "C" fn(ctx: *mut c_void, kind: YogStr, id: YogStr, data: *const u8, len: usize),

    // ── scheduler ────────────────────────────────────────────────────────────
    pub schedule_once: unsafe extern "C" fn(
        ctx: *mut c_void,
        delay_ticks: u64,
        ud: *mut c_void,
        h: YogScheduledFn,
    ),
    pub schedule_repeating: unsafe extern "C" fn(
        ctx: *mut c_void,
        period_ticks: u64,
        ud: *mut c_void,
        h: YogScheduledFn,
    ),

    // ── ABI minor 10 — client-side events ────────────────────────────────────
    pub on_client_tick: unsafe extern "C" fn(ctx: *mut c_void, ud: *mut c_void, h: YogClientFn),
    pub on_hud_render: unsafe extern "C" fn(ctx: *mut c_void, ud: *mut c_void, h: YogHudRenderFn),
    pub on_key_press: unsafe extern "C" fn(ctx: *mut c_void, ud: *mut c_void, h: YogKeyPressFn),
    pub on_screen_open: unsafe extern "C" fn(ctx: *mut c_void, ud: *mut c_void, h: YogScreenFn),
    pub on_screen_close: unsafe extern "C" fn(ctx: *mut c_void, ud: *mut c_void, h: YogScreenFn),

    // ── ABI minor 14 — world render ──────────────────────────────────────────
    /// Register a handler that fires after world geometry is rendered.
    /// `gfx.view_proj` and `gfx.camera_pos` are filled; use them to project
    /// custom 3D geometry into clip space.
    pub on_world_render:
        unsafe extern "C" fn(ctx: *mut c_void, ud: *mut c_void, h: YogWorldRenderFn),

    // ── ABI minor 19 — UI system ──────────────────────────────────────────────
    /// Register a UI tree. `ui_id` is the unique identifier (e.g. "mymod:menu").
    /// `layout_json` is the serialized layout tree.
    /// `handler` is called when an interactive element is clicked/keyed.
    pub register_ui: unsafe extern "C" fn(
        ctx: *mut c_void,
        ui_id: YogStr,
        layout_json: YogStr,
        ud: *mut c_void,
        h: YogUIEventFn,
    ),

    // ── ABI minor 20 — per-UI screen renderer ────────────────────────────────
    /// Register a render callback that fires during `YogUIScreen.render()` for a
    /// specific UI id — i.e. AFTER the screen darkening, unlike `on_hud_render`.
    /// Reuses `YogHudRenderFn` (`fn(ud, gfx)`); `gfx.screen_w/h` are set.
    /// Clicks are forwarded as `"click:X:Y"` events to the `register_ui` handler
    /// so mods can do their own hit-testing with their stored layout.
    pub on_ui_render:
        unsafe extern "C" fn(ctx: *mut c_void, ui_id: YogStr, ud: *mut c_void, h: YogHudRenderFn),

    // ── ABI minor 22 — menu entry registration ──────────────────────────────
    /// Register a button/link that the host renders on vanilla screens
    /// (TitleScreen on Fabric, ModListScreen on Forge/NeoForge).
    /// `label` is the human-readable button text (e.g. "Yog Mods").
    /// `ui_id` is the Yog UI to open when clicked (e.g. "example:menu").
    pub register_menu_entry: unsafe extern "C" fn(ctx: *mut c_void, label: YogStr, ui_id: YogStr),

    // ── ABI minor 23 — installed mods listing ───────────────────────────────
    /// All installed mods as TSV, one per line:
    /// `source \t id \t name \t version \t authors \t description`
    /// where `source` is `yog` (a .yog mod) or `platform` (a loader mod, e.g.
    /// a Fabric/Forge jar). Tabs and newlines inside fields become spaces.
    /// Callable at any time after registration (also client-side).
    pub mods_list: unsafe extern "C" fn(ctx: *mut c_void) -> YogOwnedStr,
    /// Free a `YogOwnedStr` returned by an api-table call (same allocator as
    /// `YogServer::free_str`).
    pub free_str: unsafe extern "C" fn(ptr: *mut u8, len: u32),

    // ── ABI minor 24 — open a Yog UI screen ─────────────────────────────────
    /// Open the Yog UI registered as `ui_id` on the client (schedules onto the
    /// render thread). Client-side only; a no-op on dedicated servers.
    /// `modal` blocks game input; `pause` pauses a singleplayer game.
    pub ui_open: unsafe extern "C" fn(ctx: *mut c_void, ui_id: YogStr, modal: bool, pause: bool),

    // ── ABI minor 26 — inter-mod communication ─────────────────────────────
    /// Export a function pointer under `symbol` for the calling mod (`mod_id`).
    /// Other mods can import it via `interop_import`.
    pub interop_export:
        unsafe extern "C" fn(ctx: *mut c_void, mod_id: YogStr, symbol: YogStr, ptr: *const c_void),
    /// Import a function pointer exported by `mod_id` under `symbol`.
    /// Returns null if the symbol is not (yet) registered.
    pub interop_import:
        unsafe extern "C" fn(ctx: *mut c_void, mod_id: YogStr, symbol: YogStr) -> *const c_void,

    // ── ABI minor 29 — custom dimensions ────────────────────────────────────
    /// Register a chunk generator for a previously-declared dimension `id`.
    /// `handler` is called once per chunk column that needs generating —
    /// see `YogChunkWriterApi`/`YogChunkGeneratorFn`.
    pub register_chunk_generator:
        unsafe extern "C" fn(ctx: *mut c_void, id: YogStr, ud: *mut c_void, h: YogChunkGeneratorFn),

    // ── ABI minor 33 — closing Yog UI screens, consuming UI key events ──────
    /// Close the Yog UI screen showing `ui_id` (empty = whichever Yog UI
    /// screen is open). Scheduled onto the render thread, so it's safe to
    /// call from that screen's own event handler. Client-side only.
    pub ui_close: unsafe extern "C" fn(ctx: *mut c_void, ui_id: YogStr),
    /// Called from inside a `register_ui` handler while it handles a `key:`
    /// or `char:` event: the mod used the key, so the host skips its default
    /// handling (Esc closing the screen, Tab focus navigation, ...).
    pub ui_consume_event: unsafe extern "C" fn(ctx: *mut c_void),

    // ── ABI minor 33 — translations ─────────────────────────────────────────
    /// The text of translation key `key` (e.g. `mymod.screen.title`) in the
    /// game's current language, from the loaded lang files — resource packs
    /// and `.yog` mods' `assets/<ns>/lang/*.json` (compiled from `.yres`).
    /// `YogOwnedStr::NONE` when no language defines the key. Format
    /// specifiers (`%s`, `%1$s`) come back as-is. Free with `free_str`.
    /// Client-side; a dedicated server only knows `en_us`.
    pub translate: unsafe extern "C" fn(ctx: *mut c_void, key: YogStr) -> YogOwnedStr,

    // ── ABI minor 1 — client: screen flags, sounds, held items, keys ────────
    /// Like `ui_open`, with [`ui_flags`] bits: `MODAL`, `PAUSE`,
    /// `NO_BACKGROUND` (no dimmed/blurred world behind the screen).
    /// Client-side only.
    pub ui_open_flags: unsafe extern "C" fn(ctx: *mut c_void, ui_id: YogStr, flags: u32),
    /// Play sound event `sound_id` for the local player only: at the
    /// player's position, or (`looping`) as a loop that follows the player
    /// until `client_stop_sound`. Returns a handle (0 = failed).
    pub client_play_sound: unsafe extern "C" fn(
        ctx: *mut c_void,
        sound_id: YogStr,
        volume: f32,
        pitch: f32,
        looping: bool,
    ) -> u32,
    /// Stop a sound started by `client_play_sound` (0 or unknown: no-op).
    pub client_stop_sound: unsafe extern "C" fn(ctx: *mut c_void, handle: u32),
    /// Item id in the local player's main hand (`off_hand` false) or off
    /// hand, `YogOwnedStr::NONE` for air or no player. Free with `free_str`.
    pub client_held_item: unsafe extern "C" fn(ctx: *mut c_void, off_hand: bool) -> YogOwnedStr,
    /// Tints the block at `pos` in `dim` on this client (its faces with a
    /// tint index), `color` 0xRRGGBB; -1 clears it.
    pub client_set_block_tint: unsafe extern "C" fn(ctx: *mut c_void, dim: YogStr, pos: YogBlockPos, color: i64),
    /// Whether GLFW key `key` is held down right now (client window).
    pub client_key_down: unsafe extern "C" fn(ctx: *mut c_void, key: i32) -> bool,

    // ── ABI 2.1 — book pages drawn by mods ──────────────────────────────────
    /// Draw the pictures of book pages of type `drawn` whose `drawer` is
    /// `drawer` (`hexcasting:pattern`) — see [`YogPageDrawFn`].
    pub on_book_page:
        unsafe extern "C" fn(ctx: *mut c_void, drawer: YogStr, ud: *mut c_void, f: YogPageDrawFn),

    // ── ABI 2.2 — pictures in item tooltips ─────────────────────────────────
    /// A picture under the tooltip of item `item` (Hex Casting's scrolls
    /// show their pattern): `size` says whether a stack gets one and how
    /// big, `draw` draws it — see [`YogTooltipSizeFn`], [`YogTooltipDrawFn`].
    pub on_item_tooltip: unsafe extern "C" fn(
        ctx: *mut c_void,
        item: YogStr,
        ud: *mut c_void,
        size: YogTooltipSizeFn,
        draw: YogTooltipDrawFn,
    ),

    // ── ABI 2.3 — other mods ────────────────────────────────────────────────
    /// Whether mod `id` is loaded — a Yog mod or a Java one (Fabric's,
    /// Forge's or NeoForge's mod list).
    pub is_mod_loaded: unsafe extern "C" fn(ctx: *mut c_void, id: YogStr) -> bool,
    /// Calls into a Java mod's API by reflection: `expr` is a chain from a
    /// class — `virtuoel.pehkui.api.ScaleTypes.BASE.getScaleData($0).getScale()`
    /// — `$n` the `n`-th of `args`, a list in Yog Data text (an entity is
    /// `@entity:<uuid>`). The result in Yog Data text, or
    /// [`YogOwnedStr::NONE`] when the call failed (said in the log).
    /// Free with `free_str`.
    pub java_call: unsafe extern "C" fn(ctx: *mut c_void, expr: YogStr, args: YogStr) -> YogOwnedStr,

    // ── ABI 2.4 — a stack's own name and tooltip ────────────────────────────
    /// The name and tooltip lines of stacks of `item` from its custom data
    /// (a written blueprint shows its design) — see [`YogItemTextFn`].
    pub on_item_text: unsafe extern "C" fn(ctx: *mut c_void, item: YogStr, ud: *mut c_void, f: YogItemTextFn),

    // ── ABI 2.5 — machines ──────────────────────────────────────────────────
    /// A machine making a recipe — see [`YogMachineCraftEvent`].
    pub on_machine_craft: unsafe extern "C" fn(ctx: *mut c_void, ud: *mut c_void, f: YogMachineCraftFn),

    // ── ABI 3.0 — bodies, camera, movement (yog-body) ───────────────────────
    /// Asks the mods about entity `uuid`'s body each frame (`on`) or not.
    pub client_body_track: unsafe extern "C" fn(ctx: *mut c_void, uuid: YogStr, on: bool),
    /// The same for every entity of type `entity_type`.
    pub client_body_track_type: unsafe extern "C" fn(ctx: *mut c_void, entity_type: YogStr, on: bool),
    /// The body of a tracked entity, each frame — see [`YogBodyFn`].
    pub on_body: unsafe extern "C" fn(ctx: *mut c_void, ud: *mut c_void, f: YogBodyFn),
    /// The camera, each frame — see [`YogCameraFn`].
    pub on_camera: unsafe extern "C" fn(ctx: *mut c_void, ud: *mut c_void, f: YogCameraFn),
    /// The local player's travel step, each tick — see [`YogTravelFn`].
    pub on_travel: unsafe extern "C" fn(ctx: *mut c_void, ud: *mut c_void, f: YogTravelFn),

    // ── ABI 3.1 — entity dimensions (client) ────────────────────────────────
    /// This client's side of `entity_set_dimensions` (the local player
    /// collides with it); `width` < 0 gives vanilla's back.
    pub client_set_dimensions: unsafe extern "C" fn(ctx: *mut c_void, uuid: YogStr, width: f32, height: f32, eye: f32),

    // ── ABI 3.2 — entity data (client) ──────────────────────────────────────
    /// What this client was told the entity keeps under `key`, written to
    /// `sink`; `false` if nothing.
    pub client_entity_data:
        unsafe extern "C" fn(ctx: *mut c_void, uuid: YogStr, key: YogStr, sink: *mut c_void, write: YogBytesSink) -> bool,
}

/// Flag bits for [`YogApi::ui_open_flags`].
pub mod ui_flags {
    /// Blocks game input (what `ui_open`'s `modal` does).
    pub const MODAL: u32 = 1;
    /// Pauses a singleplayer game.
    pub const PAUSE: u32 = 1 << 1;
    /// Draws no background behind the screen: the world stays visible.
    pub const NO_BACKGROUND: u32 = 1 << 2;
}

unsafe impl Send for YogApi {}
unsafe impl Sync for YogApi {}

#[cfg(test)]
mod tests {
    use super::*;
    use std::mem::{align_of, size_of};

    /// Sizes and alignments of every type crossing the ABI, folded together.
    fn layout_fingerprint() -> u64 {
        macro_rules! layouts {
            ($($t:ty),* $(,)?) => { [$((stringify!($t), size_of::<$t>(), align_of::<$t>())),*] };
        }
        let all = layouts!(
            YogStr, YogOwnedStr, YogBlockPos, YogVec3, YogBlockBreakEvent, YogChatEvent, YogPlayerEvent,
            YogUseItemEvent, YogUseBlockEvent, YogAttackEntityEvent, YogEntityDamageEvent, YogEntityDeathEvent,
            YogEntitySpawnEvent, YogPlayerDeathEvent, YogPlayerRespawnEvent, YogAdvancementEvent,
            YogEntityInteractEvent, YogCraftEvent, YogExplosionEvent, YogItemPickupEvent, YogItemInsertEvent, YogPlayerMoveEvent,
            YogContainerOpenEvent, YogContainerCloseEvent, YogProjectileHitEvent, YogPlaceBlockEvent,
            YogPacketEvent, YogCommandEvent,
            YogKeyPressEvent, YogGfxApi, YogServer, YogChunkWriterApi, YogApi,
        );
        // FNV-1a over (name, size, align).
        let mut h: u64 = 0xcbf2_9ce4_8422_2325;
        for (name, size, align) in all {
            for b in name.bytes().chain((size as u64).to_le_bytes()).chain((align as u64).to_le_bytes()) {
                h = (h ^ b as u64).wrapping_mul(0x0100_0000_01b3);
            }
        }
        h
    }

    /// A type crossing the ABI changed without `ABI_VERSION` changing: bump
    /// `ABI_MINOR` (fields appended at the end) or `ABI_MAJOR` (anything
    /// else), then record the new fingerprint here.
    #[test]
    #[cfg(target_pointer_width = "64")]
    fn the_layout_matches_its_version() {
        assert_eq!((ABI_VERSION, layout_fingerprint()), (30002, 0x73ec_636f_fee7_29d4), "layout fingerprint: {:#x}", layout_fingerprint());
    }

    #[test]
    fn strings_cross_and_come_back() {
        let s = YogStr::from_str("Ünïcode ✓");
        assert_eq!(unsafe { s.as_str() }, "Ünïcode ✓");
        assert!(YogStr::EMPTY.is_empty());
        assert_eq!(unsafe { YogStr::EMPTY.as_str() }, "");
        let owned = YogOwnedStr::from_string("runtime".to_string());
        assert!(!owned.is_none() && owned.len == 7);
        assert!(YogOwnedStr::NONE.is_none());
        // What `free_str` does with it.
        drop(unsafe { Box::from_raw(std::ptr::slice_from_raw_parts_mut(owned.ptr, owned.len as usize)) });
    }
}