ZX FFI Reference Skill | Agent Skills

ZX FFI Reference

The ZX console provides a broad FFI surface. Always read nethercore/include/zx.rs for accurate signatures.

FFI Categories

| Category | Key Functions | Find In zx.rs | |----------|--------------|---------------| | System | delta_time, tick_count, log | Lines 1-100 | | Random | random, random_range, random_f32 | Search "random" | | Input | button_held, button_pressed, left_stick_x | Search "button" | | Camera | camera_set, camera_fov | Search "camera" | | Transforms | push_translate, push_rotate_y, push_scale, push_identity | Search "push_" | | Meshes | load_mesh, draw_mesh, cube, sphere | Search "mesh" | | Textures | load_texture, texture_bind | Search "texture" | | Materials | material_albedo, material_mre, material_normal | Search "material" | | Audio | load_sound, play_sound, music_play | Search "sound" | | 2D Drawing | draw_sprite, draw_text, draw_rect | Search "draw_" | | Environment | epu_set, epu_textures, epu_asset, draw_epu | Search "epu_" | | Debug | debug_register_*, debug_watch_*, debug_group_* | Search "debug_" |

Init-Only Functions

Must call only during init():

set_clear_color(color) - 0xRRGGBBAA
All rom_*(), load_*(), procedural mesh functions

Render-Only Functions

Call only during render():

All draw_* functions
camera_set(), camera_fov()
push_translate(), push_rotate_y(), push_scale()
texture_bind(), font_bind()
begin_pass(), begin_pass_stencil_write()
set_color(), z_index()
epu_set(), epu_textures(), epu_asset(), draw_epu()

Asset Loading

// In init()
let tex = rom_texture_str("player");
let mesh = rom_mesh_str("character");
let sfx = rom_sound_str("jump");
let music = rom_tracker_str("theme");

Transform State

There is no generic push/pop transform API. Compose transforms with the push_* calls, then use push_identity() (or transform_set() with a column-major 4x4 matrix) when starting an independent object.

// In render()
push_translate(x, y, z);
push_rotate_y(angle_degrees);
push_scale_uniform(scale);
draw_mesh(MESH);
push_identity();  // Reset before the next independent object

Resource Lifetime

Resource creation/loading is init-only. The FFI exposes no resource unload or free call; loaded handles live until game shutdown.

EPU Environment

The current EPU config is 16 u64 values (128 bytes). Select a source with epu_set(config_ptr), epu_textures(px, nx, py, ny, pz, nz), or epu_asset(id_ptr, id_len) before the geometry that should use it, then call draw_epu() afterward to draw the environment background. There is no EPU time-setting API; animate deterministic instruction parameters from game state.

For packed animation clips, keep rigs at 255 bones or fewer: the runtime skeleton path accepts 256, but the packed keyframe format stores bone_count as u8.

Coordinate System

Y-up, right-handed, -Z forward
When yaw=0, camera looks toward -Z
Angles in degrees for FFI functions

Agent Skills: ZX FFI Reference

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