Emberware ZX API Reference

Emberware ZX is a 5th-generation fantasy console targeting PS1/N64/Saturn aesthetics with modern conveniences like deterministic rollback netcode.

Console Specs

Game Lifecycle

Games export three functions:

#![allow(unused)]
fn main() {
#[no_mangle]
pub extern "C" fn init() {
    // Called once at startup
    // Load resources, configure console settings
}

#[no_mangle]
pub extern "C" fn update() {
    // Called every tick (deterministic for rollback)
    // Update game state, handle input
}

#[no_mangle]
pub extern "C" fn render() {
    // Called every frame (skipped during rollback replay)
    // Draw to screen
}
}

Memory Model

Emberware ZX uses a 12MB ROM + 4MB RAM memory model:

• ROM (12MB): WASM bytecode + data pack (textures, meshes, sounds)
• RAM (4MB): WASM linear memory for game state
• VRAM (4MB): GPU textures and mesh buffers

Assets loaded via rom_* functions go directly to VRAM/audio memory, keeping RAM free for game state.

API Categories

Screen Capture

The host application includes screenshot and GIF recording capabilities:

Files are saved to:

• Screenshots: ~/.emberware/Emberware/screenshots/
• GIFs: ~/.emberware/Emberware/gifs/

Filenames include game name and timestamp (e.g., platformer_screenshot_2025-01-15_14-30-45.png).

Configuration (~/.emberware/config.toml):

[capture]
screenshot = "F9"
gif_toggle = "F10"
gif_fps = 30          # GIF framerate
gif_max_seconds = 60  # Max duration

Quick Links

• Cheat Sheet - All functions on one page
• Getting Started - Your first game
• Render Modes - Mode 0-3 explained
• Rollback Safety - Writing deterministic code

Building These Docs

These docs are built with mdBook.

# Install mdBook
cargo install mdbook

# Build static HTML (outputs to docs/book/book/)
cd docs/book
mdbook build

# Or serve locally with live reload
mdbook serve