opengame-engine

WebAssembly bindings for the OpenGame 2D game engine — build browser-based 2D games with a full ECS, physics, and rendering pipeline.

Installation

npm install opengame-engine

Quick Start

import init, { Engine } from 'opengame-engine';

async function main() {
  await init();

  const engine = new Engine(800, 600);
  engine.set_clear_color(0.1, 0.1, 0.15, 1.0);
  engine.set_gravity(0, -400);

  // Spawn a dynamic entity
  const player = engine.spawn();
  engine.add_transform(player, 100, 300);
  engine.add_rigid_body(player, 'dynamic');
  engine.add_collider_rect(player, 32, 32);

  // Game loop
  let lastTime = performance.now();
  function loop() {
    const now = performance.now();
    const dt = (now - lastTime) / 1000;
    lastTime = now;

    engine.update(dt);

    const pos = engine.get_position(player);
    console.log(`Player: ${pos.x}, ${pos.y}`);

    requestAnimationFrame(loop);
  }
  requestAnimationFrame(loop);
}

main();

API

Engine

| Method | Description | |--------|-------------| | new(width, height) | Create engine with viewport dimensions | | set_clear_color(r, g, b, a) | Set background color (0.0–1.0) | | set_gravity(x, y) | Set gravity vector | | set_camera_position(x, y) | Set camera world position | | set_camera_zoom(zoom) | Set camera zoom level | | update(dt) | Advance physics simulation by dt seconds | | entity_count() | Get current entity count |

Entity Management

| Method | Description | |--------|-------------| | spawn() | Spawn a new entity, returns EntityHandle | | despawn(handle) | Remove an entity | | add_transform(handle, x, y) | Add position component | | add_rigid_body(handle, type) | Add rigid body ("dynamic", "kinematic", "static") | | add_collider_rect(handle, w, h) | Add rectangle collider | | add_collider_circle(handle, r) | Add circle collider |

Physics

| Method | Description | |--------|-------------| | apply_force(handle, fx, fy) | Apply continuous force | | apply_impulse(handle, ix, iy) | Apply instant impulse | | set_velocity(handle, vx, vy) | Set velocity directly | | get_position(handle) | Get entity position ({x, y}) | | set_position(handle, x, y) | Set entity position |

Math Utilities

| Function | Description | |----------|-------------| | lerp(a, b, t) | Linear interpolation | | clamp(value, min, max) | Clamp value to range | | smoothstep(edge0, edge1, x) | Hermite interpolation | | deg_to_rad(degrees) | Degrees to radians | | rad_to_deg(radians) | Radians to degrees | | version() | Engine version string |

License

MIT