Hands-On Game Development with Rust/

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Adding the Monsters

Adding the Monsters

Learn how to add monsters.

We'll cover the following...

Monsters have a lot in common with the adventurer; they have a position and render information. However, they aren’t keyboard-controlled, and they shouldn’t have a Player tag. Instead, monsters need an Enemy tag component. Let’s add an Enemy tag component. Adding an Enemy tag in components.rs:

Rust 1.40.0
#[derive(Clone, Copy, Debug, PartialEq)]
pub struct Enemy;

An empty structure is all that’s required for a tag class. We still need a way to spawn monsters. Add aspawn_monster() function in spawner.rs. It’s very similar to the player-spawning code:

Rust 1.40.0
pub fn spawn_monster(
    ecs: &mut World, 
    rng: &mut RandomNumberGenerator, 
    pos : Point
) {
    ecs.push(
        (Enemy,
            pos,
            Render{
                color: ColorPair::new(WHITE, BLACK),
                glyph : match rng.range(0,4) {
                    0 => to_cp437('E'),
                    1 => to_cp437('O'),
                    2 => to_cp437('o'),
                    _ => to_cp437('g'),
                }
            }
        )
    );
}

To make things interesting, the spawning code ...