The dev console

The dev console opens as a bar along the bottom of the game when you press `, in editor Play and in the built game. In the editor its prompt also sits under the Console panel. Each line runs the command its first word names: one of Eggy's, or one your game or a plugin adds. Tab completes commands, entity names and Component.field paths.

Command	What it does
`help [command]`	Lists every command, or shows how to use one.
`clear`	Clears the console.
`entities [text]`	Lists the named entities, or those whose name contains `text`, with their ids (`#12`).
`get <entity> <Component.field>`	Shows a component's field as ZON.
`set <entity> <Component.field> <zon>`	Sets a component's field from ZON.
`timescale [scale]`	Shows or sets how fast game time passes. `1` is normal and `0` pauses.
`physics [debug [on\|off]]`	Shows the physics precision and whether colliders are drawn; `debug on` draws every collider and contact, `debug` alone flips it.

An <entity> is its name, or # and its id. Quote a name that has spaces:

set Player Transform.position .{ 0, 5.5, 0 }
set "Main Camera" Camera.fov 70

entities, get and set look into the game's world, and say so when no game is loaded.

Add your own commands

List the commands in console_commands and run them in consoleCommand. This game adds a lives command that shows or sets how many lives are left:

const std = @import("std");
const eggy = @import("eggy");

pub const Game = struct {
    lives: u32 = 3,

    pub const console_commands = [_]eggy.dev_console.Command{
        .{ .name = "lives", .help = "Show or set the lives left", .usage = "[count]" },
    };

    pub fn consoleCommand(self: *Game, command: usize, app: *eggy.App, call: *eggy.dev_console.Call) !void {
        _ = app;
        switch (command) {
            0 => {
                if (call.arg(0)) |text| self.lives = try std.fmt.parseInt(u32, text, 10);
                call.print("lives: {d}", .{self.lives});
            },
            else => unreachable,
        }
    }
};

command is the command's position in console_commands, counting from 0. A plugin declares commands the same way, on its Plugin type. Build and press Play: help lists lives, Tab completes it, and lives 9 sets it.

`Call`	What it gives
`arg(i)`	The `i`th word after the name, counting from 0, or null if there isn't one. A word in quotes keeps its spaces.
`rest(i)`	The line from the `i`th word on, as it was typed, for a value with spaces in it such as ZON.
`print(fmt, args)`	Writes a line of output to the console.
`arena`	Memory that's freed when the command returns.

Return an error to fail: lives many fails at parseInt, and the console shows failed: InvalidCharacter.

A command's name is one word, and unique: two plugins can't declare the same one, and none can take one of Eggy's. Either is a compile error.

Open it from code, or turn it off

app.dev_console opens and closes the console (open, close, toggle), and its toggle_key changes the key, or turns it off with null, so you can open it from your own button.

caution

The console can do anything the game can. To keep it out of the game you ship, turn off Dev console in File > Project Settings (.dev_console = false in eggy.zon). The ` key then does nothing in Play or the built game; the editor's Console panel keeps its prompt.

Add your own commands​

Open it from code, or turn it off​

Add your own commands

Open it from code, or turn it off