Scripting

[rukai]

This is a big vague issue, I'm just collecting/publishing ideas here.

Needed for

• give fighters unique special abilities.
• unique game mechanics
• Ledge getup actions will use it for the following:
  • what frame to stop hogging
  • what frame to actually land/give control back to player
  • position offset from the ledge for each frame

Language choice

There a lot of options. The main ones include:

Rlua

• lua binding

Hlua

• lua binding

Rhai

Dyon

• Functional

Gluon

• Functional

Roll our own

• Would integrate better with treeflection
• Tailor syntax to our needs
• Would never be as nice as a proper language, dont have the resources to devote to such a task.

Scope

The scope for the scripting language is very important, some potential ideas:

• Move all game logic into script callbacks, things like collisionbox/stage collision are kept in rust.
• Each character gets their own script which is called during their step method.
• A unique script is stored for each action or frame for each character

Example Lua API

For each fighter there is a fighter.lua file containing the following functions:

spawn(usize player);
action(usize player, usize action, usize frame);
hitbox_collide(usize player, usize action, usize frame, int collision_flags);
hurtbox_collide(usize player, usize action, usize frame, int collision_flags);

The functions are called by pf sandbox when each event occurs.
They have access to an api:

set_acc_player(usize player, float x, float y);
get_acc_player(usize player, float x, float y);
set_vel_player(usize player, float x, float y);
get_vel_player(usize player, float x, float y);
set_pos_player(usize player, float x, float y);
get_pos_player(usize player, float x, float y);
set_action(usize player, usize action);
generate_entity(String name, float x, float y);
random(int max); // seeded determined at start of game + frame_index
// high and low level input e.g. can_jump and press_x