lib-core.selection — v0.1.0

Click-Select + Drag-Box-Select + Selection-Set-State.

Quick Setup

local selection = require("lib-core.selection")
local input     = require("lib-core.input")

input.bind("lmb",        { "mouse_left" })
input.bind("mod_add",    { "shift" })
input.bind("mod_toggle", { "ctrl" })

selection.bind_action("lmb")
selection.bind_modifier_add("mod_add")
selection.bind_modifier_toggle("mod_toggle")

local handle = selection.register(function()
    return { x = entity.x, y = entity.y, w = entity.w, h = entity.h }
end)

-- per-frame:
function update(ctx, dt)  selection.update(dt)  end
function render(ctx)
    camera.begin()
        -- entities…
        selection.render_highlights()    -- world-space
    camera.finish()
    selection.render_drag_box()          -- screen-space
end

API

• Registry: register(aabb_fn) → handle, unregister(h), count_registered()
• Set-Query: list(), count(), contains(h), is_empty()
• Set-Mutation: add(h), remove(h), toggle(h), clear()
• Bindings: bind_action(name), bind_modifier_add(name), bind_modifier_toggle(name)
• State-Config: set_drag_threshold(px) / drag_threshold(), set_enabled(bool) / enabled()
• State-Query: drag_state() → "idle"|"ambiguous"|"dragging", box_rect() → {x,y,w,h}|nil
• Visual: set_drag_box_color(r,g,b,a) / drag_box_color(), set_highlight_color(r,g,b,a) / highlight_color()
• Per-Frame: update(dt), render_drag_box(), render_highlights()

See meta/docs/superpowers/specs/2026-05-14-p3-6-lib-selection-design.md for full design.