ludic/packages/ludic.aim
Orkuncakilkaya 56e4b6d688 feat(senses): walkers slide round still things, and lines of sight are the world's to answer
- ludic.wildlife: WildlifeWorld.push / pushed_x / pushed_z (defaults change nothing); a ground
  walker's step is slid clear of a still thing with a body from its species' size and scale, and
  a step that gets nowhere turns away as the water does. Birds are not pushed; no dice added.
- ludic.npc: NpcWorld.push / pushed_x / pushed_z (a person 0.35 m round) in npc_walk, and
  NpcWorld.clear (default true), which npc_line_ok asks at 1 m so a detour does not cut a trunk.
- ludic.aim: AimView.clear replaces AimView.ground and the ground march; the pick asks the line
  a body's width short of where the ray enters the thing (aim_clear_at(t, back)), so a solid
  thing does not hide itself. probe.ludic (the ground-agreement probe) and AimView.dry are gone.
- ludic.photo: PhotoLens.clear replaces PhotoLens.ground, PhotoLens.trunk and the march.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
2026-09-27 00:59:39 +03:00
..
tests feat(senses): walkers slide round still things, and lines of sight are the world's to answer 2026-09-27 00:59:39 +03:00
index.ludic feat(senses): walkers slide round still things, and lines of sight are the world's to answer 2026-09-27 00:59:39 +03:00
package.ludic feat(packages): ludic.aim - what the crosshair is on: a ray through the middle of the screen against upright cylinders widened by a fixed angular forgiveness, the nearest one the ground does not hide, reach floored at three metres, and which thing the use key means (that, nothing and say why, or the nearest); the probe of the ground's own answer against the aim; the camera, the ground and the body through a port 2026-09-25 09:07:51 +03:00
pick.ludic feat(senses): walkers slide round still things, and lines of sight are the world's to answer 2026-09-27 00:59:39 +03:00
ports.ludic feat(senses): walkers slide round still things, and lines of sight are the world's to answer 2026-09-27 00:59:39 +03:00
ray.ludic feat(senses): walkers slide round still things, and lines of sight are the world's to answer 2026-09-27 00:59:39 +03:00
README.md feat(senses): walkers slide round still things, and lines of sight are the world's to answer 2026-09-27 00:59:39 +03:00
use.ludic wip(0.S3): packages and examples migrated again from their pre-0.S sources in one run 2026-09-25 15:31:34 +03:00

ludic.aim

What the crosshair is on, and which thing the use key means. The crosshair is the exact middle of the screen and the projection is symmetric, so the ray through it is the camera's position along its forward - no unprojection. Each candidate is an upright cylinder widened by a fixed angular forgiveness, and the pick is the nearest one the ray enters that nothing hides: the line up to where the ray enters it is asked of the game (clear), so a thing that is itself solid does not hide itself. Uses ludic.base and nothing else.

import "ludic.aim"

The package keeps no list of things: the game offers every candidate each frame (aim_offer), keeps the object behind the id it gave, and draws the rim and the prompt.

The rule it keeps

The crosshair decides WHICH, the distance decides WHETHER (aim_use(kind)):

under the crosshair and in reach AIM_USE_THIS - that, whatever else is nearer
under the crosshair and too far, within AIM_USE_MAX (10 m) AIM_USE_NOTHING - and the prompt says why
nothing of that kind aimed at, or aimed past 10 m AIM_USE_NEAREST - proximity is right again

Every reach is floored at AIM_REACH_MIN (3 m) by aim_reach_of(reach): a per-kind reach chosen against its model was never chosen against standing between two props and looking at one. Anything that asks "am I close enough to this" asks aim_reach_of.

The port

export port AimView {
  x, y, z, fx, fy, fz, fov,       # the camera (the ray)
  clear: fn(ax, ay, az, bx, by, bz) -> bool,   # nothing between: the ground and every still thing
  body_x, body_z                  # distances and reach are the body's, not the camera's
}

Every member has a default: a camera 1.5 m up at the origin looking down -z at nothing in the way.

API

aim_begin(), aim_offer(kind, id, x, y0, y1, z, r, reach, far) -> bool a frame's candidates: true when this one is now the pick (reach AIM_NEVER is never in reach)
aim_kind() (AIM_NONE for nothing), aim_id(), aim_dist(), aim_in_reach(), aim_t(), aim_off_centre() the pick
aim_use(kind) -> AIM_USE_THIS / _NOTHING / _NEAREST, aim_reach_of(reach) the use key
aim_ray_cyl(cx, y0, y1, cz, r), aim_slack_m(dist), aim_clear_to(x, y, z), aim_clear_at(t, back), aim_range(x, z), aim_miss(cx, cz, r) the geometry, for a game's own probes (aim_clear_at: the ray clear to back short of t along it)

Tests

ludic test packages/ludic.aim

A camera over flat ground with a ridge: the ray against a cylinder, the forgiveness, near before far, the ridge hiding a thing and a solid thing not hiding itself, the reach floor and the three answers for the use key.