001 (ns walkmap.ocean
002 "Deal with (specifically, at this stage, cull) ocean areas"
003 (:require [walkmap.utils :refer [=ish]]))
004
005 (def ^:dynamic *sea-level*
006 "The sea level on heightmaps we're currently handling. If characters are to
007 be able to swin in the sea, we must model the sea bottom, so we need
008 heightmaps which cover at least the continental shelf. However, the sea
009 bottom is not walkable territory and can be culled from walkmaps.
010
011 **Note** must be a floating point number. `(= 0 0.0)` returns `false`!"
012 0.0)
013
014 (defn ocean?
015 "Of a `facet`, is the altitude of every vertice equal to `*sea-level*`?"
016 [facet]
017 (every?
018 #(=ish % *sea-level*)
019 (map :z (:vertices facet))))
020
021 (defn cull-ocean-facets
022 "Ye cannae walk on water. Remove all facets from this `stl` structure which
023 are at sea level."
024 [stl]
025 (assoc stl :facets (remove ocean? (:facets stl))))