Simon Brooke
e48ad3f891
heightmap, and, in doing so, added a potentially useful generalised function for mapping onto two dimensional arrays. Needs testing!
95 lines
3.8 KiB
Clojure
95 lines
3.8 KiB
Clojure
;; Functions to apply a heightmap to a world.
|
|
;;
|
|
;; Heightmaps are considered only as greyscale images, so colour is redundent (will be
|
|
;; ignored). Darker shades are higher.
|
|
|
|
(ns mw-engine.heightmap
|
|
(:import [java.awt.image BufferedImage])
|
|
(:use mw-engine.utils
|
|
mw-engine.world
|
|
;; interestingly the imagez load-image is failing for me, while the
|
|
;; collage version is problem free.
|
|
[mikera.image.core :only [filter-image get-pixels]]
|
|
[mikera.image.filters]
|
|
[fivetonine.collage.util]
|
|
))
|
|
|
|
(defn- abs
|
|
"Surprisingly, Clojure doesn't seem to have an abs function, or else I've
|
|
missed it. So here's one of my own. Maps natural numbers onto themselves,
|
|
and negative integers onto natural numbers. Also maps negative real numbers
|
|
onto positive real numbers.
|
|
|
|
* `n` a number, on the set of real numbers."
|
|
[n]
|
|
(cond (< n 0) (- 0 n) true n))
|
|
|
|
(defn tag-gradient
|
|
"Set the `gradient` property of this `cell` of this `world` to the difference in
|
|
altitude between its highest and lowest neghbours."
|
|
[cell world]
|
|
(let [heights (map '(:altitude %) (get-neighbours world cell))
|
|
highest (apply max heights)
|
|
lowest (apply min heights)]
|
|
#(merge cell {:gradient (- highest lowest)})))
|
|
|
|
(defn tag-gradients
|
|
"Set the `gradient` property of each cell in this `world` to the difference in
|
|
altitude between its highest and lowest neghbours."
|
|
(map-world world tag-gradient))
|
|
|
|
(defn transform-altitude
|
|
"Set the altitude of this cell from the corresponding pixel of this heightmap.
|
|
If the heightmap you supply is smaller than the world, this will break.
|
|
|
|
* `world` not actually used, but present to enable this function to be
|
|
passed as an argument to `mw-engine.utils/map-world`, q.v.
|
|
* `cell` a cell, as discussed in world.clj, q.v. Alternatively, a map;
|
|
* `heightmap` an (ideally) greyscale image, whose x and y dimensions should
|
|
exceed those of the world of which the `cell` forms part."
|
|
([world cell heightmap]
|
|
(transform-altitude cell heightmap))
|
|
([cell heightmap]
|
|
(merge cell
|
|
{:altitude
|
|
(+ (get-int cell :altitude)
|
|
(- 256
|
|
(abs
|
|
(mod
|
|
(.getRGB heightmap
|
|
(get-int cell :x)
|
|
(get-int cell :y)) 256))))})))
|
|
|
|
(defn- apply-heightmap-row
|
|
"Set the altitude of each cell in this sequence from the corresponding pixel
|
|
of this heightmap.
|
|
If the heightmap you supply is smaller than the world, this will break.
|
|
|
|
* `row` a row in a world, as discussed in world.clj, q.v. Alternatively, a
|
|
sequence of maps;
|
|
* `heightmap` an (ideally) greyscale image, whose x and y dimensions should
|
|
exceed those of the world of which the `cell` forms part."
|
|
[row heightmap]
|
|
(apply vector (map #(transform-altitude % heightmap) row)))
|
|
|
|
(defn apply-heightmap
|
|
"Apply the image file loaded from this path to this world, and return a world whose
|
|
altitudes are modified (added to) by the altitudes in the heightmap. It is assumed that
|
|
the heightmap is at least as large in x and y dimensions as the world.
|
|
|
|
* `world` a world, as defined in `world.clj`, q.v.; if world is not supplied,
|
|
a world the size of the heightmap will be created.
|
|
* `imagepath` a file path or URL which indicates an image file."
|
|
([world imagepath]
|
|
;; bizarrely, the collage load-util is working for me, but the imagez version isn't.
|
|
(let [heightmap (filter-image (grayscale)(load-image imagepath))]
|
|
(map-world
|
|
(map-world world transform-altitude (list heigtmap))
|
|
tag-gradient)))
|
|
([imagepath]
|
|
(let [heightmap (filter-image (grayscale)(load-image imagepath))
|
|
world (make-world (.getWidth heightmap) (.getHeight heightmap))]
|
|
(map-world
|
|
(map-world world transform-altitude (list heigtmap))
|
|
tag-gradient))))
|