Added a new file drainage.clj which attempts to model rivers; moved

some functions from heightmap into utils; added a -archive option to
buildall as first step towards auto-building a Debian package for
Raspberry Pi.

buildall.sh

@@ -8,12 +8,15 @@
 
 # Simon Broooke <simon@jasmine.org.uk>
 
+# Variable and glag initialisation
+archive=FALSE
 email=`grep ${USER} /etc/passwd | awk -F\: '{print $5}' | awk -F\, '{print $4}'`
 fullname=`grep ${USER} /etc/passwd | awk -F\: '{print $5}' | awk -F\, '{print $1}'`
-webappsdir="/var/lib/tomcat7/webapps"
+old="unset"
 release=""
-trial="FALSE"
 tmp=buildall.tmp.$$
+trial="FALSE"
+webappsdir="/var/lib/tomcat7/webapps"
 
 # Builds the build signature properties in the manifest map file
 # expected arguments: old version tag, version tag, full name of user,
@@ -69,6 +72,7 @@ if [ $# -lt 1 ]
 then
 	cat <<-EOF 1>&2
 	Usage:
+    -archive           Create a tar archive of the current state of the source.
 	  -build             Build all components and commit to master.
 	  -email [ADDRESS]   Your email address, to be recorded in the build signature.
 	  -fullname [NAME]   Your full name, to be recorded in the build signature.
@@ -82,6 +86,8 @@ fi
 while (( "$#" ))
 do
 	case $1 in
+    -a|-archive)
+      archive="TRUE";;
 		-b|-build)
 			# 'build' is the expected normal case.
 			trial="FALSE";
@@ -256,3 +262,26 @@ do
 done
 
 
+if [ "${archive}" ]
+then
+  for dir in mw-*
+  do
+    pushd ${dir}
+    version=`cat project.clj | grep 'defproject mw' | sed 's/.*defproject mw-[a-z]* "\([A-Za-z0-9_.-]*\)".*/\1/'`
+    lein clean
+    popd
+  done
+
+  tmp=microworld-${version}
+  mkdir ${tmp}
+  pushd ${tmp}
+  for dir in ../mw-*
+  do
+    cp -r $dir .
+  done
+  popd
+  tar czvf ${tmp}.orig.tar.gz ${tmp}
+  rm -rf ${tmp}
+fi
+
+

src/mw_engine/drainage.clj

@@ -0,0 +1,42 @@
+;; Experimental, probably of no interest to anyone else; attempt to compute drainage on a world,
+;; assumed to have altitudes already set from a heighmap.
+
+(ns mw-engine.drainage
+  (:use mw-engine.utils
+        mw-engine.world))
+
+(defn rain-world
+  "Simulate rainfall on this `world`. TODO: Doesn't really work just now - should
+   rain more on west-facing slopes, and less to the east of high ground"
+  [world]
+  (map-world world (fn [world cell] (merge cell {:rainfall 1}))))
+
+(defn flow-contributors
+  "Return a list of the cells in this `world` which are higher than this
+  `cell` and for which this cell is the lowest neighbour"
+  [world cell]
+  (remove nil?
+          (map
+           (fn [n]
+             (cond (= cell (get-least-cell (get-neighbours world n) :altitude)) n))
+           (get-neighbours-with-property-value world (:x cell) (:y cell) 1
+                                                                  :altitude
+                                                                  (or (:altitude cell) 0) >))))
+
+(defn flow
+  "Compute the total flow upstream of this `cell` in this `world`, and return a cell identical
+   to this one but having a value of its flow property set from that computation.
+
+   Flow comes from a higher cell to a lower only if the lower is the lowest neighbour of the higher."
+   [world cell]
+      (merge cell
+           {:flow (+ (:rainfall cell)
+               (apply +
+                 (map (fn [neighbour] (:flow (flow world neighbour)))
+                      (flow-contributors world cell))))}))
+
+(defn flow-world
+  "Return a world like this `world`, but with cells tagged with the amount of
+   water flowing through them."
+  [world]
+  (map-world (rain-world world) flow))

src/mw_engine/heightmap.clj

@@ -6,21 +6,12 @@
 (ns mw-engine.heightmap
   (:import [java.awt.image BufferedImage])
   (:use mw-engine.utils
-        mw-engine.world)
+        mw-engine.world
+        mw-engine.drainage)
   (:require [fivetonine.collage.util :as collage :only [load-image]]
             [mikera.image.core :as imagez :only [filter-image get-pixels]]
             [mikera.image.filters :as filters]))
 
-(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."

src/mw_engine/utils.clj

@@ -3,6 +3,16 @@
 (ns mw-engine.utils
   (:require [clojure.math.combinatorics :as combo]))
 
+(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 member?
   "True if elt is a member of col."
   [elt col] (some #(= elt %) col))
@@ -138,6 +148,22 @@
   ([world cell state]
     (get-neighbours-with-state world cell 1 state)))
 
+(defn get-least-cell
+  "Return the cell from among these `cells` which has the lowest numeric value
+  for this `property`; if the property is absent or not a number, use this
+  `default`"
+  ([cells property default]
+  (cond
+   (empty? cells) nil
+   true (let [downstream (get-least-cell (rest cells) property default)]
+          (cond (<
+                 (or (property (first cells)) default)
+                 (or (property downstream) default)) (first cells)
+                true downstream))))
+  ([cells property]
+   (get-least-cell cells property (. Integer MAX_VALUE))))
+
+
 (defn- set-cell-property
   "If this `cell`s x and y properties are equal to these `x` and `y` values,
    return a cell like this cell but with the value of this `property` set to