a.m32: add state 'for_sprites_near_picnum'.

The state quries the user for four values: ref. picnum, target picnum, max.
ldist and a lotag.  Then, for all sprites i (of ref. picnum), for all sprites j
(of target picnum), if ldist(i,j)<=maxldist, sprite j's lotag is changed to the
provided one.

Also add lunatic/test/maputil.lua, containing a similar function but allowing
to customize the selection predicates of the ref. and target sprites, as well
as the action to carry out.

git-svn-id: https://svn.eduke32.com/eduke32@4414 1a8010ca-5511-0410-912e-c29ae57300e0

polymer/eduke32/package/sdk/samples/a.m32

@@ -1610,6 +1610,35 @@ defstate uniformfloor
         set sector[i].floorz avgz
 ends
 
+defstate for_sprites_near_picnum
+    "Ch. lotag for near spr."
+
+    var ii dst
+    var picnumi picnumj maxldist lotag
+
+    getnumberfromuser picnumi "picnum i: " MAXTILES 10
+    ifvarl picnumi 0 break
+    getnumberfromuser picnumj "picnum j: " MAXTILES 10
+    ifvarl picnumj 0 break
+
+    getnumberfromuser maxldist "max ldist: " 65536 8
+    ifvarl maxldist 0 break
+
+    getnumberfromuser lotag "lotag (unsigned) to change to: " 65536 8
+    ifvarl lotag 0 break
+
+    for i allsprites ife sprite[i].picnum picnumi
+        for j allsprites ife sprite[j].picnum picnumj
+        {
+            ldist dst i j
+            ifle dst maxldist
+                set sprite[j].lotag lotag
+        }
+
+    qsprintf TQUOTE "changed lotag of sprites w/ tile %d near those w/ tile %d to %d" picnumj picnumi lotag
+    quote TQUOTE
+ends
+
 // This must be *compiled* with script_expertmode
 /*
 defstate setstartpos

polymer/eduke32/source/lunatic/test/maputil.lua

@@ -0,0 +1,63 @@
+
+local xmath = require("xmath")
+
+local sprite = sprite
+
+--
+
+local maputil = {}
+
+-- csfunc = maputil.CreateCrossSpriteFunc(use_sprite_i_func, use_sprite_j_func)
+--
+-- use_sprite_i_func: function(spri, ud), where
+--   <spri> is a reference to sprite i
+-- use_sprite_j_func: function(sprj, spri, ud), where
+--   <spri> is a reference to sprite i
+--   <sprj> is a reference to sprite j
+--
+-- csfunc: function(userdata, process_sprite_j_func), where
+--   <userdata> is passed as <ud> to the functions described above
+--   <process_sprite_j_func>: function(sprj, spri, ud), the user-provided
+--     function that processes sprite j in some way
+function maputil.CreateCrossSpriteFunc(use_sprite_i_func, use_sprite_j_func)
+    return function(userdata, process_sprite_j_func)
+        for i in sprite.all() do
+            if (use_sprite_i_func(sprite[i], userdata)) then
+                for j in sprite.all() do
+                    if (use_sprite_j_func(sprite[j], sprite[i], userdata)) then
+                        process_sprite_j_func(sprite[j], sprite[i], userdata)
+                    end
+                end
+            end
+        end
+    end
+end
+
+
+-- Functions for "for all sprites Y of tile X that are closer than D, ..."
+-- Passed userdefs: { picnumi, picnumj, maxldist }
+local function snearpic_usei(spr, ud)
+    return spr.picnum == ud[1]
+end
+
+local function snearpic_usej(sprj, spri, ud)
+    return sprj.picnum == ud[2] and xmath.ldist(spri, sprj) <= ud[3]
+end
+
+local snearpic_func = maputil.CreateCrossSpriteFunc(snearpic_usei, snearpic_usej)
+
+-- maputil.for_sprites_near_picnum(picnumi, picnumj, dist, process_sprite_func)
+--
+-- Runs the following loop:
+--
+-- for all sprites i with tile <picnumi>,
+--   for all sprites j of tile <picnumj> that are closer to sprite i than <dist> [*],
+--     call process_sprite_func(sprite[j], sprite[i])
+--
+-- [*] using xmath.ldist()
+function maputil.for_sprites_near_picnum(picnumi, picnumj, dist, process_sprite_func)
+    snearpic_func({picnumi, picnumj, dist}, process_sprite_func)
+end
+
+
+return maputil