Wiring up entities

game/entity.fnl

@@ -0,0 +1,55 @@
+(local {: lo : hi} (require :lib.util))
+
+; Entity memory layout:
+; +0 - yx
+; +2 - event handler
+; +4 - link word
+; +6 - link data
+
+; All entities exist in a single page in RAM - with this structure we can have up to 32
+; (players are handled specially and never require a link)
+; if we really need more we could have one page for entities and one page for link data
+; hellmaze level 2 from MS-DOS Neut Tower has 36 entities - good excuse to simplify IMO
+; The entity count for a level is stored after the map.
+
+(local ev {
+  :touch 0
+  :act   1
+  :deact 2
+  :tog   3
+})
+(fn install [vm entity-org]
+  (vm:word :entity-count :lit :map-entity-count :bget)
+  (vm:def :lookup-entity ; i -- entity
+    [:lda vm.TOP :x]
+    [:asl :a] [:asl :a] [:asl :a] ; x8
+    [:sta vm.TOP :x]
+    [:lda #(hi entity-org.org)]
+    [:sta vm.TOPH :x])
+  (vm:word :entity-at ; yx -- entity|0
+    :>r 0 :entity-count
+    (vm:while [:dup] :dec ; entity|0 i
+      :dup :lookup-entity :get :rtop :=
+      (vm:when :lookup-entity :swap)
+    ) :drop :rdrop)
+  (vm.code:append :responder [:dw 0])
+  (vm:word :entity>do ; entity ev --
+    :over :lit :responder :dup :get :>r :set
+    :swap 2 :+ :get :execute
+    :r> :lit :responder :set)
+
+  (vm:word :touch-entity ; yx -- f
+    :entity-at :dup (vm:when ev.touch :entity>do 1)))
+
+(fn append-from-map [map entity-org]
+  (each [_ entity (ipairs map.objects)]
+    (when entity.name
+      (entity-org:append entity.name))
+    (entity-org:append
+      [:db (- entity.x 1)] [:db (- entity.y 1)]
+      [:ref entity.func]
+      [:ref (if (and entity.linkword (> (length entity.linkword) 0)) entity.linkword :lit)]
+      (if entity.link [:dw (+ entity-org.org (* entity.link 8))] [:dw 0]))))
+
+{: ev : install : append-from-map}
+

game/init.fnl

@@ -2,13 +2,16 @@
 (local asm (require :asm.asm))
 (local VM (require :asm.vm))
 (local tile (require :game.tiles))
+(local entity (require :game.entity))
 (local link (require :link))
-(local {: lo : hi} (require :lib.util))
+(local {: lo : hi : readjson} (require :lib.util))
 (local {: walkable} tile.flag-to-bit)
 (local prg (asm.new))
 
 (local tiles-org (prg:org 0x4100))
+(local map-org (prg:org 0x4800))
 (local font-org (prg:org 0x4900))
+(local entity-org (prg:org 0x4b00))
 (local vm (VM.new prg))
 (local code1 vm.code)
 (local mapw 20)
@@ -280,8 +283,12 @@
 (vm:word :handle-key :read-key :move-jaye)
 (vm:word :bump-jaye ; dir yx -- yx
   :dup :>rot :yx+ ; yxold yxnew
+  :dup :touch-entity :not
+  (vm:when
     :dup :itile-at :lookup-flags ; yxold yxnew flags
-  walkable :& (vm:if [:swap :drop] [:drop]))
+    walkable :& (vm:when :swap)
+  )
+  :drop)
 
 (vm:word :move-jaye ; key --
   :movement-dir :dup (vm:if [
@@ -352,11 +359,13 @@
   (table.insert result :dismiss-dialog)
   result)
 
+(entity.install vm entity-org)
 (vm:word :hello-world
+  entity.ev.touch := (vm:when
     (with-footer
       (say :jaye "THAT WAS AN EARTHQUAKE!")
       (say :neut "GOLLY GEE JAYE, YOU'RE RIGHT!" "WHAT ARE WE GONNA DO??")
-    (say :jaye "WE" "MUST" "NOT" "PANIC!!")))
+      (say :jaye "WE" "MUST" "NOT" "PANIC!!"))))
 
 (tile.appendtiles tiles-org)
 
@@ -365,8 +374,10 @@
 ; but REPL debug stub should be very available as a task
 
 ; 20x12 means full map is 240 bytes - we have an extra 16 bytes at the end to mess with?
-(tile.appendmaps (prg:org 0x4800))
+(local map (readjson "game/map00001.json"))
+(tile.append-map map map-org)
 (tile.appendgfx font-org (tile.loadgfx tile.fn-font))
+(entity.append-from-map map entity-org)
 
 (code1:append :main
   [:jsr :reset]

game/map00001.json

@@ -1 +1 @@
-{"map":"212121214121212121212121212141212121212161026161610261616102616161616102616161216143C0C0E2C0C0C0C0C0C06361C0C0C0C0C0612161C0C0A282C0C0C0A2C0C0C081C0C0C0C0C2024161C0C0C0C0C0C0C0C0C2C0A2C1A2C0C0E082612161E2C08282C0C0C0C0A2C0C06161616161616121616161616161C181616161616143C0C0E282612161C0C0C0C0C0C0C0C0C0C0C061C0C0C0C0C0022161E08282A2C0C0C0C0E2C0C081C0C0C0C003612161E2C2C2C0C0C0C0C0C0C0C061C0C0C0C0C06141610303C063E2C0C0C0C0C0C061C0C0C023C061216161616161616161228161616161616161610221","objects":[{"func":"neutterm","x":17,"link":6,"y":8},{"func":"door","x":13,"y":9},{"func":"switch","x":13,"link":2,"y":8},{"func":"door","x":8,"y":6},{"func":"switch","x":7,"link":4,"y":6},{"func":"termtut","x":2,"link":1,"y":4},{"func":"scantut","x":9,"link":8,"y":1},{"x":10,"func":"exit","y":1,"name":"","linkword":""}]}
+{"map":"212121214121212121212121212141212121212161026161610261616102616161616102616161216143C0C0E2C0C0C0C0C0C06361C0C0C0C0C0612161C0C0A282C0C0C0A2C0C0C081C0C0C0C0C2024161C0C0C0C0C0C0C0C0C2C0A2C1A2C0C0E082612161E2C08282C0C0C0C0A2C0C06161616161616121616161616161C181616161616143C0C0E282612161C0C0C0C0C0C0C0C0C0C0C061C0C0C0C0C0022161E08282A2C0C0C0C0E2C0C081C0C0C0C003612161E2C2C2C0C0C0C0C0C0C0C061C0C0C0C0C06141610303C063E2C0C0C0C0C0C061C0C0C023C061216161616161616161228161616161616161610221","objects":[{"x":7,"func":"hello-world","linkword":"","name":"","y":6}]}

game/tiles.fnl

@@ -36,10 +36,9 @@
       (set flags (bit.bor flags (. flag-to-bit flag))))
     (org:append [:db flags])))
 
-(fn appendmaps [org]
-  (local map (util.readjson "game/map00001.json"))
-  (org:append :map [:bytes (map.map:fromhex)]))
+(fn append-map [map org]
+  (org:append :map [:bytes (map.map:fromhex)] :map-entity-count [:db (length map.objects)]))
 
-{: loadgfx : savegfx : appendtiles : appendgfx : appendmaps : flags : flag-to-bit
+{: loadgfx : savegfx : appendtiles : appendgfx : append-map : flags : flag-to-bit
  : fn-tiles : fn-portraits : fn-font}