40 lines
867 B
Fennel
40 lines
867 B
Fennel
(local {: lo : hi} (require :lib.util))
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(local {: vm : mapw : maph : rot8l} (require :neuttower.defs))
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(vm:def :lookup-flags ; itile -- flags
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[:lda vm.TOP :x]
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(rot8l 3) ; lllhhhhh > hhhhhlll
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[:adc #(lo ($1:lookup-addr :tileflags))]
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[:sta vm.W]
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[:lda #(hi ($1:lookup-addr :tileflags))]
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[:adc 0]
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[:sta vm.WH]
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[:ldy 0] [:lda [vm.W] :y]
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[:sta vm.TOP :x])
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(vm:def :map-at ; yx -- pmap
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[:lda (- maph 1)]
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[:sec]
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[:sbc vm.TOPH :x]
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[:asl :a] ; x2
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[:asl :a] ; x4
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[:sta vm.TOPH :x]
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[:asl :a] ; x8
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[:asl :a] ; x16
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[:clc] [:adc vm.TOPH :x] ; x20
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[:adc vm.TOP :x]
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[:sta vm.TOP :x]
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[:lda :map-page]
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[:sta vm.TOPH :x])
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(vm:word :itile-at ; yx -- itile
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:map-at :bget)
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(vm:word :update-itile ; yx itile --
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:over :map-at :bset :drawtile-at)
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(vm:word :drawtile-at ; yx --
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:dup :yx>screen :swap
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:itile-at :lookup-tile
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:drawtile)
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