4cade/src/textrank.a
2019-09-23 17:09:07 -07:00

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;license:MIT
;(c) 2018-9 by 4am & qkumba
;
; text rank - an implementation of the Quicksilver search rank algorithm
;
; Public functions
; - ResetTextRank
; - TextRankCallback (as okvs_iter_values callback)
;
; Public variables
; - InputLength ; [byte] number of characters typed in search mode
; - InputBuffer ; [25 bytes] characters typed in search mode
; - SelectedIndex ; [byte] index in gGamesListStore of currently selected game in search mode
; - MatchCount ; [byte] number of games that match InputBuffer
; - BestMatchScore ; [byte] raw ranking score (0-100) of current best match (updated during TextRankCallback)
; - BestMatchIndex ; [byte] index in gGamesListStore of current best match (updated during TextRankCallback)
MaxInputLength = 26
InputLength
!byte 0
InputBuffer
!text " "
;------------------------------------------------------------------------------
; ResetTextRank
; reset the Match variables to allow re-scanning (e.g. because of backspace)
; in: nothing
; out: X, MatchCount, BestMatchScore, BestMatchIndex zeroed
;------------------------------------------------------------------------------
ResetTextRank
ldx #0
stx MatchCount
stx BestMatchScore
dex
stx BestMatchIndex
rts
;------------------------------------------------------------------------------
; TextRankCallback
; callback called by okvs_iter_values on gGamesListStore
; to calculate a ranking score for a single game title
; against the current InputBuffer
; in: A/Y contains address of game title
; X contains 0-based index of the current record in gGamesListStore
; out: all registers and flags clobbered
; MatchCount possibly incremented (if this title was a match at all)
; BestMatchScore and BestMatchIndex possibly updated (if this title
; was the best match so far)
;------------------------------------------------------------------------------
TextRankCallback
stx tmpx ; X = OKVS index of this title
+STAY zpstring ; A/Y = address of this title
+LDADDR InputLength
+STAY zpword
ldy #0
lda (zpstring),y
cmp InputLength
bcc ++
sta gamelength
sty runningscore
sty runningscore+1
iny
sty startat
- sty i
lda (zpword),y
+LOW_ASCII_TO_LOWER
sta tmp
ldy startat
-- lda (zpstring),y
+LOW_ASCII_TO_LOWER
cmp tmp
beq +
cpy gamelength
iny
bcc --
++ rts ; no match :(
+ ldx #80
cpy startat
beq +
ldx #10
cpy #1
beq +
dey
lda (zpstring),y
iny
cmp #' '
bne +
ldx #90
+ txa
clc
adc runningscore
sta runningscore
bcc +
inc runningscore+1
+ tya
ldy i
cpy InputLength
bcs +
iny
sta startat
inc startat
cmp gamelength
bcc -
rts ; no match :(
+ lda runningscore
ldx runningscore+1
ldy gamelength
jsr @div
sta tmp
lda runningscore
ldx runningscore+1
ldy InputLength
jsr @div
clc
adc tmp
lsr
pha
ldy #1
lda (zpstring),y
+LOW_ASCII_TO_LOWER
sta firstletter
pla
ldx InputBuffer
cpx firstletter
bne +
cmp #85
bcs +
adc #15
+ cmp BestMatchScore
bcc +
beq +
sta BestMatchScore
ldx tmpx
stx BestMatchIndex
inc MatchCount
+ rts
@div
sta num1
stx num1+1
sty num2
lda #0
sta remainder
sta remainder+1
ldx #16
- asl num1
rol num1+1
rol remainder
rol remainder+1
lda remainder
sec
sbc num2
bcc +
sta remainder
dec remainder+1
inc num1
+ dex
bne -
lda num1
rts