hgr: sier: sorta going

This commit is contained in:
Vince Weaver 2021-04-12 21:39:26 -04:00
parent 39a9f765f7
commit 4d7374674e

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@ -36,8 +36,8 @@ HGR_Y = $E2
HGR_COLOR = $E4
HGR_HORIZ = $E5
NEXTCOL = $F6
SAVEX = $F7
SEVEN = $F6
NEXTCOL = $F7
XX_TH = $F8
XX_TL = $F9
YY = $FA
@ -88,6 +88,9 @@ sier_outer:
lda #$40 ; start on page2 ($4000)
sta GBASH
; lda #$7
; sta SEVEN
ldx #0 ; get X 0 for later
stx YY ; YY starts at 0
stx GBASL ; GBASL is $00
@ -131,6 +134,11 @@ sier_yloop:
ldy #0 ; y is x/7
ldx #0 ; XX
seven_loop:
lda #7
sta SEVEN
sier_xloop:
; want (YY-(XX*T)) & (XX+(YY*T)
@ -166,24 +174,22 @@ black:
ror NEXTCOL ; 5
txa ; 2
and #$7 ; 2
bne not_yet ; 2/3
inx
ror NEXTCOL ; 5
dec SEVEN
bne sier_xloop
lda NEXTCOL ; sign extend top bit,
cmp #$80 ; matches earlier cool colors
ror
; lda #$7f
lda NEXTCOL ; 3
sta (GBASL),Y ; 6
iny ; 2
not_yet:
;==================================
inx ; 2
bne sier_xloop ; 3/2
cpy #36
bne seven_loop ; 3/2
;=================