dos33fsprogs/demos/trogdor/hgr_copy_magnify.s

133 lines
2.4 KiB
ArmAsm

;=============================================================
; hgr copy from page in A to current DRAW_PAGE but magnify 2x
;=========================================================
; SPRITE_X, SPRITE_Y = offset to load from
hgr_copy_magnify:
lda SPRITE_X
sta hcm_smc1+1
clc
adc #20
sta hcm_smc2+1
ldx #0 ; start at top
magnify_outer_loop:
txa
pha ; store X on stack
clc ; offset IN to our sprite
adc SPRITE_Y
tax
lda hposn_low,X
sta INL
lda hposn_high,X
clc
adc #$40 ; hardcode at $60
sta INH
pla ; get X off stack again
pha
asl ; multiply by 2
tax
lda hposn_low,X
sta OUTL
lda hposn_high,X
clc
adc DRAW_PAGE ; adjust for draw page
sta OUTH
inx ; calculate (x*2)+1
lda hposn_low,X
sta GBASL
lda hposn_high,X
clc
adc DRAW_PAGE
sta GBASH
hcm_smc1:
ldy #0 ; 2
magnify_inner_loop:
lda (INL),Y ; 5
and #$f ; 2
tax ; 2
lda magnify_table_low,X ; 4
sta (OUTL),Y ; output at 2*X ; 6
sta (GBASL),Y ; output at (2*X)+1 ; 6
inc OUTL ; point to next xpos ; 5
inc GBASL ; " ; 5
lda (INL),Y ; 5
lsr ; 2
lsr ; 2
lsr ; 2
tax ; 2
lda magnify_table_high,X ; 4
sta (OUTL),Y ; 6
sta (GBASL),Y ; 6
iny ; 2
hcm_smc2:
cpy #20 ; 2
bne magnify_inner_loop ; 2/3
pla ; get X off stack
tax
inx ; increment
cpx #96
bne magnify_outer_loop
rts
; XXXXABCD = XA BB CC DD
magnify_table_low:
.byte $00 ; 0000 => 000 0000
.byte $03 ; 0001 => 000 0011
.byte $0C ; 0010 => 000 1100
.byte $0F ; 0011 => 000 1111
.byte $30 ; 0100 => 011 0000
.byte $33 ; 0101 => 011 0011
.byte $3C ; 0110 => 011 1100
.byte $3F ; 0111 => 011 1111
.byte $40 ; 1000 => 100 0000
.byte $43 ; 1001 => 100 0011
.byte $4C ; 1010 => 100 1100
.byte $4F ; 1011 => 100 1111
.byte $70 ; 1100 => 111 0000
.byte $73 ; 1101 => 111 0011
.byte $7C ; 1110 => 111 1100
.byte $7F ; 1111 => 111 1111
; XEFGABCD = XE EF FG GA
magnify_table_high:
.byte $00 ; 0000 => 000 0000
.byte $01 ; 0001 => 000 0001
.byte $06 ; 0010 => 000 0110
.byte $07 ; 0011 => 000 0111
.byte $18 ; 0100 => 001 1000
.byte $19 ; 0101 => 001 1001
.byte $1E ; 0110 => 001 1110
.byte $1F ; 0111 => 001 1111
.byte $60 ; 1000 => 110 0000
.byte $61 ; 1001 => 110 0001
.byte $66 ; 1010 => 110 0110
.byte $67 ; 1011 => 110 0111
.byte $78 ; 1100 => 111 1000
.byte $79 ; 1101 => 111 1001
.byte $7E ; 1110 => 111 1110
.byte $7F ; 1111 => 111 1111