mirror of
https://github.com/lscharen/iigs-game-engine.git
synced 2024-12-01 23:51:12 +00:00
Break up large source code files to help with dependency ordering
This commit is contained in:
Lucas Scharenbroich
parent
76180b6feb
commit
29d70dc567
88
src/Math.s
Normal file
88
src/Math.s
Normal file
@ -0,0 +1,88 @@
|
|||||||
|
; Math-y functions
|
||||||
|
|
||||||
|
mx %00
|
||||||
|
|
||||||
|
; Special subroutine to divide the accumulator by 164 and return remainder in the Accumulator
|
||||||
|
;
|
||||||
|
; 164 = $A4 = 1010_0100
|
||||||
|
Mod164 cmp #%1010010000000000
|
||||||
|
bcc *+5
|
||||||
|
sbc #%1010010000000000
|
||||||
|
|
||||||
|
cmp #%0101001000000000
|
||||||
|
bcc *+5
|
||||||
|
sbc #%0101001000000000
|
||||||
|
|
||||||
|
cmp #%0010100100000000
|
||||||
|
bcc *+5
|
||||||
|
sbc #%0010100100000000
|
||||||
|
|
||||||
|
cmp #%0001010010000000
|
||||||
|
bcc *+5
|
||||||
|
sbc #%0001010010000000
|
||||||
|
|
||||||
|
cmp #%0000101001000000
|
||||||
|
bcc *+5
|
||||||
|
sbc #%0000101001000000
|
||||||
|
|
||||||
|
cmp #%0000010100100000
|
||||||
|
bcc *+5
|
||||||
|
sbc #%0000010100100000
|
||||||
|
|
||||||
|
cmp #%0000001010010000
|
||||||
|
bcc *+5
|
||||||
|
sbc #%0000001010010000
|
||||||
|
|
||||||
|
cmp #%0000000101001000
|
||||||
|
bcc *+5
|
||||||
|
sbc #%0000000101001000
|
||||||
|
|
||||||
|
cmp #%0000000010100100
|
||||||
|
bcc *+5
|
||||||
|
sbc #%0000000010100100
|
||||||
|
rts
|
||||||
|
|
||||||
|
; Special subroutine to divide the accumulator by 208 and return remainder in the Accumulator
|
||||||
|
;
|
||||||
|
; 208 = $D0 = 1101_0000
|
||||||
|
;
|
||||||
|
; There are probably faster hacks to divide a 16-bit unsigned value by 208
|
||||||
|
; https://www.drdobbs.com/parallel/optimizing-integer-division-by-a-constan/184408499
|
||||||
|
; https://embeddedgurus.com/stack-overflow/2009/06/division-of-integers-by-constants/
|
||||||
|
|
||||||
|
Mod208 cmp #%1101000000000000
|
||||||
|
bcc *+5
|
||||||
|
sbc #%1101000000000000
|
||||||
|
|
||||||
|
cmp #%0110100000000000
|
||||||
|
bcc *+5
|
||||||
|
sbc #%0110100000000000
|
||||||
|
|
||||||
|
cmp #%0011010000000000
|
||||||
|
bcc *+5
|
||||||
|
sbc #%0011010000000000
|
||||||
|
|
||||||
|
cmp #%0001101000000000
|
||||||
|
bcc *+5
|
||||||
|
sbc #%0001101000000000
|
||||||
|
|
||||||
|
cmp #%0000110100000000
|
||||||
|
bcc *+5
|
||||||
|
sbc #%0000110100000000
|
||||||
|
|
||||||
|
cmp #%0000011010000000
|
||||||
|
bcc *+5
|
||||||
|
sbc #%0000011010000000
|
||||||
|
|
||||||
|
cmp #%0000001101000000
|
||||||
|
bcc *+5
|
||||||
|
sbc #%0000001101000000
|
||||||
|
|
||||||
|
cmp #%0000000110100000
|
||||||
|
bcc *+5
|
||||||
|
sbc #%0000000110100000
|
||||||
|
|
||||||
|
cmp #%0000000011010000
|
||||||
|
bcc *+5
|
||||||
|
sbc #%0000000011010000
|
||||||
|
rts
|
||||||
237
src/blitter/Rotation.s
Normal file
237
src/blitter/Rotation.s
Normal file
@ -0,0 +1,237 @@
|
|||||||
|
; Support rotating the BG1 graphics by leveraging the fact that a rotation function can be decomposed
|
||||||
|
; into an addition of two function parametertized by the angle of rotation: pixel = *(f(x, a) + f(y, a))
|
||||||
|
;
|
||||||
|
; The pre-build a number of rotation tables and then populate the direct page values and Y-register values
|
||||||
|
; for each line of the blitter, such that a single lda (00),y instruction fetched the appropriate data
|
||||||
|
;
|
||||||
|
; This is about as fast of a rotation as we can do.
|
||||||
|
;
|
||||||
|
; When possible, off-screen locations are calculate to produce an address of $FFFE, so that the last two bytes
|
||||||
|
; of the BG1 data buffer provides the "fill value".
|
||||||
|
|
||||||
|
ANGLEBNK ext
|
||||||
|
ApplyBG1XPosAngle ENT
|
||||||
|
phb
|
||||||
|
phk
|
||||||
|
plb
|
||||||
|
jsr _ApplyBG1XPosAngle
|
||||||
|
plb
|
||||||
|
rtl
|
||||||
|
|
||||||
|
_ApplyBG1XPosAngle
|
||||||
|
; phy
|
||||||
|
|
||||||
|
; lda BG1StartX
|
||||||
|
; jsr Mod164
|
||||||
|
; sta BG1StartXMod164
|
||||||
|
|
||||||
|
; lda #162
|
||||||
|
; sec
|
||||||
|
; sbc StartXMod164
|
||||||
|
; bpl *+6
|
||||||
|
; clc
|
||||||
|
; adc #164
|
||||||
|
; clc
|
||||||
|
; adc BG1StartXMod164
|
||||||
|
; cmp #164
|
||||||
|
; bcc *+5
|
||||||
|
; sbc #164
|
||||||
|
|
||||||
|
; clc
|
||||||
|
; adc 1,s
|
||||||
|
; tay ; cache the value
|
||||||
|
|
||||||
|
; pla ; pop the value
|
||||||
|
phd ; save the direct page because we are going to switch to the
|
||||||
|
lda BlitterDP ; blitter direct page space and fill in the addresses
|
||||||
|
tcd
|
||||||
|
|
||||||
|
lda #^ANGLEBNK
|
||||||
|
sta $fe
|
||||||
|
sty $fc ; Store in the new direct page
|
||||||
|
ldy #162
|
||||||
|
tyx
|
||||||
|
:loop
|
||||||
|
lda [$fc],y
|
||||||
|
sta 00,x ; store the value
|
||||||
|
dey
|
||||||
|
dey
|
||||||
|
dex
|
||||||
|
dex
|
||||||
|
bpl :loop
|
||||||
|
pld
|
||||||
|
rts
|
||||||
|
|
||||||
|
ApplyBG1YPosAngle ENT
|
||||||
|
phb
|
||||||
|
phk
|
||||||
|
plb
|
||||||
|
jsr _ApplyBG1YPosAngle
|
||||||
|
plb
|
||||||
|
rtl
|
||||||
|
|
||||||
|
_ApplyBG1YPosAngle
|
||||||
|
:virt_line equ tmp0
|
||||||
|
:lines_left equ tmp1
|
||||||
|
:draw_count equ tmp2
|
||||||
|
:ytbl_idx equ tmp3
|
||||||
|
:angle_tbl equ tmp4
|
||||||
|
|
||||||
|
sty :angle_tbl
|
||||||
|
|
||||||
|
lda BG1StartY
|
||||||
|
jsr Mod208
|
||||||
|
sta BG1StartYMod208
|
||||||
|
sta :ytbl_idx ; Start copying from the first entry in the table
|
||||||
|
|
||||||
|
lda StartYMod208 ; This is the base line of the virtual screen
|
||||||
|
sta :virt_line ; Keep track of it
|
||||||
|
|
||||||
|
lda ScreenHeight
|
||||||
|
sta :lines_left
|
||||||
|
|
||||||
|
:loop
|
||||||
|
lda :virt_line
|
||||||
|
asl
|
||||||
|
tax
|
||||||
|
ldal BTableLow,x ; Get the address of the first code field line
|
||||||
|
tay
|
||||||
|
|
||||||
|
sep #$20
|
||||||
|
ldal BTableHigh,x
|
||||||
|
pha ; push the bank on the stack
|
||||||
|
plb
|
||||||
|
rep #$20
|
||||||
|
|
||||||
|
lda :virt_line
|
||||||
|
and #$000F
|
||||||
|
eor #$FFFF
|
||||||
|
inc
|
||||||
|
clc
|
||||||
|
adc #16
|
||||||
|
min :lines_left
|
||||||
|
|
||||||
|
sta :draw_count ; Do this many lines
|
||||||
|
asl
|
||||||
|
tax
|
||||||
|
|
||||||
|
lda :ytbl_idx ; Read from this location (duplicate every 4 lines)
|
||||||
|
lsr
|
||||||
|
lsr
|
||||||
|
asl
|
||||||
|
clc
|
||||||
|
adc :angle_tbl
|
||||||
|
sec
|
||||||
|
sbc #ANGLEBNK
|
||||||
|
jsr CopyAngleYTableToBG1Addr ; or CopyBG1YTableToBG1Addr2
|
||||||
|
|
||||||
|
lda :virt_line ; advance to the virtual line after the segment we just
|
||||||
|
clc ; filled in
|
||||||
|
adc :draw_count
|
||||||
|
sta :virt_line
|
||||||
|
|
||||||
|
lda :ytbl_idx ; advance the index into the YTable
|
||||||
|
adc :draw_count
|
||||||
|
sta :ytbl_idx
|
||||||
|
|
||||||
|
lda :lines_left ; subtract the number of lines we just completed
|
||||||
|
sec
|
||||||
|
sbc :draw_count
|
||||||
|
sta :lines_left
|
||||||
|
|
||||||
|
jne :loop
|
||||||
|
|
||||||
|
phk
|
||||||
|
plb
|
||||||
|
rts
|
||||||
|
|
||||||
|
; Unrolled copy routine to move y_angle entries into BG1_ADDR position with an additional
|
||||||
|
; shift. This has to be split into two
|
||||||
|
;
|
||||||
|
; A = index into the array (x2)
|
||||||
|
; Y = starting line * $1000
|
||||||
|
; X = number of lines (x2)
|
||||||
|
CopyAngleYTableToBG1Addr
|
||||||
|
phx
|
||||||
|
phb
|
||||||
|
|
||||||
|
phk ; restore access to this bank
|
||||||
|
plb
|
||||||
|
jsr SaveBG1AngleValues
|
||||||
|
|
||||||
|
plb
|
||||||
|
plx ; x is used directly in this routine
|
||||||
|
jsr ApplyBG1OffsetValues
|
||||||
|
rts
|
||||||
|
|
||||||
|
SaveBG1AngleValues
|
||||||
|
jmp (:tbl,x)
|
||||||
|
:tbl da :none
|
||||||
|
da :do01,:do02,:do03,:do04
|
||||||
|
da :do05,:do06,:do07,:do08
|
||||||
|
da :do09,:do10,:do11,:do12
|
||||||
|
da :do13,:do14,:do15,:do16
|
||||||
|
:do15 tax
|
||||||
|
bra :x15
|
||||||
|
:do14 tax
|
||||||
|
bra :x14
|
||||||
|
:do13 tax
|
||||||
|
bra :x13
|
||||||
|
:do12 tax
|
||||||
|
bra :x12
|
||||||
|
:do11 tax
|
||||||
|
bra :x11
|
||||||
|
:do10 tax
|
||||||
|
bra :x10
|
||||||
|
:do09 tax
|
||||||
|
bra :x09
|
||||||
|
:do08 tax
|
||||||
|
bra :x08
|
||||||
|
:do16 tax
|
||||||
|
ldal ANGLEBNK+06,x
|
||||||
|
sta BG1YCache+30
|
||||||
|
:x15 ldal ANGLEBNK+06,x
|
||||||
|
sta BG1YCache+28
|
||||||
|
:x14 ldal ANGLEBNK+06,x
|
||||||
|
sta BG1YCache+26
|
||||||
|
:x13 ldal ANGLEBNK+06,x
|
||||||
|
sta BG1YCache+24
|
||||||
|
:x12 ldal ANGLEBNK+04,x
|
||||||
|
sta BG1YCache+22
|
||||||
|
:x11 ldal ANGLEBNK+04,x
|
||||||
|
sta BG1YCache+20
|
||||||
|
:x10 ldal ANGLEBNK+04,x
|
||||||
|
sta BG1YCache+18
|
||||||
|
:x09 ldal ANGLEBNK+04,x
|
||||||
|
sta BG1YCache+16
|
||||||
|
:x08 ldal ANGLEBNK+02,x
|
||||||
|
sta BG1YCache+14
|
||||||
|
:x07 ldal ANGLEBNK+02,x
|
||||||
|
sta BG1YCache+12
|
||||||
|
:x06 ldal ANGLEBNK+02,x
|
||||||
|
sta BG1YCache+10
|
||||||
|
:x05 ldal ANGLEBNK+02,x
|
||||||
|
sta BG1YCache+08
|
||||||
|
:x04 ldal ANGLEBNK+00,x
|
||||||
|
sta BG1YCache+06
|
||||||
|
:x03 ldal ANGLEBNK+00,x
|
||||||
|
sta BG1YCache+04
|
||||||
|
:x02 ldal ANGLEBNK+00,x
|
||||||
|
sta BG1YCache+02
|
||||||
|
:x01 ldal ANGLEBNK+00,x
|
||||||
|
sta BG1YCache+00
|
||||||
|
:none rts
|
||||||
|
:do07 tax
|
||||||
|
bra :x07
|
||||||
|
:do06 tax
|
||||||
|
bra :x06
|
||||||
|
:do05 tax
|
||||||
|
bra :x05
|
||||||
|
:do04 tax
|
||||||
|
bra :x04
|
||||||
|
:do03 tax
|
||||||
|
bra :x03
|
||||||
|
:do02 tax
|
||||||
|
bra :x02
|
||||||
|
:do01 tax
|
||||||
|
bra :x01
|
||||||
320
src/blitter/TemplateUtils.s
Normal file
320
src/blitter/TemplateUtils.s
Normal file
@ -0,0 +1,320 @@
|
|||||||
|
; Untility function related to patching and manipulating the blitter template code
|
||||||
|
|
||||||
|
mx %00
|
||||||
|
|
||||||
|
; Generalized routine that calculates the on-screen address of the tiles and takes the
|
||||||
|
; StartX and StartY values into consideration. This routine really exists to support
|
||||||
|
; the dirty tile rendering mode and the tiles *must* be aligned with the playfield.
|
||||||
|
; That is, StartX % 4 == 0 and StartY % 8 == 0. If these conditions are not met, then
|
||||||
|
; screen will not render correctly.
|
||||||
|
_RecalcTileScreenAddrs
|
||||||
|
NextColPtr equ tmp0
|
||||||
|
RowAddrPtr equ tmp1
|
||||||
|
OnScreenAddr equ tmp2
|
||||||
|
Counter equ tmp3
|
||||||
|
|
||||||
|
jsr _OriginToTileStore ; Get the (col,row) of the tile in the upper-left corner of the playfield
|
||||||
|
|
||||||
|
; Manually add the offsets to the NextCol and TileStoreYTable array address and put in a direct page
|
||||||
|
; location so we can free up the registers.
|
||||||
|
|
||||||
|
clc
|
||||||
|
txa
|
||||||
|
adc #NextCol
|
||||||
|
sta NextColPtr
|
||||||
|
|
||||||
|
tya
|
||||||
|
adc #TileStoreYTable
|
||||||
|
sta RowAddrPtr
|
||||||
|
|
||||||
|
; Calculate the on-screen address of the upper-left corner of the playfiled
|
||||||
|
|
||||||
|
lda ScreenY0 ; Calculate the address of the first byte
|
||||||
|
asl ; of the right side of the playfield
|
||||||
|
tax
|
||||||
|
lda ScreenAddr,x ; This is the address for the left edge of the physical screen
|
||||||
|
clc
|
||||||
|
adc ScreenX0
|
||||||
|
sta OnScreenAddr
|
||||||
|
|
||||||
|
; Now, loop through the tile store
|
||||||
|
|
||||||
|
lda #MAX_TILES
|
||||||
|
sta Counter
|
||||||
|
ldy #0
|
||||||
|
:tsloop
|
||||||
|
lda (NextColPtr),y ; Need to recalculate each time since the wrap-around could
|
||||||
|
clc ; happen anywhere
|
||||||
|
adc (RowAddrPtr) ;
|
||||||
|
tax ; NOTE: Try to rework to use new TileStore2DLookup array
|
||||||
|
|
||||||
|
lda OnScreenAddr
|
||||||
|
stal TileStore+TS_SCREEN_ADDR,x
|
||||||
|
|
||||||
|
clc
|
||||||
|
adc #4 ; Go to the next tile
|
||||||
|
|
||||||
|
iny
|
||||||
|
iny
|
||||||
|
cpy #2*41 ; If we've done 41 columns, move to the next line
|
||||||
|
bcc :nohop
|
||||||
|
|
||||||
|
inc RowAddrPtr ; Advance the row address (with wrap-around)
|
||||||
|
inc RowAddrPtr
|
||||||
|
ldy #0 ; Reset the column counter
|
||||||
|
clc
|
||||||
|
adc #{8*160}-{4*41}
|
||||||
|
:nohop
|
||||||
|
sta OnScreenAddr ; Save the updated on-screen address
|
||||||
|
dec Counter
|
||||||
|
bne :tsloop
|
||||||
|
|
||||||
|
rts
|
||||||
|
|
||||||
|
|
||||||
|
; Patch an 8-bit or 16-bit valueS into the bank. These are a set up unrolled loops to
|
||||||
|
; quickly patch in a constanct value, or a value from an array into a given set of
|
||||||
|
; templates.
|
||||||
|
;
|
||||||
|
; Because we have structured everything as parallel code blocks, most updates to the blitter
|
||||||
|
; reduce to storing a constant value and have an amortized cost of just a single store.
|
||||||
|
;
|
||||||
|
; The utility of these routines is that they also handle setting just a range of lines
|
||||||
|
; within a single bank.
|
||||||
|
;
|
||||||
|
; X = number of lines * 2, 0 to 32
|
||||||
|
; Y = starting line * $1000
|
||||||
|
; A = value
|
||||||
|
;
|
||||||
|
; Set M to 0 or 1
|
||||||
|
SetConst ; Need a blank line here, otherwise the :tbl local variable resolveds backwards
|
||||||
|
jmp (:tbl,x)
|
||||||
|
:tbl da :bottom-00,:bottom-03,:bottom-06,:bottom-09
|
||||||
|
da :bottom-12,:bottom-15,:bottom-18,:bottom-21
|
||||||
|
da :bottom-24,:bottom-27,:bottom-30,:bottom-33
|
||||||
|
da :bottom-36,:bottom-39,:bottom-42,:bottom-45
|
||||||
|
da :bottom-48
|
||||||
|
:top sta $F000,y
|
||||||
|
sta $E000,y
|
||||||
|
sta $D000,y
|
||||||
|
sta $C000,y
|
||||||
|
sta $B000,y
|
||||||
|
sta $A000,y
|
||||||
|
sta $9000,y
|
||||||
|
sta $8000,y
|
||||||
|
sta $7000,y
|
||||||
|
sta $6000,y
|
||||||
|
sta $5000,y
|
||||||
|
sta $4000,y
|
||||||
|
sta $3000,y
|
||||||
|
sta $2000,y
|
||||||
|
sta $1000,y
|
||||||
|
sta: $0000,y
|
||||||
|
:bottom rts
|
||||||
|
|
||||||
|
; SetDPAddrs
|
||||||
|
;
|
||||||
|
; A = absolute address (largest)
|
||||||
|
; Y = offset
|
||||||
|
;
|
||||||
|
; Initializes a bank of direct page offsets
|
||||||
|
SetDPAddrs
|
||||||
|
lda #$0800
|
||||||
|
sta $F000,y
|
||||||
|
lda #$0700
|
||||||
|
sta $E000,y
|
||||||
|
lda #$0600
|
||||||
|
sta $D000,y
|
||||||
|
lda #$0500
|
||||||
|
sta $C000,y
|
||||||
|
lda #$0400
|
||||||
|
sta $B000,y
|
||||||
|
lda #$0300
|
||||||
|
sta $A000,y
|
||||||
|
lda #$0200
|
||||||
|
sta $9000,y
|
||||||
|
lda #$0100
|
||||||
|
sta: $8000,y
|
||||||
|
|
||||||
|
lda #$0800
|
||||||
|
sta $7000,y
|
||||||
|
lda #$0700
|
||||||
|
sta $6000,y
|
||||||
|
lda #$0600
|
||||||
|
sta $5000,y
|
||||||
|
lda #$0500
|
||||||
|
sta $4000,y
|
||||||
|
lda #$0400
|
||||||
|
sta $3000,y
|
||||||
|
lda #$0300
|
||||||
|
sta $2000,y
|
||||||
|
lda #$0200
|
||||||
|
sta $1000,y
|
||||||
|
lda #$0100
|
||||||
|
sta: $0000,y
|
||||||
|
rts
|
||||||
|
|
||||||
|
; SetAbsAddrs
|
||||||
|
;
|
||||||
|
; A = absolute address (largest)
|
||||||
|
; Y = offset
|
||||||
|
; X = number of lines
|
||||||
|
;
|
||||||
|
; Stores a value and decrements by $1000 for each line
|
||||||
|
SetAbsAddrs sec
|
||||||
|
jmp (:tbl,x)
|
||||||
|
:tbl da :bottom-00,:bottom-03,:bottom-09,:bottom-15
|
||||||
|
da :bottom-21,:bottom-27,:bottom-33,:bottom-39
|
||||||
|
da :bottom-45,:bottom-51,:bottom-57,:bottom-63
|
||||||
|
da :bottom-69,:bottom-75,:bottom-81,:bottom-87
|
||||||
|
da :bottom-93
|
||||||
|
:top sta $F000,y
|
||||||
|
sbc #$1000
|
||||||
|
sta $E000,y
|
||||||
|
sbc #$1000
|
||||||
|
sta $D000,y
|
||||||
|
sbc #$1000
|
||||||
|
sta $C000,y
|
||||||
|
sbc #$1000
|
||||||
|
sta $B000,y
|
||||||
|
sbc #$1000
|
||||||
|
sta $A000,y
|
||||||
|
sbc #$1000
|
||||||
|
sta $9000,y
|
||||||
|
sbc #$1000
|
||||||
|
sta $8000,y
|
||||||
|
sbc #$1000
|
||||||
|
sta $7000,y
|
||||||
|
sbc #$1000
|
||||||
|
sta $6000,y
|
||||||
|
sbc #$1000
|
||||||
|
sta $5000,y
|
||||||
|
sbc #$1000
|
||||||
|
sta $4000,y
|
||||||
|
sbc #$1000
|
||||||
|
sta $3000,y
|
||||||
|
sbc #$1000
|
||||||
|
sta $2000,y
|
||||||
|
sbc #$1000
|
||||||
|
sta $1000,y
|
||||||
|
sbc #$1000
|
||||||
|
sta: $0000,y
|
||||||
|
:bottom rts
|
||||||
|
|
||||||
|
; Fill up a full bank with blitter templates. Currently we can fit 16 lines per bank, so need
|
||||||
|
; a total of 13 banks to hold the 208 lines for full-screen support
|
||||||
|
;
|
||||||
|
; A = high word of bank table
|
||||||
|
; Y = index * 4 of the bank to initialize
|
||||||
|
BuildBank
|
||||||
|
|
||||||
|
:bankArray equ tmp0
|
||||||
|
:target equ tmp2
|
||||||
|
:nextBank equ tmp4
|
||||||
|
|
||||||
|
stx :bankArray
|
||||||
|
sta :bankArray+2
|
||||||
|
|
||||||
|
stz :target
|
||||||
|
iny
|
||||||
|
iny
|
||||||
|
lda [:bankArray],y
|
||||||
|
sta :target+2
|
||||||
|
|
||||||
|
iny ; move to the next item
|
||||||
|
iny
|
||||||
|
iny ; middle byte
|
||||||
|
cpy #4*13 ; if greater than the array length, wrap back to zero
|
||||||
|
bcc :ok
|
||||||
|
ldy #1
|
||||||
|
:ok lda [:bankArray],y ; Get the middle and high bytes of the address
|
||||||
|
sta :nextBank
|
||||||
|
|
||||||
|
:next
|
||||||
|
jsr :BuildLine2
|
||||||
|
lda :target
|
||||||
|
clc
|
||||||
|
adc #$1000
|
||||||
|
sta :target
|
||||||
|
bcc :next
|
||||||
|
|
||||||
|
phb
|
||||||
|
pei :target+1
|
||||||
|
plb
|
||||||
|
plb
|
||||||
|
|
||||||
|
; Change the patched value to one of DP_ENTRY, TWO_LYR_ENTRY or ONE_LYR_ENTRY based on the capabilities
|
||||||
|
; that the engine needs.
|
||||||
|
|
||||||
|
lda #$F000+{DP_ENTRY} ; Set the address from each line to the next
|
||||||
|
ldy #CODE_EXIT+1
|
||||||
|
ldx #15*2
|
||||||
|
jsr SetAbsAddrs
|
||||||
|
|
||||||
|
ldy #DP_ADDR
|
||||||
|
jsr SetDPAddrs
|
||||||
|
|
||||||
|
ldy #$F000+CODE_EXIT ; Patch the last line with a JML to go to the next bank
|
||||||
|
lda #{$005C+{DP_ENTRY}*256}
|
||||||
|
sta [:target],y
|
||||||
|
ldy #$F000+CODE_EXIT+2
|
||||||
|
lda :nextBank
|
||||||
|
sta [:target],y
|
||||||
|
|
||||||
|
ldy #$8000+CODE_EXIT ; Patch one line per bank to enable interrupts
|
||||||
|
lda #{$004C+{ENABLE_INT}*256}
|
||||||
|
sta [:target],y
|
||||||
|
|
||||||
|
plb
|
||||||
|
rts
|
||||||
|
|
||||||
|
; This is the relocation subroutine, it is responsible for copying the template to a
|
||||||
|
; memory location and patching up the necessary instructions.
|
||||||
|
;
|
||||||
|
; X = low word of address (must be a multiple of $1000)
|
||||||
|
; A = high word of address (bank)
|
||||||
|
:BuildLine
|
||||||
|
stx :target
|
||||||
|
sta :target+2
|
||||||
|
|
||||||
|
:BuildLine2
|
||||||
|
lda #CODE_LEN ; round up to an even number of bytes
|
||||||
|
inc
|
||||||
|
and #$FFFE
|
||||||
|
beq :nocopy
|
||||||
|
dec
|
||||||
|
dec
|
||||||
|
tay
|
||||||
|
:loop lda base,y
|
||||||
|
sta [:target],y
|
||||||
|
|
||||||
|
dey
|
||||||
|
dey
|
||||||
|
bpl :loop
|
||||||
|
|
||||||
|
:nocopy lda #0 ; copy is complete, now patch up the addresses
|
||||||
|
sep #$20
|
||||||
|
|
||||||
|
ldx #0
|
||||||
|
lda :target+2 ; patch in the bank for the absolute long addressing mode
|
||||||
|
:dobank ldy BankPatches,x
|
||||||
|
sta [:target],y
|
||||||
|
inx
|
||||||
|
inx
|
||||||
|
cpx #BankPatchNum
|
||||||
|
bcc :dobank
|
||||||
|
|
||||||
|
ldx #0
|
||||||
|
:dopage ldy PagePatches,x ; patch the page addresses by adding the page offset to each
|
||||||
|
lda [:target],y
|
||||||
|
clc
|
||||||
|
adc :target+1
|
||||||
|
sta [:target],y
|
||||||
|
inx
|
||||||
|
inx
|
||||||
|
cpx #PagePatchNum
|
||||||
|
bcc :dopage
|
||||||
|
|
||||||
|
:out
|
||||||
|
rep #$20
|
||||||
|
rts
|
||||||
Loading…
Reference in New Issue
Block a user