mirror of
https://github.com/lscharen/iigs-game-engine.git
synced 2024-11-29 11:50:25 +00:00
436 lines
15 KiB
ArmAsm
436 lines
15 KiB
ArmAsm
****************************************
|
|
* Basic Error Macro *
|
|
****************************************
|
|
_Err mac
|
|
bcc NoErr
|
|
do ]0 ; (DO if true)
|
|
jsr PgmDeath ; this is conditionally compiled if
|
|
str ]1 ; we pass in an error statement
|
|
else ; (ELSE)
|
|
jmp PgmDeath0 ; we just call the simpler error handler
|
|
fin ; (FIN)
|
|
NoErr eom
|
|
|
|
;
|
|
; Dereference a handle that is on the top of the stack
|
|
;
|
|
_Deref MAC
|
|
phb ; save caller's data bank register
|
|
pha ; push high word of handle on stack
|
|
plb ; sets B to the bank byte of the pointer
|
|
lda |$0002,x ; load the high word of the master pointer
|
|
pha ; and save it on the stack
|
|
lda |$0000,x ; load the low word of the master pointer
|
|
tax ; and return it in X
|
|
pla ; restore the high word in A
|
|
plb ; pull the handle's high word high byte off the
|
|
; stack
|
|
plb ; restore the caller's data bank register
|
|
<<<
|
|
|
|
_Mul128 mac
|
|
asl
|
|
asl
|
|
asl
|
|
asl
|
|
asl
|
|
asl
|
|
asl
|
|
<<<
|
|
; Possible optimization (assumes accumulator is <512). 8 cycles/5 bytes vs 14 cycles/7 bytes
|
|
; cmp #$0100
|
|
; xba
|
|
; ror
|
|
|
|
_Div16 mac
|
|
lsr
|
|
lsr
|
|
lsr
|
|
lsr
|
|
<<<
|
|
|
|
_R0W0 mac ; Read Bank 0 / Write Bank 0
|
|
ldal STATE_REG
|
|
and #$FFCF
|
|
stal STATE_REG
|
|
<<<
|
|
|
|
_R0W1 mac ; Read Bank 0 / Write Bank 1
|
|
ldal STATE_REG
|
|
ora #$0010
|
|
stal STATE_REG
|
|
<<<
|
|
|
|
_R1W1 mac ; Read Bank 0 / Write Bank 1
|
|
ldal STATE_REG
|
|
ora #$0030
|
|
stal STATE_REG
|
|
<<<
|
|
|
|
_PushReg mac ; Used to save/restore registers when calling subroutines.
|
|
pha
|
|
phx
|
|
phy
|
|
<<<
|
|
|
|
_PullReg mac
|
|
ply
|
|
plx
|
|
pla
|
|
<<<
|
|
|
|
_PushReg2 mac ; Variation to also save the P-register to preserve m/x
|
|
pha
|
|
phx
|
|
phy
|
|
php
|
|
<<<
|
|
|
|
_PullReg2 mac
|
|
plp
|
|
ply
|
|
plx
|
|
pla
|
|
<<<
|
|
|
|
jne mac
|
|
beq *+5
|
|
jmp ]1
|
|
<<<
|
|
|
|
jeq mac
|
|
bne *+5
|
|
jmp ]1
|
|
<<<
|
|
|
|
jcc mac
|
|
bcs *+5
|
|
jmp ]1
|
|
<<<
|
|
|
|
jcs mac
|
|
bcc *+5
|
|
jmp ]1
|
|
<<<
|
|
|
|
min mac
|
|
cmp ]1
|
|
bcc mout
|
|
lda ]1
|
|
mout <<<
|
|
|
|
; Increment a value mod some number.
|
|
incmod mac
|
|
inc
|
|
cmp ]1
|
|
bcc out
|
|
lda #0
|
|
out <<<
|
|
|
|
decmod mac
|
|
dec
|
|
bpl out
|
|
lda ]1
|
|
dec
|
|
out <<<
|
|
|
|
adcmod mac
|
|
adc ]1
|
|
cmp ]2
|
|
bcc out
|
|
sbc ]2
|
|
out <<<
|
|
|
|
sbcmod mac
|
|
sbc ]1
|
|
bpl out
|
|
clc
|
|
adc ]2
|
|
out <<<
|
|
|
|
asr16 mac
|
|
cmp #$8000
|
|
ror
|
|
<<<
|
|
|
|
asr8 mac
|
|
cmp #$80
|
|
ror
|
|
<<<
|
|
|
|
; Inline macros for fast calculation of some internal values
|
|
_TileStoreOffset mac
|
|
lda ]2
|
|
asl
|
|
tay
|
|
lda ]1
|
|
asl ; Assume in range, so asl puts a 0 bit into the carry
|
|
adc TileStoreYTable,y
|
|
<<<
|
|
|
|
_TileStoreOffsetX mac
|
|
lda ]2
|
|
asl
|
|
tax
|
|
lda ]1
|
|
asl ; Assume in range, so asl puts a 0 bit into the carry
|
|
adc TileStoreYTable,x
|
|
<<<
|
|
|
|
_; Macro variant to calculate inline from any source
|
|
_SpriteVBuffAddr mac
|
|
lda ]2
|
|
clc
|
|
adc #NUM_BUFF_LINES
|
|
xba
|
|
adc ]1
|
|
<<<
|
|
|
|
; Macro to define script steps
|
|
ScriptStep MAC
|
|
IF #=]5
|
|
dw {]1+{{]5&#$000F}<<8}},]2,]3,]4
|
|
ELSE
|
|
dw ]1,]2,]3,]4
|
|
FIN
|
|
<<<
|
|
|
|
; A specialized CopyMaskedWord macro that draws a tile from a direct page workspace. Used
|
|
; to render fringe tiles and sprite tiles when BG1 is active. If there is no second background,
|
|
; then one should use the optimized functions which assumes a PEA opcode and only
|
|
; needs to copy data words
|
|
;
|
|
; ]1 : tiledata direct page address , the tilemask direct page address is tiledata + 32
|
|
; ]2 : code field offset
|
|
CopyMaskedWordD MAC
|
|
lda ]1+32 ; load the mask value
|
|
bne mixed ; a non-zero value may be mixed
|
|
|
|
; This is a solid word
|
|
lda #$00F4 ; PEA instruction
|
|
sta: ]2,y
|
|
ldal ]1 ; load the tile data
|
|
sta: ]2+1,y ; PEA operand
|
|
bra next
|
|
|
|
mixed cmp #$FFFF ; All 1's in the mask is fully transparent
|
|
beq transparent
|
|
|
|
; This is the slowest path because there is a *lot* of work to do. So much that it's
|
|
; worth it to change up the environment to optimize things a bit more.
|
|
;
|
|
; Need to fill in the first 8 bytes of the JMP handler with the following code sequence
|
|
;
|
|
; lda (00),y
|
|
; and #MASK
|
|
; ora #DATA
|
|
|
|
lda #$004C ; JMP instruction
|
|
sta: ]2,y
|
|
|
|
ldx _X_REG ; Get the addressing offset
|
|
ldal JTableOffset,x ; Get the address offset and add to the base address
|
|
adc _BASE_ADDR ; of the current code field line
|
|
adc #{]2&$F000} ; adjust for the current row offset
|
|
sta: ]2+1,y
|
|
|
|
tay ; This becomes the new address that we use to patch in
|
|
txa ; Get the offset and render a LDA (dp),y instruction
|
|
|
|
sep #$20
|
|
sta: $0001,y ; LDA (00),y operand
|
|
lda #$B1
|
|
sta: $0000,y ; LDA (00),y opcode
|
|
lda #$29
|
|
sta: $0002,y ; AND #$0000 opcode
|
|
lda #$09
|
|
sta: $0005,y ; ORA #$0000 opcode
|
|
rep #$20
|
|
|
|
lda ]1+32 ; insert the tile mask and data into the exception
|
|
sta: $0003,y ; handler.
|
|
lda ]1
|
|
sta: $0006,y
|
|
|
|
ldy _Y_REG ; restore original y-register value and move on
|
|
bra next
|
|
|
|
; This is a transparent word, so just show the second background layer
|
|
transparent
|
|
lda #$00B1 ; LDA (dp),y instruction
|
|
sta: ]2,y
|
|
lda _X_REG ; X is the logical tile offset (0, 2, 4, ... 82) left-to-right
|
|
ora #$4800 ; put a PHA after the offset
|
|
sta: ]2+1,y
|
|
next
|
|
eom
|
|
|
|
; Macros to use in the Masked Tile renderer
|
|
;
|
|
; ]1 : tiledata offset
|
|
; ]2 : tilemask offset
|
|
; ]3 : code field offset
|
|
CopyMaskedWord MAC
|
|
ldal ]2,x ; load the mask value
|
|
bne mixed ; a non-zero value may be mixed
|
|
|
|
; This is a solid word
|
|
lda #$00F4 ; PEA instruction
|
|
sta: ]3,y
|
|
ldal ]1,x ; load the tile data
|
|
sta: ]3+1,y ; PEA operand
|
|
bra next
|
|
|
|
mixed cmp #$FFFF ; All 1's in the mask is fully transparent
|
|
beq transparent
|
|
|
|
; This is the slowest path because there is a *lot* of work to do. So much that it's
|
|
; worth it to change up the environment to optimize things a bit more.
|
|
;
|
|
; Need to fill in the first 8 bytes of the JMP handler with the following code sequence
|
|
;
|
|
; lda (00),y
|
|
; and #MASK
|
|
; ora #DATA
|
|
|
|
lda #$004C ; JMP instruction
|
|
sta: ]3,y
|
|
|
|
ldx _X_REG ; Get the addressing offset
|
|
ldal JTableOffset,x ; Get the address offset and add to the base address
|
|
adc _BASE_ADDR ; of the current code field line
|
|
adc #{]3&$F000} ; adjust for the current row offset
|
|
sta: ]3+1,y
|
|
|
|
tay ; This becomes the new address that we use to patch in
|
|
txa ; Get the offset and render a LDA (dp),y instruction
|
|
|
|
sep #$20
|
|
sta: $0001,y ; LDA (00),y operand
|
|
lda #$B1
|
|
sta: $0000,y ; LDA (00),y opcode
|
|
lda #$29
|
|
sta: $0002,y ; AND #$0000 opcode
|
|
lda #$09
|
|
sta: $0005,y ; ORA #$0000 opcode
|
|
rep #$20
|
|
|
|
ldx _T_PTR ; restore the original x-register value
|
|
ldal ]2,x ; insert the tile mask and data into the exception
|
|
sta: $0003,y ; handler.
|
|
ldal ]1,x
|
|
sta: $0006,y
|
|
|
|
ldy _Y_REG ; restore original y-register value and move on
|
|
bra next
|
|
|
|
; This is a transparent word, so just show the second background layer
|
|
transparent
|
|
lda #$00B1 ; LDA (dp),y instruction
|
|
sta: ]3,y
|
|
lda _X_REG ; X is the logical tile offset (0, 2, 4, ... 82) left-to-right
|
|
ora #$4800 ; put a PHA after the offset
|
|
sta: ]3+1,y
|
|
next
|
|
eom
|
|
|
|
; Masked renderer for a dynamic tile. What's interesting about this renderer is that the mask
|
|
; value is not used directly, but simply indicates if we can use a LDA 0,x / PHA sequence,
|
|
; a LDA (00),y / PHA, or a JMP to a blended render
|
|
;
|
|
; If a dynamic tile is animated, there is the possibility to create a special mask that marks
|
|
; words of the tile that a front / back / mixed across all frames.
|
|
;
|
|
; ]1 : tiledata offset
|
|
; ]2 : tilemask offset
|
|
; ]3 : code field offset
|
|
CopyMaskedDWord MAC
|
|
|
|
; Need to fill in the first 8 bytes of the JMP handler with the following code sequence
|
|
;
|
|
; lda (00),y
|
|
; and $80,x
|
|
; ora $00,x
|
|
; bcc *+4
|
|
|
|
ldx _X_REG ; Get the addressing offset
|
|
ldal JTableOffset,x ; Get the address offset and add to the base address
|
|
adc _BASE_ADDR ; of the current code field line
|
|
adc #{]1&$F000} ; adjust for the current row offset
|
|
sta: ]1+1,y
|
|
|
|
tax ; This becomes the new address that we use to patch in
|
|
lda _X_REG ; Get the offset and render a LDA (dp),y instruction
|
|
|
|
sep #$20 ; Easier to do 8-bit operations
|
|
sta: $0001,x ; Set the LDA (00),y operand
|
|
lda #$B1
|
|
sta: $0000,x ; Set the LDA (00),y opcode
|
|
|
|
lda _T_PTR
|
|
sta: $0005,x ; Set ORA 00,x operand
|
|
ora #$80
|
|
sta: $0003,x ; Set AND 00,x operand
|
|
lda #$35
|
|
sta: $0002,x ; Set AND 00,x operand
|
|
lda #$15
|
|
sta: $0004,x ; Set ORA 00,x operand
|
|
rep #$30
|
|
|
|
lda #$0290 ; BCC *+4
|
|
sta: $0006,x
|
|
eom
|
|
|
|
|
|
; Masked renderer for a dynamic tile with sprite data overlaid. What's interesting about this renderer is that the mask
|
|
; value is not used directly, but simply indicates if we can use a LDA 0,x / PHA sequence,
|
|
; a LDA (00),y / PHA, or a JMP to a blended render
|
|
;
|
|
; If a dynamic tile is animated, there is the possibility to create a special mask that marks
|
|
; words of the tile that a front / back / mixed across all frames.
|
|
;
|
|
; ]1 : tiledata offset
|
|
; ]2 : tilemask offset
|
|
; ]3 : code field offset
|
|
CopyMaskedDynSpriteWord MAC
|
|
|
|
; Need to fill in the first 12(!!) bytes of the JMP handler with the following code sequence
|
|
;
|
|
; lda (00),y
|
|
; and $80,x
|
|
; ora $00,x
|
|
; and #MASK
|
|
; ora #DATA
|
|
;
|
|
; If MASK == 0, then we can do a PEA. If MASK == $FFFF, then fall back to the simple Dynamic Masked
|
|
; code.
|
|
|
|
|
|
ldx _X_REG ; Get the addressing offset
|
|
ldal JTableOffset,x ; Get the address offset and add to the base address
|
|
adc _BASE_ADDR ; of the current code field line
|
|
adc #{]1&$F000} ; adjust for the current row offset
|
|
sta: ]1+1,y
|
|
|
|
tax ; This becomes the new address that we use to patch in
|
|
lda _X_REG ; Get the offset and render a LDA (dp),y instruction
|
|
|
|
sep #$20 ; Easier to do 8-bit operations
|
|
sta: $0001,x ; Set the LDA (00),y operand
|
|
lda #$B1
|
|
sta: $0000,x ; Set the LDA (00),y opcode
|
|
|
|
lda _T_PTR
|
|
sta: $0005,x ; Set ORA 00,x operand
|
|
ora #$80
|
|
sta: $0003,x ; Set AND 00,x operand
|
|
lda #$35
|
|
sta: $0002,x ; Set AND 00,x operand
|
|
lda #$15
|
|
sta: $0004,x ; Set ORA 00,x operand
|
|
rep #$30
|
|
|
|
lda #$0290 ; BCC *+4
|
|
sta: $0006,x
|
|
eom
|