iigs-game-engine/macros/CORE.MACS.S

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****************************************
* 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
2020-08-23 05:25:39 +00:00
;
; 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 <<<
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
<<<
_; 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