4cade/src/fx/macros.misc.a

;license:MIT
;(c) 2019-2022 by 4am
;

!ifndef _FX_MACROS_MISC_ {

!macro HIGH_3_LOW_5 .input {
         and   #%11100000            ; second value: high 3 bits = index into tables to find bitmasks
         tax
         eor   (<.input), y          ; second value: low 5 bits = byte offset within the row (implicitly "and #%00011111")
         tay
}

; must set N flag based on Y immediately before using these macros
; e.g. LDY, INY, DEY, TYA
!macro IS_Y_OFFSCREEN {
         bpl   +
         sec
         bcs   ++
+        cpy   #40
++
}
!macro BRANCH_IF_Y_IS_OFFSCREEN .target {
         cpy   #40
         bcs   .target
}
!macro LONG_BRANCH_IF_Y_IS_OFFSCREEN .target {
         cpy   #40
         bcc   +
         jmp   .target
+
}

!macro COPY_TO_0 .start, .end {
; out:   X=0
;        Z=1
         ldx   #(.end-.start)
-        lda   .start-1, x
         sta   $FF, x
         dex
         bne   -
}

!macro OVERCOPY_TO_0 .start, .end {
; over-copy region to $00
; clobbers $FF
; out:   X=0
;        Y=last byte before start (e.g. 0 if the last instruction is JMP $0000)
         ldx   #(.end-.start+1)
-        ldy   .start-2, x
         sty   $FE, x
         dex
         bne   -
}

!macro INC_INPUT_AND_LOOP .loop {
         inc   <input
         beq   +
         jmp   .loop
+        bit   KBD
         bmi   +
         inc   <input+1
         jmp   .loop
+        rts
}

!macro DEC_INPUT_AND_LOOP .loop {
         lda   input
         php
         dec   input
         dec   input
         plp
         bne   +
         dec   input+1
         bit   KBD
         bpl   .loop
         bmi   ++
+        jmp   .loop
++       rts
}

_FX_MACROS_MISC_=*
}