4cade/src/glue.prorwts2.a

;license:MIT
;(c) 2018-9 by 4am & qkumba
;
; ProRWTS2 glue functions
;
; Public functions
; - LoadFile
; - LoadDHRFile
; - SaveSmallFile
; - SaveOrRestoreScreenHoles
;
; A general note about paths:
;
; LoadFile, LoadDHRFile, and SaveSmallFile support subdirectories.
; Directories are delimited by '/' like ProDOS. At program startup, we get the
; current directory and save it; that is the PROGRAM ROOT DIRECTORY. All
; pathnames are relative to the PROGRAM ROOT DIRECTORY. There is no concept of
; setting or changing the 'current' directory.
;
; The PROGRAM ROOT DIRECTORY is not guaranteed to be the root directory of the
; underlying ProDOS disk (although it can be). But it doesn't matter, because
; these functions provide no access to any directory above the PROGRAM ROOT
; DIRECTORY. You can't use '..' to access the parent directory, and you can't
; start a pathname with '/' to access the root directory of the underlying
; ProDOS disk.
;
; Examples:
; 'PREFS.CONF' points to a file named 'PREFS.CONF' in the PROGRAM ROOT
; DIRECTORY.
;
; 'FX/RIPPLE' points to a file named 'RIPPLE' in a directory named 'FX' in the
; PROGRAM ROOT DIRECTORY.

gRootDirectory
         !word $FDFD

;------------------------------------------------------------------------------
; LoadFile
; Load a file into memory all at once, using ProRWTS2
;
; supports paths, see note
;
; in:    stack contains 6 bytes of parameters:
;          +1 [word] address of length-prefixed pathname
;          +3 [word] address of length-prefixed filename
;          +5 [word] address to load file, or 0 to use file's default address
; out:   all flags clobbered
;        all registers clobbered
;        gPathname clobbered
;------------------------------------------------------------------------------
LoadFile
         +PARAMS_ON_STACK 6
         +LDPARAM 1
         jsr   SetPath
         +LDPARAM 3
         jsr   AddToPath
         +LDPARAM 5
         +STAY ldrlo                 ; set load address
         +LDADDR gPathname
         +STAY namlo                 ; set filename
         +READ_RAM2_WRITE_RAM2
         jsr   traverse              ; go to subdirectory, set up filename for read
         lda   #cmdread              ; read (instead of write)
         sta   reqcmd
         lda   #0                    ; 0 = read into main memory
         sta   auxreq
         lda   ldrlo+1
         bne   +                     ; if caller provided a load address, use it
         sta   sizelo                ; otherwise query the load address from file metadata
         sta   sizehi                ; 0 = query load address
         jsr   hddopendir            ; call ProRWTS2
         +LDAY ldrlo2
         +STAY ldrlo
+        lda   #$FF                  ; read entire file (ProRWTS2 will figure out exact size)
         sta   sizehi
         jsr   hddopendir            ; exit via ProRWTS2
         +READ_RAM1_WRITE_RAM1
         rts

;------------------------------------------------------------------------------
; LoadDHRFile
; load .A2FC file (uncompressed double hi-res graphics) into memory
; all at once, using ProRWTS2
; first $2000 bytes of file are loaded into auxiliary memory $4000..$5FFF
; second $2000 bytes of file are loaded into main memory $4000..$4FFF
;
; supports paths, see note
;
; in:    stack contains 6 bytes of parameters:
;          +1 [word] address of length-prefixed pathname
;          +3 [word] address of length-prefixed filename
; out:   all flags clobbered
;        all registers clobbered
;        stack set to next instruction after parameters
;------------------------------------------------------------------------------
LoadDHRFile
         +PARAMS_ON_STACK 4
         +LDPARAM 1
         jsr   SetPath
         +LDPARAM 3
         jsr   AddToPath
         +LDADDR gPathname
         +STAY namlo                 ; set filename
         +READ_RAM2_WRITE_RAM2
         jsr   traverse              ; go to subdirectory, set up filename for read
         lda   #$00                  ; read first $2000 bytes
         sta   sizelo
         sta   ldrlo
         lda   #$20
         sta   sizehi
         asl
         sta   ldrhi                 ; into $4000
         lda   #1                    ; 1 = read into aux memory
         sta   auxreq
         lda   #cmdread              ; read (instead of write)
         sta   reqcmd
         jsr   hddopendir            ; call ProRWTS2
         lda   #$20                  ; read next $2000 bytes
         sta   sizehi
         asl
         sta   ldrhi                 ; into $4000
         dec   auxreq                ; 0 = read into main memory
         clc                         ; not a subdirectory
         jsr   hddrdwrpart           ; call ProRWTS2
         +READ_RAM1_WRITE_RAM1
         rts

;------------------------------------------------------------------------------
; SaveSmallFile
; Save a file into memory all at once, using ProRWTS2.
; /!\ Only first block (512 bytes) is written. Keep those files small. /!\
; /!\ All 512 bytes are written to disk. Clear buffer before calling. /!\
;
; supports paths, see note
;
; in:    stack contains 2 bytes of parameters:
;        +1 address of data buffer
; out:   all flags clobbered
;        all registers clobbered
;        stack set to next instruction after parameters
;------------------------------------------------------------------------------
SaveSmallFile
         +PARAMS_ON_STACK 2
         +LDPARAM 1
         +STAY ldrlo                 ; set data buffer address for ProRWTS2
         +LDADDR gPathname
         +STAY namlo                 ; set filename for ProRWTS2
         +READ_RAM2_WRITE_RAM2
         jsr   traverse              ; go to subdirectory, set up filename for read
         ;;if the write address is always a fixed value then we can discard the query
         lda   #cmdread              ; read (instead of write)
         sta   reqcmd
         lda   #0                    ; 0 = read into main memory
         sta   sizelo
         sta   sizehi                ; 0 = query load address
         jsr   hddopendir            ; call ProRWTS2
         lda   ldrlo2
         sta   ldrlo
         lda   ldrhi2
         sta   ldrhi
         lda   #cmdwrite             ; write (instead of read)
         sta   reqcmd
         sta   sizelo                ; non-zero
         jsr   hddopendir            ; exit via ProRWTS2 (must re-open the file after query)
         +READ_RAM1_WRITE_RAM1
         rts

;------------------------------------------------------------------------------
; SaveOrRestoreScreenHoles
; preserve screen hole contents across demo execution
; to avoid crashing later on disk access
;
; in:    nothing
; out:   all flags clobbered
;        all registers clobbered
;------------------------------------------------------------------------------

SaveOrRestoreScreenHoles
    lda    #4
    sta    namhi
    ldx    #0
    stx    namlo
    sta    bloklo
--  ldy    #$78
-   lda    (namlo),y
    pha
    lda    holey_stuff,x
holepatch ;sta->lda
    lda    (namlo),y
    pla
    sta    holey_stuff,x
    inx
    tya
    eor    #$80
    tay
    bmi    -
    iny
    bpl    -
    inc    namhi
    dec    bloklo
    bne    --
    rts
holey_stuff
    !fill  64