4cade/src/glue.prorwts2.a

;license:MIT
;(c) 2018-9 by 4am & qkumba
;
; ProRWTS2 glue functions
;
; Public functions
; - LoadFile
; - LoadDHRFile
;
; Public variables
; - gRootDirectory
;
; 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.

;------------------------------------------------------------------------------
; 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
         +LDPARAMPTR 5, ldrlo        ; set load address
         jsr   SwitchToBank2
         jsr   LoadFileInternal
         jmp   SwitchToBank1

;------------------------------------------------------------------------------
; 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 4 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
         jsr   SwitchToBank2
         jsr   LoadDHRFileInternal
         jmp   SwitchToBank1

gRootDirectory
         !word $FDFD