; A program that says where it came from.
;
; The dullest thing on the disk, and that is the point of it: osWhereAmI and pathBeside are
; what an application with assets stands on, and both are much easier to check now, with
; nothing depending on them, than later inside a game that has gone quiet.
;
;   Where                says the path it was loaded from
;   Where splash.tune    says that, and the path of splash.tune beside it
;
; ---- The thing worth checking ----
;
; The answer follows the PROGRAM and not the person. Run this from the root and it says one
; thing; walk somewhere else and run the same copy and it says the same thing, because the
; system worked it out when the program started and a program's own place cannot move under
; it. A working directory is where the person is standing, and it is what the argument means:
; "Where notes.txt" asks about a notes.txt in the program's place, not in yours, which is
; exactly the distinction an application needs and the reason cwd could not serve both.

#Include services.asm

#Program

  #Base 0x5000

start:
  SETD.0 MyPath
  INIB 0d192
  SWI osWhereAmI

  SETD.0 FromText
  SWI osPrintString
  SETD.0 MyPath
  SWI osPrintString
  CALL newLine

  ; With nothing after it, that is the whole of what it has to say.
  SETD.0 Given
  INIB 0d64
  SWI osArgument
  SETD.0 Given
  LDA.0
  BRA whereDone

  SETD.0 MyPath
  SETD.1 Given
  SETD.2 Beside
  INIB 0d192
  CALL pathBeside
  BNQ whereTooLong

  SETD.0 BesideText
  SWI osPrintString
  SETD.0 Beside
  SWI osPrintString
  CALL newLine

whereDone:
  RSTA
  SWI osExit

whereTooLong:
  ; A path that did not fit is a wrong answer, and saying it would be worse than saying so.
  SETD.0 TooLongText
  SWI osPrintString
  CALL newLine
  INIA 0x01
  SWI osExit

newLine:
  SETD.0 NewLine
  SWI osPrintString
  RET

#Data

  #Base 0x3000

FromText:
"loaded from "
BesideText:
"beside it: "
TooLongText:
"that path would not fit"
NewLine:
  0x0A 0x00

MyPath:
  #Reserve 0d192
Beside:
  #Reserve 0d192
Given:
  #Reserve 0d64

; ---- Included last, after both segments have been based ----
;
; A #Base says where a whole segment begins and so has to be the first thing in it, and a
; library brings code and data of its own. Put in front, its #Data would be the first thing
; in the Data Segment and this program's own #Base would be too late. This is where Lander
; keeps its seven, for the same reason.
#Include path.asm