From 47f494288d0ab525ddc93efefaf08dfb084dd10c Mon Sep 17 00:00:00 2001
From: "B. Watson" <yalhcru@gmail.com>
Date: Mon, 19 Apr 2021 15:26:48 -0400
Subject: Allow pressing Enter to abort buy/sell (costs 15 bytes)

---
 taipan.c      | 13 ++++++------
 timed_getch.s | 68 +++++++++++++++++++++++++++++++++++++++++------------------
 2 files changed, 54 insertions(+), 27 deletions(-)

diff --git a/taipan.c b/taipan.c
index 933fd2f..36993bc 100644
--- a/taipan.c
+++ b/taipan.c
@@ -251,10 +251,9 @@ void backspace() {
 }
 */
 
-/* get an inventory item, return its index into items[].
-	if allow_all is true, allows '*', which is used for
-	'throw cargo' in sea_battle. */
-extern unsigned char get_item(unsigned char allow_all);
+
+extern unsigned char get_item_port(void);
+extern unsigned char get_item_battle(void);
 
 /*
 	rewritten in asm, in timed_getch.s, here's the original:
@@ -1319,7 +1318,7 @@ char sea_battle(char id, int num_ships) {
 				print_msg(M_what_shall_i_throw);
 				cprint_taipan_prompt();
 
-				choice = get_item(1);
+				choice = get_item_battle();
 
 				if(choice < 4) {
 					gotox0y(6);
@@ -3082,7 +3081,7 @@ char what_do_you_wish_me_to(char *buy_or_sell) {
 	print_msg(M_me_to);
 	cputs(buy_or_sell);
 	cprint_taipan_prompt();
-	return get_item(0);
+	return get_item_port();
 }
 #ifdef CART_TARGET
 # pragma code-name (pop)
@@ -3093,6 +3092,7 @@ void buy(void) {
    unsigned long afford, amount;
 
 	choice = what_do_you_wish_me_to("buy");
+	if(choice == 5) return;
 
    for (;;) {
       gotoxy(31, 21);
@@ -3152,6 +3152,7 @@ void sell(void) {
    unsigned long amount;
 
 	choice = what_do_you_wish_me_to("sell");
+	if(choice == 5) return;
 
    for (;;) {
       gotox0y22();
diff --git a/timed_getch.s b/timed_getch.s
index 5c5ff7c..6ea1bff 100644
--- a/timed_getch.s
+++ b/timed_getch.s
@@ -1,6 +1,6 @@
 
  .export _timed_getch, _set_jiffy_timer, _agetc, _numgetc
- .export  _yngetc, _lcgetc, _jsleep, _get_item, _tjsleep
+ .export  _yngetc, _lcgetc, _jsleep, _get_item_port, _get_item_battle, _tjsleep
  .import _cgetc, _cblank, putchar, _rand, _turbo
 
  .include "atari.inc"
@@ -175,28 +175,54 @@ _yngetc:
  beq _yngetc ; no default, get another keypress
  rts         ; else return the default
 
-; extern unsigned char get_item(unsigned char allow_all);
-_get_item:
- sta FR0 ; stash arg
+; extern unsigned char get_item_port(void)
+; return 0-3 for opium, silk, arms, general.
+; return 5 for Enter key (nothing chosen)
+_get_item_port:
+ lda #4
+ .byte $2c
+
+; extern unsigned char get_item_battle(void)
+; return 0-4 for opium, silk, arms, general, all.
+_get_item_battle:
+ lda #5
+ sta FR0
+@get_loop:
+ jsr get_item
+ cmp FR0
+ beq @get_loop
+ rts
+
+
+get_item:
 @getkey:
  jsr _lcgetc ; switch(lcgetc()) {
- ldx #0
- cmp #'o'
- beq @gi_done ; case 'o': return 0;
- inx
- cmp #'s'
- beq @gi_done ; case 's': return 1;
- inx
- cmp #'a'
- beq @gi_done ; case 'a': return 2;
- inx
- cmp #'g'
- beq @gi_done ; case 'g': return 3;
- ldy FR0
- beq @getkey ; if allow_all is false, get another key
- inx
- cmp #'*'    ; case '*': return 4;
- bne @getkey ; if none of the above, get another key
+ sta FR0+1
+
+;;; ldx #0
+;;; cmp #'o'
+;;; beq @gi_done ; case 'o': return 0;
+;;; inx
+;;; cmp #'s'
+;;; beq @gi_done ; case 's': return 1;
+;;; inx
+;;; cmp #'a'
+;;; beq @gi_done ; case 'a': return 2;
+;;; inx
+;;; cmp #'g'
+;;; beq @gi_done ; case 'g': return 3;
+
+ ldx #5
+@giloop:
+ lda items_tbl,x
+ cmp FR0+1
+ beq @gi_done
+ dex
+ bpl @giloop
+ bmi @getkey
 @gi_done:
  txa
  rts
+
+.rodata
+ items_tbl: .byte "osag*",$9b
-- 
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