1 files changed, 85 insertions, 0 deletions
diff --git a/src/home/effect_commands.asm b/src/home/effect_commands.asm
new file mode 100644
index 0000000..e28e170
--- /dev/null
+++ b/src/home/effect_commands.asm
@@ -0,0 +1,85 @@
+; Checks if the command type at a is one of the commands of the attack or
+; card effect currently in use, and executes its associated function if so.
+; input:
+   ; a = command type to check
+   ; [wLoadedAttackEffectCommands] = pointer to list of commands of current attack or trainer card
+   TryExecuteEffectCommandFunction: ; 2fd9 (0:2fd9)
+   push af
+   ; grab pointer to command list from wLoadedAttackEffectCommands
+   ld hl, wLoadedAttackEffectCommands
+   ld a, [hli]
+   ld h, [hl]
+   ld l, a
+   pop af
+   call CheckMatchingCommand
+   jr nc, .execute_function
+   ; return if no matching command was found
+   or a
+   ret
+
+.execute_function
+   ; execute the function at [wEffectFunctionsBank]:hl
+   ldh a, [hBankROM]
+   push af
+   ld a, [wEffectFunctionsBank]
+   call BankswitchROM
+   or a
+   call CallHL
+   push af
+   ; restore original bank and return
+   pop bc
+   pop af
+   call BankswitchROM
+   push bc
+   pop af
+   ret
+
+; input:
+  ; a = command type to check
+  ; hl = list of commands of current attack or trainer card
+; return nc if command type matching a is found, carry otherwise
+CheckMatchingCommand: ; 2ffe (0:2ffe)
+   ld c, a
+   ld a, l
+   or h
+   jr nz, .not_null_pointer
+   ; return carry if pointer is NULL
+   scf
+   ret
+
+.not_null_pointer
+   ldh a, [hBankROM]
+   push af
+   ld a, BANK(EffectCommands)
+   call BankswitchROM
+   ; store the bank number of command functions ($b) in wEffectFunctionsBank
+   ld a, BANK("Effect Functions")
+   ld [wEffectFunctionsBank], a
+.check_command_loop
+   ld a, [hli]
+   or a
+   jr z, .no_more_commands
+   cp c
+   jr z, .matching_command_found
+   ; skip function pointer for this command and move to the next one
+   inc hl
+   inc hl
+   jr .check_command_loop
+
+.matching_command_found
+   ; load function pointer for this command
+   ld a, [hli]
+   ld h, [hl]
+   ld l, a
+   ; restore bank and return nc
+   pop af
+   call BankswitchROM
+   or a
+   ret
+
+.no_more_commands
+   ; restore bank and return c
+   pop af
+   call BankswitchROM
+   scf
+   ret