From 09f5292c0a67675898b30eb4b52bdd82ee44ecda Mon Sep 17 00:00:00 2001
From: nmlgc <nmlgc@nmlgc.net>
Date: Sat, 13 Apr 2024 17:06:53 +0200
Subject: [PATCH] [Decompilation] [th03] Player: Position update and clamping

Part of P0280, funded by [Anonymous], Blue Bolt, and JonathKane.
---
 th01/math/clamp.hpp       |  8 +++++
 th03/main/player/move.cpp | 24 ++++++++++++++-
 th03/main/player/move.hpp |  2 ++
 th03_main.asm             | 65 ++++-----------------------------------
 4 files changed, 39 insertions(+), 60 deletions(-)

diff --git a/th01/math/clamp.hpp b/th01/math/clamp.hpp
index 55213c91..9e42d13f 100644
--- a/th01/math/clamp.hpp
+++ b/th01/math/clamp.hpp
@@ -11,6 +11,14 @@
 #define clamp_min_2(v, min) ((v) < min ? min : (v))
 #define clamp_max_2_ge(v, max) ((v) >= max ? max : (v))
 
+#define clamp_minmax(v, min, max) { \
+	if(v < min) { \
+		v = min; \
+	} else if(v > max) { \
+		v = max; \
+	} \
+}
+
 #define clamp_inc(v, max) \
 	(v)++; \
 	if((v) > (max)) { \
diff --git a/th03/main/player/move.cpp b/th03/main/player/move.cpp
index 19887c8c..705982f8 100644
--- a/th03/main/player/move.cpp
+++ b/th03/main/player/move.cpp
@@ -1,13 +1,35 @@
 #pragma option -zPmain_01 -G
 
+#include <stddef.h>
 #include "platform.h"
 #include "pc98.h"
-#include "th01/math/subpixel.hpp"
+#include "th01/math/clamp.hpp"
 #include "th03/hardware/input.h"
+#include "th03/common.h"
 #include "th03/playchar.hpp"
+#include "th03/main/playfld.hpp"
+#include "th03/main/collmap.hpp"
+#include "th03/main/sprite16.hpp"
 #include "th03/main/chars/speed.hpp"
+#include "th03/main/player/shot.hpp"
+#include "th03/main/player/player.hpp"
 #include "th03/main/player/move.hpp"
 
+void pascal near player_pos_update_and_clamp(player_t near& player)
+{
+	subpixel_t x = player.center.x;
+	subpixel_t y = player.center.y;
+
+	x += player_velocity.x.v;
+	y += player_velocity.y.v;
+
+	clamp_minmax(x, to_sp( 8), to_sp(PLAYFIELD_W -  8));
+	clamp_minmax(y, to_sp(24), to_sp(PLAYFIELD_H - 16));
+
+	player.center.x.v = x;
+	player.center.y.v = y;
+}
+
 #pragma option -a2
 
 inline void move(Subpixel8& dim, const Subpixel8& speed, int8_t direction) {
diff --git a/th03/main/player/move.hpp b/th03/main/player/move.hpp
index db3cafe5..169502aa 100644
--- a/th03/main/player/move.hpp
+++ b/th03/main/player/move.hpp
@@ -7,5 +7,7 @@ enum move_ret_t {
 extern speed_t player_speed_base; // of [player_cur]
 extern SPPoint8 player_velocity; // of [player_cur]
 
+void pascal near player_pos_update_and_clamp(player_t near& player);
+
 // Sets [player_velocity] according to [input].
 move_ret_t pascal near player_move(input_t input);
diff --git a/th03_main.asm b/th03_main.asm
index d7f75133..369aa34f 100644
--- a/th03_main.asm
+++ b/th03_main.asm
@@ -4343,8 +4343,7 @@ loc_C4E8:
 		call	@player_move$qui pascal, di
 		cmp	al, MOVE_VALID
 		jnz	short loc_C505
-		push	si
-		call	sub_D6D4
+		call	@player_pos_update_and_clamp$qr8player_t pascal, si
 
 loc_C505:
 		call	@player_hittest$qi pascal, (8 / 2)
@@ -4627,8 +4626,7 @@ loc_C6C7:
 		call	@player_move$qui pascal, di
 		cmp	al, MOVE_VALID
 		jnz	short loc_C6D3
-		push	si
-		call	sub_D6D4
+		call	@player_pos_update_and_clamp$qr8player_t pascal, si
 
 loc_C6D3:
 		cmp	[bp+var_B], 0
@@ -6663,61 +6661,12 @@ sub_D6C0	endp
 ; ---------------------------------------------------------------------------
 		nop
 
-; =============== S U B	R O U T	I N E =======================================
-
-; Attributes: bp-based frame
-
-sub_D6D4	proc near
-
-arg_0		= word ptr  4
-
-		push	bp
-		mov	bp, sp
-		push	si
-		mov	si, [bp+arg_0]
-		mov	dx, [si]
-		mov	cx, [si+2]
-		mov	al, _player_velocity.x8
-		cbw
-		add	dx, ax
-		mov	al, _player_velocity.y8
-		cbw
-		add	cx, ax
-		cmp	dx, 80h
-		jge	short loc_D6F7
-		mov	dx, 80h
-		jmp	short loc_D700
-; ---------------------------------------------------------------------------
-
-loc_D6F7:
-		cmp	dx, 1180h
-		jle	short loc_D700
-		mov	dx, 1180h
-
-loc_D700:
-		cmp	cx, 180h
-		jge	short loc_D70B
-		mov	cx, 180h
-		jmp	short loc_D714
-; ---------------------------------------------------------------------------
-
-loc_D70B:
-		cmp	cx, 1600h
-		jle	short loc_D714
-		mov	cx, 1600h
-
-loc_D714:
-		mov	[si], dx
-		mov	[si+2],	cx
-		pop	si
-		pop	bp
-		retn	2
-sub_D6D4	endp
-
 MOVE_INVALID = 0
 MOVE_VALID = 1
 MOVE_NOINPUT = 2
 
+	@PLAYER_POS_UPDATE_AND_CLAMP$QR8PLAYER_T procdesc pascal near \
+		player:word
 	@PLAYER_MOVE$QUI procdesc pascal near \
 		input:word
 PLAYER_M_TEXT	ends
@@ -7143,8 +7092,7 @@ loc_DAC7:
 loc_DAEF:
 		cmp	[bp+var_5], MOVE_VALID
 		jnz	short loc_DAF9
-		push	si
-		call	sub_D6D4
+		call	@player_pos_update_and_clamp$qr8player_t pascal, si
 
 loc_DAF9:
 		cmp	[bp+var_6], 0
@@ -7797,8 +7745,7 @@ loc_E036:
 		mov	_player_velocity.x8, al
 		mov	al, [bp+@@vector_y]
 		mov	_player_velocity.y8, al
-		push	si
-		call	sub_D6D4
+		call	@player_pos_update_and_clamp$qr8player_t pascal, si
 		jmp	short loc_E078
 ; ---------------------------------------------------------------------------