From 79dff95b844bfab7bf35b0e4359e352df9b62034 Mon Sep 17 00:00:00 2001
From: Holger Schemel <info@artsoft.org>
Date: Sun, 10 Mar 2024 17:40:10 +0100
Subject: [PATCH] added support for line-shifting wrap-around in BD engine to
 level editor

---
 src/editor.c | 12 +++++++++++-
 src/files.c  | 10 ++++++++++
 src/main.h   |  1 +
 3 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/src/editor.c b/src/editor.c
index 6d8bd174..f0c1cc23 100644
--- a/src/editor.c
+++ b/src/editor.c
@@ -664,6 +664,7 @@ enum
   GADGET_ID_RANDOM_RESTRICTED,
   GADGET_ID_BD_INTERMISSION,
   GADGET_ID_BD_PAL_TIMING,
+  GADGET_ID_BD_LINE_SHIFTING_BORDERS,
   GADGET_ID_STICK_ELEMENT,
   GADGET_ID_EM_SLIPPERY_GEMS,
   GADGET_ID_EM_EXPLODES_BY_FIRE,
@@ -991,6 +992,7 @@ enum
   ED_CHECKBUTTON_ID_CUSTOM_USE_TEMPLATE_2,
   ED_CHECKBUTTON_ID_BD_INTERMISSION,
   ED_CHECKBUTTON_ID_BD_PAL_TIMING,
+  ED_CHECKBUTTON_ID_BD_LINE_SHIFTING_BORDERS,
   ED_CHECKBUTTON_ID_STICK_ELEMENT,
   ED_CHECKBUTTON_ID_EM_SLIPPERY_GEMS,
   ED_CHECKBUTTON_ID_EM_EXPLODES_BY_FIRE,
@@ -1072,7 +1074,7 @@ enum
 #define ED_CHECKBUTTON_ID_EDITOR_LAST	ED_CHECKBUTTON_ID_CUSTOM_USE_TEMPLATE_2
 
 #define ED_CHECKBUTTON_ID_ENGINE_FIRST	ED_CHECKBUTTON_ID_BD_INTERMISSION
-#define ED_CHECKBUTTON_ID_ENGINE_LAST	ED_CHECKBUTTON_ID_BD_PAL_TIMING
+#define ED_CHECKBUTTON_ID_ENGINE_LAST	ED_CHECKBUTTON_ID_BD_LINE_SHIFTING_BORDERS
 
 #define ED_CHECKBUTTON_ID_CUSTOM1_FIRST	ED_CHECKBUTTON_ID_CUSTOM_USE_GRAPHIC
 #define ED_CHECKBUTTON_ID_CUSTOM1_LAST	ED_CHECKBUTTON_ID_CUSTOM_INDESTRUCTIBLE
@@ -3343,6 +3345,14 @@ static struct
     NULL, NULL,
     "PAL timing",			"use slower timer (like PAL C64)"
   },
+  {
+    ED_CHECKBUTTON_ID_BD_LINE_SHIFTING_BORDERS,
+    ED_LEVEL_SETTINGS_XPOS(0),		ED_LEVEL_SETTINGS_YPOS(5),
+    GADGET_ID_BD_LINE_SHIFTING_BORDERS,	GADGET_ID_NONE,
+    &level.bd_line_shifting_borders,
+    NULL, NULL,
+    "line-shifting borders",		"use line-shifting wrap-around"
+  },
 
   // ---------- element settings: configure (various elements) ----------------
 
diff --git a/src/files.c b/src/files.c
index 8044d338..e6e22816 100644
--- a/src/files.c
+++ b/src/files.c
@@ -315,6 +315,12 @@ static struct LevelFileConfigInfo chunk_config_INFO[] =
     &li.bd_hatching_delay_seconds,	2
   },
 
+  {
+    -1,					-1,
+    TYPE_BOOLEAN,			CONF_VALUE_8_BIT(20),
+    &li.bd_line_shifting_borders,	FALSE
+  },
+
   {
     -1,					-1,
     -1,					-1,
@@ -3768,6 +3774,8 @@ static void CopyNativeLevel_RND_to_BD(struct LevelInfo *level)
   cave->intermission			= level->bd_intermission;
   cave->diagonal_movements		= level->bd_diagonal_movements;
 
+  cave->lineshift			= level->bd_line_shifting_borders;
+
   strncpy(cave->name, level->name, sizeof(GdString));
   cave->name[sizeof(GdString) - 1] = '\0';
 
@@ -3804,6 +3812,8 @@ static void CopyNativeLevel_BD_to_RND(struct LevelInfo *level)
   level->bd_intermission		= cave->intermission;
   level->bd_diagonal_movements		= cave->diagonal_movements;
 
+  level->bd_line_shifting_borders	= cave->lineshift;
+
   char *cave_name = getStringPrint("%s / %d", cave->name, bd_level_nr + 1);
 
   strncpy(level->name, cave_name, MAX_LEVEL_NAME_LEN);
diff --git a/src/main.h b/src/main.h
index 90bd7ae0..fcdcaf26 100644
--- a/src/main.h
+++ b/src/main.h
@@ -3486,6 +3486,7 @@ struct LevelInfo
   int bd_hatching_delay_seconds;	// BD hatching delay (in seconds)
   int bd_scheduling_type;		// BD engine scheduling type
   boolean bd_pal_timing;		// BD engine uses special PAL timing
+  boolean bd_line_shifting_borders;	// BD engine uses line-shifting wrap-around
   boolean bd_intermission;		// BD level is intermission
   boolean bd_diagonal_movements;	// BD style diagonal movements
   boolean em_slippery_gems;		// EM style "gems slip from wall" behaviour
-- 
2.34.1