From 4e4b7a3f5581e495af3d0bcf0ca8bb5424306a52 Mon Sep 17 00:00:00 2001
From: Holger Schemel <info@artsoft.org>
Date: Fri, 8 Sep 2017 16:00:53 +0200
Subject: [PATCH] added using single button for snap and drop when using native
 EM engine

---
 src/events.c          | 6 ++++++
 src/game.c            | 3 +++
 src/game_em/convert.c | 3 +++
 src/game_em/export.h  | 8 ++++++++
 src/game_em/input.c   | 3 +++
 5 files changed, 23 insertions(+)

diff --git a/src/events.c b/src/events.c
index 8ddf4e9b..6f6d41fa 100644
--- a/src/events.c
+++ b/src/events.c
@@ -1560,6 +1560,9 @@ void HandleKey(Key key, int key_status)
     static boolean element_dropped[MAX_PLAYERS] = { FALSE,FALSE,FALSE,FALSE };
     int pnr;
 
+    /* initialize unifying snap and drop buttons (EM engine) */
+    game_em.use_single_button = game_em.use_single_button_initial;
+
     for (pnr = 0; pnr < MAX_PLAYERS; pnr++)
     {
       byte key_action = 0;
@@ -1606,6 +1609,9 @@ void HandleKey(Key key, int key_status)
 
       if (tape.single_step && tape.recording && tape.pausing)
       {
+	/* do not unify snap and drop buttons in single-step mode (EM engine) */
+	game_em.use_single_button = FALSE;
+
 	if (key_status == KEY_PRESSED && key_action & KEY_MOTION)
 	{
 	  TapeTogglePause(TAPE_TOGGLE_AUTOMATIC);
diff --git a/src/game.c b/src/game.c
index 89e0c110..e87dcd04 100644
--- a/src/game.c
+++ b/src/game.c
@@ -2698,6 +2698,9 @@ static void InitGameEngine()
   game.use_block_last_field_bug =
     (game.engine_version < VERSION_IDENT(3,1,1,0));
 
+  game_em.use_single_button = game_em.use_single_button_initial =
+    (game.engine_version > VERSION_IDENT(4,0,0,2));
+
   /* ---------------------------------------------------------------------- */
 
   /* set maximal allowed number of custom element changes per game frame */
diff --git a/src/game_em/convert.c b/src/game_em/convert.c
index d240739e..32c4b600 100644
--- a/src/game_em/convert.c
+++ b/src/game_em/convert.c
@@ -1109,6 +1109,9 @@ void prepare_em_level(void)
 
   game_em.any_player_moving = FALSE;
   game_em.any_player_snapping = FALSE;
+
+  game_em.use_single_button = game_em.use_single_button_initial = TRUE;
+
   game_em.last_moving_player = 0;	/* default: first player */
 
   for (i = 0; i < MAX_PLAYERS; i++)
diff --git a/src/game_em/export.h b/src/game_em/export.h
index 0968f1d6..065d6214 100644
--- a/src/game_em/export.h
+++ b/src/game_em/export.h
@@ -666,6 +666,10 @@ struct GameInfo_EM
 {
   boolean any_player_moving;
   boolean any_player_snapping;
+
+  boolean use_single_button_initial;
+  boolean use_single_button;
+
   int last_moving_player;
   int last_player_direction[MAX_PLAYERS];
 };
@@ -678,6 +682,9 @@ struct LevelInfo_EM
 
   struct LEVEL *lev;
   struct PLAYER *ply[MAX_PLAYERS];
+
+  /* used for runtime values */
+  struct GameInfo_EM *game_em;
 };
 
 struct GraphicInfo_EM
@@ -721,6 +728,7 @@ struct EngineSnapshotInfo_EM
 /* ------------------------------------------------------------------------- */
 
 extern struct GlobalInfo_EM global_em_info;
+extern struct GameInfo_EM game_em;
 extern struct LevelInfo_EM native_em_level;
 extern struct GraphicInfo_EM graphic_info_em_object[TILE_MAX][8];
 extern struct GraphicInfo_EM graphic_info_em_player[MAX_PLAYERS][SPR_MAX][8];
diff --git a/src/game_em/input.c b/src/game_em/input.c
index b2c79ac7..b8e2e663 100644
--- a/src/game_em/input.c
+++ b/src/game_em/input.c
@@ -119,6 +119,9 @@ void readjoy(byte action, struct PLAYER *ply)
   int north = 0, east = 0, south = 0, west = 0;
   int snap = 0, drop = 0;
 
+  if (game_em.use_single_button && action & (JOY_BUTTON_1 | JOY_BUTTON_2))
+    action |= JOY_BUTTON_1 | JOY_BUTTON_2;
+
   if (action & JOY_LEFT)
     west = 1;
 
-- 
2.34.1