Make shift the default descent control on ladders and when flying

"aux1_descends" setting switches to the old descend control.

minetest.conf.example

@@ -15,7 +15,7 @@
 # https://bitbucket.org/celeron55/minetest/src/tip/src/defaultsettings.cpp
 #
 # A vim command to convert most of defaultsettings.cpp to conf file format:
-# :'<,'>s/\tg_settings\.setDefault("\([^"]*\)", "\([^"]*\)");.*/#\1 = \2/g
+# :'<,'>s/\tsettings->setDefault("\([^"]*\)", "\([^"]*\)");.*/#\1 = \2/g
 # Note: Some of the settings are implemented in Lua
 
 #
@@ -49,8 +49,14 @@
 #keymap_freemove = KEY_KEY_K
 #keymap_fastmove = KEY_KEY_J
 #keymap_screenshot = KEY_F12
+# If true, keymap_special1 instead of keymap_sneak is used for climbing down and descending
+#aux1_descends = false
 # Some (temporary) keys for debugging
 #keymap_print_debug_stacks = KEY_KEY_P
+#keymap_quicktune_prev = KEY_HOME
+#keymap_quicktune_next = KEY_END
+#keymap_quicktune_dec = KEY_NEXT
+#keymap_quicktune_inc = KEY_PRIOR
 
 # Minimum FPS
 # The amount of rendered stuff is dynamically set according to this

src/defaultsettings.cpp

@@ -52,6 +52,7 @@ void set_default_settings(Settings *settings)
 	settings->setDefault("keymap_toggle_profiler", "KEY_F6");
 	settings->setDefault("keymap_increase_viewing_range_min", "+");
 	settings->setDefault("keymap_decrease_viewing_range_min", "-");
+	settings->setDefault("aux1_descends", "false");
 	// Some (temporary) keys for debugging
 	settings->setDefault("keymap_print_debug_stacks", "KEY_KEY_P");
 	settings->setDefault("keymap_quicktune_prev", "KEY_HOME");

src/localplayer.cpp

@@ -359,6 +359,9 @@ void LocalPlayer::applyControl(float dtime)
 	if(free_move && fast_move)
 		superspeed = true;
 	
+	// Old descend control
+	if(g_settings->getBool("aux1_descends"))
+	{
 		// Auxiliary button 1 (E)
 		if(control.aux1)
 		{
@@ -386,6 +389,42 @@ void LocalPlayer::applyControl(float dtime)
 					superspeed = true;
 			}
 		}
+	}
+	// New minecraft-like descend control
+	else
+	{
+		// Auxiliary button 1 (E)
+		if(control.aux1)
+		{
+			if(!free_move && !is_climbing)
+			{
+				// If not free movement but fast is allowed, aux1 is
+				// "Turbo button"
+				if(fast_move)
+					superspeed = true;
+			}
+		}
+
+		if(control.sneak)
+		{
+			if(free_move)
+			{
+				// In free movement mode, sneak descends
+				v3f speed = getSpeed();
+				if(fast_move)
+					speed.Y = -20*BS;
+				else
+					speed.Y = -walkspeed_max;
+					setSpeed(speed);
+			}
+			else if(is_climbing)
+			{
+				v3f speed = getSpeed();
+				speed.Y = -3*BS;
+				setSpeed(speed);
+			}
+		}
+	}
 
 	if(continuous_forward)
 		speed += move_direction;