Add disable_jump and fall_damage_add_percent node groups

doc/lua_api.txt

@@ -453,6 +453,8 @@ Special groups
   - 2: node is removed without tool wear after 0.5 seconds or so
        (rail, sign)
   - 3: node is removed without tool wear immediately (torch)
+- disable_jump: Player (and possibly other things) cannot jump from node
+- fall_damage_add_percent: damage speed = speed * (1 + value/100)
 
 Known damage and digging time defining groups
 ----------------------------------------------

src/environment.cpp

@@ -2040,6 +2040,11 @@ void ClientEnvironment::step(float dtime)
 			//f32 tolerance = BS*12; // 3 without damage
 			f32 tolerance = BS*14; // 5 without damage
 			f32 factor = 1;
+			const ContentFeatures &f = m_gamedef->ndef()->
+					get(m_map->getNodeNoEx(lplayer->getStandingNodePos()));
+			// Determine fall damage multiplier
+			int addp = itemgroup_get(f.groups, "fall_damage_add_percent");
+			info.speed *= (1.0 + (float)addp/100.0);
 			if(info.speed > tolerance)
 			{
 				f32 damage_f = (info.speed - tolerance)/BS*factor;

src/localplayer.cpp

@@ -38,7 +38,8 @@ LocalPlayer::LocalPlayer(IGameDef *gamedef):
 	m_sneak_node_exists(false),
 	m_old_node_below(32767,32767,32767),
 	m_old_node_below_type("air"),
-	m_need_to_get_new_sneak_node(true)
+	m_need_to_get_new_sneak_node(true),
+	m_can_jump(false)
 {
 	// Initialize hp to 0, so that no hearts will be shown if server
 	// doesn't support health points
@@ -314,6 +315,15 @@ void LocalPlayer::move(f32 dtime, Map &map, f32 pos_max_d,
 	*/
 	m_old_node_below = floatToInt(position - v3f(0,BS/2,0), BS);
 	m_old_node_below_type = nodemgr->get(map.getNodeNoEx(m_old_node_below)).name;
+	
+	/*
+		Check properties of the node on which the player is standing
+	*/
+	const ContentFeatures &f = nodemgr->get(map.getNodeNoEx(getStandingNodePos()));
+	// Determine if jumping is possible
+	m_can_jump = touching_ground;
+	if(itemgroup_get(f.groups, "disable_jump"))
+		m_can_jump = false;
 }
 
 void LocalPlayer::move(f32 dtime, Map &map, f32 pos_max_d)
@@ -459,7 +469,7 @@ void LocalPlayer::applyControl(float dtime)
 				speed.Y = walkspeed_max;
 			setSpeed(speed);
 		}
-		else if(touching_ground)
+		else if(m_can_jump)
 		{
 			/*
 				NOTE: The d value in move() affects jump height by

src/localplayer.h

@@ -101,6 +101,7 @@ private:
 	std::string m_old_node_below_type;
 	// Whether recalculation of the sneak node is needed
 	bool m_need_to_get_new_sneak_node;
+	bool m_can_jump;
 };
 
 #endif