Air failsafe boost

While in the air: release accelerate while at nearly-still speeds, and you'll preform a minisucle air drift boost. This mechanic is meant to fix the long-standing issue where you can get stuck in 0 speed in the air and not be able to do anything.

src/d_clisrv.c

@@ -617,6 +617,7 @@ static inline void resynch_write_player(resynch_pak *rsp, const size_t i)
 
 	rsp->airtime = (tic_t)LONG(players[i].airtime);
 	rsp->driftInput = players[i].driftInput;
+	rsp->airFailsafe = players[i].airFailsafe;
 
 	rsp->trickpanel = (UINT8)players[i].trickpanel;
 	rsp->trickdelay = (boolean)players[i].trickdelay;
@@ -779,6 +780,7 @@ static void resynch_read_player(resynch_pak *rsp)
 
 	players[i].airtime = (tic_t)LONG(rsp->airtime);
 	players[i].driftInput = (boolean)rsp->driftInput;
+	players[i].airFailsafe = (boolean)rsp->airFailsafe;
 
 	players[i].trickpanel = (UINT8)rsp->trickpanel;
 	players[i].trickdelay = (boolean)rsp->trickdelay;

src/d_clisrv.h

@@ -281,6 +281,7 @@ typedef struct
 	INT32 kartstuff[NUMKARTSTUFF];
 	tic_t airtime;
 	boolean driftInput;
+	boolean airFailsafe;
 	UINT8 trickpanel;
 	boolean trickdelay;
 	fixed_t trickmomx;

src/d_player.h

@@ -525,6 +525,7 @@ typedef struct player_s
 	respawnvars_t respawn; // Respawn info
 	tic_t airtime; 		// Keep track of how long you've been in the air
 	boolean driftInput; // Whenever or not try drifting.
+	boolean airFailsafe; // Whenever or not try the air boost
 
 	UINT8 trickpanel; 	// Trick panel state
 	boolean trickdelay;	// Prevent tricks until control stick is neutral

src/k_kart.c

@@ -6984,6 +6984,7 @@ INT32 K_GetKartDriftSparkValue(player_t *player)
 Stage 1: red sparks
 Stage 2: blue sparks
 Stage 3: big large rainbow sparks
+Stage 0: air failsafe
 */
 void K_SpawnDriftBoostExplosion(player_t *player, int stage)
 {
@@ -7014,6 +7015,11 @@ void K_SpawnDriftBoostExplosion(player_t *player, int stage)
 			S_StartSound(player->mo, sfx_kc5b);
 			S_StartSound(player->mo, sfx_s3kc4l);
 			break;
+
+		case 0:
+			overlay->color = SKINCOLOR_SILVER;
+			overlay->fuse = 16;
+			break;
 	}
 
 	overlay->extravalue1 = stage;
@@ -7574,6 +7580,39 @@ static void K_KartSpindash(player_t *player)
 	}
 }
 
+static void K_AirFailsafe(player_t *player)
+{
+	const fixed_t maxSpeed = 6*player->mo->scale;
+	const fixed_t thrustSpeed = 6*player->mo->scale; // 10*player->mo->scale
+
+	ticcmd_t *cmd = &player->cmd;
+
+	if (player->speed > maxSpeed)
+	{
+		// Above the max speed that you're allowed to use this technique.
+		player->airFailsafe = false;
+		return;
+	}
+
+	if ((cmd->buttons & BT_ACCELERATE) || K_GetForwardMove(player) != 0)
+	{
+		// Queue up later
+		player->airFailsafe = true;
+		return;
+	}
+
+	if (player->airFailsafe == true)
+	{
+		// Push the player forward
+		P_Thrust(player->mo, K_MomentumAngle(player->mo), thrustSpeed);
+
+		S_StartSound(player->mo, sfx_s23c);
+		K_SpawnDriftBoostExplosion(player, 0);
+
+		player->airFailsafe = false;
+	}
+}
+
 //
 // K_AdjustPlayerFriction
 //
@@ -8447,9 +8486,18 @@ void K_MoveKartPlayer(player_t *player, boolean onground)
 		}
 	}
 
-	K_KartDrift(player, P_IsObjectOnGround(player->mo)); // Not using onground, since we don't want this affected by spring pads
+	K_KartDrift(player, onground);
 	K_KartSpindash(player);
 
+	if (onground == false)
+	{
+		K_AirFailsafe(player);
+	}
+	else
+	{
+		player->airFailsafe = false;
+	}
+
 	// Play the starting countdown sounds
 	if (player == &players[g_localplayers[0]]) // Don't play louder in splitscreen
 	{

src/lua_playerlib.c

@@ -220,6 +220,8 @@ static int player_get(lua_State *L)
 		lua_pushinteger(L, plr->airtime);
 	else if (fastcmp(field,"driftInput"))
 		lua_pushboolean(L, plr->driftInput);
+	else if (fastcmp(field,"airFailsafe"))
+		lua_pushboolean(L, plr->airFailsafe);
 	else if (fastcmp(field,"tumbleBounces"))
 		lua_pushinteger(L, plr->tumbleBounces);
 	else if (fastcmp(field,"tumbleHeight"))
@@ -533,6 +535,8 @@ static int player_set(lua_State *L)
 		plr->airtime = (tic_t)luaL_checkinteger(L, 3);
 	else if (fastcmp(field,"driftInput"))
 		plr->driftInput = luaL_checkboolean(L, 3);
+	else if (fastcmp(field,"airFailsafe"))
+		plr->airFailsafe = luaL_checkboolean(L, 3);
 	else if (fastcmp(field,"tumbleBounces"))
 		plr->tumbleBounces = (UINT8)luaL_checkinteger(L, 3);
 	else if (fastcmp(field,"tumbleHeight"))

src/p_mobj.c

@@ -6743,6 +6743,10 @@ static boolean P_MobjRegularThink(mobj_t *mobj)
 				if (mobj->fuse == 16)/* to red*/
 					K_SpawnDriftBoostClip(mobj->target->player);
 				break;
+
+			case 0:/* air failsafe boost */
+				mobj->color = SKINCOLOR_SILVER; // force white
+				break;
 		}
 
 		{

src/p_saveg.c

@@ -258,6 +258,7 @@ static void P_NetArchivePlayers(void)
 
 		WRITEUINT32(save_p, players[i].airtime);
 		WRITEUINT8(save_p, players[i].driftInput);
+		WRITEUINT8(save_p, players[i].airFailsafe);
 
 		WRITEUINT8(save_p, players[i].trickpanel);
 		WRITEUINT8(save_p, players[i].trickdelay);
@@ -463,6 +464,7 @@ static void P_NetUnArchivePlayers(void)
 
 		players[i].airtime = READUINT32(save_p);
 		players[i].driftInput = (boolean)READUINT8(save_p);
+		players[i].airFailsafe = (boolean)READUINT8(save_p);
 
 		players[i].trickpanel = READUINT8(save_p);
 		players[i].trickdelay = READUINT8(save_p);