Better steering

- If they're already turning in one direction, they are more likely to steer in that direction for objects
- Bots have to want to turn in 1 direction for a few frames in a row before it'll let them

Prevents twitching & makes them less indecisive in general

src/d_clisrv.c

@@ -650,7 +650,7 @@ static inline void resynch_write_player(resynch_pak *rsp, const size_t i)
 	rsp->bot_difficulty = players[i].botvars.difficulty;
 	rsp->bot_itemdelay = players[i].botvars.itemdelay;
 	rsp->bot_itemconfirm = players[i].botvars.itemconfirm;
-	rsp->bot_lastturn = players[i].botvars.lastturn;
+	rsp->bot_turnconfirm = players[i].botvars.turnconfirm;
 
 	rsp->hasmo = false;
 	//Transfer important mo information if the player has a body.
@@ -779,7 +779,7 @@ static void resynch_read_player(resynch_pak *rsp)
 	players[i].botvars.difficulty = rsp->bot_difficulty;
 	players[i].botvars.itemdelay = rsp->bot_itemdelay;
 	players[i].botvars.itemconfirm = rsp->bot_itemconfirm;
-	players[i].botvars.lastturn = rsp->bot_lastturn;
+	players[i].botvars.turnconfirm = rsp->bot_turnconfirm;
 
 	//We get a packet for each player in game.
 	if (!playeringame[i])

src/d_clisrv.h

@@ -289,7 +289,7 @@ typedef struct
 	UINT8 bot_difficulty;
 	tic_t bot_itemdelay;
 	tic_t bot_itemconfirm;
-	INT16 bot_lastturn;
+	SINT8 bot_turnconfirm;
 
 	//player->mo stuff
 	UINT8 hasmo; // Boolean

src/d_player.h

@@ -428,7 +428,7 @@ typedef struct botvars_s
 	tic_t itemdelay;
 	tic_t itemconfirm;
 
-	INT16 lastturn;
+	SINT8 turnconfirm;
 } botvars_t;
 
 // ========================================================================

src/k_bot.c

@@ -410,6 +410,7 @@ fixed_t distancetocheck = 0;
 
 fixed_t closestlinedist = INT32_MAX;
 
+INT16 curturn = 0;
 INT16 badsteerglobal = 0;
 
 fixed_t eggboxx, eggboxy;
@@ -761,30 +762,60 @@ static void K_SteerFromObject(mobj_t *bot, mobj_t *thing, fixed_t fulldist, fixe
 {
 	angle_t destangle = R_PointToAngle2(bot->x, bot->y, thing->x, thing->y);
 	angle_t angle;
+	SINT8 flip = 1;
 
 	amount = (amount * FixedDiv(distancetocheck - fulldist, distancetocheck)) / FRACUNIT;
 
+	if (amount == 0)
+	{
+		// Shouldn't happen
+		return;
+	}
+
 	if (towards)
 	{
-		if (xdist < (bot->radius + thing->radius))
+		if (xdist < FixedHypot(bot->radius, thing->radius))
 		{
 			// Don't need to turn any harder!
+
+			if (abs(badsteerglobal) <= amount)
+			{
+				badsteerglobal = 0;
+			}
+			else
+			{
+				if (badsteerglobal > 0)
+				{
+					badsteerglobal -= amount;
+				}
+				else if (badsteerglobal < 0)
+				{
+					badsteerglobal += amount;
+				}
+			}
+
 			return;
 		}
 
-		amount = -amount;
+		// Still turning towards it, flip.
+		flip = -flip;
 	}
 
 	angle = (bot->angle - destangle);
-
 	if (angle < ANGLE_180)
 	{
-		badsteerglobal -= amount;
+		flip = -flip;
 	}
-	else
+
+	// If going in the opposite direction of where you wanted to turn,
+	// then reduce the amount that you can turn in that direction.
+	if ((flip == 1 && curturn < 0)
+	|| (flip == -1 && curturn > 0))
 	{
-		badsteerglobal += amount;
+		amount /= 4;
 	}
+
+	badsteerglobal += amount * flip;
 }
 
 static boolean K_BotSteerObjects(mobj_t *thing)
@@ -876,7 +907,7 @@ static boolean K_BotSteerObjects(mobj_t *thing)
 			K_SteerFromObject(botmo, thing, fulldist, xdist, false, 2 * (KART_FULLTURN + dodge));
 			break;
 		case MT_RANDOMITEM:
-			if (anglediff > 90)
+			if (anglediff >= 60)
 			{
 				break;
 			}
@@ -887,7 +918,7 @@ static boolean K_BotSteerObjects(mobj_t *thing)
 			}
 			break;
 		case MT_EGGMANITEM:
-			if (anglediff > 90)
+			if (anglediff >= 60)
 			{
 				break;
 			}
@@ -908,7 +939,7 @@ static boolean K_BotSteerObjects(mobj_t *thing)
 			}
 			break;
 		case MT_FLOATINGITEM:
-			if (anglediff > 90)
+			if (anglediff >= 60)
 			{
 				break;
 			}
@@ -920,7 +951,7 @@ static boolean K_BotSteerObjects(mobj_t *thing)
 			break;
 		case MT_RING:
 		case MT_FLINGRING:
-			if (anglediff > 90)
+			if (anglediff >= 60)
 			{
 				break;
 			}
@@ -932,8 +963,8 @@ static boolean K_BotSteerObjects(mobj_t *thing)
 			{
 				K_SteerFromObject(botmo, thing, fulldist, xdist, true,
 					(RINGTOTAL(botmo->player) < 3
-					? (2 * (KART_FULLTURN + attack))
-					: ((KART_FULLTURN + attack) / 2))
+					? (4 * (KART_FULLTURN + attack))
+					: (KART_FULLTURN + attack))
 				);
 			}
 			break;
@@ -985,7 +1016,7 @@ static boolean K_BotSteerObjects(mobj_t *thing)
 					fixed_t theirweight = K_GetMobjWeight(thing, botmo);
 					fixed_t weightdiff = 0;
 
-					if (anglediff > 90)
+					if (anglediff >= 90)
 					{
 						weightdiff = theirweight - ourweight;
 					}
@@ -1006,6 +1037,11 @@ static boolean K_BotSteerObjects(mobj_t *thing)
 			}
 			break;
 		case MT_BOTHINT:
+			if (anglediff >= 60)
+			{
+				break;
+			}
+
 			if (thing->extravalue1 == 0)
 			{
 				K_SteerFromObject(botmo, thing, fulldist, xdist, false, thing->extravalue2 * (KART_FULLTURN + dodge));
@@ -1025,14 +1061,15 @@ static boolean K_BotSteerObjects(mobj_t *thing)
 	return true;
 }
 
-static INT16 K_BotFindObjects(player_t *player)
+static INT16 K_BotFindObjects(player_t *player, INT16 turn)
 {
 	INT32 xl, xh, yl, yh, bx, by;
 
 	badsteerglobal = 0;
 
 	botmo = player->mo;
-	distancetocheck = (player->mo->radius * 32) + (player->speed * 4);
+	curturn = turn;
+	distancetocheck = 2048*mapobjectscale;
 
 	xl = (unsigned)(botmo->x - distancetocheck - bmaporgx)>>MAPBLOCKSHIFT;
 	xh = (unsigned)(botmo->x + distancetocheck - bmaporgx)>>MAPBLOCKSHIFT;
@@ -1409,11 +1446,6 @@ void K_BuildBotTiccmd(player_t *player, ticcmd_t *cmd)
 				cmd->forwardmove /= 2;
 				cmd->buttons |= BT_BRAKE;
 			}
-			else if (dirdist <= realrad)
-			{
-				// Steer towards/away from objects!
-				turnamt += K_BotFindObjects(player);
-			}
 
 			if (dirdist <= rad)
 			{
@@ -1446,6 +1478,12 @@ void K_BuildBotTiccmd(player_t *player, ticcmd_t *cmd)
 					turnamt /= 4;
 				}
 			}
+
+			if (anglediff < 60)
+			{
+				// Steer towards/away from objects!
+				turnamt += K_BotFindObjects(player, turnamt);
+			}
 		}
 	}
 
@@ -2169,8 +2207,6 @@ void K_BuildBotTiccmd(player_t *player, ticcmd_t *cmd)
 
 	if (turnamt != 0)
 	{
-		const INT16 minturn = KART_FULLTURN/2;
-
 		if (turnamt > KART_FULLTURN)
 		{
 			turnamt = KART_FULLTURN;
@@ -2180,26 +2216,39 @@ void K_BuildBotTiccmd(player_t *player, ticcmd_t *cmd)
 			turnamt = -KART_FULLTURN;
 		}
 
-		if ((turnamt > minturn && player->botvars.lastturn >= 0)
-			|| (turnamt < -minturn && player->botvars.lastturn <= 0))
+		if (turnamt > 0)
 		{
-			if (turnamt > 0)
+			if (player->botvars.turnconfirm < 0)
 			{
-				player->botvars.lastturn = 1;
-			}
-			else if (turnamt < 0)
-			{
-				player->botvars.lastturn = -1;
+				// Reset turn confirm
+				player->botvars.turnconfirm = 0;
 			}
 
+			if (player->botvars.turnconfirm < BOTTURNCONFIRM)
+			{
+				player->botvars.turnconfirm++;
+			}
+		}
+		else if (turnamt < 0)
+		{
+			if (player->botvars.turnconfirm > 0)
+			{
+				// Reset turn confirm
+				player->botvars.turnconfirm = 0;
+			}
+
+			if (player->botvars.turnconfirm > -BOTTURNCONFIRM)
+			{
+				player->botvars.turnconfirm--;
+			}
+		}
+
+		if (abs(player->botvars.turnconfirm) >= BOTTURNCONFIRM)
+		{
+			// You're probably commiting to your turn, here you go.
 			cmd->driftturn = turnamt;
 			cmd->angleturn += K_GetKartTurnValue(player, turnamt);
 		}
-		else
-		{
-			// Can reset turn dir
-			player->botvars.lastturn = 0;
-		}
 	}
 
 	if (predict != NULL)

src/k_bot.h

@@ -13,8 +13,13 @@
 #include "k_waypoint.h"
 #include "d_player.h"
 
+// Maximum value of botvars.difficulty
 #define MAXBOTDIFFICULTY 9
 
+// How many tics in a row do you need to turn in this direction before we'll let you turn.
+// Made it as small as possible without making it look like the bots are twitching constantly.
+#define BOTTURNCONFIRM 7
+
 // Path that bot will attempt to take
 typedef struct botprediction_s {
 	fixed_t x, y;

src/p_saveg.c

@@ -272,7 +272,7 @@ static void P_NetArchivePlayers(void)
 		WRITEUINT8(save_p, players[i].botvars.difficulty);
 		WRITEUINT32(save_p, players[i].botvars.itemdelay);
 		WRITEUINT32(save_p, players[i].botvars.itemconfirm);
-		WRITEINT16(save_p, players[i].botvars.lastturn);
+		WRITESINT8(save_p, players[i].botvars.turnconfirm);
 	}
 }
 
@@ -448,7 +448,7 @@ static void P_NetUnArchivePlayers(void)
 		players[i].botvars.difficulty = READUINT8(save_p);
 		players[i].botvars.itemdelay = READUINT32(save_p);
 		players[i].botvars.itemconfirm = READUINT32(save_p);
-		players[i].botvars.lastturn = READINT16(save_p);
+		players[i].botvars.turnconfirm = READSINT8(save_p);
 	}
 }