Add mass parameter to bullets (fixes #444)

Bump bullet json version to 2; old version will
have mass default to power

Also adjust some bullet mass:
- flamer mass 1 (low impulse)
- pulse rifle mass 1 (low impulse)
- heatseeker mass 15 (slightly higher impulse)
- swarmer mass 10 (higher impulse)
- pistol mass 5 (lower impulse)

data/bullets.json

@@ -1,5 +1,5 @@
 {
-  "Version": 1,
+  "Version": 2,
   "DefaultBullet": {
     "Pic": {
       "Type": "Directional",
@@ -31,7 +31,8 @@
       "Name": "mg",
       "Speed": 768,
       "Range": 60,
-      "Power": 10
+      "Power": 10,
+      "Mass": 10.0
     },
     {
       "Name": "shotgun",
@@ -41,7 +42,8 @@
       },
       "Speed": 640,
       "Range": 50,
-      "Power": 15
+      "Power": 15,
+      "Mass": 15.0
     },
     {
       "Name": "flame",
@@ -53,6 +55,7 @@
       "Speed": 384,
       "Range": 30,
       "Power": 12,
+      "Mass": 1.0,
       "Size": [10, 10],
       "Special": "Flame",
       "Spark": "",
@@ -73,6 +76,7 @@
       "Speed": 1024,
       "Range": 90,
       "Power": 20,
+      "Mass": 20.0,
       "Size": [4, 4]
     },
     {
@@ -85,13 +89,15 @@
       "Speed": 1024,
       "Range": 90,
       "Power": 50,
+      "Mass": 50.0,
       "Size": [4, 4]
     },
     {
       "Name": "frag",
       "Speed": 640,
       "Range": 50,
       "Power": 40,
+      "Mass": 40.0,
       "HurtAlways": true
     },
     {
@@ -260,7 +266,8 @@
       "Spark": "spark_blue",
       "Speed": 1280,
       "Range": 25,
-      "Power": 6
+      "Power": 6,
+      "Mass": 1.0
     },
     {
       "Name": "heatseeker",
@@ -271,6 +278,7 @@
       "Speed": 512,
       "Range": 60,
       "Power": 20,
+      "Mass": 40.0,
       "Size": [6, 6],
       "Spark": "boom",
       "HitSounds": {
@@ -290,6 +298,7 @@
       "Speed": 768,
       "Range": 45,
       "Power": 15,
+      "Mass": 15.0,
       "Erratic": true
     },
     {
@@ -350,6 +359,7 @@
       "Speed": 700,
       "Range": 70,
       "Power": 12,
+      "Mass": 15.0,
       "Size": [4, 4],
       "Spark": "boom",
       "HitSounds": {
@@ -389,6 +399,7 @@
       "Speed": 256,
       "Range": 53,
       "Power": 5,
+      "Mass": 5.0,
       "Size": [14, 10],
       "HurtAlways": true,
       "Persists": true,
@@ -415,6 +426,7 @@
       "Speed": 192,
       "Range": 71,
       "Power": 5,
+      "Mass": 5.0,
       "Size": [14, 10],
       "HurtAlways": true,
       "Persists": true,
@@ -441,6 +453,7 @@
       "Speed": 128,
       "Range": 79,
       "Power": 5,
+      "Mass": 5.0,
       "Size": [14, 10],
       "HurtAlways": true,
       "Persists": true,
@@ -573,6 +586,7 @@
       "Speed": 0,
       "Range": 27,
       "Power": 3,
+      "Mass": 10.0,
       "Size": [64, 64],
       "Persists": true,
       "Spark": "",
@@ -615,7 +629,8 @@
       },
       "Speed": 1100,
       "Range": 27,
-      "Power": 12
+      "Power": 12,
+      "Mass": 5.0
     }
   ]
 }

missions/doom.cdogscpn/bullets.json

@@ -1,5 +1,5 @@
 {
-  "Version": 1,
+  "Version": 2,
   "Bullets": [
     {
       "Name": "10mm",
@@ -9,7 +9,8 @@
       },
       "Speed": 1100,
       "Range": 50,
-      "Power": 10
+      "Power": 10,
+      "Mass": 5.0
     },
     {
       "Name": "fireball",
@@ -21,6 +22,7 @@
       "Speed": 350,
       "Range": 200,
       "Power": 18,
+      "Mass": 18.0,
       "Size": [3, 3],
       "Special": "Flame",
       "Spark": "fireball_hit",
@@ -40,6 +42,7 @@
       "Speed": 550,
       "Range": 300,
       "Power": 40,
+      "Mass": 40.0,
       "Size": [3, 3],
       "Special": "Flame",
       "Spark": "fireball_green_hit",
@@ -50,4 +53,4 @@
       }
     }
   ]
-}
+}

src/cdogs/actors.c

@@ -1441,8 +1441,6 @@ void ActorAddBloodSplatters(TActor *a, const int power, const Vec2i hitVector)
 	int bloodPower = power * 2;
 	// Randomly cycle through the blood types
 	int bloodSize = 1;
-	// Spray the blood back with the shot if pushback enabled
-	const bool shotsPushBack = ConfigGetBool(&gConfig, "Game.ShotsPushback");
 	while (bloodPower > 0)
 	{
 		Emitter *em = NULL;
@@ -1463,18 +1461,9 @@ void ActorAddBloodSplatters(TActor *a, const int power, const Vec2i hitVector)
 		{
 			bloodSize = 1;
 		}
-		Vec2i vel;
-		if (shotsPushBack)
-		{
-			vel = Vec2iScaleDiv(
-				Vec2iScale(hitVector, (rand() % 8 + 8) * power),
-				15 * SHOT_IMPULSE_DIVISOR);
-		}
-		else
-		{
-			vel = Vec2iScaleDiv(
-				Vec2iScale(hitVector, rand() % 8 + 8), 20);
-		}
+		const Vec2i vel = Vec2iScaleDiv(
+			Vec2iScale(hitVector, (rand() % 8 + 8) * power),
+			15 * SHOT_IMPULSE_DIVISOR);
 		EmitterStart(em, a->Pos, 10, vel);
 		switch (ga)
 		{

src/cdogs/bullet_class.c

@@ -407,7 +407,8 @@ static bool HitItemFunc(TTileItem *ti, void *data)
 	int targetUID = -1;
 	hData->HitType = GetHitType(ti, hData->Obj, &targetUID);
 	Damage(
-		hData->Obj->vel, hData->Obj->bulletClass->Power,
+		hData->Obj->vel,
+		hData->Obj->bulletClass->Power, hData->Obj->bulletClass->Mass,
 		hData->Obj->flags, hData->Obj->PlayerUID, hData->Obj->ActorUID,
 		ti->kind, targetUID,
 		hData->Obj->bulletClass->Special);
@@ -459,9 +460,10 @@ static HitType GetHitType(
 
 
 
-#define VERSION 1
+#define VERSION 2
 static void LoadBullet(
-	BulletClass *b, json_t *node, const BulletClass *defaultBullet);
+	BulletClass *b, json_t *node, const BulletClass *defaultBullet,
+	const int version);
 void BulletInitialize(BulletClasses *bullets)
 {
 	memset(bullets, 0, sizeof *bullets);
@@ -486,21 +488,22 @@ void BulletLoadJSON(
 	if (defaultNode != NULL)
 	{
 		BulletClassFree(&bullets->Default);
-		LoadBullet(&bullets->Default, defaultNode->child, NULL);
+		LoadBullet(&bullets->Default, defaultNode->child, NULL, version);
 	}
 
 	json_t *bulletsNode = json_find_first_label(bulletNode, "Bullets")->child;
 	for (json_t *child = bulletsNode->child; child; child = child->next)
 	{
 		BulletClass b;
-		LoadBullet(&b, child, &bullets->Default);
+		LoadBullet(&b, child, &bullets->Default, version);
 		CArrayPushBack(classes, &b);
 	}
 
 	bullets->root = bulletNode;
 }
 static void LoadBullet(
-	BulletClass *b, json_t *node, const BulletClass *defaultBullet)
+	BulletClass *b, json_t *node, const BulletClass *defaultBullet,
+	const int version)
 {
 	memset(b, 0, sizeof *b);
 	if (defaultBullet != NULL)
@@ -565,6 +568,17 @@ static void LoadBullet(
 	b->RangeLow = MIN(b->RangeLow, b->RangeHigh);
 	b->RangeHigh = MAX(b->RangeLow, b->RangeHigh);
 	LoadInt(&b->Power, node, "Power");
+
+	if (version < 2)
+	{
+		// Old version default mass = power
+		b->Mass = b->Power;
+	}
+	else
+	{
+		LoadDouble(&b->Mass, node, "Mass");
+	}
+
 	LoadVec2i(&b->Size, node, "Size");
 	tmp = NULL;
 	LoadStr(&tmp, node, "Special");

src/cdogs/bullet_class.h

@@ -72,6 +72,7 @@ typedef struct
 	int RangeLow;
 	int RangeHigh;
 	int Power;
+	double Mass;
 	Vec2i Size;
 	special_damage_e Special;
 	bool HurtAlways;

src/cdogs/config.c

@@ -557,7 +557,6 @@ Config ConfigDefault(void)
 		"SwitchMoveStyle", SWITCHMOVE_SLIDE,
 		SWITCHMOVE_SLIDE, SWITCHMOVE_NONE,
 		StrSwitchMoveStyle, SwitchMoveStyleStr));
-	ConfigGroupAdd(&game, ConfigNewBool("ShotsPushback", true));
 	ConfigGroupAdd(&game, ConfigNewEnum(
 		"AllyCollision", ALLYCOLLISION_REPEL,
 		ALLYCOLLISION_NORMAL, ALLYCOLLISION_NONE,

src/cdogs/game_events.h

@@ -70,8 +70,6 @@ typedef enum
 	GAME_EVENT_ACTOR_STATE,
 	GAME_EVENT_ACTOR_DIR,
 	GAME_EVENT_ACTOR_SLIDE,
-	// TODO: event only used by actor hit and screen boundaries
-	// If the latter is removed, it can be incorporated into actor hit
 	GAME_EVENT_ACTOR_IMPULSE,
 	GAME_EVENT_ACTOR_SWITCH_GUN,
 	GAME_EVENT_ACTOR_PICKUP_ALL,

src/cdogs/handle_game_events.c

@@ -338,9 +338,10 @@ static void HandleGameEvent(
 			}
 			if (!gCampaign.IsClient)
 			{
+				// TODO: melee hitback (vel)?
 				Damage(
 					Vec2iZero(),
-					b->Power,
+					b->Power, b->Mass,
 					a->flags, a->PlayerUID, a->uid,
 					(TileItemKind)e.u.Melee.TargetKind, e.u.Melee.TargetUID,
 					SPECIAL_NONE);

src/cdogs/net_server.c

@@ -419,7 +419,6 @@ void NetServerSendGameStartMessages(NetServer *n, const int peerId)
 	SendConfig(&gConfig, "Game.Ammo", n, peerId);
 	SendConfig(&gConfig, "Game.Fog", n, peerId);
 	SendConfig(&gConfig, "Game.SightRange", n, peerId);
-	SendConfig(&gConfig, "Game.ShotsPushback", n, peerId);
 	SendConfig(&gConfig, "Game.AllyCollision", n, peerId);
 
 	NetServerSendMsg(n, peerId, GAME_EVENT_NET_GAME_START, NULL);

src/cdogs/objs.c

@@ -211,6 +211,7 @@ bool HasHitSound(
 static void DoDamageCharacter(
 	const Vec2i hitVector,
 	const int power,
+	const double mass,
 	const int flags,
 	const int playerUID,
 	const int uid,
@@ -219,6 +220,7 @@ static void DoDamageCharacter(
 void Damage(
 	const Vec2i hitVector,
 	const int power,
+	const double mass,
 	const int flags,
 	const int playerUID,
 	const int uid,
@@ -230,7 +232,7 @@ void Damage(
 	case KIND_CHARACTER:
 		DoDamageCharacter(
 			hitVector,
-			power, flags, playerUID, uid,
+			power, mass, flags, playerUID, uid,
 			ActorGetByUID(targetUID), special);
 		break;
 	case KIND_OBJECT:
@@ -252,6 +254,7 @@ void Damage(
 static void DoDamageCharacter(
 	const Vec2i hitVector,
 	const int power,
+	const double mass,
 	const int flags,
 	const int playerUID,
 	const int uid,
@@ -262,12 +265,16 @@ static void DoDamageCharacter(
 	CASSERT(actor->isInUse, "Cannot damage nonexistent player");
 	CASSERT(CanHitCharacter(flags, uid, actor), "damaging undamageable actor");
 
-	if (ConfigGetBool(&gConfig, "Game.ShotsPushback"))
+	// Shot pushback, based on mass and velocity
+	const double impulseFactor = mass / SHOT_IMPULSE_DIVISOR;
+	const Vec2i vel = Vec2iNew(
+		(int)Round(hitVector.x * impulseFactor),
+		(int)Round(hitVector.y * impulseFactor));
+	if (!Vec2iIsZero(vel))
 	{
 		GameEvent ei = GameEventNew(GAME_EVENT_ACTOR_IMPULSE);
 		ei.u.ActorImpulse.UID = actor->uid;
-		ei.u.ActorImpulse.Vel = Vec2i2Net(Vec2iScaleDiv(
-			Vec2iScale(hitVector, power), SHOT_IMPULSE_DIVISOR));
+		ei.u.ActorImpulse.Vel = Vec2i2Net(vel);
 		ei.u.ActorImpulse.Pos = Vec2i2Net(actor->Pos);
 		GameEventsEnqueue(&gGameEvents, ei);
 	}

src/cdogs/objs.h

@@ -105,6 +105,7 @@ bool HasHitSound(
 void Damage(
 	const Vec2i hitVector,
 	const int power,
+	const double mass,
 	const int flags, const int playerUID, const int uid,
 	const TileItemKind targetKind, const int targetUID,
 	const special_damage_e special);