More work on explosions and wreckage

shipdata.plist gets show_damage property to control if sparks, etc. are shown default to no if energy recharge is zero, yes otherwise, to mimic existing behaviour. Set hermit explicitly.
2015-04-03 14:42:47 +01:00 · 2015-04-03 14:42:47 +01:00 · d483a2a18b
commit d483a2a18b
parent 9a42498ab2
7 changed files with 237 additions and 52 deletions
--- a/Resources/Config/explosions.plist
+++ b/Resources/Config/explosions.plist
@ -1,4 +1,5 @@
 {
+	// main ship explosion
 	"oolite-default-ship-explosion" = {
 		"alpha" = 0.85;
 		"color_order" = "rgb";
@ -9,13 +10,24 @@
 		"texture" = "oolite-particle-cloud2.png";
 	};

+	// slower clouds from fragment explosions
+	"oolite-wreckage-explosion" = {
+		"alpha" = 0.85;
+		"color_order" = "rgb";
+		"count" = 10;
+		"duration" = 4.5;
+		"growth_rate" = 0.6;
+		"size" = 2.5;
+		"texture" = "oolite-particle-cloud2.png";
+	};

 	"oolite-fragment-explosion" = {
 		"alpha" = 0.25;
 		"color_order" = "rgb";
 		"count" = 5;
-		"duration" = 1.2;
-		"growth_rate" = 14;
+		"duration" = 1.85;
+		"growth_rate" = 7;
+		"spread" = 0.3;
 		"size" = 1.0;
 		"texture" = "oolite-particle-fragments.png";
 	};
@ -24,13 +36,68 @@
 		"alpha" = 0.25;
 		"color_order" = "rgb";
 		"count" = 5;
-		"duration" = 1.2;
-		"growth_rate" = 14;
+		"duration" = 1.75;
+		"growth_rate" = 5;
 		"size" = 1.0;
 		"texture" = "oolite-particle-fragments2.png";
 	};

-	
+
+	// spark effects as ships badly hit
+	"oolite-wreckage-chunk" = {
+		"alpha" = 0.85;
+		"color_order" = "rgb";
+		"count" = 10;
+		"duration" = 1.2;
+		"growth_rate" = 2.6;
+		"size" = 2.5;
+		"texture" = "oolite-particle-cloud2.png";
+	};
+
+	"oolite-wreckage-chunk-fragment" = {
+		"alpha" = 0.25;
+		"color_order" = "rgb";
+		"count" = 5;
+		"duration" = 0.3;
+		"growth_rate" = 18;
+		"spread" = 0.3;
+		"size" = 1.0;
+		"texture" = "oolite-particle-fragments.png";
+	};
+
+	"oolite-wreckage-chunk-fragment-b" = {
+		"alpha" = 0.25;
+		"color_order" = "rgb";
+		"count" = 5;
+		"duration" = 0.4;
+		"growth_rate" = 12;
+		"size" = 1.0;
+		"texture" = "oolite-particle-fragments2.png";
+	};
+
+	"oolite-hull-spark" = {
+		"alpha" = 0.65;
+		"color_order" = "bgr";
+		"count" = 5;
+		"duration" = 0.22;
+		"growth_rate" = 3;
+		"spread" = 0.5;
+		"size" = 0.12;
+		"texture" = "oolite-particle-fragments.png";
+	};
+
+	"oolite-hull-spark-b" = {
+		"alpha" = 0.85;
+		"color_order" = "white";
+		"count" = 5;
+		"duration" = 0.25;
+		"growth_rate" = 3;
+		"spread" = 0.5;
+		"size" = 0.15;
+		"texture" = "oolite-particle-fragments2.png";
+	};
+
+	// explosion for rocky bodies
 	"oolite-default-asteroid-explosion" = {
 		"alpha" = 0.85;
 		"color_order" = "white";
--- a/Resources/Config/shipdata.plist
+++ b/Resources/Config/shipdata.plist
@ -3108,6 +3108,7 @@
 		rotating = yes;
 		requires_docking_clearance = no;
 		scan_class = "CLASS_ROCK";
+		show_damage = no;
 		smooth = yes;
 		station_roll = "0.06"; // 0.5G at rim
 		subentities = 
@ -3957,13 +3958,13 @@
 		ai_type = "nullAI.plist";
 		cargo_type = "CARGO_NOT_CARGO";
 		energy_recharge_rate = 0;
-		explosion_type = ("oolite-default-ship-explosion","oolite-fragment-explosion"); // no flash
+		explosion_type = ("oolite-wreckage-explosion","oolite-fragment-explosion"); // no flash
 		forward_weapon_type = "WEAPON_NONE";
 		fragment_chance = 0.0;
 		is_template = 1;
-		max_energy = 2000;
-		max_flight_pitch = 2;
-		max_flight_roll = 2;
+		max_energy = 20000;
+		max_flight_pitch = 0.2;
+		max_flight_roll = 0.2;
 		max_flight_speed = 500;
 		model = "wreck1.dat";
 		name = "Wreckage";
@ -3973,6 +3974,13 @@
 		counts_as_kill = false;
 	};

+	"oolite_template_wreckage-chunk" = 
+	{
+		like_ship = "oolite_template_wreckage-component";
+		explosion_type = ("oolite-wreckage-chunk-explosion");
+		roles = "oolite-wreckage-chunk";
+	};
+
 		/* Begin entity definitions. Graphics-modifying OXPs should
 		 * generally extend or copy these entries. OXPs should like_ship
 		 * these entries if they want their variant to look like
@ -4282,13 +4290,13 @@
 	"more-wreckage2" =
 	{
 		like_ship = "oolite_template_wreckage-component";
-		explosion_type = ("oolite-default-ship-explosion","oolite-fragment-explosion-b");
+		explosion_type = ("oolite-wreckage-explosion","oolite-fragment-explosion-b");
 		model = "wreck2.dat";
 	};
 	"more-wreckage3" =
 	{
 		like_ship = "oolite_template_wreckage-component";
-		explosion_type = ("oolite-default-ship-explosion");
+		explosion_type = ("oolite-wreckage-explosion");
 		model = "wreck3.dat";
 	};
 	"more-wreckage4" =
@ -4303,6 +4311,21 @@
 		explosion_type = ("oolite-fragment-explosion-b");
 		model = "wreck5.dat";
 	};
+	"wreckage-chunk" = 
+	{
+		like_ship = "oolite_template_wreckage-chunk";
+	};
+	"wreckage-chunk2" = 
+	{
+		like_ship = "oolite_template_wreckage-chunk";
+		explosion_type = ("oolite-wreckage-chunk-fragment");
+	};
+	"wreckage-chunk3" = 
+	{
+		like_ship = "oolite_template_wreckage-chunk";
+		explosion_type = ("oolite-wreckage-chunk-fragment-b");
+	};
+


 	/* Begin definitions for entities used in the tutorial */
--- a/src/Core/Entities/OOExplosionCloudEntity.m
+++ b/src/Core/Entities/OOExplosionCloudEntity.m
@ -43,6 +43,7 @@ static NSString * const kExplosionCount			= @"count";
 static NSString * const kExplosionDuration		= @"duration";
 static NSString * const kExplosionGrowth		= @"growth_rate";
 static NSString * const kExplosionSize			= @"size";
+static NSString * const kExplosionSpread		= @"spread";
 static NSString * const kExplosionTexture		= @"texture";


@ -78,6 +79,8 @@ static NSString * const kExplosionTexture		= @"texture";
 	_alpha = [_settings oo_floatForKey:kExplosionAlpha defaultValue:kExplosionCloudAlpha];
 	_cloudDuration = [_settings oo_floatForKey:kExplosionDuration defaultValue:kExplosionCloudDuration];

+	GLfloat spread = [_settings oo_floatForKey:kExplosionSpread defaultValue:1.0];
+
 	NSString *textureFile = [_settings oo_stringForKey:kExplosionTexture defaultValue:@"oolite-particle-cloud2.png"];
 	
 	_texture = [[OOTexture textureWithName:textureFile
@ -99,7 +102,7 @@ static NSString * const kExplosionTexture		= @"texture";
 		vel = vector_multiply_scalar(vector_normal(vel),1000);
 	}

-	if ((self = [super initWithPosition:pos velocity:vel count:count minSpeed:size*0.8 maxSpeed:size*1.2 duration:_cloudDuration baseColor:baseColor]))
+	if ((self = [super initWithPosition:pos velocity:vel count:count minSpeed:size*0.8*spread maxSpeed:size*1.2*spread duration:_cloudDuration baseColor:baseColor]))
 	{
 		NSString *color_order = [_settings oo_stringForKey:kExplosionColors defaultValue:@"rgb"];
 		
--- a/src/Core/Entities/ShipEntity.h
+++ b/src/Core/Entities/ShipEntity.h
@ -265,6 +265,8 @@ typedef enum
 							cloakPassive: 1,			// cloak deactivates when main weapons or missiles are fired
 							cloakAutomatic: 1,			// cloak activates itself automatic during attack
 							canFragment: 1,				// Can it break into wreckage?
+							isWreckage: 1,              // Is it wreckage?
+							_showDamage: 1,             // Show damage?
 							suppressExplosion: 1,		// Avoid exploding on death (script hook)
 							suppressAegisMessages: 1,	// No script/AI messages sent by -checkForAegis,
 							isMissile: 1,				// Whether this was launched by fireMissile (used to track submunitions).
@ -976,6 +978,8 @@ typedef enum
 - (void) becomeLargeExplosion:(double) factor;
 - (void) becomeEnergyBlast;
 - (void) broadcastEnergyBlastImminent;
+- (void) setIsWreckage:(BOOL)isw;
+- (BOOL) showDamage;

 - (Vector) positionOffsetForAlignment:(NSString*) align;
 Vector positionOffsetForShipInRotationToAlignment(ShipEntity* ship, Quaternion q, NSString* align);
--- a/src/Core/Entities/ShipEntity.m
+++ b/src/Core/Entities/ShipEntity.m
@ -298,6 +298,7 @@ static ShipEntity *doOctreesCollide(ShipEntity *prime, ShipEntity *other);
 	maxEnergy = [shipDict oo_floatForKey:@"max_energy" defaultValue:200.0f];
 	energy_recharge_rate = [shipDict oo_floatForKey:@"energy_recharge_rate" defaultValue:1.0f];
 	
+	_showDamage = [shipDict oo_boolForKey:@"show_damage" defaultValue:(energy_recharge_rate > 0)];
 	// Each new ship should start in seemingly good operating condition, unless specifically told not to - this does not affect the ship's energy levels
 	[self setThrowSparks:[shipDict oo_boolForKey:@"throw_sparks" defaultValue:NO]];
 	
@ -359,6 +360,8 @@ static ShipEntity *doOctreesCollide(ShipEntity *prime, ShipEntity *other);
 	
 	// can it be 'mined' for alloys?
 	canFragment = [shipDict oo_fuzzyBooleanForKey:@"fragment_chance" defaultValue:0.9];
+	isWreckage = NO;
+
 	// can subentities be destroyed separately?
 	isFrangible = [shipDict oo_boolForKey:@"frangible" defaultValue:YES];
 	
@ -2007,6 +2010,12 @@ static ShipEntity *doOctreesCollide(ShipEntity *prime, ShipEntity *other);
 	{	
 		return NO;
 	}
+
+	if (isWreckage)
+	{
+		// wreckage won't collide
+		return NO;
+	}
 	
 	if (isMissile && [self shotTime] < 0.25) // not yet fused
 	{
@ -2430,7 +2439,7 @@ ShipEntity* doOctreesCollide(ShipEntity* prime, ShipEntity* other)
 		[self takeHeatDamage: delta_t * ship_temperature];

 	// are we burning due to low energy
-	if ((energy < maxEnergy * 0.20)&&(energy_recharge_rate > 0.0))	// prevents asteroid etc. from burning
+	if ((energy < maxEnergy * 0.20)&&_showDamage)	// prevents asteroid etc. from burning
 		throw_sparks = YES;
 	
 	// burning effects
@ -8796,9 +8805,9 @@ NSComparisonResult ComparePlanetsBySurfaceDistance(id i1, id i2, void* context)
 				double ecr = [e2 collisionRadius];
 				double d2 = magnitude2(p2) - ecr * ecr;
 				// limit momentum transfer to relatively sensible levels
-				if (d2 < 1.0)
+				if (d2 < 0.1)
 				{
-					d2 = 1.0;
+					d2 = 0.1;
 				}
 				double moment = amount*desired_range/d2;
 				[e2 addImpactMoment:vector_normal(p2) fraction:moment];
@ -8893,9 +8902,26 @@ NSComparisonResult ComparePlanetsBySurfaceDistance(id i1, id i2, void* context)

 - (void) rescaleBy:(GLfloat)factor
 {
-	// rescale mesh (and collision detection stuff)
-	[self setMesh:[[self mesh] meshRescaledBy:factor]];
-	
+	_scaleFactor *= factor;
+	OOMesh *mesh = nil;
+
+	NSDictionary *shipDict = [self shipInfoDictionary];
+	NSString *modelName = [shipDict oo_stringForKey:@"model"];
+	if (modelName != nil)
+	{
+		mesh = [OOMesh meshWithName:modelName
+						   cacheKey:[NSString stringWithFormat:@"%@-%.3f",_shipKey,_scaleFactor]
+				 materialDictionary:[shipDict oo_dictionaryForKey:@"materials"]
+				  shadersDictionary:[shipDict oo_dictionaryForKey:@"shaders"]
+							 smooth:[shipDict oo_boolForKey:@"smooth" defaultValue:NO]
+					   shaderMacros:OODefaultShipShaderMacros()
+					   shaderBindingTarget:self
+						scaleFactor:factor];
+
+		if (mesh == nil)  return;
+		[self setMesh:mesh];
+	}
+
 	// rescale subentities
 	Entity<OOSubEntity>	*se = nil;
 	foreach (se, [self subEntities])
@ -8981,6 +9007,19 @@ NSComparisonResult ComparePlanetsBySurfaceDistance(id i1, id i2, void* context)

 }

+
+- (void) setIsWreckage:(BOOL)isw
+{
+	isWreckage = isw;
+}
+
+
+- (BOOL) showDamage
+{
+	return _showDamage;
+}
+
+
 - (void) becomeExplosion
 {
 	
@ -9010,6 +9049,7 @@ NSComparisonResult ComparePlanetsBySurfaceDistance(id i1, id i2, void* context)
 	int speed_low = 200;
 	GLfloat n_alloys = sqrtf(sqrtf(mass / 6000.0f));
 	NSUInteger numAlloys = 0;
+	BOOL canReleaseSubWreckage = isWreckage && ([UNIVERSE detailLevel] >= DETAIL_LEVEL_EXTRAS);

 	if ([self status] == STATUS_DEAD)
 	{
@ -9024,7 +9064,7 @@ NSComparisonResult ComparePlanetsBySurfaceDistance(id i1, id i2, void* context)
 		
 		if (!suppressExplosion)
 		{
-			if (mass > 500000.0f && randf() < 0.25f) // big!
+			if (!isWreckage && mass > 500000.0f && randf() < 0.25f) // big!
 			{
 				// draw an expanding ring
 				OORingEffectEntity *ring = [OORingEffectEntity ringFromEntity:self];
@ -9164,7 +9204,7 @@ NSComparisonResult ComparePlanetsBySurfaceDistance(id i1, id i2, void* context)

 				// throw out burning chunks of wreckage
 				//
-				if (n_alloys && canFragment)
+				if ((n_alloys && canFragment) || canReleaseSubWreckage)
 				{
 					NSUInteger n_wreckage = 0;
 					
@ -9173,42 +9213,27 @@ NSComparisonResult ComparePlanetsBySurfaceDistance(id i1, id i2, void* context)
 						// Create wreckage only when UNIVERSE is less than half full.
 						// (condition set in r906 - was < 0.75 before) --Kaks 2011.10.17
 						NSUInteger maxWrecks = 3;
-						// if it can cope with extra detail, allow more wreckage
-						if ([UNIVERSE detailLevel] >= DETAIL_LEVEL_EXTRAS)
+						if (n_alloys == 0)
 						{
-							maxWrecks = 8;
+							// must be sub-wreckage here
+							n_wreckage = (mass > 600.0 && randf() < 0.2)?2:0;
+						}
+						else
+						{
+							n_wreckage = (n_alloys < maxWrecks)? floorf(randf()*(n_alloys+2)) : maxWrecks;
 						}
-						n_wreckage = (n_alloys < maxWrecks)? floorf(n_alloys) : maxWrecks;
 					}
 					
 					for (i = 0; i < n_wreckage; i++)
 					{
-						ShipEntity* wreck = [UNIVERSE newShipWithRole:@"wreckage"];   // retain count = 1
-						if (wreck)
-						{
-							GLfloat expected_mass = 0.1f * mass * (0.75 + 0.5 * randf());
-							GLfloat wreck_mass = [wreck mass];
-							GLfloat scale_factor = powf(expected_mass / wreck_mass, 0.33333333f);	// cube root of volume ratio
-							[wreck rescaleBy: scale_factor];
-							
-							Vector r1 = [octree randomPoint];
-							HPVector rpos = HPvector_add(vectorToHPVector(quaternion_rotate_vector([self normalOrientation], r1)), xposition);
-							[wreck setPosition:rpos];
-							
-							[wreck setVelocity:[self velocity]];
+						Vector r1 = [octree randomPoint];
+						Vector dir = quaternion_rotate_vector([self normalOrientation], r1);
+						HPVector rpos = HPvector_add(vectorToHPVector(dir), xposition);
+						GLfloat lifetime = 750.0 * randf() + 250.0 * i + 100.0;
+						ShipEntity *wreck = [UNIVERSE addWreckageFrom:self withRole:@"wreckage" at:rpos scale:1.0 lifetime:lifetime/2];
+
+						[wreck setVelocity:vector_add([wreck velocity],vector_multiply_scalar(vector_normal(dir),randf()*[wreck collisionRadius]))];

-							quaternion_set_random(&q);
-							[wreck setOrientation:q];
-							
-							[wreck setTemperature: 1000.0];		// take 1000e heat damage per second
-							[wreck setHeatInsulation: 1.0e7];	// very large! so it won't cool down
-							[wreck setEnergy: 750.0 * randf() + 250.0 * i + 100.0];	// burn for 0.25s -> 1.25s
-							
-							[UNIVERSE addEntity:wreck];	// STATUS_IN_FLIGHT, AI state GLOBAL
-							[wreck performTumble];
-							[wreck rescaleBy: 1.0/scale_factor];
-							[wreck release];
-						}
 					}
 					n_alloys = randf() * n_alloys;
 				}
@ -11575,7 +11600,7 @@ Vector positionOffsetForShipInRotationToAlignment(ShipEntity* ship, Quaternion q
 			[shot setRange:hitAtRange];
 			Vector vd = vector_forward_from_quaternion([shot orientation]);
 			HPVector flash_pos = HPvector_add([shot position], vectorToHPVector(vector_multiply_scalar(vd, hitAtRange)));
-			[UNIVERSE addEntity:[OOFlashEffectEntity laserFlashWithPosition:flash_pos velocity:[victim velocity] color:laser_color]];
+			[UNIVERSE addLaserHitEffectsAt:flash_pos against:victim damage:weapon_damage color:laser_color];
 		}
 	}
 	else
@ -11700,7 +11725,7 @@ Vector positionOffsetForShipInRotationToAlignment(ShipEntity* ship, Quaternion q
 			[shot setRange:hit_at_range];
 			Vector vd = vector_forward_from_quaternion([shot orientation]);
 			HPVector flash_pos = HPvector_add([shot position], vectorToHPVector(vector_multiply_scalar(vd, hit_at_range)));
-			[UNIVERSE addEntity:[OOFlashEffectEntity laserFlashWithPosition:flash_pos velocity:[victim velocity] color:laser_color]];
+			[UNIVERSE addLaserHitEffectsAt:flash_pos against:victim damage:weapon_damage color:laser_color];
 		}
 	}
 	
@ -11787,7 +11812,7 @@ Vector positionOffsetForShipInRotationToAlignment(ShipEntity* ship, Quaternion q
 			[shot setRange:hit_at_range];
 			Vector vd = vector_forward_from_quaternion([shot orientation]);
 			HPVector flash_pos = HPvector_add([shot position], vectorToHPVector(vector_multiply_scalar(vd, hit_at_range)));
-			[UNIVERSE addEntity:[OOFlashEffectEntity laserFlashWithPosition:flash_pos velocity:[victim velocity] color:laser_color]];
+			[UNIVERSE addLaserHitEffectsAt:flash_pos against:victim damage:weapon_damage color:laser_color];
 		}
 	}
 	else
--- a/src/Core/Universe.h
+++ b/src/Core/Universe.h
@ -524,6 +524,8 @@ enum
 - (Entity*) hazardOnRouteFromEntity:(Entity *) e1 toDistance:(double)dist fromPoint:(HPVector) p2;
 - (HPVector) getSafeVectorFromEntity:(Entity *) e1 toDistance:(double)dist fromPoint:(HPVector) p2;

+- (ShipEntity *) addWreckageFrom:(ShipEntity *)ship withRole:(NSString *)wreckRole at:(HPVector)rpos scale:(GLfloat)scale lifetime:(GLfloat)lifetime;
+- (void) addLaserHitEffectsAt:(HPVector)pos against:(ShipEntity *)target damage:(float)damage color:(OOColor *)color;
 - (ShipEntity *) firstShipHitByLaserFromShip:(ShipEntity *)srcEntity inDirection:(OOWeaponFacing)direction offset:(Vector)offset gettingRangeFound:(GLfloat*)range_ptr;
 - (Entity *) firstEntityTargetedByPlayer;
 - (Entity *) firstEntityTargetedByPlayerPrecisely;
--- a/src/Core/Universe.m
+++ b/src/Core/Universe.m
@ -5473,6 +5473,67 @@ static BOOL MaintainLinkedLists(Universe *uni)
 }


+- (ShipEntity*) addWreckageFrom:(ShipEntity *)ship withRole:(NSString *)wreckRole at:(HPVector)rpos scale:(GLfloat)scale lifetime:(GLfloat)lifetime
+{
+	ShipEntity* wreck = [UNIVERSE newShipWithRole:wreckRole];   // retain count = 1
+	Quaternion q;
+	if (wreck)
+	{
+		GLfloat expected_mass = 0.1f * [ship mass] * (0.75 + 0.5 * randf());
+		GLfloat wreck_mass = [wreck mass];
+		GLfloat scale_factor = powf(expected_mass / wreck_mass, 0.33333333f) * scale;	// cube root of volume ratio
+		[wreck rescaleBy: scale_factor];
+
+		[wreck setPosition:rpos];
+
+		[wreck setVelocity:[ship velocity]];
+
+		quaternion_set_random(&q);
+		[wreck setOrientation:q];
+							
+		[wreck setTemperature: 1000.0];		// take 1000e heat damage per second
+		[wreck setHeatInsulation: 1.0e7];	// very large! so it won't cool down
+		[wreck setEnergy: lifetime];
+							
+		[wreck setIsWreckage:YES];
+
+		[UNIVERSE addEntity:wreck];	// STATUS_IN_FLIGHT, AI state GLOBAL
+		[wreck performTumble];
+		//	[wreck rescaleBy: 1.0/scale_factor];
+		[wreck release];
+	}
+	return wreck;
+}
+
+
+
+- (void) addLaserHitEffectsAt:(HPVector)pos against:(ShipEntity *)target damage:(float)damage color:(OOColor *)color
+{
+	// low energy, start getting small surface explosions
+	if ([target showDamage] && [target energy] < [target maxEnergy]/2)
+	{
+		NSString *key = (randf() < 0.5) ? @"oolite-hull-spark" : @"oolite-hull-spark-b";
+		NSDictionary *settings = [UNIVERSE explosionSetting:key];
+		OOExplosionCloudEntity* burst = [OOExplosionCloudEntity explosionCloudFromEntity:target withSettings:settings];
+		[burst setPosition:pos];
+		[self addEntity: burst];
+		if ([target energy] * randf() < damage)
+		{
+			ShipEntity *wreck = [self addWreckageFrom:target withRole:@"oolite-wreckage-chunk" at:pos scale:0.05 lifetime:(125.0+(randf()*200.0))];
+			if (wreck)
+			{
+				Vector direction = HPVectorToVector(HPvector_normal(HPvector_subtract(pos,[target position])));
+				[wreck setVelocity:vector_add([wreck velocity],vector_multiply_scalar(direction,10+20*randf()))];
+			}
+		}
+	}
+	else
+	{
+		[self addEntity:[OOFlashEffectEntity laserFlashWithPosition:pos velocity:[target velocity] color:color]];
+	}
+}
+
+
 - (ShipEntity *) firstShipHitByLaserFromShip:(ShipEntity *)srcEntity inDirection:(OOWeaponFacing)direction offset:(Vector)offset gettingRangeFound:(GLfloat *)range_ptr
 {
 	if (srcEntity == nil) return nil;