266 lines
10 KiB
C#

// ClassicalSharp copyright 2014-2016 UnknownShadow200 | Licensed under MIT
using System;
using OpenTK;
namespace ClassicalSharp.Entities {
/// <summary> Entity component that performs collision detection. </summary>
public sealed class PhysicsComponent {
bool useLiquidGravity = false; // used by BlockDefinitions.
bool canLiquidJump = true;
internal bool firstJump, secondJump, jumping;
Entity entity;
Game game;
BlockInfo info;
internal float jumpVel = 0.42f, serverJumpVel = 0.42f;
internal HacksComponent hacks;
internal CollisionsComponent collisions;
public PhysicsComponent( Game game, Entity entity ) {
this.game = game;
this.entity = entity;
info = game.BlockInfo;
}
public void UpdateVelocityState( float xMoving, float zMoving ) {
if( !hacks.NoclipSlide && (hacks.Noclip && xMoving == 0 && zMoving == 0) )
entity.Velocity = Vector3.Zero;
if( hacks.Flying || hacks.Noclip ) {
entity.Velocity.Y = 0; // eliminate the effect of gravity
int dir = (hacks.FlyingUp || jumping) ? 1 : (hacks.FlyingDown ? -1 : 0);
entity.Velocity.Y += 0.12f * dir;
if( hacks.Speeding && hacks.CanSpeed ) entity.Velocity.Y += 0.12f * dir;
if( hacks.HalfSpeeding && hacks.CanSpeed ) entity.Velocity.Y += 0.06f * dir;
} else if( jumping && entity.TouchesAnyRope() && entity.Velocity.Y > 0.02f ) {
entity.Velocity.Y = 0.02f;
}
if( !jumping ) {
canLiquidJump = false; return;
}
bool touchWater = entity.TouchesAnyWater();
bool touchLava = entity.TouchesAnyLava();
if( touchWater || touchLava ) {
AABB bounds = entity.CollisionBounds;
int feetY = Utils.Floor( bounds.Min.Y ), bodyY = feetY + 1;
int headY = Utils.Floor( bounds.Max.Y );
if( bodyY > headY ) bodyY = headY;
bounds.Max.Y = bounds.Min.Y = feetY;
bool liquidFeet = entity.TouchesAny( bounds, StandardLiquid );
bounds.Min.Y = Math.Min( bodyY, headY );
bounds.Max.Y = Math.Max( bodyY, headY );
bool liquidRest = entity.TouchesAny( bounds, StandardLiquid );
bool pastJumpPoint = liquidFeet && !liquidRest && (entity.Position.Y % 1 >= 0.4);
if( !pastJumpPoint ) {
canLiquidJump = true;
entity.Velocity.Y += 0.04f;
if( hacks.Speeding && hacks.CanSpeed ) entity.Velocity.Y += 0.04f;
if( hacks.HalfSpeeding && hacks.CanSpeed ) entity.Velocity.Y += 0.02f;
} else if( pastJumpPoint ) {
// either A) jump bob in water B) climb up solid on side
if( collisions.HorCollision )
entity.Velocity.Y += touchLava ? 0.30f : 0.13f;
else if( canLiquidJump )
entity.Velocity.Y += touchLava ? 0.20f : 0.10f;
canLiquidJump = false;
}
} else if( useLiquidGravity ) {
entity.Velocity.Y += 0.04f;
if( hacks.Speeding && hacks.CanSpeed ) entity.Velocity.Y += 0.04f;
if( hacks.HalfSpeeding && hacks.CanSpeed ) entity.Velocity.Y += 0.02f;
canLiquidJump = false;
} else if( entity.TouchesAnyRope() ) {
entity.Velocity.Y += (hacks.Speeding && hacks.CanSpeed) ? 0.15f : 0.10f;
canLiquidJump = false;
} else if( entity.onGround ) {
DoNormalJump();
}
}
public void DoNormalJump() {
entity.Velocity.Y = jumpVel;
if( hacks.Speeding && hacks.CanSpeed ) entity.Velocity.Y += jumpVel;
if( hacks.HalfSpeeding && hacks.CanSpeed ) entity.Velocity.Y += jumpVel / 2;
canLiquidJump = false;
}
bool StandardLiquid( byte block ) {
return info.Collide[block] == CollideType.SwimThrough;
}
static Vector3 waterDrag = new Vector3( 0.8f, 0.8f, 0.8f ),
lavaDrag = new Vector3( 0.5f, 0.5f, 0.5f ),
ropeDrag = new Vector3( 0.5f, 0.85f, 0.5f ),
normalDrag = new Vector3( 0.91f, 0.98f, 0.91f ),
airDrag = new Vector3( 0.6f, 1f, 0.6f );
const float liquidGrav = 0.02f, ropeGrav = 0.034f, normalGrav = 0.08f;
internal const float Gravity = normalGrav;
public void PhysicsTick( float xMoving, float zMoving ) {
if( hacks.Noclip ) entity.onGround = false;
float multiply = GetBaseMultiply( true );
float yMultiply = GetBaseMultiply( hacks.CanSpeed );
float modifier = LowestSpeedModifier();
float yMul = Math.Max( 1f, yMultiply / 5 ) * modifier;
float horMul = multiply * modifier;
if( !(hacks.Flying || hacks.Noclip) ) {
if( secondJump ) { horMul *= 93f; yMul *= 10f; }
else if( firstJump ) { horMul *= 46.5f; yMul *= 7.5f; }
}
if( entity.TouchesAnyWater() && !hacks.Flying && !hacks.Noclip ) {
MoveNormal( xMoving, zMoving, 0.02f * horMul, waterDrag, liquidGrav, yMul );
} else if( entity.TouchesAnyLava() && !hacks.Flying && !hacks.Noclip ) {
MoveNormal( xMoving, zMoving, 0.02f * horMul, lavaDrag, liquidGrav, yMul );
} else if( entity.TouchesAnyRope() && !hacks.Flying && !hacks.Noclip ) {
MoveNormal( xMoving, zMoving, 0.02f * 1.7f, ropeDrag, ropeGrav, yMul );
} else {
float factor = !(hacks.Flying || hacks.Noclip) && entity.onGround ? 0.1f : 0.02f;
float gravity = useLiquidGravity ? liquidGrav : normalGrav;
if( hacks.Flying || hacks.Noclip )
MoveFlying( xMoving, zMoving, factor * horMul, normalDrag, gravity, yMul );
else
MoveNormal( xMoving, zMoving, factor * horMul, normalDrag, gravity, yMul );
if( entity.BlockUnderFeet == Block.Ice && !(hacks.Flying || hacks.Noclip) ) {
// limit components to +-0.25f by rescaling vector to [-0.25, 0.25]
if( Math.Abs( entity.Velocity.X ) > 0.25f || Math.Abs( entity.Velocity.Z ) > 0.25f ) {
float scale = Math.Min(
Math.Abs( 0.25f / entity.Velocity.X ), Math.Abs( 0.25f / entity.Velocity.Z ) );
entity.Velocity.X *= scale;
entity.Velocity.Z *= scale;
}
} else if( entity.onGround || hacks.Flying ) {
entity.Velocity *= airDrag; // air drag or ground friction
}
}
if( entity.onGround ) { firstJump = false; secondJump = false; }
}
void AdjHeadingVelocity( float x, float z, float factor ) {
float dist = (float)Math.Sqrt( x * x + z * z );
if( dist < 0.00001f ) return;
if( dist < 1 ) dist = 1;
float multiply = factor / dist;
entity.Velocity += Utils.RotateY( x * multiply, 0, z * multiply, entity.HeadYawRadians );
}
void MoveFlying( float xMoving, float zMoving, float factor, Vector3 drag, float gravity, float yMul ) {
AdjHeadingVelocity( zMoving, xMoving, factor );
float yVel = (float)Math.Sqrt( entity.Velocity.X * entity.Velocity.X + entity.Velocity.Z * entity.Velocity.Z );
// make horizontal speed the same as vertical speed.
if( (xMoving != 0 || zMoving != 0) && yVel > 0.001f ) {
entity.Velocity.Y = 0;
yMul = 1;
if( hacks.FlyingUp || jumping ) entity.Velocity.Y += yVel;
if( hacks.FlyingDown ) entity.Velocity.Y -= yVel;
}
Move( xMoving, zMoving, factor, drag, gravity, yMul );
}
void MoveNormal( float xMoving, float zMoving, float factor, Vector3 drag, float gravity, float yMul ) {
AdjHeadingVelocity( zMoving, xMoving, factor );
Move( xMoving, zMoving, factor, drag, gravity, yMul );
}
void Move( float xMoving, float zMoving, float factor, Vector3 drag, float gravity, float yMul ) {
entity.Velocity.Y *= yMul;
if( !hacks.Noclip )
collisions.MoveAndWallSlide();
entity.Position += entity.Velocity;
entity.Velocity.Y /= yMul;
entity.Velocity *= drag;
entity.Velocity.Y -= gravity;
}
float GetBaseMultiply( bool canSpeed ) {
float multiply = 0;
if( hacks.Flying || hacks.Noclip ) {
if( hacks.Speeding && canSpeed ) multiply += hacks.SpeedMultiplier * 8;
if( hacks.HalfSpeeding && canSpeed ) multiply += hacks.SpeedMultiplier * 8 / 2;
if( multiply == 0 ) multiply = 8f;
} else {
if( hacks.Speeding && canSpeed ) multiply += hacks.SpeedMultiplier;
if( hacks.HalfSpeeding && canSpeed ) multiply += hacks.SpeedMultiplier / 2;
if( multiply == 0 ) multiply = 1;
}
return hacks.CanSpeed ? multiply : Math.Min( multiply, hacks.MaxSpeedMultiplier );
}
const float inf = float.PositiveInfinity;
float LowestSpeedModifier() {
AABB bounds = entity.CollisionBounds;
useLiquidGravity = false;
float baseModifier = LowestModifier( bounds, false );
bounds.Min.Y -= 0.5f/16f; // also check block standing on
float solidModifier = LowestModifier( bounds, true );
if( baseModifier == inf && solidModifier == inf ) return 1;
return baseModifier == inf ? solidModifier : baseModifier;
}
float LowestModifier( AABB bounds, bool checkSolid ) {
Vector3I bbMin = Vector3I.Floor( bounds.Min );
Vector3I bbMax = Vector3I.Floor( bounds.Max );
float modifier = inf;
for( int y = bbMin.Y; y <= bbMax.Y; y++ )
for( int z = bbMin.Z; z <= bbMax.Z; z++ )
for( int x = bbMin.X; x <= bbMax.X; x++ )
{
byte block = game.World.SafeGetBlock( x, y, z );
if( block == 0 ) continue;
CollideType type = info.Collide[block];
if( type == CollideType.Solid && !checkSolid )
continue;
Vector3 min = new Vector3( x, y, z ) + info.MinBB[block];
Vector3 max = new Vector3( x, y, z ) + info.MaxBB[block];
AABB blockBB = new AABB( min, max );
if( !blockBB.Intersects( bounds ) ) continue;
modifier = Math.Min( modifier, info.SpeedMultiplier[block] );
if( block >= BlockInfo.CpeCount && type == CollideType.SwimThrough )
useLiquidGravity = true;
}
return modifier;
}
/// <summary> Calculates the jump velocity required such that when a client presses
/// the jump binding they will be able to jump up to the given height. </summary>
internal void CalculateJumpVelocity( float jumpHeight ) {
jumpVel = 0;
if( jumpHeight >= 256 ) jumpVel = 10.0f;
if( jumpHeight >= 512 ) jumpVel = 16.5f;
if( jumpHeight >= 768 ) jumpVel = 22.5f;
while( GetMaxHeight( jumpVel ) <= jumpHeight )
jumpVel += 0.001f;
}
public static double GetMaxHeight( float u ) {
// equation below comes from solving diff(x(t, u))= 0
// We only work in discrete timesteps, so test both rounded up and down.
double t = 49.49831645 * Math.Log( 0.247483075 * u + 0.9899323 );
return Math.Max( YPosAt( (int)t, u ), YPosAt( (int)t + 1, u ) );
}
static double YPosAt( int t, float u ) {
// v(t, u) = (4 + u) * (0.98^t) - 4, where u = initial velocity
// x(t, u) = Σv(t, u) from 0 to t (since we work in discrete timesteps)
// plugging into Wolfram Alpha gives 1 equation as
// (0.98^t) * (-49u - 196) - 4t + 50u + 196
double a = Math.Exp( -0.0202027 * t ); //~0.98^t
return a * ( -49 * u - 196 ) - 4 * t + 50 * u + 196;
}
}
}