The verlet Reference Manual

Table of Contents

The verlet Reference Manual

This is the verlet Reference Manual, version 0.0.8, generated automatically by Declt version 3.0 "Montgomery Scott" on Sun May 15 06:25:56 2022 GMT+0.

1 Introduction

Verlet physics library

Table of Contents

• 1 VERLET ASDF System Details
• 2 Interface
  • 2.1 Force
  • 2.2 Physics System
  • 2.3 Particles
  • 2.4 Springs
    • 2.4.1 Linear Springs
    • 2.4.2 Area Springs
    • 2.4.3 Volume Springs
  • 2.5 Modificators
    • 2.5.1 Damper
    • 2.5.2 Gravity
      • 2.5.2.1 Global Gravity
      • 2.5.2.2 Mutual Gravity
      • 2.5.2.3 Field Gravity
    • 2.5.3 Constraints
      • 2.5.3.1 Plane Constraints
      • 2.5.3.2 Sphere Constraints
      • 2.5.3.3 Triangle Constraints
    • 2.5.4 Friction
      • 2.5.4.1 Global Friction
      • 2.5.4.2 Field Friction
      • 2.5.4.3 Constraint Friction

[in package VERLET]

1 VERLET ASDF System Details

• Version: 0.0.8
• Description: Verlet is a simple physics engine based on verlet integration. It supports particles with position and direction, springs between particles, global gravity as well as gravity between particles, and spacial constraints.
• Licence: BSD-3
• Author: Thomas Bartscher thomas-bartscher@weltraumschlangen.de

2 Interface

• [generic-function] UPDATE! OBJECT &OPTIONAL DELTA

2.1 Force

• [macro] DEFORCE NAME MODE (&REST LAMBDA-LIST) &BODY BODY

  Define a force so it is usable in the BUILD-SYSTEM macro.

  MODE is required to be one of :FORCE, :VELOCITY-DEPENDENT-FORCE, :CONSTRAINT, and :COLLISION. Reference the STEP! function for more information on what these mean.

  The LAMBDA-LIST is tha lambda list used by the local macro in the BUILD-SYSTEM macro call, BODY is it's body. The resulting code should return the object to add to the system under construction. PARTICLES is an anaphoric variable in the BODY, containing a list of the particles defined by PARTICLES in the BUILD-SYSTEM macro, in the order they are defined in.

• [locative] FORCE

2.2 Physics System

• [class] SYSTEM

• [function] [SYSTEM]

• [macro] BUILD-SYSTEM (&REST PARTICLES) &BODY FORCES

  Build up a standard physics SYSTEM using defined forces.

  PARTICLES is a list with items of the form ((X Y Z) &KEY (MASS 1.0) PREVIOUS-POSITION VELOCITY). The list at the beginning describes the position of the particle, for the meaning of the keyword arguments reference the [PARTICLE] function.

  FORCES is a list of force descriptors, as defined by the DEFORCE macro. The respective forces are going to be added to the final system.

• [accessor] PARTICLES<- SYSTEM (= (SET))

• [accessor] FORCES<- SYSTEM (= (SET))

• [accessor] VELOCITY-DEPENDENT-FORCES<- SYSTEM (= (SET))

• [accessor] COLLISIONS<- SYSTEM (= (SET))

• [accessor] CONSTRAINTS<- SYSTEM (= (SET))

• [function] STEP! SYSTEM DELTA &KEY (RESOLVE-STEPS 1)

  Updates a physical SYSTEM by timestep DELTA.

  1. Apply all forces not dependent on the velocity of particles (:FORCE in the DEFORCE macro)

  2. Calculate forces depending on velocities of particles, using the memoized velocities so far (:VELOCITY-DEPENDENT-FORCE in the DEFORCE macro)

  3. Repeat RESOLVE-STEPS times:

  4. Resolve all static constraints (:CONSTRAINT in the DEFORCE macro)

  5. Resolve collisions (:COLLISION in the DEFORCE macro)

  Please note after STEP! returns, no collisions should be happening, but static constraints might be violated.

2.3 Particles

• [class] PARTICLE

• [function] [PARTICLE] POSITION &KEY (MASS 1.0) PREVIOUS-POSITION VELOCITY

  Returns an instance of class PARTICLE at POSITION. Provide only one keyword argument among PREVIOUS-POSITION and VELOCITY, since the respective other is calculated from the provided. If none are provided, assume a velocity of 0.

• [accessor] POSITION<- PARTICLE (:POSITION)

• [accessor] MASS<- PARTICLE (:MASS)

• [function] VELOCITY<- PARTICLE

  Return the velocity of PARTICLE as a (SIMPLE-ARRAY SINGLE-FLOAT (3)).

  Please note that this is a best guess at the current velocity, based on the forces applied so far in the current frame.

• [function] SPEED<- PARTICLE

  Return the speed of PARTICLE as a SINGLE-FLOAT.

  Please note that this is a best guess at the current speed, based on the forces applied so far in the current frame.

• [function] ACCELERATE! PARTICLE DV

• [function] DEFLECT! PARTICLE DIRECTION

  Moves PARTICLE to TARGET and mirrors the PARTICLE's velocity on the plane containing TARGET with the change in position as normal.

• [method] UPDATE! (PARTICLE PARTICLE)

  Move PARTICLE by DELTA times the PARTICLEs velocity.

2.4 Springs

• [force] SPRING (P1 P2 &OPTIONAL P3 P4) K &OPTIONAL VOLUME

2.4.1 Linear Springs

• [class] SPRING

• [function] [SPRING] P1 P2 K &KEY (LENGTH (RTG-MATH.VECTOR3:DISTANCE (POSITION<- P1) (POSITION<- P2)))

  Create a SPRING connecting the PARTICLEs P1 and P2, with ideal length LENGTH and spring constant K. LENGTH defaults to the distance between P1 and P2.

• [accessor] K<- SPRING (:K)

• [accessor] LENGTH<- SPRING (:LENGTH)

• [method] UPDATE! (OBJECT SPRING)

  Exert a length-restoring force on the endpoints of the linear spring.

2.4.2 Area Springs

Area springs are hard to predict and may be buggy in unknown ways. Combining them with standard or volume springs seems to violato conservation of momentum.

• [class] AREA-SPRING

• [function] [AREA-SPRING] P1 P2 P3 K &KEY (AREA (/ (RTG-MATH.VECTOR3:LENGTH (RTG-MATH.VECTOR3:CROSS (RTG-MATH.VECTOR3:- (POSITION<- P1) (POSITION<- P2)) (RTG-MATH.VECTOR3:- (POSITION<- P1) (POSITION<- P3)))) 2.0))

  Creates an AREA-SPRING with corners P1, P2 and P3, ideal area AREA, and spring constant K. AREA defaults to the area enclosed by the supplied particles.

• [accessor] AREA<- AREA-SPRING (:AREA)

• [accessor] K<- AREA-SPRING (:K)

• [method] UPDATE! (OBJECT AREA-SPRING)

  Exert an area-restoring force on the corners of the area spring

2.4.3 Volume Springs

Volume springs are hard to predict and may be buggy in unknown ways. Combining them with standard or area springs seems to violate conservation of momentum.

• [class] VOLUME-SPRING

• [function] [VOLUME-SPRING] P1 P2 P3 P4 K &KEY (VOLUME (ABS (/ (RTG-MATH.VECTOR3:DOT (RTG-MATH.VECTOR3:- (POSITION<- P4) (POSITION<- P1)) (RTG-MATH.VECTOR3:CROSS (RTG-MATH.VECTOR3:- (POSITION<- P3) (POSITION<- P1)) (RTG-MATH.VECTOR3:- (POSITION<- P2) (POSITION<- P1)))) 6)))

  Create a VOLUME-SPRING with corners P1, P2, P3 and P4, ideal volume VOLUME, and spring constant K. VOLUME defaults to the volume enclosed by the given particles.

• [accessor] VOLUME<- VOLUME-SPRING (:VOLUME)

• [accessor] K<- VOLUME-SPRING (:K)

• [method] UPDATE! (OBJECT VOLUME-SPRING)

  Exert a volume-restoring force on the corners of the volume spring.

2.5 Modificators

• [class] MODIFICATOR

  MODIFICATOR objects keep track of other objects to modify in a uniform fashion. The MODIFICATOR class itself is not meant to be instanciated. An inheriting class should implement a method for UPDATE! to make use of its subjects.

• [generic-function] ADD-SUBJECT MODIFICATOR SUBJECT

  Adds a SUBJECT to the MODIFICATOR for tracking.

• [method] ADD-SUBJECT (MODIFICATOR MODIFICATOR) (SUBJECT PARTICLE)

• [generic-function] REMOVE-SUBJECT MODIFICATOR SUBJECT

  Remove a SUBJECT to the MODIFICATOR so it won't be tracked anymore.

• [method] REMOVE-SUBJECT (MODIFICATOR MODIFICATOR) (SUBJECT PARTICLE)

2.5.1 Damper

• [force] DAMPER (&REST INDICE) D

• [class] DAMPER MODIFICATOR

• [function] [DAMPER] D &REST PARTICLES

• [accessor] D<- DAMPER (:D)

• [method] UPDATE! (DAMPER DAMPER)

2.5.2 Gravity

2.5.2.1 Global Gravity

• [force] GLOBAL-GRAVITY X Y Z

• [class] GLOBAL-GRAVITY MODIFICATOR

• [function] [GLOBAL-GRAVITY] GRAVITY

  Creates an instance of GLOBAL-GRAVITY which accelerates all its subjects by GRAVITY on each frame.

• [method] UPDATE! (GRAVITY GLOBAL-GRAVITY)

  Accelerate the subjects of GRAVITY by the gravity vector.

2.5.2.2 Mutual Gravity

• [force] MUTUAL-GRAVITY

• [class] MUTUAL-GRAVITY MODIFICATOR

  Applies gravitational force to the tracked particles according to the mass of the other tracked particles.

• [function] [MUTUAL-GRAVITY]

• [method] UPDATE! (GRAVITY MUTUAL-GRAVITY)

2.5.2.3 Field Gravity

• [force] FIELD-GRAVITY POSITION-VAR &BODY BODY

• [class] FIELD-GRAVITY MODIFICATOR

• [function] [FIELD-GRAVITY] FIELD

  Creates FIELD-GRAVITY with gravity field FIELD. FIELD must map positions (SIMPLE-ARRAY SINGLE-FLOAT (3))s to gravity vectors (SIMPLE-ARRAY SINGLE-FLOAT (3)).

• [accessor] FIELD<- FIELD-GRAVITY (:FIELD)

• [method] UPDATE! (OBJECT FIELD-GRAVITY)

2.5.3 Constraints

• [class] CONSTRAINT MODIFICATOR

• [generic-function] VIOLATED? CONSTRAINT PARTICLE

  Returns NIL when the constraint is fulfilled and a truthy value otherwise.

• [generic-function] DEFLECTION-VECTOR CONSTRAINT PARTICLE

  Returns the cange in position for PARTICLE to obey CONSTRAINT again.

• [method] UPDATE! (CONSTRAINT CONSTRAINT)

  Deflects all subjects violating the constraint as per VIOLATED? by the vector defined by DEFLECTION-VECTOR.

2.5.3.1 Plane Constraints

• [force] PLANE-CONSTRAINT (X Y Z) (NX NY NZ)

• [class] PLANE-CONSTRAINT CONSTRAINT

• [function] [PLANE-CONSTRAINT] POINT NORMAL

  Creates a PLANE-CONSTRAINT restricting all subjects to a half-space defined by the plane containing POINT with normal NORMAL. The usable half-space is the closed half-space that NORMAL is pointing into.

• [method] VIOLATED? (CONSTRAINT PLANE-CONSTRAINT) (PARTICLE PARTICLE)

• [method] DEFLECTION-VECTOR (CONSTRAINT PLANE-CONSTRAINT) (PARTICLE PARTICLE)

2.5.3.2 Sphere Constraints

• [force] SPHERE-CONSTRAINT (CX CY CZ) R &OPTIONAL OUTER-WALL?

• [class] SPHERE-CONSTRAINT CONSTRAINT

• [function] [SPHERE-CONSTRAINT] CENTER RADIUS &OPTIONAL OUTER-WALL?

  Creates a SPHERE-CONSTRAINT with center CENTER and radius RADIUS. CENTER is a (SIMPLE-ARRAY SINGLE-FLOAT (3)), RADIUS a SINGLE-FLOAT. When OUTER-WALL? is truthy, movement is restricted to the closed ball described by the sphere, otherwise movement is constricted to the outside of the open ball described by the sphere.

• [method] VIOLATED? (CONSTRAINT SPHERE-CONSTRAINT) (PARTICLE PARTICLE)

• [method] DEFLECTION-VECTOR (CONSTRAINT SPHERE-CONSTRAINT) (PARTICLE PARTICLE)

2.5.3.3 Triangle Constraints

• [force] TRIANGLE-CONSTRAINT (X1 Y1 Z1) (X2 Y2 Z2) (X3 Y3 Z3)

• [class] TRIANGLE-CONSTRAINT CONSTRAINT

• [function] [TRIANGLE-CONSTRAINT] P1 P2 P3

  Create a TRIANGLE-CONSTRAINT preventing particles moving through the triangle enclosed by P1, P2, and P3

• [method] VIOLATED? (CONSTRAINT TRIANGLE-CONSTRAINT) (PARTICLE PARTICLE)

• [method] DEFLECTION-VECTOR (CONSTRAINT TRIANGLE-CONSTRAINT) (PARTICLE PARTICLE)

2.5.4 Friction

• [function] FRICTION! PARTICLE FRICTION DELTA

  Reduce the speed of PARTICLE by FRICTION·DELTA to a minimum of speed 0. This means that the PARTICLE's velocity's direction is never reversed by this function. Modifies PARTICLE.

2.5.4.1 Global Friction

• [force] GLOBAL-FRICTION F

• [class] GLOBAL-FRICTION MODIFICATOR

• [function] [GLOBAL-FRICTION] FRICTION

• [accessor] FRICTION<- GLOBAL-FRICTION (:FRICTION)

• [method] UPDATE! (OBJECT GLOBAL-FRICTION)

  Apply the global friction to all subjects.

2.5.4.2 Field Friction

• [force] FIELD-FRICTION POSITION-VAR &BODY BODY

• [class] FIELD-FRICTION MODIFICATOR

• [function] [FIELD-FRICTION] FIELD

  Creates FIELD-FRICTION with friction field FIELD. FIELD must map 3D positions to friction values.

• [accessor] FIELD<- FIELD-FRICTION (:FIELD)

2.5.4.3 Constraint Friction

• [class] CONSTRAINT-FRICTION MODIFICATOR

• [function] [CONSTRAINT-FRICTION] CONSTRAINT FRICTION

  Creates CONSTRAINT-FRICTION which applies friction FRICTION to subjects on collision with CONSTRAINT. Note that the subject of the CONSTRAINT-FRICTION instance and of the constraint need not necessarily be the same.

• [accessor] FRICTION<- CONSTRAINT-FRICTION (:FRICTION)

• [method] UPDATE! (OBJECT CONSTRAINT-FRICTION)

2 Systems

The main system appears first, followed by any subsystem dependency.

2.1 verlet

Author

Thomas Bartscher <thomas-bartscher@weltraumschlangen.de>

License

BSD-3

Description

Verlet is a simple physics engine based on verlet
integration. It supports particles with position and direction, springs between particles, global gravity as well as gravity between particles, and spacial constraints.

Version

0.0.8

Dependencies

• chain
• metabang-bind
• rtg-math
• fset
• mgl-pax

Source

verlet.asd (file)

Components

• package.lisp (file)
• utility (module)
• source (module)

3 Modules

Modules are listed depth-first from the system components tree.

3.1 verlet/utility

Dependency

package.lisp (file)

Parent

verlet (system)

Location

utility/

Components

• algebra.lisp (file)
• set.lisp (file)

3.2 verlet/source

Dependencies

• package.lisp (file)
• utility (module)

Parent

verlet (system)

Location

source/

Components

• force.lisp (file)
• particle.lisp (file)
• physics-loop.lisp (file)
• spring (module)
• modificator.lisp (file)
• damper.lisp (file)
• gravity (module)
• constraint (module)
• friction (module)

3.3 verlet/source/spring

Dependencies

• force.lisp (file)
• particle.lisp (file)

Parent

source (module)

Location

source/spring/

Components

• linear.lisp (file)
• area.lisp (file)
• volume.lisp (file)
• force.lisp (file)

3.4 verlet/source/gravity

Dependencies

• force.lisp (file)
• particle.lisp (file)
• modificator.lisp (file)

Parent

source (module)

Location

source/gravity/

Components

• gravity.lisp (file)
• global.lisp (file)
• mutual.lisp (file)
• field.lisp (file)

3.5 verlet/source/constraint

Dependencies

• force.lisp (file)
• particle.lisp (file)
• modificator.lisp (file)

Parent

source (module)

Location

source/constraint/

Components

• constraint.lisp (file)
• plane.lisp (file)
• sphere.lisp (file)
• triangle.lisp (file)

3.6 verlet/source/friction

Dependencies

• force.lisp (file)
• particle.lisp (file)

Parent

source (module)

Location

source/friction/

Components

• friction.lisp (file)
• global.lisp (file)
• field.lisp (file)
• constraint.lisp (file)

4 Files

Files are sorted by type and then listed depth-first from the systems components trees.

4.1 Lisp

4.1.1 verlet.asd

Location

verlet.asd

Systems

verlet (system)

4.1.2 verlet/package.lisp

Parent

verlet (system)

Location

package.lisp

Packages

verlet

Exported Definitions

• @interface (special variable)
• @verlet (special variable)

4.1.3 verlet/utility/algebra.lisp

Parent

utility (module)

Location

utility/algebra.lisp

Internal Definitions

• mirror (function)
• orthogonalize (function)
• project (function)
• towards (function)

4.1.4 verlet/utility/set.lisp

Parent

utility (module)

Location

utility/set.lisp

Internal Definitions

union* (function)

4.1.5 verlet/source/force.lisp

Parent

source (module)

Location

source/force.lisp

Exported Definitions

• @force (special variable)
• deforce (macro)

Internal Definitions

• find-force (function)
• register-force (function)

4.1.6 verlet/source/particle.lisp

Parent

source (module)

Location

source/particle.lisp

Exported Definitions

• @particle (special variable)
• [particle] (function)
• accelerate! (function)
• deflect! (function)
• mass<- (method)
• (setf mass<-) (method)
• particle (class)
• position<- (method)
• position<- (method)
• (setf position<-) (method)
• speed<- (function)
• update! (generic function)
• update! (method)
• velocity<- (function)

Internal Definitions

• acceleration<- (method)
• (setf acceleration<-) (method)
• actual-previous-position<- (method)
• (setf actual-previous-position<-) (method)
• apply-force! (function)
• center-of-mass (function)
• next-position (function)
• previous-delta<- (method)
• (setf previous-delta<-) (method)
• previous-position<- (method)
• (setf previous-position<-) (method)
• temp-velocity<- (method)
• (setf temp-velocity<-) (method)

4.1.7 verlet/source/physics-loop.lisp

Dependency

force.lisp (file)

Parent

source (module)

Location

source/physics-loop.lisp

Exported Definitions

• @physics-system (special variable)
• [system] (function)
• build-system (macro)
• collisions<- (method)
• (setf collisions<-) (method)
• constraints<- (method)
• (setf constraints<-) (method)
• forces<- (method)
• (setf forces<-) (method)
• particles<- (method)
• (setf particles<-) (method)
• step! (function)
• system (class)
• velocity-dependent-forces<- (method)
• (setf velocity-dependent-forces<-) (method)

4.1.8 verlet/source/spring/linear.lisp

Parent

spring (module)

Location

source/spring/linear.lisp

Exported Definitions

• @linear-spring (special variable)
• @spring (special variable)
• [spring] (function)
• k<- (method)
• (setf k<-) (method)
• length<- (method)
• (setf length<-) (method)
• spring (class)
• update! (method)

Internal Definitions

• p1<- (method)
• p2<- (method)

4.1.9 verlet/source/spring/area.lisp

Parent

spring (module)

Location

source/spring/area.lisp

Exported Definitions

• @area-spring (special variable)
• [area-spring] (function)
• area-spring (class)
• area<- (method)
• (setf area<-) (method)
• k<- (method)
• (setf k<-) (method)
• update! (method)

Internal Definitions

• p1<- (method)
• p2<- (method)
• p3<- (method)

4.1.10 verlet/source/spring/volume.lisp

Parent

spring (module)

Location

source/spring/volume.lisp

Exported Definitions

• @volume-spring (special variable)
• [volume-spring] (function)
• k<- (method)
• (setf k<-) (method)
• update! (method)
• volume-spring (class)
• volume<- (method)
• (setf volume<-) (method)

Internal Definitions

• p1<- (method)
• p2<- (method)
• p3<- (method)
• p4<- (method)

4.1.11 verlet/source/spring/force.lisp

Dependencies

• linear.lisp (file)
• area.lisp (file)
• volume.lisp (file)

Parent

spring (module)

Location

source/spring/force.lisp

4.1.12 verlet/source/modificator.lisp

Dependency

particle.lisp (file)

Parent

source (module)

Location

source/modificator.lisp

Exported Definitions

• @modificator (special variable)
• add-subject (generic function)
• add-subject (method)
• modificator (class)
• remove-subject (generic function)
• remove-subject (method)

Internal Definitions

• subjects<- (method)
• (setf subjects<-) (method)

4.1.13 verlet/source/damper.lisp

Dependencies

• force.lisp (file)
• particle.lisp (file)
• modificator.lisp (file)

Parent

source (module)

Location

source/damper.lisp

Exported Definitions

• @damper (special variable)
• [damper] (function)
• d<- (method)
• (setf d<-) (method)
• damper (class)
• update! (method)

4.1.14 verlet/source/gravity/gravity.lisp

Parent

gravity (module)

Location

source/gravity/gravity.lisp

Exported Definitions

@gravity (special variable)

4.1.15 verlet/source/gravity/global.lisp

Parent

gravity (module)

Location

source/gravity/global.lisp

Exported Definitions

• @global-gravity (special variable)
• [global-gravity] (function)
• global-gravity (class)
• update! (method)

Internal Definitions

• gravity<- (method)
• (setf gravity<-) (method)

4.1.16 verlet/source/gravity/mutual.lisp

Parent

gravity (module)

Location

source/gravity/mutual.lisp

Exported Definitions

• @mutual-gravity (special variable)
• [mutual-gravity] (function)
• mutual-gravity (class)
• update! (method)

4.1.17 verlet/source/gravity/field.lisp

Parent

gravity (module)

Location

source/gravity/field.lisp

Exported Definitions

• @field-gravity (special variable)
• [field-gravity] (function)
• field-gravity (class)
• field<- (method)
• (setf field<-) (method)
• update! (method)

4.1.18 verlet/source/constraint/constraint.lisp

Parent

constraint (module)

Location

source/constraint/constraint.lisp

Exported Definitions

• @constraint (special variable)
• constraint (class)
• deflection-vector (generic function)
• update! (method)
• violated? (generic function)

4.1.19 verlet/source/constraint/plane.lisp

Dependency

constraint.lisp (file)

Parent

constraint (module)

Location

source/constraint/plane.lisp

Exported Definitions

• @plane-constraint (special variable)
• [plane-constraint] (function)
• deflection-vector (method)
• plane-constraint (class)
• violated? (method)

Internal Definitions

• normal<- (method)
• point<- (method)

4.1.20 verlet/source/constraint/sphere.lisp

Dependency

constraint.lisp (file)

Parent

constraint (module)

Location

source/constraint/sphere.lisp

Exported Definitions

• @sphere-constraint (special variable)
• [sphere-constraint] (function)
• deflection-vector (method)
• sphere-constraint (class)
• violated? (method)

Internal Definitions

• center<- (method)
• outer-wall? (method)
• radius<- (method)

4.1.21 verlet/source/constraint/triangle.lisp

Dependency

constraint.lisp (file)

Parent

constraint (module)

Location

source/constraint/triangle.lisp

Exported Definitions

• @triangle-constraint (special variable)
• [triangle-constraint] (function)
• deflection-vector (method)
• triangle-constraint (class)
• violated? (method)

Internal Definitions

• p1<- (method)
• p2<- (method)
• p3<- (method)

4.1.22 verlet/source/friction/friction.lisp

Parent

friction (module)

Location

source/friction/friction.lisp

Exported Definitions

• @friction (special variable)
• friction! (function)

4.1.23 verlet/source/friction/global.lisp

Dependency

friction.lisp (file)

Parent

friction (module)

Location

source/friction/global.lisp

Exported Definitions

• @global-friction (special variable)
• [global-friction] (function)
• friction<- (method)
• (setf friction<-) (method)
• global-friction (class)
• update! (method)

4.1.24 verlet/source/friction/field.lisp

Dependency

friction.lisp (file)

Parent

friction (module)

Location

source/friction/field.lisp

Exported Definitions

• @field-friction (special variable)
• [field-friction] (function)
• field-friction (class)
• field<- (method)
• (setf field<-) (method)
• update! (method)

4.1.25 verlet/source/friction/constraint.lisp

Dependency

friction.lisp (file)

Parent

friction (module)

Location

source/friction/constraint.lisp

Exported Definitions

• @constraint-friction (special variable)
• [constraint-friction] (function)
• constraint-friction (class)
• friction<- (method)
• (setf friction<-) (method)
• update! (method)

Internal Definitions

constraint<- (method)

5 Packages

Packages are listed by definition order.

5.1 verlet

Source

package.lisp (file)

Use List

• mgl-pax
• rtg-math
• chain
• metabang.bind
• common-lisp

Exported Definitions

• @area-spring (special variable)
• @constraint (special variable)
• @constraint-friction (special variable)
• @damper (special variable)
• @field-friction (special variable)
• @field-gravity (special variable)
• @force (special variable)
• @friction (special variable)
• @global-friction (special variable)
• @global-gravity (special variable)
• @gravity (special variable)
• @interface (special variable)
• @linear-spring (special variable)
• @modificator (special variable)
• @mutual-gravity (special variable)
• @particle (special variable)
• @physics-system (special variable)
• @plane-constraint (special variable)
• @sphere-constraint (special variable)
• @spring (special variable)
• @triangle-constraint (special variable)
• @verlet (special variable)
• @volume-spring (special variable)
• [area-spring] (function)
• [constraint-friction] (function)
• [damper] (function)
• [field-friction] (function)
• [field-gravity] (function)
• [global-friction] (function)
• [global-gravity] (function)
• [mutual-gravity] (function)
• [particle] (function)
• [plane-constraint] (function)
• [sphere-constraint] (function)
• [spring] (function)
• [system] (function)
• [triangle-constraint] (function)
• [volume-spring] (function)
• accelerate! (function)
• add-subject (generic function)
• add-subject (method)
• area-spring (class)
• area<- (generic function)
• area<- (method)
• (setf area<-) (method)
• (setf area<-) (generic function)
• build-system (macro)
• collisions<- (generic function)
• collisions<- (method)
• (setf collisions<-) (method)
• (setf collisions<-) (generic function)
• constraint (class)
• constraint-friction (class)
• constraints<- (generic function)
• constraints<- (method)
• (setf constraints<-) (method)
• (setf constraints<-) (generic function)
• d<- (generic function)
• d<- (method)
• (setf d<-) (method)
• (setf d<-) (generic function)
• damper (class)
• deflect! (function)
• deflection-vector (generic function)
• deflection-vector (method)
• deflection-vector (method)
• deflection-vector (method)
• deforce (macro)
• field-friction (class)
• field-gravity (class)
• field<- (generic function)
• field<- (method)
• (setf field<-) (method)
• field<- (method)
• (setf field<-) (method)
• (setf field<-) (generic function)
• forces<- (generic function)
• forces<- (method)
• (setf forces<-) (method)
• (setf forces<-) (generic function)
• friction! (function)
• friction<- (generic function)
• friction<- (method)
• (setf friction<-) (method)
• friction<- (method)
• (setf friction<-) (method)
• (setf friction<-) (generic function)
• global-friction (class)
• global-gravity (class)
• k<- (generic function)
• k<- (method)
• (setf k<-) (method)
• k<- (method)
• (setf k<-) (method)
• k<- (method)
• (setf k<-) (method)
• (setf k<-) (generic function)
• length<- (generic function)
• length<- (method)
• (setf length<-) (method)
• (setf length<-) (generic function)
• mass<- (generic function)
• mass<- (method)
• (setf mass<-) (method)
• (setf mass<-) (generic function)
• modificator (class)
• mutual-gravity (class)
• particle (class)
• particles<- (generic function)
• particles<- (method)
• (setf particles<-) (method)
• (setf particles<-) (generic function)
• plane-constraint (class)
• position<- (generic function)
• position<- (method)
• position<- (method)
• (setf position<-) (method)
• (setf position<-) (generic function)
• remove-subject (generic function)
• remove-subject (method)
• speed<- (function)
• sphere-constraint (class)
• spring (class)
• step! (function)
• system (class)
• triangle-constraint (class)
• update! (generic function)
• update! (method)
• update! (method)
• update! (method)
• update! (method)
• update! (method)
• update! (method)
• update! (method)
• update! (method)
• update! (method)
• update! (method)
• update! (method)
• update! (method)
• velocity-dependent-forces<- (generic function)
• velocity-dependent-forces<- (method)
• (setf velocity-dependent-forces<-) (method)
• (setf velocity-dependent-forces<-) (generic function)
• velocity<- (function)
• violated? (generic function)
• violated? (method)
• violated? (method)
• violated? (method)
• volume-spring (class)
• volume<- (generic function)
• volume<- (method)
• (setf volume<-) (method)
• (setf volume<-) (generic function)

Internal Definitions

• acceleration<- (generic function)
• acceleration<- (method)
• (setf acceleration<-) (method)
• (setf acceleration<-) (generic function)
• actual-previous-position<- (generic function)
• actual-previous-position<- (method)
• (setf actual-previous-position<-) (method)
• (setf actual-previous-position<-) (generic function)
• apply-force! (function)
• center-of-mass (function)
• center<- (generic function)
• center<- (method)
• constraint<- (generic function)
• constraint<- (method)
• find-force (function)
• gravity<- (generic function)
• gravity<- (method)
• (setf gravity<-) (method)
• (setf gravity<-) (generic function)
• mirror (function)
• next-position (function)
• normal<- (generic function)
• normal<- (method)
• orthogonalize (function)
• outer-wall? (generic function)
• outer-wall? (method)
• p1<- (generic function)
• p1<- (method)
• p1<- (method)
• p1<- (method)
• p1<- (method)
• p2<- (generic function)
• p2<- (method)
• p2<- (method)
• p2<- (method)
• p2<- (method)
• p3<- (generic function)
• p3<- (method)
• p3<- (method)
• p3<- (method)
• p4<- (generic function)
• p4<- (method)
• point<- (generic function)
• point<- (method)
• previous-delta<- (generic function)
• previous-delta<- (method)
• (setf previous-delta<-) (method)
• (setf previous-delta<-) (generic function)
• previous-position<- (generic function)
• previous-position<- (method)
• (setf previous-position<-) (method)
• (setf previous-position<-) (generic function)
• project (function)
• radius<- (generic function)
• radius<- (method)
• register-force (function)
• subjects<- (generic function)
• subjects<- (method)
• (setf subjects<-) (method)
• (setf subjects<-) (generic function)
• temp-velocity<- (generic function)
• temp-velocity<- (method)
• (setf temp-velocity<-) (method)
• (setf temp-velocity<-) (generic function)
• towards (function)
• union* (function)

6 Definitions

Definitions are sorted by export status, category, package, and then by lexicographic order.

6.1 Exported definitions

6.1.1 Special variables

Special Variable: @area-spring

Package

verlet

Source

area.lisp (file)

Special Variable: @constraint

Package

verlet

Source

constraint.lisp (file)

Special Variable: @constraint-friction

Package

verlet

Source

constraint.lisp (file)

Special Variable: @damper

Package

verlet

Source

damper.lisp (file)

Special Variable: @field-friction

Package

verlet

Source

field.lisp (file)

Special Variable: @field-gravity

Package

verlet

Source

field.lisp (file)

Special Variable: @force

Package

verlet

Source

force.lisp (file)

Special Variable: @friction

Package

verlet

Source

friction.lisp (file)

Special Variable: @global-friction

Package

verlet

Source

global.lisp (file)

Special Variable: @global-gravity

Package

verlet

Source

global.lisp (file)

Special Variable: @gravity

Package

verlet

Source

gravity.lisp (file)

Special Variable: @interface

Package

verlet

Source

package.lisp (file)

Special Variable: @linear-spring

Package

verlet

Source

linear.lisp (file)

Special Variable: @modificator

Package

verlet

Source

modificator.lisp (file)

Special Variable: @mutual-gravity

Package

verlet

Source

mutual.lisp (file)

Special Variable: @particle

Package

verlet

Source

particle.lisp (file)

Special Variable: @physics-system

Package

verlet

Source

physics-loop.lisp (file)

Special Variable: @plane-constraint

Package

verlet

Source

plane.lisp (file)

Special Variable: @sphere-constraint

Package

verlet

Source

sphere.lisp (file)

Special Variable: @spring

Package

verlet

Source

linear.lisp (file)

Special Variable: @triangle-constraint

Package

verlet

Source

triangle.lisp (file)

Special Variable: @verlet

Package

verlet

Source

package.lisp (file)

Special Variable: @volume-spring

Package

verlet

Source

volume.lisp (file)

6.1.2 Macros

Macro: build-system (&rest PARTICLES) &body FORCES

Build up a standard physics SYSTEM using defined forces.

PARTICLES is a list with items of the form
‘((X Y Z) &KEY (MASS 1.0) PREVIOUS-POSITION VELOCITY)‘.
The list at the beginning describes the position of the particle, for the meaning of the keyword arguments reference the ‘[PARTICLE]‘ function.

FORCES is a list of force descriptors, as defined by the DEFORCE macro. The respective forces are going to be added to the final system.

Package

verlet

Source

physics-loop.lisp (file)

Macro: deforce NAME MODE (&rest LAMBDA-LIST) &body BODY

Define a force so it is usable in the BUILD-SYSTEM macro.

MODE is required to be one of :FORCE, :VELOCITY-DEPENDENT-FORCE, :CONSTRAINT, and :COLLISION. Reference the STEP! function for more information on what these mean.

The LAMBDA-LIST is tha lambda list used by the local macro in the BUILD-SYSTEM macro call, BODY is it’s body. The resulting code should return the object to add to the system under construction. PARTICLES is an anaphoric variable in the BODY, containing a list of the particles defined by PARTICLES in the BUILD-SYSTEM macro, in the order they are defined in.

Package

verlet

Source

force.lisp (file)

6.1.3 Functions

Function: [area-spring] P1 P2 P3 K &key AREA

Creates an AREA-SPRING with corners P1, P2 and P3, ideal area AREA, and spring constant K. AREA defaults to the area enclosed by the supplied particles.

Package

verlet

Source

area.lisp (file)

Function: [constraint-friction] CONSTRAINT FRICTION

Creates CONSTRAINT-FRICTION which applies friction FRICTION to subjects on collision with CONSTRAINT. Note that the subject of the CONSTRAINT-FRICTION instance and of the constraint need not necessarily be the same.

Package

verlet

Source

constraint.lisp (file)

Function: [damper] D &rest PARTICLES

Package

verlet

Source

damper.lisp (file)

Function: [field-friction] FIELD

Creates [FIELD-FRICTION][class] with friction field FIELD. FIELD must map 3D positions to friction values.

Package

verlet

Source

field.lisp (file)

Function: [field-gravity] FIELD

Creates [FIELD-GRAVITY][class] with gravity field FIELD. FIELD must map positions ‘(SIMPLE-ARRAY SINGLE-FLOAT (3))‘s to gravity vectors ‘(SIMPLE-ARRAY SINGLE-FLOAT (3))‘.

Package

verlet

Source

field.lisp (file)

Function: [global-friction] FRICTION

Package

verlet

Source

global.lisp (file)

Function: [global-gravity] GRAVITY

Creates an instance of [GLOBAL-GRAVITY][class] which accelerates all its subjects by GRAVITY on each frame.

Package

verlet

Source

global.lisp (file)

Function: [mutual-gravity] ()

Package

verlet

Source

mutual.lisp (file)

Function: [particle] POSITION &key MASS PREVIOUS-POSITION VELOCITY

Returns an instance of class PARTICLE at POSITION. Provide only one keyword argument among PREVIOUS-POSITION and VELOCITY, since the respective other is calculated from the provided. If none are provided, assume a velocity of 0.

Package

verlet

Source

particle.lisp (file)

Function: [plane-constraint] POINT NORMAL

Creates a [PLANE-CONSTRAINT][class] restricting all subjects to a half-space defined by the plane containing POINT with normal NORMAL. The usable half-space is the closed half-space that NORMAL is pointing into.

Package

verlet

Source

plane.lisp (file)

Function: [sphere-constraint] CENTER RADIUS &optional OUTER-WALL?

Creates a [SPHERE-CONSTRAINT][class] with center CENTER and radius
RADIUS. CENTER is a ‘(SIMPLE-ARRAY SINGLE-FLOAT (3))‘, RADIUS a SINGLE-FLOAT. When OUTER-WALL? is truthy, movement is restricted to the closed ball described by the sphere, otherwise movement is constricted to the outside of the open ball described by the sphere.

Package

verlet

Source

sphere.lisp (file)

Function: [spring] P1 P2 K &key LENGTH

Create a [SPRING][class] connecting the ‘PARTICLE‘s P1 and P2, with ideal length LENGTH and spring constant K. LENGTH defaults to the distance between P1 and P2.

Package

verlet

Source

linear.lisp (file)

Function: [system] ()

Package

verlet

Source

physics-loop.lisp (file)

Function: [triangle-constraint] P1 P2 P3

Create a [TRIANGLE-CONSTRAINT][class] preventing particles moving through the triangle enclosed by P1, P2, and P3

Package

verlet

Source

triangle.lisp (file)

Function: [volume-spring] P1 P2 P3 P4 K &key VOLUME

Create a VOLUME-SPRING with corners P1, P2, P3 and P4, ideal volume VOLUME, and spring constant K. VOLUME defaults to the volume enclosed by the given particles.

Package

verlet

Source

volume.lisp (file)

Function: accelerate! PARTICLE DV

Package

verlet

Source

particle.lisp (file)

Function: deflect! PARTICLE DIRECTION

Moves PARTICLE to TARGET and mirrors the PARTICLE’s velocity on the plane containing TARGET with the change in position as normal.

Package

verlet

Source

particle.lisp (file)

Function: friction! PARTICLE FRICTION DELTA

Reduce the speed of PARTICLE by FRICTION·DELTA to a minimum of speed 0. This means that the PARTICLE’s velocity’s direction is never reversed by this function. Modifies PARTICLE.

Package

verlet

Source

friction.lisp (file)

Function: speed<- PARTICLE

Return the speed of PARTICLE as a SINGLE-FLOAT.

Please note that this is a best guess at the current speed, based on the forces applied so far in the current frame.

Package

verlet

Source

particle.lisp (file)

Function: step! SYSTEM DELTA &key RESOLVE-STEPS

Updates a physical SYSTEM by timestep DELTA.

1. Apply all forces not dependent on the velocity of particles (:FORCE in the DEFORCE macro)
2. Calculate forces depending on velocities of particles, using the memoized velocities so far (:VELOCITY-DEPENDENT-FORCE in the DEFORCE macro)
3. Repeat RESOLVE-STEPS times:
1. Resolve all static constraints (:CONSTRAINT in the DEFORCE macro)
2. Resolve collisions (:COLLISION in the DEFORCE macro)

Please note after STEP! returns, no collisions should be happening, but static constraints might be violated.

Package

verlet

Source

physics-loop.lisp (file)

Function: velocity<- PARTICLE

Return the velocity of PARTICLE as a ‘(SIMPLE-ARRAY SINGLE-FLOAT (3))‘.

Please note that this is a best guess at the current velocity, based on the forces applied so far in the current frame.

Package

verlet

Source

particle.lisp (file)

6.1.4 Generic functions

Generic Function: add-subject MODIFICATOR SUBJECT

Adds a SUBJECT to the MODIFICATOR for tracking.

Package

verlet

Source

modificator.lisp (file)

Methods

Method: add-subject (MODIFICATOR modificator) (SUBJECT particle)

Generic Function: area<- OBJECT

Generic Function: (setf area<-) NEW-VALUE OBJECT

Package

verlet

Methods

Method: area<- (AREA-SPRING area-spring)

automatically generated reader method

Source

area.lisp (file)

Method: (setf area<-) NEW-VALUE (AREA-SPRING area-spring)

automatically generated writer method

Source

area.lisp (file)

Generic Function: collisions<- OBJECT

Generic Function: (setf collisions<-) NEW-VALUE OBJECT

Package

verlet

Methods

Method: collisions<- (SYSTEM system)

automatically generated reader method

Source

physics-loop.lisp (file)

Method: (setf collisions<-) NEW-VALUE (SYSTEM system)

automatically generated writer method

Source

physics-loop.lisp (file)

Generic Function: constraints<- OBJECT

Generic Function: (setf constraints<-) NEW-VALUE OBJECT

Package

verlet

Methods

Method: constraints<- (SYSTEM system)

automatically generated reader method

Source

physics-loop.lisp (file)

Method: (setf constraints<-) NEW-VALUE (SYSTEM system)

automatically generated writer method

Source

physics-loop.lisp (file)

Generic Function: d<- OBJECT

Generic Function: (setf d<-) NEW-VALUE OBJECT

Package

verlet

Methods

Method: d<- (DAMPER damper)

automatically generated reader method

Source

damper.lisp (file)

Method: (setf d<-) NEW-VALUE (DAMPER damper)

automatically generated writer method

Source

damper.lisp (file)

Generic Function: deflection-vector CONSTRAINT PARTICLE

Returns the cange in position for PARTICLE to obey CONSTRAINT again.

Package

verlet

Source

constraint.lisp (file)

Methods

Method: deflection-vector (CONSTRAINT triangle-constraint) (PARTICLE particle)

Source

triangle.lisp (file)

Method: deflection-vector (CONSTRAINT sphere-constraint) (PARTICLE particle)

Source

sphere.lisp (file)

Method: deflection-vector (CONSTRAINT plane-constraint) (PARTICLE particle)

Source

plane.lisp (file)

Generic Function: field<- OBJECT

Generic Function: (setf field<-) NEW-VALUE OBJECT

Package

verlet

Methods

Method: field<- (FIELD-FRICTION field-friction)

automatically generated reader method

Source

field.lisp (file)

Method: (setf field<-) NEW-VALUE (FIELD-FRICTION field-friction)

automatically generated writer method

Source

field.lisp (file)

Method: field<- (FIELD-GRAVITY field-gravity)

automatically generated reader method

Source

field.lisp (file)

Method: (setf field<-) NEW-VALUE (FIELD-GRAVITY field-gravity)

automatically generated writer method

Source

field.lisp (file)

Generic Function: forces<- OBJECT

Generic Function: (setf forces<-) NEW-VALUE OBJECT

Package

verlet

Methods

Method: forces<- (SYSTEM system)

automatically generated reader method

Source

physics-loop.lisp (file)

Method: (setf forces<-) NEW-VALUE (SYSTEM system)

automatically generated writer method

Source

physics-loop.lisp (file)

Generic Function: friction<- OBJECT

Generic Function: (setf friction<-) NEW-VALUE OBJECT

Package

verlet

Methods

Method: friction<- (CONSTRAINT-FRICTION constraint-friction)

automatically generated reader method

Source

constraint.lisp (file)

Method: (setf friction<-) NEW-VALUE (CONSTRAINT-FRICTION constraint-friction)

automatically generated writer method

Source

constraint.lisp (file)

Method: friction<- (GLOBAL-FRICTION global-friction)

automatically generated reader method

Source

global.lisp (file)

Method: (setf friction<-) NEW-VALUE (GLOBAL-FRICTION global-friction)

automatically generated writer method

Source

global.lisp (file)

Generic Function: k<- OBJECT

Generic Function: (setf k<-) NEW-VALUE OBJECT

Package

verlet

Methods

Method: k<- (VOLUME-SPRING volume-spring)

automatically generated reader method

Source

volume.lisp (file)

Method: (setf k<-) NEW-VALUE (VOLUME-SPRING volume-spring)

automatically generated writer method

Source

volume.lisp (file)

Method: k<- (AREA-SPRING area-spring)

automatically generated reader method

Source

area.lisp (file)

Method: (setf k<-) NEW-VALUE (AREA-SPRING area-spring)

automatically generated writer method

Source

area.lisp (file)

Method: k<- (SPRING spring)

automatically generated reader method

Source

linear.lisp (file)

Method: (setf k<-) NEW-VALUE (SPRING spring)

automatically generated writer method

Source

linear.lisp (file)

Generic Function: length<- OBJECT

Generic Function: (setf length<-) NEW-VALUE OBJECT

Package

verlet

Methods

Method: length<- (SPRING spring)

automatically generated reader method

Source

linear.lisp (file)

Method: (setf length<-) NEW-VALUE (SPRING spring)

automatically generated writer method

Source

linear.lisp (file)

Generic Function: mass<- OBJECT

Generic Function: (setf mass<-) NEW-VALUE OBJECT

Package

verlet

Methods

Method: mass<- (PARTICLE particle)

automatically generated reader method

Source

particle.lisp (file)

Method: (setf mass<-) NEW-VALUE (PARTICLE particle)

automatically generated writer method

Source

particle.lisp (file)

Generic Function: particles<- OBJECT

Generic Function: (setf particles<-) NEW-VALUE OBJECT

Package

verlet

Methods

Method: particles<- (SYSTEM system)

automatically generated reader method

Source

physics-loop.lisp (file)

Method: (setf particles<-) NEW-VALUE (SYSTEM system)

automatically generated writer method

Source

physics-loop.lisp (file)

Generic Function: position<- OBJECT

Generic Function: (setf position<-) NEW-VALUE OBJECT

Package

verlet

Methods

Method: position<- (OBJECT simple-array)

Source

particle.lisp (file)

Method: position<- (PARTICLE particle)

automatically generated reader method

Source

particle.lisp (file)

Method: (setf position<-) NEW-VALUE (PARTICLE particle)

automatically generated writer method

Source

particle.lisp (file)

Generic Function: remove-subject MODIFICATOR SUBJECT

Remove a SUBJECT to the MODIFICATOR so it won’t be tracked anymore.

Package

verlet

Source

modificator.lisp (file)

Methods

Method: remove-subject (MODIFICATOR modificator) (SUBJECT particle)

Generic Function: update! OBJECT &optional DELTA

Package

verlet

Source

particle.lisp (file)

Methods

Method: update! (OBJECT constraint-friction) &optional DELTA

Source

constraint.lisp (file)

Method: update! (OBJECT field-friction) &optional DELTA

Source

field.lisp (file)

Method: update! (OBJECT global-friction) &optional DELTA

Apply the global friction to all subjects.

Source

global.lisp (file)

Method: update! (CONSTRAINT constraint) &optional DELTA

Deflects all subjects violating the constraint as per VIOLATED? by the vector defined by DEFLECTION-VECTOR.

Source

constraint.lisp (file)

Method: update! (OBJECT field-gravity) &optional DELTA

Source

field.lisp (file)

Method: update! (GRAVITY mutual-gravity) &optional DELTA

Source

mutual.lisp (file)

Method: update! (GRAVITY global-gravity) &optional DELTA

Accelerate the subjects of GRAVITY by the gravity vector.

Source

global.lisp (file)

Method: update! (DAMPER damper) &optional DELTA

Source

damper.lisp (file)

Method: update! (OBJECT volume-spring) &optional DELTA

Exert a volume-restoring force on the corners of the volume spring.

Source

volume.lisp (file)

Method: update! (OBJECT area-spring) &optional DELTA

Exert an area-restoring force on the corners of the area spring

Source

area.lisp (file)

Method: update! (OBJECT spring) &optional DELTA

Exert a length-restoring force on the endpoints of the linear spring.

Source

linear.lisp (file)

Method: update! (PARTICLE particle) &optional DELTA

Move PARTICLE by DELTA times the ‘PARTICLE‘s velocity.

Generic Function: velocity-dependent-forces<- OBJECT

Generic Function: (setf velocity-dependent-forces<-) NEW-VALUE OBJECT

Package

verlet

Methods

Method: velocity-dependent-forces<- (SYSTEM system)

automatically generated reader method

Source

physics-loop.lisp (file)

Method: (setf velocity-dependent-forces<-) NEW-VALUE (SYSTEM system)

automatically generated writer method

Source

physics-loop.lisp (file)

Generic Function: violated? CONSTRAINT PARTICLE

Returns NIL when the constraint is fulfilled and a truthy value otherwise.

Package

verlet

Source

constraint.lisp (file)

Methods

Method: violated? (CONSTRAINT triangle-constraint) (PARTICLE particle)

Source

triangle.lisp (file)

Method: violated? (CONSTRAINT sphere-constraint) (PARTICLE particle)

Source

sphere.lisp (file)

Method: violated? (CONSTRAINT plane-constraint) (PARTICLE particle)

Source

plane.lisp (file)

Generic Function: volume<- OBJECT

Generic Function: (setf volume<-) NEW-VALUE OBJECT

Package

verlet

Methods

Method: volume<- (VOLUME-SPRING volume-spring)

automatically generated reader method

Source

volume.lisp (file)

Method: (setf volume<-) NEW-VALUE (VOLUME-SPRING volume-spring)

automatically generated writer method

Source

volume.lisp (file)

6.1.5 Classes

Class: area-spring ()

Package

verlet

Source

area.lisp (file)

Direct superclasses

standard-object (class)

Direct methods

• update! (method)
• area<- (method)
• area<- (method)
• k<- (method)
• k<- (method)
• p3<- (method)
• p2<- (method)
• p1<- (method)

Direct slots

Slot: %p1

Type

verlet:particle

Initargs

:p1

Readers

p1<- (generic function)

Slot: %p2

Type

verlet:particle

Initargs

:p2

Readers

p2<- (generic function)

Slot: %p3

Type

verlet:particle

Initargs

:p3

Readers

p3<- (generic function)

Slot: %k

Type

(single-float (0.0))

Initargs

:k

Readers

k<- (generic function)

Writers

(setf k<-) (generic function)

Slot: %area

Type

(single-float 0.0)

Initargs

:area

Readers

area<- (generic function)

Writers

(setf area<-) (generic function)

Class: constraint ()

Package

verlet

Source

constraint.lisp (file)

Direct superclasses

modificator (class)

Direct subclasses

• plane-constraint (class)
• sphere-constraint (class)
• triangle-constraint (class)

Direct methods

update! (method)

Class: constraint-friction ()

Package

verlet

Source

constraint.lisp (file)

Direct superclasses

modificator (class)

Direct methods

• update! (method)
• friction<- (method)
• friction<- (method)
• constraint<- (method)

Direct slots

Slot: %constraint

Type

verlet:constraint

Initargs

:constraint

Readers

constraint<- (generic function)

Slot: %friction

Type

(single-float (0.0))

Initargs

:friction

Readers

friction<- (generic function)

Writers

(setf friction<-) (generic function)

Class: damper ()

Package

verlet

Source

damper.lisp (file)

Direct superclasses

modificator (class)

Direct methods

• update! (method)
• d<- (method)
• d<- (method)

Direct slots

Slot: %d

Type

(single-float (0.0))

Initargs

:d

Readers

d<- (generic function)

Writers

(setf d<-) (generic function)

Class: field-friction ()

Package

verlet

Source

field.lisp (file)

Direct superclasses

modificator (class)

Direct methods

• update! (method)
• field<- (method)
• field<- (method)

Direct slots

Slot: %field

Type

(function ((simple-array single-float (3))) (single-float 0.0))

Initargs

:field

Readers

field<- (generic function)

Writers

(setf field<-) (generic function)

Class: field-gravity ()

Package

verlet

Source

field.lisp (file)

Direct superclasses

modificator (class)

Direct methods

• update! (method)
• field<- (method)
• field<- (method)

Direct slots

Slot: %field

Type

(function ((simple-array single-float (3))) (simple-array single-float (3)))

Initargs

:field

Readers

field<- (generic function)

Writers

(setf field<-) (generic function)

Class: global-friction ()

Package

verlet

Source

global.lisp (file)

Direct superclasses

modificator (class)

Direct methods

• update! (method)
• friction<- (method)
• friction<- (method)

Direct slots

Slot: %friction

Type

(single-float (0.0))

Initargs

:friction

Readers

friction<- (generic function)

Writers

(setf friction<-) (generic function)

Class: global-gravity ()

Package

verlet

Source

global.lisp (file)

Direct superclasses

modificator (class)

Direct methods

• update! (method)
• gravity<- (method)
• gravity<- (method)

Direct slots

Slot: %gravity

Type

(simple-array single-float (3))

Initargs

:gravity

Readers

gravity<- (generic function)

Writers

(setf gravity<-) (generic function)

Class: modificator ()

MODIFICATOR objects keep track of other objects to modify in a uniform fashion. The MODIFICATOR class itself is not meant to be instanciated. An inheriting class should implement a method for UPDATE! to make use of its subjects.

Package

verlet

Source

modificator.lisp (file)

Direct superclasses

standard-object (class)

Direct subclasses

• damper (class)
• global-gravity (class)
• mutual-gravity (class)
• field-gravity (class)
• constraint (class)
• global-friction (class)
• field-friction (class)
• constraint-friction (class)

Direct methods

• remove-subject (method)
• add-subject (method)
• subjects<- (method)
• subjects<- (method)

Direct slots

Slot: %subjects

Type

fset:set

Initform

(fset:set)

Readers

subjects<- (generic function)

Writers

(setf subjects<-) (generic function)

Class: mutual-gravity ()

Applies gravitational force to the tracked particles according to the mass of the other tracked particles.

Package

verlet

Source

mutual.lisp (file)

Direct superclasses

modificator (class)

Direct methods

update! (method)

Class: particle ()

Package

verlet

Source

particle.lisp (file)

Direct superclasses

standard-object (class)

Direct methods

• deflection-vector (method)
• violated? (method)
• deflection-vector (method)
• violated? (method)
• deflection-vector (method)
• violated? (method)
• remove-subject (method)
• add-subject (method)
• update! (method)
• print-object (method)
• mass<- (method)
• mass<- (method)
• actual-previous-position<- (method)
• actual-previous-position<- (method)
• previous-delta<- (method)
• previous-delta<- (method)
• previous-position<- (method)
• previous-position<- (method)
• temp-velocity<- (method)
• temp-velocity<- (method)
• acceleration<- (method)
• acceleration<- (method)
• position<- (method)
• position<- (method)

Direct slots

Slot: %position

Type

(simple-array single-float (3))

Initargs

:position

Readers

position<- (generic function)

Writers

(setf position<-) (generic function)

Slot: %acceleration

Type

(simple-array single-float (3))

Initform

(rtg-math.base-vectors:v! 0 0 0)

Readers

acceleration<- (generic function)

Writers

(setf acceleration<-) (generic function)

Slot: %temp-velocity

Type

(simple-array single-float (3))

Initform

(rtg-math.base-vectors:v! 0 0 0)

Readers

temp-velocity<- (generic function)

Writers

(setf temp-velocity<-) (generic function)

Slot: %previous-position

Type

(simple-array single-float (3))

Initargs

:previous-position

Readers

previous-position<- (generic function)

Writers

(setf previous-position<-) (generic function)

Slot: %previous-delta

Type

(real (0))

Initform

1.0

Readers

previous-delta<- (generic function)

Writers

(setf previous-delta<-) (generic function)

Slot: %actual-previous-position

Type

(simple-array single-float (3))

Initargs

:actual-previous-position

Readers

actual-previous-position<- (generic function)

Writers

(setf actual-previous-position<-) (generic function)

Slot: %mass

Type

(single-float (0.0))

Initargs

:mass

Readers

mass<- (generic function)

Writers

(setf mass<-) (generic function)

Class: plane-constraint ()

Package

verlet

Source

plane.lisp (file)

Direct superclasses

constraint (class)

Direct methods

• deflection-vector (method)
• violated? (method)
• normal<- (method)
• point<- (method)

Direct slots

Slot: %point

Type

(simple-array single-float (3))

Initargs

:point

Readers

point<- (generic function)

Slot: %normal

Type

(simple-array single-float (3))

Initargs

:normal

Readers

normal<- (generic function)

Class: sphere-constraint ()

Package

verlet

Source

sphere.lisp (file)

Direct superclasses

constraint (class)

Direct methods

• deflection-vector (method)
• violated? (method)
• outer-wall? (method)
• radius<- (method)
• center<- (method)

Direct slots

Slot: %center

Type

(simple-array single-float (3))

Initargs

:center

Readers

center<- (generic function)

Slot: %radius

Type

(single-float (0.0))

Initargs

:radius

Readers

radius<- (generic function)

Slot: %outer-wall?

Type

boolean

Initargs

:outer-wall?

Readers

outer-wall? (generic function)

Class: spring ()

Package

verlet

Source

linear.lisp (file)

Direct superclasses

standard-object (class)

Direct methods

• update! (method)
• length<- (method)
• length<- (method)
• k<- (method)
• k<- (method)
• p2<- (method)
• p1<- (method)

Direct slots

Slot: %p1

Type

verlet:particle

Initargs

:p1

Readers

p1<- (generic function)

Slot: %p2

Type

verlet:particle

Initargs

:p2

Readers

p2<- (generic function)

Slot: %k

Type

(single-float (0.0))

Initargs

:k

Readers

k<- (generic function)

Writers

(setf k<-) (generic function)

Slot: %length

Type

(single-float 0.0)

Initargs

:length

Readers

length<- (generic function)

Writers

(setf length<-) (generic function)

Class: system ()

Package

verlet

Source

physics-loop.lisp (file)

Direct superclasses

standard-object (class)

Direct methods

• constraints<- (method)
• constraints<- (method)
• collisions<- (method)
• collisions<- (method)
• velocity-dependent-forces<- (method)
• velocity-dependent-forces<- (method)
• forces<- (method)
• forces<- (method)
• particles<- (method)
• particles<- (method)

Direct slots

Slot: %particles

Type

fset:set

Initform

(fset:set)

Readers

particles<- (generic function)

Writers

(setf particles<-) (generic function)

Slot: %forces

Type

fset:set

Initform

(fset:set)

Readers

forces<- (generic function)

Writers

(setf forces<-) (generic function)

Slot: %velocity-dependent-forces

Type

fset:set

Initform

(fset:set)

Readers

velocity-dependent-forces<- (generic function)

Writers

(setf velocity-dependent-forces<-) (generic function)

Slot: %collisions

Type

fset:set

Initform

(fset:set)

Readers

collisions<- (generic function)

Writers

(setf collisions<-) (generic function)

Slot: %constraints

Type

fset:set

Initform

(fset:set)

Readers

constraints<- (generic function)

Writers

(setf constraints<-) (generic function)

Class: triangle-constraint ()

Package

verlet

Source

triangle.lisp (file)

Direct superclasses

constraint (class)

Direct methods

• deflection-vector (method)
• violated? (method)
• p3<- (method)
• p2<- (method)
• p1<- (method)

Direct slots

Slot: %p1

Type

(simple-array single-float (3))

Initargs

:p1

Readers

p1<- (generic function)

Slot: %p2

Type

(simple-array single-float (3))

Initargs

:p2

Readers

p2<- (generic function)

Slot: %p3

Type

(simple-array single-float (3))

Initargs

:p3

Readers

p3<- (generic function)

Class: volume-spring ()

Package

verlet

Source

volume.lisp (file)

Direct superclasses

standard-object (class)

Direct methods

• update! (method)
• k<- (method)
• k<- (method)
• volume<- (method)
• volume<- (method)
• p4<- (method)
• p3<- (method)
• p2<- (method)
• p1<- (method)

Direct slots

Slot: %p1

Type

verlet:particle

Initargs

:p1

Readers

p1<- (generic function)

Slot: %p2

Type

verlet:particle

Initargs

:p2

Readers

p2<- (generic function)

Slot: %p3

Type

verlet:particle

Initargs

:p3

Readers

p3<- (generic function)

Slot: %p4

Type

verlet:particle

Initargs

:p4

Readers

p4<- (generic function)

Slot: %volume

Type

(single-float 0.0)

Initargs

:volume

Readers

volume<- (generic function)

Writers

(setf volume<-) (generic function)

Slot: %k

Type

(single-float (0.0))

Initargs

:k

Readers

k<- (generic function)

Writers

(setf k<-) (generic function)