Scheme Extensions Ra thru Zz

 

 

Technical Article
Scheme is a public domain programming language, based on the LISP language, that uses an interpreter to run commands. ACIS provides extensions (written in C++) to the native Scheme language that can be used by an application to interact with ACIS through its Scheme Interpreter. The C++ source files for ACIS Scheme extensions are provided with the product. Spatial's Scheme based demonstration application, Scheme ACIS Interface Driver Extension (Scheme AIDE), also uses these Scheme extensions and the Scheme Interpreter.

ray

Action
Creates a ray given a base position and gvector.

Filename
scm/scmext/kern/ray_scm.cpp

APIs
None

Syntax
(ray position gvector)

Arg Types
gvector gvector
position position

Returns
ray

Description
A ray is not visible. An important usage for a ray is to pierce a body or object for selection purposes.

Arguments
gvector specifies the direction of the ray.
 
position specifies the starting position.
; ray
; Create ray1 from a position and a gvector.
(define ray1
    (ray (position 0 0 0) (gvector 0 1 0)))
;; ray1
; Create ray2 from a position and a gvector.
(ray (position 78 5 12) (gvector 0 0 1))
;; #[ray (78 5 12) (0 0 1)]
; Do something useful with ray.
; Create a block.
(define block1
    (solid:block (position -10 -5 -15)
    (position 25 25 25)))
;; block1
; Remember the face.
(define face1 (pick:face ray1))
;; face1
; Highlight the face crossed by the ray.
(entity:set-highlight face1 #t)
;; #[entity 3 1]

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ray:gvector

Action
Gets the gvector component of a ray.

Filename
scm/scmext/kern/ray_scm.cpp

APIs
None

Syntax
(ray:gvector ray)

Arg Types
ray ray

Returns
gvector

Description
The argument ray specifies a position and a gvector. This extension returns the gvector direction from a ray.

Arguments
ray specifies a ray.
; ray:gvector
; Define a ray.
(define ray1 (ray (position -5 -5 -5)
    (gvector 1 0 0)))
;; ray1
; Extract the gvector component of a ray.
(ray:gvector ray1)
;; #[gvector 1 0 0]
; Get the gvector component of a read event.
(ray:gvector (pick:ray (read-event)))
; Using the mouse, select a screen position.
;; #[gvector 0.119924328873844 0.949842878199001
;; 0.288819428153296]

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ray:position

Action
Gets the position component of a ray.

Filename
scm/scmext/kern/ray_scm.cpp

APIs
None

Syntax
(ray:position ray)

Arg Types
ray ray

Returns
position

Description
The argument ray specifies a position and a gvector. This extension returns the position of the ray.

Arguments
ray specifies a ray.
; ray:position
; Define a ray.
(define ray1 (ray (position -5 -5 -5)
    (gvector 1 0 0)))
;; ray1
; Extract the position component of a ray.
(ray:position ray1)
;; #[position -5 -5 -5]
; get position component of a read event
(ray:position (pick:ray (read-event)))
;; #[position -35.0111607852786 -48.3518844171113
;; -1.77635683940025e-15]

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ray:queue

Action
Adds a ray to the ray queue.

Filename
scm/scmext/kern/ray_scm.cpp

APIs
None

Syntax
(ray:queue posx posy posz vecx vecy vecz radius)

Arg Types
posx real
posy real
posz real
vecx real
vecy real
vecz real
radius real

Returns
ray

Description
The parameters describe the position and vector for a ray as six reals. The given ray is constructed and added to the ray queue. It may later be read by read-ray.

Arguments
posx, posy and posz specifies the x, y and z positions of the ray.
 
vecx, vecy and vecz specifies the x, y and z components of the ray vector.
 
radius is used for picking.
; ray:queue
; Create a ray and add it to the ray queue
(ray:queue 1 2 3 4 5 6 7)
;; #[ray (1 2 3) (0.455842 0.569803 0.683763)]

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ray:valid?

Action
Tests whether a ray is valid.

Filename
scm/scmext/kern/ray_scm.cpp

APIs
None

Syntax
(ray:valid? ray)

Arg Types
ray ray

Returns
boolean

Description
A ray is considered invalid if the length of the vector is zero.

Arguments
ray specifies the ray to be tested for validity.
; ray:valid?
; Test whether an interactively read ray is valid.
(ray:valid? (read-ray))
;; #t

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ray?

Action
Determines if a Scheme object is a ray.

Filename
scm/scmext/kern/ray_scm.cpp

APIs
None

Syntax
(ray? object)

Arg Types
object scheme-object

Returns
boolean
Arguments
object specifies the scheme-object to be queried for a ray.
; ray?
; Create a ray.
(define ray1 (ray (position -5 -5 -5)
    (gvector 1 0 0)))
;; ray1
; Determine if the ray is actually a ray.
(ray? ray1)
;; #t
; Determine if a position is a ray.
(ray? (position 0 0 0))
;; #f

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read-ray

Action
Reads a ray from the ray queue or from a pick-event.

Filename
scm/scmext/kern/ray_scm.cpp

APIs
None

Syntax
(read-ray)

Arg Types
None

Returns
ray

Description
If the ray queue contains a ray, it is removed and returned and the ray size option is set from the queued information. Otherwise, a pick-event is read, using read-event, and converted to a ray. If journaling is on, a (ray:queue ....) command is written to the journal file. This results in a ray in the queue when the journal is replayed.

If the pick-event is from the right mouse button, the ray vector is set to an invalid zero length. This can be used as a stop condition in picking loops.

; read-ray
; Create a ray using the mouse.
(read-ray)
; Use the left mouse button to create a pick-event.
;; #[ray (94.7806 -194.257 116.706)
;; (-0.408248 0.816497 -0.408248)]

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shell?

Action
Determines if a Scheme object is a shell.

Filename
scm/scmext/kern/ent_scm.cpp

APIs
None

Syntax
(shell? object)

Arg Types
object scheme-object

Returns
boolean

Description
This extension returns #t if the specified object is a shell; otherwise, it returns #f.

Arguments
object specifies the scheme-object to be queried for a shell.
; shell?
; Create a solid block.
(define block1
    (solid:block (position 0 0 0) (position 8 8 8)))
;; block1
; Get a list of the block's shells.
(define shells1
    (entity:shells block1))
;; shells1
; Determine if one of the shells
; is actually a shell.
(shell? (car shells1))
;; #t
; Determine if the block is a shell.
(shell? block1)
;; #f

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solid?

Action
Determines if a Scheme object is a solid.

Filename
scm/scmext/kern/ent_scm.cpp

APIs
None

Syntax
(solid? object)

Arg Types
object scheme-object

Returns
boolean
Arguments
object specifies the scheme-object to be queried for a solid.
; solid?
; Create a solid block.
(define block1
    (solid:block (position 0 0 0)
    (position 40 40 40)))
;; block1
; Determine if the solid block is a solid.
(solid? block1)
;; #t
; Create a solid sphere.
(define sphere1 (solid:sphere (position 0 0 0) 38))
;; sphere1
; Determine if the solid sphere is a solid.
(solid? sphere1)
;; #t
; Create a circular edge.
(define edge-1
    (edge:circular (position 0 0 0) 25 0 180))
;; edge-1
; Determine if the edge is a solid.
(solid? edge-1)
;; #f

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surface:domain

Action
Determines the domain of a face's surface.

Filename
scm/scmext/kern/qfac_scm.cpp

APIs
None

Syntax
(surface:domain face)

Arg Types
face face

Returns
unspecified

Description
Given a face, returns the underlying surface's domain.

; surface:domain
; Create a face to use.
(define face1 (face:law "vec(cos(x), y, x)"
    -20 (law:eval "10*pi") -10 10))
;; face1
(surface:domain face1)
;; ()
; Surface domain:
; -20 : 31.415926535898
; -10 : 10

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surface:eval

Action
Evaluates a position on a parametric surface.

Filename
scm/scmext/kern/surf_scm.cpp

APIs
None

Syntax
(surface:eval srf su sv [level])

Arg Types
srf surface
su real
sv real
level integer

Returns
(real ...)

Description
This extension finds the position on a parametric surface with the given parameter values and optionally calculates the first and second derivatives.

Arguments
srf specifies the surface to evaluate.
 
su specifies the u parameter value.
 
sv specifies the v parameter value.
 
level specifies the depth of evaluation, and it has the following valid values:
0        = turns the position
1        = Returns the position and the first derivative (xu, xv)
2        = Returns the position, and the first and second derivatives (xuu, xuv, xvv)
; surface:eval
; Create a planar face.
(define face1
    (face:plane (position 0 0 0) 30 40))
;; face1
; Evaluate the position of a point
; on the planar surface.
(surface:eval (surface:from-face face1) 15 15 0)
;; (#[position 15 15 0])
; Create a conical surface.
(define cone1
    (face:cone (position 0 0 0) (position 0 50 0)
    30 20 0 180))
;; cone1
; Evaluate the position and the first derivative
; of a point on the conical surface.
(surface:eval (surface:from-face cone1) 0.5 0.5 1)
;; (#[position 23.7458553521721 14.7087101353638
;; -12.9724199023621] #[gvector -5.16324300907818
;; 29.4174202707276 2.82069251152796]
;; #[gvector -12.9724199023621 0
;; -23.7458553521721])

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surface:eval-curvatures

Action
Evaluates a the principal curvatures and directions at the given uv on the surface.

Filename
scm/scmext/kern/surf_scm.cpp

APIs
None

Syntax
(surface:eval-curvatures srf su sv )

Arg Types
srf surface
su real
sv real

Returns
real

Description
This extension finds the two principal curvatures of the surface at the given parameter values. It also returns the directions of the principal curvatures.

Arguments
srf specifies the surface to evaluate.
 
su specifies a u parameter value.
 
sv specifies a v parameter value.
Limitations
This extension does not take account of surface discontinuities, so that evaluating the curvatures at such points may be unreliable, as no attempt is made to compute sided curvatures.
;surface:eval-curvatures
;; Create the surface
(solid:wiggle 50 50 50 "anti")
;; #[entity 1 1]
;; (ray:queue 258.188 -312.023 293.684 -0.537024 0.628851 -0.562273 1)
(define f (pick-face))
;; f
(surface:eval-curvatures (surface:from-face f) .5 .5)
;; (0.067385584485619 #[gvector -0.576407926659592
;; -0.281960099592504 -0.766976143254649]
;; 0.120983661175455 #[gvector -0.595361733728196
;; 0.787806079907338 0.157816306106784])

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surface:eval-normal

Action
Gets the normal of a surface at the specified parameter values.

Filename
scm/scmext/kern/surf_scm.cpp

APIs
None

Syntax
(surface:eval-normal surf u v)

Arg Types
surf surface
u real
v real

Returns
gvector
Arguments
surf specifies a surface.

u specifies a u parameter value.

v specifies a v parameter value.
; surface:eval-normal
; Create a solid block.
(define block1
    (solid:block (position 0 0 0)
    (position 40 40 40)))
;; block1
; Get a list of the faces of the solid block.
(define entities1
    (entity:faces block1))
;; entities1
; Convert one face to a surface.
(define surface1 (surface:from-face
    (car entities1)))
;; surface1
; Evaluate the normal of the surface with the
; specified parameter values.
(surface:eval-normal surface1 1 1)
;; #[gvector 0 0 1]

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surface:eval-pos

Action
Gets the position on a surface at the specified parameter values.

Filename
scm/scmext/kern/surf_scm.cpp

APIs
None

Syntax
(surface:eval-pos surf u v)

Arg Types
surf surface
u real
v real

Returns
position
Arguments
surf specifies a surface.
 
u specifies a u parameter value.
 
v specifies a v parameter value.
; surface:eval-pos
; Create a solid block.
(define block1
    (solid:block (position 0 0 0)
    (position 40 40 40)))
;; block1
; Get a list of the faces of the solid block.
(define entities1
    (entity:faces block1))
;; entities1
; Convert one face to a surface.
(define surface1 (surface:from-face
    (car entities1)))
;; surface1
; Evaluate the position on the surface at the
; specified parameter values.
(surface:eval-pos surface1 1 1)
;; #[position 21 21 40]

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surface:from-face

Action
Creates a surface from a face.

Filename
scm/scmext/kern/surf_scm.cpp

APIs
None

Syntax
(surface:from-face face)

Arg Types
face face

Returns
surface
Arguments
face specifies a face.
; surface:from-face
; Create a solid block.
(define block1
    (solid:block (position 0 0 0)
    (position 20 30 40)))
;; block1
; Get a list of the block's faces.
(define entities1
    (entity:faces block1))
;; entities1
; Convert one of the block's faces to a surface.
(surface:from-face (car (cdr entities1)))
;; #[plane surface 401c2310]

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surface:point-perp

Action
Reverse evaluates a position on a parametric surface.

Filename
scm/scmext/kern/surf_scm.cpp

APIs
None

Syntax
(surface:point-perp srf pos)

Arg Types
srf surface
pos position pair (position point_on_surface gvector)

Returns
boolean

Description
Given a surface and a position on the surface, this extension returns the surface position and gvector.

Arguments
srf specifies a parametric surface.
 
pos specifies a position on the surface.
; surface:point-perp
; Create a conical surface.
(define cone1(face:cone (position 20 20 4)
    (position 20 20 8)2.5 0 0 360 0.6))
;; cone1
; Demonstrate the C++ function surface::point_perp()
; through the Scheme interface.
(surface:point-perp (surface:from-face cone1)
    (position 22 20 2.5))
;; (#[position 23.0337078651685 20 3.14606741573034]
;; #[gvector 0.847998304005088 0 0.52999894000318]
;; #[par-pos -0.402799194402416 0])

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surface:range

Action
Returns the parameter range of a surface.

Filename
scm/scmext/kern/surf_scm.cpp

APIs
None

Syntax
(surface:range srf [box-pos-1 box-pos-2])

Arg Types
srf surface
box-pos-1 position
box-pos-2 position

Returns
pair

Description
Given a surface and (optionally) a 3-space box, returns the u and v parameter ranges of the surface. Interfaces to the C++ surface::param_range member function.

The returned value is a pair with the first being the u range and the second one being the v range. Note that #f is used when any end of an interval is unbounded, so for example, (0 . #f) represents an interval starting at 0 but which is unbounded above. An empty interval can be recognized by the first value of the pair being greater than the second.

Arguments
srf specifies a surface.
 
box-pos-1 defines the first of diagonal corners of an option box.
 
box-pos-2 defines the other diagonal corner.
; surface:range
; Create a conical surface.
(define cone1 (face:cone (position 20 20 4)
    (position 20 20 8) 2.5 0 0 360 0.6))
;; cone1
(surface:range (surface:from-face cone1))
;; ((#f . 1.88679622641132)
;;  (-3.14159265358979 . 3.14159265358979))

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surface?

Action
Determines if a Scheme entity is a surface.

Filename
scm/scmext/kern/surf_scm.cpp

APIs
None

Syntax
(surface? object)

Arg Types
object scheme-object

Returns
boolean

Description
The extension returns #t if the object is a surface, and #f if it is not a surface.

Arguments
object specifies the scheme-object that has to be queried for a surface.
; surface?
; Create a solid block.
(define block1
    (solid:block (position 0 0 0)
    (position 10 10 10)))
;; block1
; Create a cylindrical face.
(define cyl1
    (face:cylinder (position 0 0 0)
    (position 0 20 0) 10))
;; cyl1
; Determine if the solid block is a surface.
(surface? block1)
;; #f
; Get a list of the faces of the block.
(define entities1
    (entity:faces block1))
;; entities1
; Convert one face to a surface.
(define surface1 (surface:from-face
    (car entities1)))
;; surface1
; Determine if one of the surfaces of the block
; is actually a surface.
(surface? surface1)
;; #t

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test:deep-copy

Action
Tests the deep copy functionality for improper sharing.

Filename
scm/scmext/kern/ent_scm.cpp

APIs
api_test_deep_copy

Syntax
(test:deep-copy entity-list [tolerance] [report-all]
    [file1 [file2]] [ao])

Arg Types
entity-list entity | (entity ...)
tolerance real
report-all boolean
file1 string
file2 string
ao acis-options

Returns
boolean

Description
The entities are saved and restored to test for sharing after api_deep_copy_entity has been called. If the command is used in a debug build, pattern filling the original entities allows a greater level of checking. For debug or release builds, the original and the deep copy SAT files can be compared for differences.

This function is primarily for internal testing. However, if derived entities are used outside of ACIS, this command can verify if the entities are deep copyable.

Arguments
entity-list specifies a list of any entities.
 
If tolerance is specified, the geometry is compared before and after the deep copy.
 
If report-all is set to true (#t), then all the attributes that could not be deep copied are reported.
 
file1 specifies the name of the file for storing the entities before deep-copy.
 
file2 specifies the name of the file for storing the entities after deep-copy.

ao contains journaling and versioning information.
; test:deep-copy
; Create a wiggle
(define wiggle1 (solid:wiggle 25 25 25 "anti"))
;; wiggle1
(test:deep-copy wiggle1)
;; #t

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test:equal

Action
Compares two arguments for equality.

Filename
scm/scmext/kern/law_scm.cpp

APIs
None

Syntax
(test:equal arg1 arg2 [tolerance] [msg])

Arg Types
arg1 boolean | real | position | gvector |

 

 par-pos | number_array | graph |

 

 string
arg2 boolean | real | position | gvector |

 

 par-pos | number_array | graph |

 

 string
tolerance real
msg string

Returns
boolean

Description
Compares arg1 and arg2 and returns true if they are equal. "Equality" for reals, positions, gvectors, and the elements of number arrays, is defined as being within the tolerance value (default PAresabs).

Arguments
arg1 and arg2 specify the arguments to be tested for equality.
 
tolerance specifies the tolerance value to be used if the input arguments belong to one of the following types: reals, positions, gvectors, elements of number arrays.
 
If a msg string is specified, this string prints out to the debug file if the result is false.
; test:equal
(test:equal 2 2)
;; #t
(test:equal (position 0 0 0) (position 0 0 1))
;; #f
(test:equal 5 5 "different number")
;; #t
(test:equal 5 2 "different number")
;; *** Error test:equal: different number
;; #f

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test:greater-than

Action
Compares two real numbers.

Filename
scm/scmext/kern/law_scm.cpp

APIs
None

Syntax
(test:greater-than variable fixed [tolerance] [msg])

Arg Types
variable real
fixed real
tolerance real
msg string

Returns
boolean

Description
Compares variable to fixed, returning true if the variable is greater than the fixed. If the variable is less than the fixed by an amount less than the tolerance, the result is also true.

Arguments
variable and fixed specify the arguments to be tested.
 
tolerance specifies the tolerance value to be used.
 
If a msg string is specified, this string prints out to the debug file if the result is false.
; test:greater-than
(test:greater-than 2 1)
;; #t
(test:greater-than 2.0 2.1 0.2
    "greater within tolerance")
;; #t

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test:less-than

Action
Compares two real numbers.

Filename
scm/scmext/kern/law_scm.cpp

APIs
None

Syntax
(test:less-than variable fixed [tolerance] [msg])

Arg Types
variable real
fixed real
tolerance real
msg string

Returns
boolean

Description
Compares variable to fixed, returning true if the variable is less than the fixed. If the variable is greater than the fixed by an amount less than the tolerance, the result is also true.

Arguments
variable and fixed specify the arguments to be tested.
 
tolerance specifies the tolerance value to be used.
 
If a msg string is specified, this string prints out to the debug file if the result is false.
; test:less-than
(test:less-than 1 2)
;; #t
(test:less-than 2.1 2.0 0.2
    "less-than within tolerance")
;; #t

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test:performance

Action
Runs the performance test(s).

Filename
scm/scmext/kern/perf_scm.cpp

APIs
None

Syntax
(test:performance string)

Arg Types
string string

Returns
string

Description
Runs performance test(s) specified by the string argument. The format of string varies based on the test(s) requested. Currently, only the ENTITY_LIST performance test is available.

The format for string is: "ENTITY_LIST [all | add | clear | assign | lookup | next | index] list_size iteration". list_size is the size of the ENTITY_LIST and iteration specifies how many times the test is to be run. If list_size and iteration are not specified, the default values 1000 and 1 (respectively) are assigned.

Limitations
          Only the ENTITY_LIST performance test is currently available.

; test:performance
; Run entity_list performance test. Request list_size
; and iteration different from defaults.
(test:performance "entity_list all 100 10000")
;; ()
; Size of the list = 100
; Number of iteration = 10000
; 0.810000 seconds to add 100 items 10000 times
; 0.390000 seconds to clear 100 items 10000 times
; 1.151000 seconds to assign 100 items 10000 times
; 0.190000 seconds to lookup 100 items 10000 times
; 0.170000 seconds to next 100 items 10000 times
; 0.541000 seconds to index 100 items 10000 times

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text:font

Action
Gets a text entity's font.

Filename
scm/scmext/kern/text_scm.cpp

APIs
None

Syntax
(text:font text-entity)

Arg Types
text-entity text

Returns
string

Description
This extension returns the font name assigned to the text-entity, which is enclosed in quotes. The font name is composed of foundry, the family, the weight, the slant, and the set-width. In X Windows, use the xlsfonts tool to display a list of available fonts.

Arguments
text-entity specifies a text entity.
; text:font
; Create a text entity.
(define words (text (position 5 10 15)
    "Hello World"
    "new century schoolbook-bold-i-normal" 20))
;; words
; Get the font value of the text entity.
(text:font words)
;; "new century schoolbook-bold-i-normal"

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text:location

Action
Gets a text entity's location.

Filename
scm/scmext/kern/text_scm.cpp

APIs
None

Syntax
(text:location text-entity)

Arg Types
text-entity text

Returns
position

Description
This extension returns the position of the point of origin of the text-entity. The origin is located at the left edge of the left-most (leading) character in the string, at the baseline on which the character sits.

Arguments
text-entity specifies a text entity.
; text:location
; Create a text entity.
(define words (text (position 5 10 15)
    "Hello World"
    "new century schoolbook-bold-i-normal" 20))
;; words
; Get the location of the text entity.
(text:location words)
;; #[position 5 10 15]

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text:set-font

Action
Sets a text entity's font.

Filename
scm/scmext/kern/text_scm.cpp

APIs
None

Syntax
(text:set-font text-entity font)

Arg Types
text-entity text
font string

Returns
text
Arguments
text-entity specifies a text entity.
 
font specifies a text font to be used, which is enclosed in quotes. font is interpreted by the current windowing driver; for example, if the system is running X Windows, available fonts are those listed by running the xlsfonts tool. If the specified font name is not a perfect match, this extension inserts wild cards into the font at various places to search for an approximate match.
 
X Windows specifies fonts as the foundry, the family, the weight, the slant, the set-width, any additional style, the pixel size, the point size, the x-resolution, the y-resolution, the spacing, the average width, the registry, and the encoding. For example:
 
        -adobe-courier-medium-r-normal--8-80-75-75-m-50-iso8859-1
 
The only fields used in this extension are family, weight, slant, and set-width. In the preceding example, these fields are the substring: courier-medium-r-normal.
; text:set-font
; Create the first text entity.
(define words (text (position -20 0 0)
    "abcdefghijklm" "symbol-medium-r-normal" 30))
;; words
; Create the second text entity.
(define words2 (text (position -20 -20 -20)
    "nopqrstuvwxyz" "symbol-medium-r-normal" 30))
;; words2
; OUTPUT Original
; Set the font of the first text entity.
(text:set-font words "courier-bold-r-normal")
;; #[entity 2 1]
; Set the font of the second text entity.
(text:set-font words2 "helvetica-bold-r-normal")
;; #[entity 3 1]
; OUTPUT Result

Figure. 1

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text:set-location

Action
Sets a text entity's location.

Filename
scm/scmext/kern/text_scm.cpp

APIs
None

Syntax
(text:set-location text-entity location)

Arg Types
text-entity text
location position

Returns
text

Description
This extension sets the point of origin (location) for a text-entity. The origin is located at the left edge of the left-most (leading) character in the string, at the baseline on which the character sits.

Arguments
text-entity specifies a text entity.
 
location specifies the origin for the text entity.
; text:set-location
; Create a text entity.
(define words (text
    (position 0 0 0) "Hello World."
    "times-medium-r-normal" 30))
;; words
; Set the location of the text entity.
(define location (text:set-location words
    (position 50 -20 10)))
;; location

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text:set-size

Action
Sets a text entity's font size in points.

Filename
scm/scmext/kern/text_scm.cpp

APIs
None

Syntax
(text:set-size text-entity size)

Arg Types
text-entity text
size integer

Returns
text

Description
This extension sets the size of a text-entity.

Arguments
text-entity specifies a text entity.
 
size is an integer that specifies the size of the font in points. (Usually, business correspondence uses 10 or 12 point fonts.) If the exact size font cannot be found, the font nearest in size is used. When searching for a font, the size specified as part of font is discarded and replaced with the size specified in size.
; text:set-size
; Create a text entity.
(define words (text
    (position 0 0 0) "Hello World."
    "times-medium-r-normal" 30))
;; words
; Set the size of the text entity.
(define size (text:set-size words 10))
;; size

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text:set-string

Action
Sets a text entity's string.

Filename
scm/scmext/kern/text_scm.cpp

APIs
None

Syntax
(text:set-string text-entity string)

Arg Types
text-entity text
string string

Returns
text
Arguments
text-entity specifies a text entity.
 
string is enclosed in quotes, specifies the text string to be displayed by a text-entity.
; text:set-string
; Create a text entity.
(define words (text
    (position 0 0 0) "Hello World."
    "times-medium-r-normal" 30))
;; words
; Set the string of the text entity.
(define string
    (text:set-string words "Hello Universe!"))
;; string

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text:size

Action
Gets a text entity's font size in points.

Filename
scm/scmext/kern/text_scm.cpp

APIs
None

Syntax
(text:size text-entity)

Arg Types
text-entity text

Returns
integer

Description
This extension returns the font size, in points, of a text-entity.

Arguments
text-entity specifies a text entity.
; text:size
; Create a text entity.
(define words (text
    (position 0 0 0) "Hello World."
    "times-medium-r-normal" 20))
;; words
; Get the size of the text entity.
(text:size words)
;; 20

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text:string

Action
Gets a text entity's string.

Filename
scm/scmext/kern/text_scm.cpp

APIs
None

Syntax
(text:string text-entity)

Arg Types
text-entity text

Returns
string

Description
This extension returns the text string in a text-entity, which is enclosed in quotes.

; text:string
; Create a text entity.
(define words (text (position 0 0 0) "Hello World."
    "times-medium-r-normal" 30))
;; words
; Get the text entity string.
(text:string words)
;; "Hello World."

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text?

Action
Determines if a Scheme object is a text entity.

Filename
scm/scmext/kern/text_scm.cpp

APIs
None

Syntax
(text? object)

Arg Types
object scheme-object

Returns
boolean

Description
This extension returns #t if the object is a text entity; otherwise, it returns #f.

Arguments
object specifies a scheme-object that has to be queried for a text entity.
; text?
; Create a text string.
(define words (text (position 0 0 0) "Hello World."
    "times-medium-r-normal" 30))
;; words
; Determine if the string is a text string.
(text? words)
;; #t

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timer:end

Action
Stops the timer.

Filename
scm/scmext/kern/law_scm.cpp

APIs
None

Syntax
(timer:end)

Arg Types
None

Returns
string

Description
The commands timer:start, timer:end, timer:show-time, and timer:get-time are used to measure performance of some command or series of commands. They measure only the CPU time required to execute the command and not any delays incurred from entering the commands into Scheme.

; timer:end
; Start the timer
(timer:start)
;; "timer on"
; Create a solid block.
(define blockA (solid:block
    (position 0 0 0) (position 20 20 20)))
;; blockA
; Create another solid block
(define blockB (solid:block (position 0 0 0)
    (position -20 -20 -20)))
;; blockB
;Stop timer.
(timer:end)
;; "timer off, use timer:get-time"
(timer:get-time)
;; 21.271

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timer:get-time

Action
Calculates and returns the amount of time elapsed since timer:start was executed.

Filename
scm/scmext/kern/law_scm.cpp

APIs
None

Syntax
(timer:get-time)

Arg Types
None

Returns
real

Description
The commands timer:start, timer:end, timer:show-time, and timer:get-time are used to measure performance of some command or series of commands. They measure only the CPU time required to execute the command and not any delays that might incur from entering the commands into Scheme. They are used most often to determine the time required to execute one or more commands.

timer:get-time can be executed/interspersed any number of times throughout a command or series of commands. You can also use timer:show-time to display the amount of time elapsed since timer:start was executed.

; timer:get-time
; Start the timer
(timer:start)
;; "timer on"
; Create a solid block.
(define blockA (solid:block
    (position 0 0 0) (position 20 20 20)))
;; blockA
; Create another solid block
(define blockB (solid:block (position 0 0 0)
    (position -20 -20 -20)))
;; blockB
;Stop timer.
(timer:end)
;; "timer off, use timer:get-time"
(timer:get-time)
;; 21.271

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timer:show-time

Action
Calculates and returns the amount of time elapsed since the timer:start command was executed. This is most often used to measure performance.

Filename
scm/scmext/kern/law_scm.cpp

APIs
None

Syntax
(timer:show-time)

Arg Types
None

Returns
real

Description
The commands timer:start, timer:end, timer:get-time and timer:show-time are used to measure performance of some command or series of commands. This feature measures only the CPU time required to execute the command and not any delays incurred from entering the commands into Scheme or any other interference or condition.

timer:show-time can be executed/interspersed any number of times throughout a command or series of commands. timer:show-time returns a real number only after timer:start is executed. If timer:start has not been executed, timer:show-time returns zero (0). You can also use timer:get-time to display the amount of time elapsed since timer:start was executed.

; timer:show-time
; Start the timer
(timer:start)
;; "timer on"
; Create a solid block
(define blockA (solid:block (position 0 0 0)
    (position 20 20 20)))
;; blockA
; Create another solid block
(define blockB (solid:block (position 0 0 0)
    (position -20 -20 -20)))
;; blockB
; Set color for blockB
(entity:set-color blockB 7)
;; ()
;show how much time has passed.
(timer:show-time)
;; Elapsed time = 33.989
;; 356.722
; Create a third solid block
(define blockC (solid:block (position 0 0 0)
    (position 40 40 40)))
;; blockC
; Set color for blockB
(entity:set-color blockC 4)
;; ()
;turn timer off.
(timer:end)
;; "timer off, use timer:get-time"
(timer:get-time)
;; 4.556

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timer:start

Action
Starts an internal clock/timer. The timer: commands are most often used to measure performance of some command or series of commands.

Filename
scm/scmext/kern/law_scm.cpp

APIs
None

Syntax
(timer:start)

Arg Types
None

Returns
string

Description
The commands timer:start, timer:end, timer:show-time, and timer:get-time are used to measure performance of some command or series of commands. It measures only the CPU time required to execute the command and not any delays that might incur from entering the commands into Scheme.

; timer:start
; Start the timer
(timer:start)
;; "timer on"
; Create a solid block.
(define blockA (solid:block
    (position 0 0 0) (position 20 20 20)))
;; blockA
; Create another solid block
(define blockB (solid:block (position 0 0 0)
    (position -20 -20 -20)))
;; blockB
;Stop timer.
(timer:end)
;; "timer off, use timer:get-time"
(timer:get-time)
;; 2.274

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tolmod:check-edge-errors

Action
Checks whether edges have errors worse than a defined tolerance.

Filename
scm/scmext/kern/ck_err.cpp

APIs
api_check_edge_errors

Syntax
tolmod:check-edge-errors edges [tol][stop_immediately][ao])

Arg Types
edges edge | (edge...)
tol integer
stop_immediately bool
ao acis-options

Returns
(edge...)

Description
Checks the edges in the given list for tolerance. Only edges whose tolerance is above tol are returned.

Arguments
edges is the list of edges to be checked.
 
tol specifies the tolerance.
 
stop_immediately is an indicator. If set to TRUE, the process stops after the first bad edge is found.
 
ao contains journaling and versioning information.
; tolmod:check-edge-errors
; create a block
(define block1 (solid:block (position 0 0 0) (position 20 20 20)))
;; block1
; create a sphere
(define sphere1 (solid:sphere (position 5 5 5) 40))
;; sphere1
; check edges of all entities
(tolmod:check-edge-errors (entity:edges (part:entities)))
;; Worst error : 000000e+000

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tolmod:fix-edge-errors

Action
Converts intolerant edges into tolerant edges.

Filename
kern/kern_scm/ck_err.cxx

APIs
api_check_edge_errors

Syntax
(tolmod:fix-edge-errors edges [tol][stop_immediately][ao])

Arg Types
edges edge | (edge...)
tol integer
stop_immediately bool
ao acis-options

Returns
(edge...)

Description
Fixes the edges in the list to be tolerant. When tol is defined, the only edges made tolerant are those with worse tolerance levels than defined.

Arguments
edges is the list of edges to be checked.
 
tol specifies the tolerance.
 
stop_immediately is an indicator. If set to TRUE, the process stops after the first bad edge is found.
 
ao contains journaling and versioning information.
; tolmod:check-edge-errors
; create a block
(define block1 (solid:block (position 0 0 0) (position 20 20 20)))
;; block1
; create a sphere
(define sphere1 (solid:sphere (position 5 5 5) 40))
;; sphere1
; check and fix bad edges of all entities
(tolmod:fix-edge-errors (entity:edges (part:entities)))
;; Worst error : 000000e+000

[Top]

transform:axes

Action
Creates a transform that takes an object from model space to the space defined by the new origin and axes.

Filename
scm/scmext/kern/tran_scm.cpp

APIs
None

Syntax
(transform:axes origin-position x-axis y-axis)

Arg Types
origin-position position
x-axis gvector
y-axis gvector

Returns
transform

Description
After applying this transform to an entity, the entity has the same relationship to the working coordinate system that it had to the model coordinate system.

Arguments
origin-position specifies the origin of the new coordinate system.
 
x-axis specifies the x-axis gvector.
 
y-axis specifies the y-axis gvector. The y-axis is perpendicular to the x-axis.
; transform:axes
; Create a WCS.
(define wcs1
    (wcs (position 0 0 0) (gvector 1 0 0)
    (gvector 0 1 0)))
;; wcs1
; Set the color of the wcs.
(entity:set-color wcs1 6)
;; ()
; Create a solid block.
(define block1
    (solid:block (position 0 0 0)
    (position 15 20 15)))
;; block1
; OUTPUT Original
; Transform the solid block from model space to
; the created working space as defined by the WCS.
(define transform (entity:transform block1
    (transform:axes (position 0 0 0)
    (gvector -8 0 0) (gvector 0 6 0))))
;; transform
; OUTPUT Result

Figure. 2

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transform:compose

Action
Concatenates two transforms.

Filename
scm/scmext/kern/tran_scm.cpp

APIs
None

Syntax
(transform:compose transform1 transform2)

Arg Types
transform1 transform
transform2 transform

Returns
transform

Description
Concatenates two transforms. Permits the creation of more complex transforms from simpler transforms such as reflection, rotation, scaling, and translation.

Arguments
transform1 and transform2 arguments specify the transformations to be concatenated.
; transform:compose
; Create a WCS.
(define wcs1 (wcs (position 0 0 0) (gvector 1 0 0)
    (gvector 0 1 0)))
;; wcs1
; Set a color for the wcs.
(entity:set-color wcs1 6)
;; ()
; Create a solid block.
(define block1
    (solid:block (position 0 0 0)
    (position 5 10 15)))
;; block1
; OUTPUT Original
; Transform the solid block from model space to
; the created working space as defined by the WCS.
; Concatenate two transforms.
(define comp1 (transform:compose
    (transform:rotation (position 0 0 0)
    (gvector -3 0 0) 45)
    (transform:axes (position 0 0 0)
    (gvector -8 0 0) (gvector 0 6 0))))
;; comp1
; comp1
(define transform (entity:transform block1 comp1))
;; transform
; OUTPUT Result

Figure. 3

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transform:copy

Action
Copies a transform.

Filename
scm/scmext/kern/tran_scm.cpp

APIs
None

Syntax
(transform:copy transform)

Arg Types
transform transform

Returns
transform

Description
Copies a transform into a duplicate but distinct transform.

Arguments
transform specifies the transformation to be copied.
; transform:copy
; Create a WCS.
(define wcs1
    (wcs (position 0 0 0) (gvector 1 0 0)
    (gvector 0 1 0)))
;; wcs1
; Set a color for the wcs.
(entity:set-color wcs1 6)
;; ()
; Create a solid block.
(define block1
    (solid:block (position 0 0 0)
    (position 5 10 15)))
;; block1
; OUTPUT Original
; Apply a new transform by copying the existing
; transform and adding a translation.
(define transform1
    (transform:translation (gvector 4 0 0)))
;; transform1
(define copy1 (transform:copy transform1))
;; copy1
(define entity1
    (entity:transform block1 transform1))
;; entity1
(roll -1)
;; -1
(define entity1
    (entity:transform block1 copy1))
;; entity1
; OUTPUT Result

Figure. 4

[Top]

transform:identity

Action
Creates an identity transform.

Filename
scm/scmext/kern/tran_scm.cpp

APIs
None

Syntax
(transform:identity)

Arg Types
None

Returns
transform

Description
This extension creates an identity transform with the following rotation matrix and translation elements:
          |   1   0   0   |
R   =   |   0   1   0   |   T   =   (0 0 0)
          |   0   0   1   |

transform:identity is useful as a starting point and for operations that require a transform as an input, but nothing is required to be accomplished.
; transform:identity
; Create an identity transform.
(transform:identity)
;; #[transform 1074574992]

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transform:inverse

Action
Creates an inverse transform.

Filename
scm/scmext/kern/tran_scm.cpp

APIs
None

Syntax
(transform:inverse transform)

Arg Types
transform transform

Returns
transform
Arguments
transform specifies the transformation whose inverse is needed.
; transform:inverse
; Create a transform, and then create its inverse.
(define transform1 (transform:axes
    (position 0 0 0) (gvector 1 0 0)
    (gvector 0 0 1)))
;; transform1
(define inverse1 (transform:inverse transform1))
;; inverse1
; Create a WCS.
(define wcs1
    (wcs (position 0 0 0) (gvector 1 0 0)
    (gvector 0 1 0)))
;; wcs1
; Set a color for the wcs.
(entity:set-color wcs1 6)
;; ()
; Create a solid block.
(define block1
    (solid:block (position 0 0 0)
    (position 5 10 15)))
;; block1
(define transform
    (entity:transform block1 transform1))
;; transform
; OUTPUT Original
(define transform2
    (entity:transform block1 inverse1))
;; transform2
; OUTPUT Result

Figure. 5

[Top]

transform:print

Action
Prints a transform.

Filename
scm/scmext/kern/tran_scm.cpp

APIs
None

Syntax
(transform:print transform)

Arg Types
transform transform

Returns
transform

Description
Prints the details of a transform.

Arguments
transform specifies the transform to use.
; transform:print
; create a scaling transform
(define s (transform:scaling 1 2 3))
;; s
; create a rotation transform
(define r (transform:rotation
    (position 0 0 0) (gvector 0 0 1) 30))
;; r
; create a translation transform
(define t (transform:translation (gvector 3 4 5)))
;; t
; compose the three
(define sr (transform:compose s r))
;; sr
(define srt (transform:compose
    (transform:compose s r) t))
;; srt
; print the result
(transform:print srt)
;; #[transform 72496304]
; rotation no reflection shear not identity
; translation part:
; 3.000000  4.000000  5.000000
; affine part:
; 0.231455  0.133631  0.000000
; -0.267261 0.462910  0.000000
; 0.000000  0.000000  0.801784
; scaling part:
; 3.741657

[Top]

transform:reflection

Action
Creates a transform to mirror an object through an axis.

Filename
scm/scmext/kern/tran_scm.cpp

APIs
None

Syntax
(transform:reflection plane-position
    plane-direction)

Arg Types
plane-position position
plane-direction gvector

Returns
transform
Arguments
plane-position specifies the location to mirror an object.
 
plane-direction specifies the normal of the mirror in the plane.
; transform:reflection
; Define a working coordinate system.
(define wcs1
    (wcs (position 0 0 0) (gvector 1 0 0)
    (gvector 0 1 0)))
;; wcs1
; Set a color for the wcs.
(entity:set-color wcs1 6)
;; ()
; Create a solid block.
(define block1
    (solid:block (position 0 0 0)
    (position 5 10 15)))
;; block1
; OUTPUT Original
; Create a transform and then create its reflection.
(define transform1
    (transform:reflection
    (position 0 0 0) (gvector -1 0 0)))
;; transform1
; Apply the transform to reflect the block.
(define transform
    (entity:transform block1 transform1))
;; transform
; OUTPUT Result

Figure. 6

[Top]

transform:rotation

Action
Creates a transform to rotate an object about an axis.

Filename
scm/scmext/kern/tran_scm.cpp

APIs
None

Syntax
(transform:rotation origin-position
    axis-direction angle)

Arg Types
origin-position position
axis-direction gvector
angle real

Returns
transform
Arguments
origin-position specifies the start location of the rotate.
 
axis-direction specifies the axis direction of rotation. The right-hand rule determines the direction of rotation.
 
angle specifies the angle in degrees to rotate the object.
; transform:rotation
; Define a working coordinate system.
(define wcs1
    (wcs (position 0 0 0) (gvector 1 0 0)
    (gvector 0 1 0)))
;; wcs1
; Set a color for the wcs.
(entity:set-color wcs1 6)
;; ()
; Create a solid block.
(define block1
    (solid:block (position 0 0 0)
    (position 5 10 15)))
;; block1
; OUTPUT Original
; Create a transform and then create its reflection.
(define transform1
    (transform:rotation
    (position 0 0 0) (gvector -3 0 0) 45))
;; transform1
; Apply the transform to reflect the block.
(define transform
    (entity:transform block1 transform1))
;; transform
; OUTPUT Result

Figure. 7

[Top]

transform:scaling

Action
Creates a scaling transform.

Filename
scm/scmext/kern/tran_scm.cpp

APIs
None

Syntax
(transform:scaling x-scale [y-scale z-scale])

Arg Types
x-scale real
y-scale real
z-scale real

Returns
transform

Description
The specified scale must be positive definite. When only the x-scale term is supplied, a uniform scaling transform is obtained, with which all three components of positions, gvectors, and entity dimensions are multiplied by the same factor. When three scaling terms are supplied, a non-uniform scaling transform is created (unless all three terms are equal). The application of non-uniform scaling transforms to entities invokes the Space Warping component.

Arguments
x-scale specifies the scaling factor for the x-axis direction.
 
y-scale is an optional argument that specifies the scaling factor for the y-axis direction.
 
z-scale is an optional argument that specifies the scaling factor for the z-axis direction.
; transform:scaling
; Define a working coordinate system.
(define wcs1
    (wcs (position 0 0 0) (gvector 1 0 0)
    (gvector 0 1 0)))
;; wcs1
; Set a color for the wcs.
(entity:set-color wcs1 6)
;; ()
; Create a solid block.
(define block1
    (solid:block (position 0 0 0)
    (position 15 20 15)))
;; block1
; OUTPUT Original
; Create a transform and then create its reflection.
(define transform1
    (transform:scaling 0.75 0.75 0.25))
;; transform1
; Apply the transform to reflect the block.
(define transform
    (entity:transform block1 transform1))
;; transform
; OUTPUT Result

Figure. 8

[Top]

transform:translation

Action
Creates a translation transform.

Filename
scm/scmext/kern/tran_scm.cpp

APIs
None

Syntax
(transform:translation gvector)

Arg Types
gvector gvector

Returns
transform
Arguments
gvector translates an object based on the supplied direction vector.
; transform:translation
; Define a working coordinate system.
(define wcs1
    (wcs (position 0 0 0) (gvector 1 0 0)
    (gvector 0 1 0)))
;; wcs1
; Set a color for the wcs.
(entity:set-color wcs1 6)
;; ()
; Create a solid block.
(define block1
    (solid:block (position 0 0 0)
    (position 15 20 15)))
;; block1
; OUTPUT Original
; Create a transform and then create its reflection.
(define transform1
    (transform:translation (gvector 10 12.5 0)))
;; transform1
; Apply the transform to reflect the block.
(define transform
    (entity:transform block1 transform1))
;; transform
; OUTPUT Result

Figure. 9

[Top]

transform?

Action
Determines if a Scheme object is a transform.

Filename
scm/scmext/kern/tran_scm.cpp

APIs
None

Syntax
(transform? object)

Arg Types
object scheme-object

Returns
boolean
Arguments
object specifies the scheme-object that has to be queried for a transform.
; transform?
; Create a transform.
(define transform1
    (transform:translation
    (gvector 1 0 0)))
;; transform1
; Determine if the transform and its identity
; are actually transforms.
(transform? transform1)
;; #t
(transform? (transform:identity))
;; #t

[Top]

versiontag

Action
Gets the current version tag or creates a new version tag scheme object. Default is the current version.

Filename
scm/scmext/kern/version_tag_scm.cpp

APIs
None

Syntax
(versiontag [major minor release])

Arg Types
major integer
minor integer
release integer

Returns
scheme-object

Description
Returns a version tag scheme object.

Arguments
major specifies the major version number.
 
minor specifies the minor version number.
 
release specifies the release number.
; versiontag
; Query for the current versiontag.
(versiontag)
;; #[Major=7 Minor=0 Point=0 Tag=70000]
; Create a new version tag scheme object.
(versiontag 7 1 0)
;; #[Major=7 Minor=1 Point=0 Tag=70100]

[Top]

vertex:position

Action
Gets the position of a vertex.

Filename
scm/scmext/kern/vrtx_scm.cpp

APIs
None

Syntax
(vertex:position vertex)

Arg Types
vertex vertex

Returns
position

Description
Returns the position of a vertex.

Arguments
vertex specifies a vertex.
; vertex:position
; Create a solid block.
(define block1
    (solid:block (position 0 0 0)
    (position 35 35 35)))
;; block1
; Get a list of the vertices.
(entity:vertices block1)
;; (#[entity 3 1] #[entity 4 1] #[entity 5 1]
;; #[entity 6 1] #[entity 7 1] #[entity 8 1]
;; #[entity 9 1] #[entity 10 1])
; Determine the position of one vertex.
(vertex:position (entity 7))
;; #[position 35 35 0]

[Top]

vertex?

Action
Determines if a Scheme object is a vertex.

Filename
scm/scmext/kern/vrtx_scm.cpp

APIs
None

Syntax
(vertex? object)

Arg Types
object scheme-object

Returns
boolean
Arguments
object specifies the scheme-object that has to be queried for a vertex.
; vertex?
; Create a solid block.
(define block1
    (solid:block (position 0 0 0)
    (position 35 35 35)))
;; block1
; Get a list of the block's vertices.
(entity:vertices block1)
;; (#[entity 3 1] #[entity 4 1] #[entity 5 1]
;; #[entity 6 1] #[entity 7 1] #[entity 8 1]
;; #[entity 9 1] #[entity 10 1])
; Determine if a vertex is actually a vertex.
(vertex? (entity 6))
;; #t

[Top]

wcs

Action
Creates a work coordinate system.

Filename
scm/scmext/kern/wcs_scm.cpp

APIs
api_wcs_create

Syntax
(wcs origin-pos {x-pos | x-vec} {y-pos | y-vec})

Arg Types
origin-pos position
x-pos position
x-vec gvector
y-pos position
y-vec gvector

Returns
wcs

Description
The origin-pos, x-pos and y-pos are used to define the xy-plane. The z-axis is defined by the right hand rule.

Arguments
origin-pos specifies the center of model space.
 
x-pos specifies the x-axis location.
 
y-pos specifies the y-axis location. The y-axis is defined perpendicularly to the x-axis in the xy-plane.
 
x-vec specifies the axis in the x-direction.
 
y-vec specifies the axis in the y-direction.
; wcs
; Create a new WCS.
(define wcs1
    (wcs (position 0 0 0) (gvector 1 0 0)
    (gvector 0 1 0)))
;; wcs1
; OUTPUT WCS 1
; Create a second WCS.
(define wcs2
    (wcs (position 30 0 0)
    (position 30 30 0) (position 30 0 10)))
;; wcs2
; Set a color for the wcs.
(entity:set-color wcs1 6)
;; ()
; OUTPUT WCS 2

Figure. 10

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wcs:active

Action
Gets the active work coordinate system.

Filename
scm/scmext/kern/wcs_scm.cpp

APIs
api_wcs_get_active

Syntax
(wcs:active)

Arg Types
None

Returns
wcs | boolean

Description
This extension returns the active WCS; otherwise, it returns #f if no WCS is active.

; wcs:active
; Create a WCS.
(define wcs1 (wcs (position 0 0 0) (gvector 1 0 0)
    (gvector 0 1 0)))
;; wcs1
; Determine if the WCS is active.
(wcs:active)
;; #f
; Set the new WCS to be active.
(wcs:set-active wcs1)
;; ()
; Get the active WCS.
(wcs:active)
;; #[entity 2 1]

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wcs:from-transform

Action
Creates a work coordinate system given a transform.

Filename
scm/scmext/kern/wcs_scm.cpp

APIs
None

Syntax
(wcs:from-transform transform)

Arg Types
transform transform

Returns
wcs
Arguments
transform maps from the model space to the new working coordinate system.
; wcs:from-transform
; Create a new WCS.
(define wcs1
    (wcs (position 0 0 0) (position 5 0 0)
    (position 0 5 0)))
;; wcs1
(define transform1 (transform:rotation
    (position 0 0 0) (gvector -10 0 0) 60))
;; transform1
; Create a new WCS from a transform rotation.
(define wcs2 (wcs:from-transform transform1))
;; wcs2
(define transform2
    (transform:translation (gvector 10 10 20)))
;; transform2
; Create a new WCS from a transform translation.
(define wcs3 (wcs:from-transform transform2))
;; wcs3
; OUTPUT Example

Figure. 11

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wcs:origin

Action
Gets the origin of the active WCS.

Filename
scm/scmext/kern/wcs_scm.cpp

APIs
None

Syntax
(wcs:origin [wcs])

Arg Types
wcs wcs

Returns
position
Arguments
wcs is an optional argument that specifies the working coordinate system to search. If wcs is not specified, the active WCS is used.
; wcs:origin
; Get the origin position of the current WCS.
(wcs:origin)
;; #[position 0 0 0]
; Define a new WCS.
(define wcs1 (wcs (position -10 -10 -10)
    (position 0 10 0) (position 10 0 0)))
;; wcs1
; Get the origin position of the new WCS.
(wcs:origin wcs1)
;; #[position -10 -10 -10]

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wcs:set-active

Action
Sets the active work coordinate system to the specified WCS.

Filename
scm/scmext/kern/wcs_scm.cpp

APIs
api_wcs_set_active

Syntax
(wcs:set-active wcs)

Arg Types
wcs wcs

Returns
unspecified
Arguments
If a wcs is specified, it becomes the active wcs. If boolean #f is specified, the system is returned to its initial state of no active wcs.
; wcs:set-active
; Define working coordinate system.
(define wcs1 (wcs (position 0 0 0)
    (position 5 0 0) (position 0 5 0)))
;; wcs1
; Set a color for wcs1.
(entity:set-color wcs1 6)
;; ()
; Define a solid block.
(define block1
    (solid:block (position 0 0 0)
    (position 10 10 10)))
;; block1
; Set a color for block 1.
(entity:set-color block1 3)
;; ()
; Define a second working coordinate system.
(define wcs2 (wcs (position 15 0 0)
    (position 20 0 0) (position 0 20 0)))
;; wcs2
; OUTPUT WCS1 and Block1
; Set the specified WCS to be the active WCS.
(wcs:set-active wcs2)
;; ()
; Define another solid block in the specified WCS.
(define block2
    (solid:block (position 0 0 0)
    (position 10 10 10)))
;; block2
; Set a color for the second block.
(entity:set-color block2 1)
;; ()
; OUTPUT WCS2 and Block2

Figure. 12

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wcs:to-model-transform

Action
Gets the transform of the active WCS to model space.

Filename
scm/scmext/kern/wcs_scm.cpp

APIs
None

Syntax
(wcs:to-model-transform [wcs])

Arg Types
wcs wcs

Returns
transform
Arguments
wcs is an optional argument that specifies the WCS to search. If wcs is not specified, the active WCS is used.
; wcs:to-model-transform
; Find the transform of the current WCS to
; model space.
(define transform1 (wcs:to-model-transform))
;; transform1
; Define a new WCS.
(define wcs1 (wcs (position -10 -10 -10)
    (position 0 10 0) (position 10 0 0)))
;; wcs1
; Find the transform of the new WCS to model space.
(wcs:to-model-transform wcs1)
;; #[transform 1074571672]

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wcs:to-wcs-transform

Action
Gets the transform from the active WCS to the specified WCS.

Filename
scm/scmext/kern/wcs_scm.cpp

APIs
None

Syntax
(wcs:to-wcs-transform [wcs])

Arg Types
wcs wcs

Returns
transform
Arguments
wcs is an optional argument that specifies the WCS to search. If wcs is not specified, the active WCS is used.
; wcs:to-wcs-transform
; Get the transform from the active coordinate
; system to the current WCS.
(define transform1 (wcs:to-wcs-transform))
;; transform1
; Define a new WCS.
(define wcs1 (wcs (position 0 0 0)
    (position 0 10 0) (gvector 1 0 0)))
;; wcs1
; Get the transform from the active coordinate
; system to the new WCS.
(wcs:to-wcs-transform wcs1)
;; #[transform 1074571664]

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wcs:x-axis

Action
Gets the x-direction of the active coordinate system.

Filename
scm/scmext/kern/wcs_scm.cpp

APIs
None

Syntax
(wcs:x-axis [wcs])

Arg Types
wcs wcs

Returns
gvector
Arguments
wcs is an optional argument that specifies the WCS to search. If wcs is not specified, the active WCS is used.
; wcs:x-axis
; Find the x-direction of the current WCS.
(wcs:x-axis)
;; #[gvector 1 0 0]
; Define a new WCS.
(define wcs1 (wcs (position 10 10 10)
    (position 10 0 0) (position 0 10 0)))
;; wcs1
; Get the x-direction of the new WCS.
(wcs:x-axis wcs1)
;; #[gvector 0 -0.707106781186548
;; -0.707106781186548]
; Define WCS wcs3.
(define wcs13 (wcs (position 3 2 1) (gvector 0 1 0)
    (position 1 0 0)))
;; wcs13
; Find the x-direction of WCS wcs3.
(wcs:x-axis wcs13)
;; #[gvector 0 1 0]

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wcs:y-axis

Action
Gets the y-direction of the active coordinate system.

Filename
scm/scmext/kern/wcs_scm.cpp

APIs
None

Syntax
(wcs:y-axis [wcs])

Arg Types
wcs wcs

Returns
gvector
Arguments
wcs is an optional argument that specifies the WCS to search. If wcs is not specified, the active WCS is used.
; wcs:y-axis
; Get the y-direction of the current WCS.
(wcs:y-axis)
;; #[gvector 0 1 0]
; Define a new WCS.
(define wcs1 (wcs (position 10 10 10)
    (position 10 0 0) (position 0 10 0)))
;; wcs1
; Get the y-direction of the new WCS.
(wcs:y-axis wcs1)
;; #[gvector -0.816496580927726 0.408248290463863
;; -0.408248290463863]
; Define WCS wcs3.
(define wcs3 (wcs (position 3 2 1) (gvector 0 1 0)
    (position 1 0 0)))
;; wcs3
; Get the y-direction of wcs3.
(wcs:y-axis wcs3)
;; #[gvector -0.894427190999916 0
;; -0.447213595499958]

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wcs:z-axis

Action
Gets the z-direction of the active coordinate system.

Filename
scm/scmext/kern/wcs_scm.cpp

APIs
None

Syntax
(wcs:z-axis [wcs])

Arg Types
wcs wcs

Returns
gvector
Arguments
wcs is an optional argument that specifies the WCS to search. If wcs is not specified, the active WCS is used.
; wcs:z-axis
; Get the z-axis of the current WCS.
(wcs:z-axis)
;; #[gvector 0 0 1]
; Define a new WCS.
(define wcs1 (wcs (position 10 10 10)
    (position 10 0 0) (position 0 10 0)))
;; wcs1
; Get the z-axis of the new WCS.
(wcs:z-axis wcs1)
;; #[gvector 0.577350269189626 0.577350269189626
;; -0.577350269189626]
; Define wcs3.
(define wcs3 (wcs (position 3 2 1) (gvector 0 1 0)
    (position 1 0 0)))
;; wcs3
; Get the z-axis of wcs3.
(wcs:z-axis wcs3)
;; #[gvector -0.447213595499958 0 0.894427190999916]

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wcs?

Action
Determines if a Scheme object is a WCS.

Filename
scm/scmext/kern/wcs_scm.cpp

APIs
None

Syntax
(wcs? object)

Arg Types
object scheme-object

Returns
boolean

Description
This extension returns #t if the specified object is a WCS entity; otherwise, it returns #f.

Arguments
object specifies the scheme-object that has to be queried for a wcs.
; wcs?
; Create a wcs.
(define wcs1 (wcs (position 0 0 0) (gvector 0 -1 0)
    (gvector 1 0 0)))
;; wcs1
; Determine if the WCS is actually a WCS.
(wcs? wcs1)
;; #t

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wire-body:area

Action
Gets the area of a planar wire.

Filename
scm/scmext/oper/ware_scm.cpp

APIs
api_wire_area

Syntax
(wire-body:area wire)

Arg Types
wire wire

Returns
real

Description
Entity requires a wire entity. If the specified wire entity is open, it temporarily closes the wire with a line from the start point to the end point and computes the area of this closed wire. If the wire is non-planar, this extension returns zero. This extension does not check if the wire is self-intersecting or that the resultant area is incorrect.  

Arguments
wire specifies a planar wire.
; wire-body:area
; Create first edge.
(define edge1 (edge:circular
    (position 0 0 0) 25 0 180))
;; edge1
; Create second edge.
(define edge2 (edge:circular
    (position 0 0 0) 25 180 270))
;; edge2
; Create third edge.
(define edge3 (edge:linear (position 0 0 0)
    (position 25 0 0)))
;; edge3
; Create the wire-body.
(define wirebody1 (wire-body
    (list edge3 edge1 edge2)))
;; wirebody1
; Get the area of the planar wire-body.
(wire-body:area wirebody1)
;; 1472.62155637022

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wire-body:normal

Action
Determines if a Scheme object is a planar wire body and returns its normal.

Filename
scm/scmext/kern/ent_scm.cpp

APIs
None

Syntax
(wire-body:normal object)

Arg Types
object scheme-object

Returns
gvector or NULL

Description
Queries the wire body if it is planar and returns its normal.  

Arguments
object specifies the scheme-object that has to be queried for a planar wire body.
; wire-body:normal
; Create edge 1.
(define edge1 (edge:linear (position -20 -10 0)
                          (position 10 -10 0)))
;; edge1
; Create edge:circular 2.
(define edge2 (edge:circular (position 10 0 0) 10 270 360))
;; edge2
; Create edge 3.
(define edge3 (edge:linear (position 20 0 0)
            (position 20 20 0)))
;; edge3
; Create edge 4.
(define edge4 (edge:linear (position 20 20 0)
            (position -10 20 0)))
;; edge4
; Create edge:circular 5.
(define edge5 (edge:circular (position -10 10 0) 10 90 180))
;; edge5
; Create edge 6.
(define edge6 (edge:linear (position -20 10 0)
            (position -20 -10 0)))
;; edge6
; Create a wire-body from the edges.
(define wirebody1 (wire-body (list
                 edge1 edge2 edge3 edge4 edge5 edge6)))
;; wirebody1
; Determine if the wire-body is actually a wire-body.
(wire-body:planar? wirebody1)
;; #t
; Determine the wire-body normal
(wire-body:normal wirebody1)
;; #[gvector 0 0 -1]

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wire-body:planar?

Action
Determines if a Scheme object is a planar wire body.

Filename
scm/scmext/kern/ent_scm.cpp

APIs
None

Syntax
(wire-body:planar? object)

Arg Types
object scheme-object

Returns
boolean
Arguments
object specifies the scheme-object that has to be queried for a planar wire body.
; wire-body:planar?
; Create edge 1.
(define edge1 (edge:linear (position -20 -10 0)
    (position 10 -10 0)))
;; edge1
; Create edge:circular 2.
(define edge2 (edge:circular
    (position 10 0 0) 10 270 360))
;; edge2
; Create edge 3.
(define edge3 (edge:linear
    (position 20 0 0) (position 20 20 0)))
;; edge3
; Create edge 4.
(define edge4 (edge:linear
    (position 20 20 0) (position -10 20 0)))
;; edge4
; Create edge:circular 5.
(define edge5 (edge:circular
    (position -10 10 0) 10 90 180))
;; edge5
; Create edge 6.
(define edge6 (edge:linear
    (position -20 10 0) (position -20 -10 0)))
;; edge6
; Create a wire-body from the edges.
(define wirebody1 (wire-body (list
    edge1 edge2 edge3
    edge4 edge5 edge6)))
;; wirebody1
; Determine if the wire-body is actually a wire-body.
(wire-body:planar? wirebody1)
;; #t

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wire-body?

Action
Determines if a Scheme object is a wire body.

Filename
scm/scmext/kern/ent_scm.cpp

APIs
None

Syntax
(wire-body? object)

Arg Types
object scheme-object

Returns
boolean

Description
This extension returns #t if the specified object is a wire body; otherwise, it returns #f.

Arguments
object specifies the scheme-object that has to be queried for a wire body.
; wire-body?
; Create an edge.
(define edge1 (edge:circular
    (position 0 0 0) 25 180 270))
;; edge1
; Check to see if the edge is a wire-body.
(wire-body? edge1)
;; #f
; Create a wire-body from the edge.
(define wirebody1 (wire-body edge1))
;; wirebody1
; Check to see if the wire-body is a wire-body.
(wire-body? wirebody1)
;; #t

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wire:closed?

Action
Determines if a Scheme object is a closed wire.

Filename
scm/scmext/kern/ent_scm.cpp

APIs
None

Syntax
(wire:closed? object)

Arg Types
object scheme-object

Returns
boolean

Description
This extension returns #t if the specified object is a wire body; otherwise, it returns #f.

Arguments
object specifies the scheme-object that has to be queried for a closed wire.
; wire:closed?
; Create an edge.
(define edge1 (edge:circular
    (position 0 0 0) 25 180 270))
;; edge1
; Check to see if the edge is a wire-body.
(wire-body? edge1)
;; #f
; Create a wire-body from the edge.
(define wirebody1 (wire-body edge1))
;; wirebody1
; Check to see if the wire-body is a wire-body.
(wire:closed? wirebody1)
; Entity is not a wire.
;; #f

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wire:planar?

Action
Determines if a Scheme object is a planar wire.

Filename
scm/scmext/kern/ent_scm.cpp

APIs
None

Syntax
(wire:planar? object)

Arg Types
object scheme-object

Returns
boolean
Arguments
object specifies the scheme-object that has to be queried for a planar wire.
; wire:planar?
; Create edge 1.
(define edge1 (edge:linear (position -20 -10 0)
    (position 10 -10 0)))
;; edge1
; Create edge:circular 2.
(define edge2 (edge:circular
    (position 10 0 0) 10 270 360))
;; edge2
; Create edge 3.
(define edge3 (edge:linear
    (position 20 0 0) (position 20 20 0)))
;; edge3
; Create edge 4.
(define edge4 (edge:linear
    (position 20 20 0) (position -10 20 0)))
;; edge4
; Create edge:circular 5.
(define edge5 (edge:circular
    (position -10 10 0) 10 90 180))
;; edge5
; Create edge 6.
(define edge6 (edge:linear
    (position -20 10 0) (position -20 -10 0)))
;; edge6
; Create a wire-body from the edges.
(define wirebody1 (wire-body (list
    edge1 edge2 edge3
    edge4 edge5 edge6)))
;; wirebody1
; Determine if the wire-body is actually a wire-body.
(wire:planar? wirebody1)
;; #f
(wire:planar? (car (entity:wires wirebody1)))
;; #t

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wire?

Action
Determines if a Scheme object is a wire.

Filename
scm/scmext/kern/ent_scm.cpp

APIs
None

Syntax
(wire? object)

Arg Types
object scheme-object

Returns
boolean

Description
This extension returns #t if the object is a wire; otherwise, it returns #f. (Use entity:wires to extract a list of wires from a wire body.)

Arguments
object specifies the scheme-object that has to be queried for a wire.
; wire?
; Create an edge.
(define edge1 (edge:circular
    (position 0 0 0) 25 180 270))
;; edge1
; Check to see if the edge is a wire.
(wire? edge1)
;; #f
; Create a wire-body from the edge.
(define body1 (wire-body edge1))
;; body1
; Check to see if the wire-body is a wire.
(wire? body1)
;; #f
; Create a wire from the wire-body.
(define wires1 (entity:wires body1))
;; wires1
; Check to see if the wire is a wire.
(wire? (car wires1))
;; #t

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