allbery@uunet.UU.NET (Brandon S. Allbery - comp.sources.misc) (09/24/89)
Posting-number: Volume 8, Issue 57
Submitted-by: net@tub.UUCP (Oliver Laumann)
Archive-name: elk/part09
[Let this be a lesson to submitters: this was submitted as uuencoded,
compressed files. I lost the source information while unpacking it; this
is the best approximation I could come up with. ++bsa]
#! /bin/sh
# This is a shell archive. Remove anything before this line, then unpack
# it by saving it into a file and typing "sh file". To overwrite existing
# files, type "sh file -c". You can also feed this as standard input via
# unshar, or by typing "sh <file", e.g.. If this archive is complete, you
# will see the following message at the end:
# "End of archive 9 (of 14)."
# Contents: tst/billiard lib/xlib/examples/properties
# lib/xlib/examples/track lib/xlib/examples/picture
# lib/xlib/examples/useful lib/xlib/pixel.c
# Wrapped by net@tub on Sun Sep 17 17:32:32 1989
PATH=/bin:/usr/bin:/usr/ucb ; export PATH
if test -f tst/billiard -a "${1}" != "-c" ; then
echo shar: Will not over-write existing file \"tst/billiard\"
else
echo shar: Extracting \"tst/billiard\" \(46118 characters\)
sed "s/^X//" >tst/billiard <<'END_OF_tst/billiard'
X;;;
X;;; BILLIARD.SCM: This file contains code for a very simple billiard ball
X;;; simulator. The simulation takes place in two dimensions.
X;;; The balls are really disks in that their height is not taken
X;;; into account. All interactions are assumed to be
X;;; frictionless so spin in irrelevant and not accounted for.
X;;; (See section on limitations.)
X;;;
X;;; NOTES: A simulation is initiated by creating a number of balls and bumpers
X;;; and and specifying a duration for the simulation. For each ball,
X;;; its mass, radius, initial position, and initial velocity must be
X;;; specified. For each bumper, the location of its two ends must be
X;;; specified. (Bumpers are assumed to have zero width.)
X;;;
X;;; A sample run might be started as follows:
X;;; (simulate
X;;; (list (make-ball 2 1 9 5 -1 -1)
X;;; (make-ball 4 2 2 5 1 -1))
X;;; (list (make-bumper 0 0 0 10)
X;;; (make-bumper 0 0 10 0)
X;;; (make-bumper 0 10 10 10)
X;;; (make-bumper 10 0 10 10))
X;;; 30)
X;;;
X;;; It would create one billiard ball of mass 2 and radius 1 at position
X;;; (9, 5) with initial velocity (-1, -1) and a second ball of mass 4
X;;; and radius 2 at position (2, 5) with initial velocity (1, -1). The
X;;; table would be a 10X10 square. (See diagram below)
X;;;
X;;; +---------------------------+
X;;; | |
X;;; | |
X;;; | XXXX |
X;;; | XXXXXXXX XX |
X;;; |XXXXXX4XXXXX XXX2XX|
X;;; | XXXXXXXX /XX |
X;;; | XXXX \ |
X;;; | |
X;;; | |
X;;; +---------------------------+
X;;;
X;;; LIMITATIONS: This simulator does not handle 3 body problems correctly. If
X;;; 3 objects interact at one time, only the interactions of 2 of
X;;; the bodies will be accounted for. This can lead to strange
X;;; effects like balls tunneling through walls and other balls.
X;;; It is also possible to get balls bouncing inside of each
X;;; other in this way.
X;;;
X
X
X;;MAKE-QUEUE-RECORD returns a queue record with the given next, previous, and
X;;value values
X;;NEXT = The next record pointer
X;;PREV = The previous record pointer
X;;REST = A list of values for any optional fields (this can be used for
X;; creating structure inheritance)
X(define-macro (make-queue-record next prev . rest)
X `(vector ,next ,prev ,@rest))
X
X;;QUEUE-RECORD-NEXT returns the next field of the given queue record
X;;QUEUE-RECORD = The queue record whose next field is to be returned
X(define-macro (queue-record-next queue-record)
X `(vector-ref ,queue-record 0))
X
X;;SET-QUEUE-RECORD-NEXT! sets the next field of the given queue record
X;;QUEUE-RECORD = The queue record whose next field is to be set
X;;VALUE = The value to which the next field is to be set
X(define-macro (set-queue-record-next! queue-record value)
X `(vector-set! ,queue-record 0 ,value))
X
X;;QUEUE-RECORD-PREV returns the prev field of the given queue record
X;;QUEUE-RECORD = The queue record whose prev field is to be returned
X(define-macro (queue-record-prev queue-record)
X `(vector-ref ,queue-record 1))
X
X;;SET-QUEUE-RECORD-PREV! sets the prev field of the given queue record
X;;QUEUE-RECORD = The queue record whose prev field is to be set
X;;VALUE = The value to which the prev field is to be set
X(define-macro (set-queue-record-prev! queue-record value)
X `(vector-set! ,queue-record 1 ,value))
X
X;;QUEUE-RECORD-LEN returns the length of a queue record which has no optional
X;;fields
X(define-macro (queue-record-len) 2)
X
X;;QUEUE-HEAD returns a dummy record at the end of the queue with the record
X;;with the smallest key.
X;;QUEUE = the queue whose head record is to be returned
X(define-macro (queue-head queue)
X `(vector-ref ,queue 0))
X
X;;QUEUE-TAIL returns a dummy record at the end of the queue with the record
X;;with the largest key.
X;;QUEUE = the queue whose tail record is to be returned
X(define-macro (queue-tail queue)
X `(vector-ref ,queue 1))
X
X;;QUEUE-<? returns the less-than comparitor to be used in sorting
X;;records into the queue
X;;QUEUE = The queue whose comparitor is to be returned
X(define-macro (queue-<? queue)
X `(vector-ref ,queue 2))
X
X
X;;MAKE-SORTED-QUEUE returns a queue object. A queue header is a vector which
X;;contains a head pointer, a tail pointer, and a less-than comparitor.
X;;QUEUE-<? = A predicate for sorting queue items
X(define (make-sorted-queue queue-<?)
X (let ((queue
X (vector
X (make-queue-record ;The queue head record has no initial
X '() ;next, previous, or value values
X '())
X (make-queue-record ;The queue tail record has no intial
X '() ;next, previous, or value values
X '())
X queue-<?)))
X (set-queue-record-next!
X (queue-head queue)
X (queue-tail queue))
X (set-queue-record-prev!
X (queue-tail queue)
X (queue-head queue))
X queue))
X
X;;MAKE-EVENT-QUEUE-RECORD returns an event queue record with the given next,
X;;previous, object, and collision-time values
X;;NEXT = The next record pointer
X;;PREV = The previous record pointer
X;;OBJECT = The simulation object associated with this record
X;;COLLISION-TIME = The collision time for this object
X(define-macro (make-event-queue-record next prev object collision-time)
X `(make-queue-record ,next ,prev ,object ,collision-time))
X
X;;EVENT-QUEUE-RECORD-OBJECT returns the object associated with the given record
X;;QUEUE-RECORD = The queue record whose object field is to be returned
X(define-macro (event-queue-record-object queue-record)
X `(vector-ref ,queue-record ,(queue-record-len)))
X
X;;EVENT-QUEUE-COLLISION-TIME returns the collision time associated with the
X;;given queue record
X;;QUEUE-RECORD = The queue record whose collision time field is to be returned
X(define-macro (event-queue-record-collision-time queue-record)
X `(vector-ref ,queue-record ,(1+ (queue-record-len))))
X
X;;SET-EVENT-QUEUE-COLLISION-TIME! sets the collision time associated with the
X;;given queue record
X;;QUEUE-RECORD = The queue record whose collision time field is to be returned
X;;VALUE = The value to which it is to be set
X(define-macro (set-event-queue-record-collision-time! queue-record value)
X `(vector-set! ,queue-record ,(1+ (queue-record-len)) ,value))
X
X
X;;QUEUE-INSERT inserts the given record in the given queue based on its value
X;;QUEUE = The queue into which the record is to be inserted
X;;QUEUE-RECORD = The record to be inserted in the queue
X(define (queue-insert queue queue-record)
X (define (actual-insert insert-record next-record)
X (if (or ;If the insert position has been found
X (eq? next-record ;or the end on the queue has been
X (queue-tail queue)) ;reached
X ((queue-<? queue)
X insert-record
X next-record))
X (sequence ;Link the insert record into the queue
X (set-queue-record-next! ;just prior to next-record
X (queue-record-prev
X next-record)
X insert-record)
X (set-queue-record-prev!
X insert-record
X (queue-record-prev
X next-record))
X (set-queue-record-next!
X insert-record
X next-record)
X (set-queue-record-prev!
X next-record
X insert-record))
X (actual-insert ;Else, continue searching for the
X insert-record ;insert position
X (queue-record-next
X next-record))))
X (actual-insert ;Search for the correct position to
X queue-record ;perform the insert starting at the
X (queue-record-next ;queue head and perform the insert
X (queue-head queue)))) ;once this position has been found
X
X;;QUEUE-REMOVE removes the given queue record from its queue
X;;QUEUE-RECORD = The record to be removed from the queue
X(define (queue-remove queue-record)
X (set-queue-record-next!
X (queue-record-prev
X queue-record)
X (queue-record-next
X queue-record))
X (set-queue-record-prev!
X (queue-record-next
X queue-record)
X (queue-record-prev
X queue-record)))
X
X;;QUEUE-SMALLEST returns the queue record with the smallest key on the given
X;;queue
X;;QUEUE = The queue from which the smallest record is to be extracted
X(define (queue-smallest queue)
X (queue-record-next
X (queue-head queue)))
X
X
X;;CLEAR-QUEUE! clears the given queue by destructively removing all the records
X;;QUEUE = The queue to be cleared
X(define (clear-queue queue)
X (set-queue-record-next!
X (queue-head queue)
X (queue-tail queue))
X (set-queue-record-prev!
X (queue-tail queue)
X (queue-head queue)))
X
X;;EMPTY-QUEUE? returns true if the given queue is empty
X;;QUEUE = The queue to be tested for emptiness
X(define (empty-queue? queue)
X (eq? (queue-record-next
X (queue-head queue))
X (queue-tail queue)))
X
X
X;;MAKE-SIMULATION-OBJECT returns a simulation object containing the given
X;;fields
X;;COLLISION-PROCEDURE = A function for processing information about a potential
X;; collision between this object and some ball
X;;REST = A list of values for any optional fields (this can be used for
X;; creating structure inheritance)
X(define-macro (make-simulation-object collision-procedure . rest)
X `(vector ,collision-procedure ,@rest))
X
X;;SIMULATION-OBJECT-COLLLISION-PROCEDURE returns the collision procedure for
X;;the given simulation object
X;;OBJECT = The object whose collision procedure is to be returned
X(define-macro (simulation-object-collision-procedure object)
X `(vector-ref ,object 0))
X
X;;SIMULATION-OBJECT-LEN returns the length of a simulation object which has no
X;;optional fields
X(define-macro (simulation-object-len) 1)
X
X
X;;ACTUAL-MAKE-BALL returns a ball object
X;;BALL-NUMBER = An index into the ball vector for this ball
X;;MASS = The ball's mass
X;;RADIUS = The ball's radius
X;;PX = The x-coordinate of the ball's initial position
X;;PY = The y-coordinate of the ball's initial position
X;;VX = The x-coordinate of the ball's initial velocity
X;;VY = The y-coordinate of the ball's initial velocity
X(define-macro (actual-make-ball ball-number mass radius px py vx vy)
X `(make-simulation-object
X ball-collision-procedure ;The collision procedure for a ball
X ,ball-number
X ,mass
X ,radius
X (make-sorted-queue ;The event queue
X collision-time-<?)
X 0 ;Time of last collision
X ,px ;Position of last collision
X ,py ; "
X ,vx ;Velocity following last colliosion
X ,vy ; "
X '() ;No vector of queue records for ball's
X ;with smaller numbers
X '() ;No vector of queue records for bumpers
X '() ;No list of balls with larger numbers
X '())) ;No global event queue record, yet
X
X(define (make-ball mass radius px py vx vy)
X (actual-make-ball '() mass radius px py vx vy))
X
X;;BALL-NUMBER returns the index of the given ball
X;;BALL = The ball whose index is to be returned
X(define-macro (ball-number ball)
X `(vector-ref ,ball ,(simulation-object-len)))
X
X;;SET-BALL-NUMBER! set the index of the given ball to the given value
X;;BALL = The ball whose index is to be set
X;;VALUE = The value to which it is to be set
X(define-macro (set-ball-number! ball value)
X `(vector-set! ,ball ,(simulation-object-len) ,value))
X
X;;BALL-MASS returns the mass of the given ball
X;;BALL = The ball whose mass is to be returned
X(define-macro (ball-mass ball)
X `(vector-ref ,ball ,(+ (simulation-object-len) 1)))
X
X;;BALL-RADIUS returns the radius of the given ball
X;;BALL = The ball whose radius is to be returned
X(define-macro (ball-radius ball)
X `(vector-ref ,ball ,(+ (simulation-object-len) 2)))
X
X;;BALL-EVENT-QUEUE returns the sort queue of collision events for the given
X;;ball
X;;BALL = The ball whose event is to be returned
X(define-macro (ball-event-queue ball)
X `(vector-ref ,ball ,(+ (simulation-object-len) 3)))
X
X;;BALL-COLLISION-TIME returns the time of the last collision for the given ball
X;;BALL = The ball whose collision time is to be returned
X(define-macro (ball-collision-time ball)
X `(vector-ref ,ball ,(+ (simulation-object-len) 4)))
X
X
X;;SET-BALL-COLLISION-TIME! sets the time of the last collision for the given
X;;ball
X;;BALL = The ball whose collision time is to be set
X;;VALUE = The value to which the ball's collision time is to be set
X(define-macro (set-ball-collision-time! ball value)
X `(vector-set! ,ball ,(+ (simulation-object-len) 4) ,value))
X
X;;BALL-COLLISION-X-POSITION returns the x-coordinate of the position of the
X;;last collision for the given ball
X;;BALL = The ball whose collision position is to be returned
X(define-macro (ball-collision-x-position ball)
X `(vector-ref ,ball ,(+ (simulation-object-len) 5)))
X
X;;SET-BALL-COLLISION-X-POSITION! sets the x-coordinate of the position of the
X;;last collision for the given ball
X;;BALL = The ball whose collision position is to be set
X;;VALUE = The value to which the ball's collision position is to be set
X(define-macro (set-ball-collision-x-position! ball value)
X `(vector-set! ,ball ,(+ (simulation-object-len) 5) ,value))
X
X;;BALL-COLLISION-Y-POSITION returns the y-coordinate of the position of the
X;;last collision for the given ball
X;;BALL = The ball whose collision position is to be returned
X(define-macro (ball-collision-y-position ball)
X `(vector-ref ,ball ,(+ (simulation-object-len) 6)))
X
X;;SET-BALL-COLLISION-Y-POSITION! sets the y-coordinate of the position of the
X;;last collision for the given ball
X;;BALL = The ball whose collision position is to be set
X;;VALUE = The value to which the ball's collision position is to be set
X(define-macro (set-ball-collision-y-position! ball value)
X `(vector-set! ,ball ,(+ (simulation-object-len) 6) ,value))
X
X;;BALL-X-VELOCITY returns the x-coordinate of the velocity of the given ball
X;;following its last collision
X;;BALL = The ball whose velocity is to be returned
X(define-macro (ball-x-velocity ball)
X `(vector-ref ,ball ,(+ (simulation-object-len) 7)))
X
X;;SET-BALL-X-VELOCITY! sets the x-coordinate of the velocity of the given ball
X;;BALL = The ball whose velocity is to be set
X;;VALUE = The value to which the ball's velocity is to be set
X(define-macro (set-ball-x-velocity! ball value)
X `(vector-set! ,ball ,(+ (simulation-object-len) 7) ,value))
X
X;;BALL-Y-VELOCITY returns the y-coordinate of the velocity of the given ball
X;;following its last collision
X;;BALL = The ball whose velocity is to be returned
X(define-macro (ball-y-velocity ball)
X `(vector-ref ,ball ,(+ (simulation-object-len) 8)))
X
X;;SET-BALL-Y-VELOCITY! sets the y-coordinate of the velocity of the given ball
X;;BALL = The ball whose velocity is to be set
X;;VALUE = The value to which the ball's velocity is to be set
X(define-macro (set-ball-y-velocity! ball value)
X `(vector-set! ,ball ,(+ (simulation-object-len) 8) ,value))
X
X
X;;BALL-BALL-VECTOR returns the vector of queue records for balls with smaller
X;;ball numbers
X;;BALL = The ball whose ball vector is to be returned
X(define-macro (ball-ball-vector ball)
X `(vector-ref ,ball ,(+ (simulation-object-len) 9)))
X
X;;SET-BALL-BALL-VECTOR! sets the vector of queue records for balls with smaller
X;;ball numbers
X;;BALL = The ball whose ball vector is to be set
X;;VALUE = The vector to which the field is to be set
X(define-macro (set-ball-ball-vector! ball value)
X `(vector-set! ,ball ,(+ (simulation-object-len) 9) ,value))
X
X;;BALL-BUMPER-VECTOR returns the vector of queue records for bumpers
X;;BALL = The ball whose bumper vector is to be returned
X(define-macro (ball-bumper-vector ball)
X `(vector-ref ,ball ,(+ (simulation-object-len) 10)))
X
X;;SET-BALL-BUMPER-VECTOR! sets the vector of queue records for bumpers
X;;BALL = The ball whose bumper vector is to be set
X;;VALUE = The vector to which the field is to be set
X(define-macro (set-ball-bumper-vector! ball value)
X `(vector-set! ,ball ,(+ (simulation-object-len) 10) ,value))
X
X;;BALL-BALL-LIST returns a list of balls with larger ball numbers than the
X;;given ball
X;;BALL = The ball whose ball list is to be returned
X(define-macro (ball-ball-list ball)
X `(vector-ref ,ball ,(+ (simulation-object-len) 11)))
X
X;;SET-BALL-BALL-LIST! sets the list of balls with larger ball numbers than the
X;;given ball
X;;BALL = The ball whose ball list is to be set
X;;VALUE = The value to which the ball list is to be set
X(define-macro (set-ball-ball-list! ball value)
X `(vector-set! ,ball ,(+ (simulation-object-len) 11) ,value))
X
X;;BALL-GLOBAL-EVENT-QUEUE-RECORD returns the global event queue record for the
X;;given ball
X;;BALL = The ball whose global event queue record is to be returned
X(define-macro (ball-global-event-queue-record ball)
X `(vector-ref ,ball ,(+ (simulation-object-len) 12)))
X
X;;SET-BALL-GLOBAL-EVENT-QUEUE-RECORD! set the global event queue record for the
X;;given ball to the given value
X;;BALL = The ball whose global event queue record is to be set
X;;VALUE = The value to which the global event queue record field is to be set
X(define-macro (set-ball-global-event-queue-record! ball value)
X `(vector-set! ,ball ,(+ (simulation-object-len) 12) ,value))
X
X
X
X;;ACTUAL-MAKE-BUMPER returns a bumper object
X;;BUMPER-NUMBER = An index into the bumper vector for this bumper
X;;X1 = The x-coordiante of one end of the bumper
X;;Y1 = The y-coordiante of one end of the bumper
X;;X2 = The x-coordiante of the other end of the bumper
X;;Y2 = The y-coordiante of the other end of the bumper
X(define-macro (actual-make-bumper bumper-number x1 y1 x2 y2)
X `(make-simulation-object
X bumper-collision-procedure ;The collision procedure for a bumper
X ,bumper-number
X ,x1 ;The bumper endpoints
X ,y1
X ,x2
X ,y2))
X
X(define (make-bumper x1 y1 x2 y2)
X (actual-make-bumper '() x1 y1 x2 y2))
X
X;;BUMPER-NUMBER returns the index of the given bumper
X;;BUMPER = The bumper whose index is to be returned
X(define-macro (bumper-number bumper)
X `(vector-ref ,bumper ,(simulation-object-len)))
X
X;;SET-BUMPER-NUMBER! set the index of the given bumper to the given value
X;;BUMPER = The bumper whose index is to be set
X;;VALUE = The value to which it is to be set
X(define-macro (set-bumper-number! bumper value)
X `(vector-set! ,bumper ,(simulation-object-len) ,value))
X
X;;BUMPER-X1 returns the x-coordinate of one end of the given bumber
X;;BUMPER = the bumper whose x-coordinate is to be returned
X(define-macro (bumper-x1 bumper)
X `(vector-ref ,bumper ,(1+ (simulation-object-len))))
X
X;;SET-BUMPER-X1! sets the x-coordinate of one end of the given bumber
X;;BUMPER = the bumper whose x-coordinate is to be set
X;;VALUE = The value to which the bumpers x-coordinate is to be set
X(define-macro (set-bumper-x1! bumper value)
X `(vector-set! ,bumper ,(1+ (simulation-object-len)) ,value))
X
X;;BUMPER-Y1 returns the y-coordinate of one end of the given bumber
X;;BUMPER = the bumper whose y-coordinate is to be returned
X(define-macro (bumper-y1 bumper)
X `(vector-ref ,bumper ,(+ (simulation-object-len) 2)))
X
X;;SET-BUMPER-Y1! sets the y-coordinate of one end of the given bumber
X;;BUMPER = the bumper whose y-coordinate is to be set
X;;VALUE = The value to which the bumpers y-coordinate is to be set
X(define-macro (set-bumper-y1! bumper value)
X `(vector-set! ,bumper ,(+ (simulation-object-len) 2) ,value))
X
X;;BUMPER-X2 returns the x-coordinate of the other end of the given bumber
X;;BUMPER = the bumper whose x-coordinate is to be returned
X(define-macro (bumper-x2 bumper)
X `(vector-ref ,bumper ,(+ (simulation-object-len) 3)))
X
X;;SET-BUMPER-X2! sets the x-coordinate of the other end of the given bumber
X;;BUMPER = the bumper whose x-coordinate is to be set
X;;VALUE = The value to which the bumpers x-coordinate is to be set
X(define-macro (set-bumper-x2! bumper value)
X `(vector-set! ,bumper ,(+ (simulation-object-len) 3) ,value))
X
X
X;;BUMPER-Y2 returns the y-coordinate of the other end of the given bumber
X;;BUMPER = the bumper whose y-coordinate is to be returned
X(define-macro (bumper-y2 bumper)
X `(vector-ref ,bumper ,(+ (simulation-object-len) 4)))
X
X;;SET-BUMPER-Y2! sets the y-coordinate of the other end of the given bumber
X;;BUMPER = the bumper whose y-coordinate is to be set
X;;VALUE = The value to which the bumpers y-coordinate is to be set
X(define-macro (set-bumper-y2! bumper value)
X `(vector-set! ,bumper ,(+ (simulation-object-len) 4) ,value))
X
X;;COLLISION-TIME-<? is a predicate which returns true if the first event queueu
X;;record represents a collision that will take place at an earlier time than
X;;the one for the second event queue record
X;;EVENT-QUEUE-RECORD1 = The first event queue record
X;;EVENT-QUEUE-RECORD2 = The second event queue record
X(define (collision-time-<? event-queue-record1 event-queue-record2)
X (time-<?
X (event-queue-record-collision-time
X event-queue-record1)
X (event-queue-record-collision-time
X event-queue-record2)))
X
X;;TIME-<? is a predicate which returns true if the first time is smaller than
X;;the second. '() represents a time infinitly large.
X(define (time-<? time1 time2)
X (if (null? time1)
X #f
X (if (null? time2)
X #t
X (< time1 time2))))
X
X;;SQUARE returns the square of its argument
X(define (square x)
X (* x x))
X
X
X;;BALL-BALL-COLLISION-TIME returns the time at which the two given balls would
X;;collide if neither interacted with any other objects, '() if never. This
X;;calculation is performed by setting the distance between the balls to the sum
X;;of their radi and solving for the contact time.
X;;BALL1 = The first ball
X;;BALL2 = The second ball
X(define (ball-ball-collision-time ball1 ball2)
X (let ((delta-x-velocity ;Cache the difference in the ball's
X ( - (ball-x-velocity ball2) ;velocities,
X (ball-x-velocity ball1)))
X (delta-y-velocity
X ( - (ball-y-velocity ball2)
X (ball-y-velocity ball1)))
X (radius-sum ;the sum of their radi,
X (+ (ball-radius ball1)
X (ball-radius ball2)))
X (alpha-x ;and common subexpressions in the time
X (- ;equation
X (- (ball-collision-x-position
X ball2)
X (ball-collision-x-position
X ball1))
X (-
X (* (ball-x-velocity ball2)
X (ball-collision-time
X ball2))
X (* (ball-x-velocity ball1)
X (ball-collision-time
X ball1)))))
X (alpha-y
X (-
X (- (ball-collision-y-position
X ball2)
X (ball-collision-y-position
X ball1))
X (-
X (* (ball-y-velocity ball2)
X (ball-collision-time
X ball2))
X (* (ball-y-velocity ball1)
X (ball-collision-time
X ball1))))))
X (let* ((delta-velocity-magnitude-squared
X (+ (square
X delta-x-velocity)
X (square
X delta-y-velocity)))
X (discriminant
X (- (* (square radius-sum)
X delta-velocity-magnitude-squared)
X (square
X (- (* delta-y-velocity
X alpha-x)
X (* delta-x-velocity
X alpha-y))))))
X
X
X (if (or (negative? discriminant) ;If the balls don't colloide:
X (zero?
X delta-velocity-magnitude-squared))
X '() ;Return infinity
X (let ((time ;Else, calculate the collision time
X (/
X (- 0
X (+ (sqrt discriminant)
X (+
X (* delta-x-velocity
X alpha-x)
X (* delta-y-velocity
X alpha-y))))
X (+ (square
X delta-x-velocity)
X (square
X delta-y-velocity)))))
X (if (and ;If the balls collide in the future:
X (time-<?
X (ball-collision-time
X ball1)
X time)
X (time-<?
X (ball-collision-time
X ball2)
X time))
X time ;Return the collision time
X '())))))) ;Else, return that they never collide
X
X;;BALL-BUMPER-COLLISION-TIME returns the time at which the given ball would
X;;collide with the given bumper if the ball didn't interacted with any other
X;;objects, '() if never. This is done by first calculating the time at which
X;;the ball would collide with a bumper of infinite length and then checking if
X;;the collision position represents a portion of the actual bumper.
X;;BALL = The ball
X;;BUMPER = The bumper
X(define (ball-bumper-collision-time ball bumper)
X (let ((delta-x-bumper ;Collision time with the bumper of
X (- (bumper-x2 bumper) ;infinite extent is calculated by
X (bumper-x1 bumper))) ;setting the distance between the ball
X (delta-y-bumper ;and the bumper to be the radius of the
X (- (bumper-y2 bumper) ;ball and solving for the time. The
X (bumper-y1 bumper)))) ;distance is calculated by |aXb|/|a|,
X (let ((bumper-length-squared ;where 'a' is the vector from one end
X (+ (square delta-x-bumper) ;of the bumper to the other and 'b' is
X (square delta-y-bumper))) ;the vector from the first end of the
X (denominator ;bumper to the center of the ball
X (- (* (ball-y-velocity ball)
X delta-x-bumper)
X (* (ball-x-velocity ball)
X delta-y-bumper))))
X (if (zero? denominator) ;If the ball's motion is parallel to
X ;the bumper:
X '() ;Return infinity
X (let ((delta-t ;Calculate the collision time
X (-
X (/
X (+
X (*
X (- (ball-collision-x-position
X ball)
X (bumper-x1 bumper))
X delta-y-bumper)
X (*
X (- (ball-collision-y-position
X ball)
X (bumper-y1 bumper))
X delta-x-bumper))
X denominator)
X (/
X (* (ball-radius
X ball)
X (sqrt
X bumper-length-squared))
X (abs denominator)))))
X (if (not (positive? ;If the ball is moving away from the
X delta-t)) ;bumper:
X '() ;Return infinity
X
X
X (let ((ball-x-contact ;Whether the ball contacts the actual
X (+ (ball-collision-x-position ;bumper of limited extent
X ball) ;will be determined by comparing |b.a|
X (* (ball-x-velocity ;with |a|^2
X ball)
X delta-t)))
X (ball-y-contact
X (+ (ball-collision-y-position
X ball)
X (* (ball-y-velocity
X ball)
X delta-t))))
X (let ((delta-x-ball
X (- ball-x-contact
X (bumper-x1
X bumper)))
X (delta-y-ball
X (- ball-y-contact
X (bumper-y1
X bumper))))
X (let ((dot-product
X (+
X (* delta-x-ball
X delta-x-bumper)
X (* delta-y-ball
X delta-y-bumper))))
X (if (or ;If the ball misses the bumper on
X (negative? ;either end:
X dot-product)
X (> dot-product
X bumper-length-squared))
X '() ;Return infinity
X (+ delta-t ;Else, return the contact time
X (ball-collision-time
X ball))))))))))))
X
X
X;;BALL-COLLISION-PROCEDURE calculates the new velocities of the given balls
X;;based on their collision at the given time. Also, tells all other balls
X;;about the new trajectories of these balls so they can update their event
X;;queues
X;;BALL1 = The first ball
X;;BALL2 = The second ball
X;;COLLISION-TIME = The collision time
X;;GLOBAL-EVENT-QUEUE = The global queue of earliest events for each ball
X(define (ball-collision-procedure ball1 ball2 collision-time
X global-event-queue)
X (queue-remove ;Remove the earliest event associated
X (ball-global-event-queue-record ;with each ball from the global event
X ball1)) ;queue
X (queue-remove
X (ball-global-event-queue-record
X ball2))
X (let ((ball1-collision-x-position ;Calculate the positions of both balls
X (+ (ball-collision-x-position ;when they collide
X ball1)
X (* (ball-x-velocity
X ball1)
X (- collision-time
X (ball-collision-time
X ball1)))))
X (ball1-collision-y-position
X (+ (ball-collision-y-position
X ball1)
X (* (ball-y-velocity
X ball1)
X (- collision-time
X (ball-collision-time
X ball1)))))
X (ball2-collision-x-position
X (+ (ball-collision-x-position
X ball2)
X (* (ball-x-velocity
X ball2)
X (- collision-time
X (ball-collision-time
X ball2)))))
X (ball2-collision-y-position
X (+ (ball-collision-y-position
X ball2)
X (* (ball-y-velocity
X ball2)
X (- collision-time
X (ball-collision-time
X ball2))))))
X (let ((delta-x ;Calculate the displacements of the
X (- ball2-collision-x-position ;centers of the two balls
X ball1-collision-x-position))
X (delta-y
X (- ball2-collision-y-position
X ball1-collision-y-position)))
X
X
X (let* ((denominator ;Calculate the angle of the line
X (sqrt (+ (square ;joining the centers at the collision
X delta-x) ;time with the x-axis (this line is
X (square ;the normal to the balls at the
X delta-y)))) ;collision point)
X (cos-theta
X (/ delta-x denominator))
X (sin-theta
X (/ delta-y denominator)))
X (let ((ball1-old-normal-velocity ;Convert the velocities of the balls
X (+ (* (ball-x-velocity ;into the coordinate system defined by
X ball1) ;the normal and tangential lines at
X cos-theta) ;the collision point
X (* (ball-y-velocity
X ball1)
X sin-theta)))
X (ball1-tang-velocity
X (- (* (ball-y-velocity
X ball1)
X cos-theta)
X (* (ball-x-velocity
X ball1)
X sin-theta)))
X (ball2-old-normal-velocity
X (+ (* (ball-x-velocity
X ball2)
X cos-theta)
X (* (ball-y-velocity
X ball2)
X sin-theta)))
X (ball2-tang-velocity
X (- (* (ball-y-velocity
X ball2)
X cos-theta)
X (* (ball-x-velocity
X ball2)
X sin-theta)))
X (mass1 (ball-mass
X ball1))
X (mass2 (ball-mass
X ball2)))
X (let ((ball1-new-normal-velocity ;Calculate the new velocities
X (/ ;following the collision (the
X (+ ;tangential velocities are unchanged
X (* ;because the balls are assumed to be
X (* 2 ;frictionless)
X mass2)
X ball2-old-normal-velocity)
X (*
X (- mass1 mass2)
X ball1-old-normal-velocity))
X (+ mass1 mass2)))
X
X
X (ball2-new-normal-velocity
X (/
X (+
X (*
X (* 2
X mass1)
X ball1-old-normal-velocity)
X (*
X (- mass2 mass1)
X ball2-old-normal-velocity))
X (+ mass1 mass2))))
X (set-ball-x-velocity! ;Store data about the collision in the
X ball1 ;structure for each ball after
X (- (* ball1-new-normal-velocity ;converting the information back
X cos-theta) ;to the x,y frame
X (* ball1-tang-velocity
X sin-theta)))
X (set-ball-y-velocity!
X ball1
X (+ (* ball1-new-normal-velocity
X sin-theta)
X (* ball1-tang-velocity
X cos-theta)))
X (set-ball-x-velocity!
X ball2
X (- (* ball2-new-normal-velocity
X cos-theta)
X (* ball2-tang-velocity
X sin-theta)))
X (set-ball-y-velocity!
X ball2
X (+ (* ball2-new-normal-velocity
X sin-theta)
X (* ball2-tang-velocity
X cos-theta)))
X (set-ball-collision-time!
X ball1
X collision-time)
X (set-ball-collision-time!
X ball2
X collision-time)
X (set-ball-collision-x-position!
X ball1
X ball1-collision-x-position)
X (set-ball-collision-y-position!
X ball1
X ball1-collision-y-position)
X (set-ball-collision-x-position!
X ball2
X ball2-collision-x-position)
X (set-ball-collision-y-position!
X ball2
X ball2-collision-y-position))))))
X
X
X (newline)
X (display "Ball ")
X (display (ball-number ball1))
X (display " collides with ball ")
X (display (ball-number ball2))
X (display " at time ")
X (display (ball-collision-time ball1))
X (newline)
X (display " Ball ")
X (display (ball-number ball1))
X (display " has a new velocity of ")
X (display (ball-x-velocity ball1))
X (display ",")
X (display (ball-y-velocity ball1))
X (display " starting at ")
X (display (ball-collision-x-position ball1))
X (display ",")
X (display (ball-collision-y-position ball1))
X (newline)
X (display " Ball ")
X (display (ball-number ball2))
X (display " has a new velocity of ")
X (display (ball-x-velocity ball2))
X (display ",")
X (display (ball-y-velocity ball2))
X (display " starting at ")
X (display (ball-collision-x-position ball2))
X (display ",")
X (display (ball-collision-y-position ball2))
X
X (recalculate-collisions ball1 global-event-queue)
X (recalculate-collisions ball2 global-event-queue))
X
X
X;;BUMPER-COLLISION-PROCEDURE calculates the new velocity of the given ball
X;;following its collision with the given bumper at the given time. Also, tells
X;;other balls about the new trajectory of the given ball so they can update
X;;their event queues.
X;;BALL = The ball
X;;BUMPER = The bumper
X;;COLLISION-TIME = The collision time
X;;GLOBAL-EVENT-QUEUE = The global queue of earliest events for each ball
X(define (bumper-collision-procedure ball bumper collision-time
X global-event-queue)
X (queue-remove ;Remove the earliest event associated
X (ball-global-event-queue-record ;with the ball from the global event
X ball)) ;queue
X (let ((delta-x-bumper ;Compute the bumper's delta-x
X (- (bumper-x2 bumper)
X (bumper-x1 bumper)))
X (delta-y-bumper ;delta-y
X (- (bumper-y2 bumper)
X (bumper-y1 bumper))))
X (let ((bumper-length ;length
X (sqrt
X (+ (square
X delta-x-bumper)
X (square
X delta-y-bumper)))))
X (let ((cos-theta ;and cosine and sine of its angle with
X (/ delta-x-bumper ;respect to the positive x-axis
X bumper-length))
X (sin-theta
X (/ delta-y-bumper
X bumper-length))
X (x-velocity ;Cache the ball's velocity in the x,y
X (ball-x-velocity ball)) ;frame
X (y-velocity
X (ball-y-velocity ball)))
X (let ((tang-velocity ;Calculate the ball's velocity in the
X (+ (* x-velocity ;bumper frame
X cos-theta)
X (* y-velocity
X sin-theta)))
X (normal-velocity
X (- (* y-velocity
X cos-theta)
X (* x-velocity
X sin-theta))))
X
X
X (set-ball-collision-x-position! ;Store the collision position
X ball
X (+ (ball-collision-x-position
X ball)
X (* (- collision-time
X (ball-collision-time
X ball))
X (ball-x-velocity
X ball))))
X (set-ball-collision-y-position!
X ball
X (+ (ball-collision-y-position
X ball)
X (* (- collision-time
X (ball-collision-time
X ball))
X (ball-y-velocity
X ball))))
X (set-ball-x-velocity! ;Calculate the new velocity in the
X ball ;x,y frame based on the fact that
X (+ (* tang-velocity ;tangential velocity is unchanged and
X cos-theta) ;the normal velocity is inverted when
X (* normal-velocity ;the ball collides with the bumper
X sin-theta)))
X (set-ball-y-velocity!
X ball
X (- (* tang-velocity
X sin-theta)
X (* normal-velocity
X cos-theta)))
X (set-ball-collision-time!
X ball
X collision-time)))))
X (newline)
X (display "Ball ")
X (display (ball-number ball))
X (display " collides with bumper ")
X (display (bumper-number bumper))
X (display " at time ")
X (display (ball-collision-time ball))
X (newline)
X (display " Ball ")
X (display (ball-number ball))
X (display " has a new velocity of ")
X (display (ball-x-velocity ball))
X (display ",")
X (display (ball-y-velocity ball))
X (display " starting at ")
X (display (ball-collision-x-position ball))
X (display ",")
X (display (ball-collision-y-position ball))
X
X (recalculate-collisions ball global-event-queue))
X
X
X;;RECALCULATE-COLLISIONS removes all old collisions for the given ball from
X;;all other balls' event queues and calcultes new collisions for these balls
X;;and places them on the event queues. Also, updates the global event queue if
X;;the recalculation of the collision effects the earliest collision for any
X;;other balls.
X;;BALL = The ball whose collisions are being recalculated
X;;GLOBAL-EVENT-QUEUE = The global queue of earliest events for each ball
X(define (recalculate-collisions ball global-event-queue)
X (clear-queue (ball-event-queue ;Clear the queue of events for this
X ball)) ;ball as they have all changed
X (let ((event-queue ;Calculate all ball collision events
X (ball-event-queue ball))) ;with balls of lower number
X (let ((ball-vector
X (ball-ball-vector ball)))
X (do ((i (-1+ (ball-number ball))
X (-1+ i)))
X ((negative? i))
X (let ((ball2-queue-record
X (vector-ref
X ball-vector
X i)))
X (set-event-queue-record-collision-time!
X ball2-queue-record
X (ball-ball-collision-time
X ball
X (event-queue-record-object
X ball2-queue-record)))
X (queue-insert
X event-queue
X ball2-queue-record))))
X (let ((bumper-vector ;Calculate all bumper collision events
X (ball-bumper-vector ball)))
X (do ((i (-1+ (vector-length
X bumper-vector))
X (-1+ i)))
X ((negative? i))
X (let ((bumper-queue-record
X (vector-ref
X bumper-vector
X i)))
X (set-event-queue-record-collision-time!
X bumper-queue-record
X (ball-bumper-collision-time
X ball
X (event-queue-record-object
X bumper-queue-record)))
X (queue-insert
X event-queue
X bumper-queue-record))))
X
X
X (let ((global-queue-record ;Get the global event queue record
X (ball-global-event-queue-record ;for this ball
X ball)))
X (set-event-queue-record-collision-time! ;Set the new earliest event time
X global-queue-record ;for this ball
X (if (empty-queue? event-queue)
X '()
X (event-queue-record-collision-time
X (queue-smallest event-queue))))
X (queue-insert ;Enqueue on the global event queue
X global-event-queue ;the earliest event between this ball
X global-queue-record))) ;and any ball of lower number or any
X ;bumper
X (for-each ;For each ball on the ball list:
X (lambda (ball2)
X (let ((ball2-event-queue
X (ball-event-queue ball2)))
X (let ((alter-global-event-queue? ;Set flag to update global event queue
X (and ;if the earliest event for ball2 was
X (not (empty-queue? ;with the deflected ball
X ball2-event-queue))
X (eq? ball
X (event-queue-record-object
X (queue-smallest
X ball2-event-queue)))))
X (ball-event-queue-record ;Get the queue record for the deflected
X (vector-ref ;ball for this ball
X (ball-ball-vector
X ball2)
X (ball-number ball))))
X (queue-remove ;Remove the queue record for the
X ball-event-queue-record) ;deflected ball
X (set-event-queue-record-collision-time! ;Recalculate the collision
X ball-event-queue-record ;time for this ball and the deflected
X (ball-ball-collision-time ;ball
X ball
X ball2))
X (queue-insert ;Enqueue the new collision event
X ball2-event-queue
X ball-event-queue-record)
X (if (or alter-global-event-queue? ;If the earliest collision event for
X (eq? ball ;this ball has changed:
X (event-queue-record-object
X (queue-smallest
X ball2-event-queue))))
X (let ((queue-record ;Remove the old event from the global
X (ball-global-event-queue-record ;event queue and replace it
X ball2))) ;with the new event
X (set-event-queue-record-collision-time!
X queue-record
X (event-queue-record-collision-time
X (queue-smallest
X ball2-event-queue)))
X (queue-remove
X queue-record)
X (queue-insert
X global-event-queue
X queue-record))))))
X (ball-ball-list ball)))
X
X
X;;SIMULATE performs the billiard ball simulation for the given ball list and
X;;bumper list until the specified time.
X;;BALL-LIST = A list of balls
X;;BUMPER-LIST = A list of bumpers
X;;END-TIME = The time at which the simulation is to terminate
X(define (simulate ball-list bumper-list end-time)
X (let ((num-of-balls ;Cache the number of balls and bumpers
X (length ball-list))
X (num-of-bumpers
X (length bumper-list))
X (global-event-queue ;Build the global event queue
X (make-sorted-queue
X collision-time-<?)))
X (let ((complete-ball-vector ;Build a vector for the balls
X (make-vector
X num-of-balls)))
X (let loop ((ball-num 0) ;For each ball:
X (ball-list ball-list))
X (if (not (null? ball-list))
X (let ((ball (car ball-list)))
X (set-ball-number! ;Store the ball's number
X ball
X ball-num)
X (vector-set! ;Place it in the ball vector
X complete-ball-vector
X ball-num
X ball)
X (set-ball-ball-list! ;Save the list of balls with ball
X ball ;numbers greater than the current ball
X (cdr ball-list))
X (display-ball-state
X ball)
X (loop
X (1+ ball-num)
X (cdr ball-list)))))
X (let loop ((bumper-num 0) ;For each bumper:
X (bumper-list
X bumper-list))
X (if (not (null? bumper-list))
X (sequence
X (set-bumper-number! ;Store the bumper's number
X (car bumper-list)
X bumper-num)
X (display-bumper-state
X (car bumper-list))
X (loop
X (1+ bumper-num)
X (cdr bumper-list)))))
X
X (do ((ball-num 0 (1+ ball-num))) ;For each ball:
X ((= ball-num num-of-balls))
X (let* ((ball (vector-ref ;Cache a reference to the ball
X complete-ball-vector
X ball-num))
X (ball-vector ;Build a vector for the queue records
X (make-vector ;of balls with smaller numbers than
X ball-num)) ;this ball
X (bumper-vector ;Build a vector for the queue records
X (make-vector ;of bumpers
X num-of-bumpers))
X (event-queue ;Build an event queue for this ball
X (ball-event-queue
X ball)))
X (set-ball-ball-vector! ;Install the vector of ball queue
X ball ;records
X ball-vector)
X (do ((i 0 (1+ i))) ;For each ball of smaller number than
X ((= i ball-num)) ;the current ball:
X (let* ((ball2 ;Cache the ball
X (vector-ref
X complete-ball-vector
X i))
X (queue-record ;Create a queue record for this ball
X (make-event-queue-record ;based on the collision time
X '() ;of the two balls
X '()
X ball2
X (ball-ball-collision-time
X ball
X ball2))))
X (vector-set! ;Install the queue record in the ball
X ball-vector ;vector for this ball
X i
X queue-record)
X (queue-insert ;Insert the queue record into the event
X event-queue ;queue for this ball
X queue-record)))
X
X (set-ball-bumper-vector! ;Install the vector of bumper queue
X ball ;records
X bumper-vector)
X (let loop ((bumper-num 0)
X (bumper-list
X bumper-list))
X (if (not (null? bumper-list))
X (let* ((bumper ;Cache the bumper
X (car
X bumper-list))
X (queue-record ;Create a queue record for this bumper
X (make-event-queue-record ;based on the collision time
X '() ;of the current ball and this bumper
X '()
X bumper
X (ball-bumper-collision-time
X ball
X bumper))))
X (vector-set! ;Install the queue record in the bumper
X bumper-vector ;vector for this ball
X bumper-num
X queue-record)
X (queue-insert ;Insert the queue record into the event
X event-queue ;queue for this ball
X queue-record)
X (loop
X (1+ bumper-num)
X (cdr bumper-list)))))
X (let ((queue-record ;Build a global event queue record for
X (make-event-queue-record ;the earliest event on this ball's
X '() ;event queue
X '()
X ball
X (if (empty-queue?
X event-queue)
X '()
X (event-queue-record-collision-time
X (queue-smallest
X event-queue))))))
X (set-ball-global-event-queue-record! ;Store this queue record in
X ball ;the frame for this ball
X queue-record)
X (queue-insert ;Insert this queue record in the global
X global-event-queue ;event queue
X queue-record)))))
X (actually-simulate ;Now that all of the data structures
X global-event-queue ;have been built, actually start the
X end-time))) ;simulation
X
X
X;;DISPLAY-BALL-STATE displays the ball number, mass, radius, position, and
X;;velocity of the given ball
X;;BALL = The ball whose state is to be displayed
X(define (display-ball-state ball)
X (newline)
X (display "Ball ")
X (display (ball-number ball))
X (display " has mass ")
X (display (ball-mass ball))
X (display " and radius ")
X (display (ball-radius ball))
X (newline)
X (display " Its position at time ")
X (display (ball-collision-time ball))
X (display " was ")
X (display (ball-collision-x-position ball))
X (display ",")
X (display (ball-collision-y-position ball))
X (display " and its velocity is ")
X (display (ball-x-velocity ball))
X (display ",")
X (display (ball-y-velocity ball)))
X
X;;DISPLAY-BUMPER-STATE displays the bumper number and position of the given
X;;bumper
X;;BUMPER = The bumper whose state is to be displayed
X(define (display-bumper-state bumper)
X (newline)
X (display "Bumper ")
X (display (bumper-number bumper))
X (display " extends from ")
X (display (bumper-x1 bumper))
X (display ",")
X (display (bumper-y1 bumper))
X (display " to ")
X (display (bumper-x2 bumper))
X (display ",")
X (display (bumper-y2 bumper)))
X
X
X;;ACTUALLY-SIMULATE performs the actual billiard ball simulation
X;;GLOBAL-EVENT-QUEUE = The global queue of earliest events for each ball.
X;; Contains a single event for each ball which is the
X;; earliest collision it would have with a ball of a
X;; smaller number or a bumper, if no other collisions took
X;; place first.
X;;END-TIME = The time at which the simulation should be terminated
X(define (actually-simulate global-event-queue end-time)
X (letrec ((loop
X (lambda ()
X (let* ((record ;Get the globally earliest event and
X (queue-smallest ;its time
X global-event-queue))
X (collision-time
X (event-queue-record-collision-time
X record)))
X (if (not ;If this event happens before the
X (time-<? ;simulation termination time:
X end-time
X collision-time))
X (let* ((ball ;Get the ball involved in the event,
X (event-queue-record-object
X record))
X (ball-queue ;the queue of events for that ball,
X (ball-event-queue
X ball))
X (other-object ;and the first object with which the
X (event-queue-record-object ;ball interacts
X (queue-smallest
X ball-queue))))
X ((simulation-object-collision-procedure ;Process this
X other-object) ;globally earliest collision
X ball
X other-object
X collision-time
X global-event-queue)
X (loop))))))) ;Process the next interaction
X (loop)))
X
X
X(require 'cscheme)
X(set! autoload-notify? #f)
X
X (simulate
X (list (make-ball 2 1 9 5 -1 -1)
X (make-ball 4 2 2 5 1 -1))
X (list (make-bumper 0 0 0 10)
X (make-bumper 0 0 10 0)
X (make-bumper 0 10 10 10)
X (make-bumper 10 0 10 10))
X 100)
END_OF_tst/billiard
if test 46118 -ne `wc -c <tst/billiard`; then
echo shar: \"tst/billiard\" unpacked with wrong size!
fi
# end of overwriting check
fi
if test -f lib/xlib/examples/properties -a "${1}" != "-c" ; then
echo shar: Will not over-write existing file \"lib/xlib/examples/properties\"
else
echo shar: Extracting \"lib/xlib/examples/properties\" \(969 characters\)
sed "s/^X//" >lib/xlib/examples/properties <<'END_OF_lib/xlib/examples/properties'
X;;; -*-Scheme-*-
X;;;
X;;; Display all properties of all windows (with name, type, format,
X;;; and data).
X
X(require 'xlib)
X
X(define (properties)
X (let ((dpy (open-display)))
X (unwind-protect
X (let* ((w (car (query-tree (display-root-window dpy))))
X (l (map (lambda (win) (cons win (list-properties win)))
X (cons (display-root-window dpy) (vector->list w))))
X (tab (lambda (obj n)
X (let* ((s (format #f "~s" obj))
X (n (- n (string-length s))))
X (display s)
X (if (positive? n)
X (do ((i 0 (1+ i))) ((= i n)) (display #\space)))))))
X (for-each
X (lambda (w)
X (format #t "Window ~s:~%" (car w))
X (for-each
X (lambda (p)
X (tab (atom-name dpy p) 20)
X (display "= ")
X (let ((p (get-property (car w) p #f 0 20 #f)))
X (tab (atom-name dpy (car p)) 18)
X (tab (cadr p) 3)
X (format #t "~s~%" (caddr p))))
X (vector->list (cdr w)))
X (newline))
X l))
X (close-display dpy))))
X
X(properties)
END_OF_lib/xlib/examples/properties
if test 969 -ne `wc -c <lib/xlib/examples/properties`; then
echo shar: \"lib/xlib/examples/properties\" unpacked with wrong size!
fi
# end of overwriting check
fi
if test -f lib/xlib/examples/track -a "${1}" != "-c" ; then
echo shar: Will not over-write existing file \"lib/xlib/examples/track\"
else
echo shar: Extracting \"lib/xlib/examples/track\" \(1062 characters\)
sed "s/^X//" >lib/xlib/examples/track <<'END_OF_lib/xlib/examples/track'
X;;; -*-Scheme-*-
X
X(require 'xlib)
X
X(define (track)
X (let* ((dpy (open-display))
X (root (display-root-window dpy))
X (gc (make-gcontext (window root)
X (function 'xor)
X (foreground (black-pixel dpy))
X (subwindow-mode 'include-inferiors)))
X (lx 0) (ly 0) (lw 0) (lh 0)
X (move-outline
X (lambda (x y w h)
X (if (not (and (= x lx) (= y ly) (= w lw) (= h lh)))
X (begin
X (draw-rectangle root gc lx ly lw lh)
X (draw-rectangle root gc x y w h)
X (set! lx x) (set! ly y)
X (set! lw w) (set! lh h))))))
X (unwind-protect
X (case (grab-pointer root #f '(pointer-motion button-press)
X #f #f 'none 'none 'now)
X (success
X (with-server-grabbed dpy
X (draw-rectangle root gc lx ly lw lh)
X (display-flush-output dpy)
X (handle-events dpy
X (motion-notify
X (lambda (event root win subwin time x y . rest)
X (move-outline x y 300 300) #f))
X (else (lambda args #t)))))
X (else
X (format #t "Not grabbed!~%")))
X (begin
X (draw-rectangle root gc lx ly lw lh)
X (close-display dpy)))))
X
X(track)
END_OF_lib/xlib/examples/track
if test 1062 -ne `wc -c <lib/xlib/examples/track`; then
echo shar: \"lib/xlib/examples/track\" unpacked with wrong size!
fi
# end of overwriting check
fi
if test -f lib/xlib/examples/picture -a "${1}" != "-c" ; then
echo shar: Will not over-write existing file \"lib/xlib/examples/picture\"
else
echo shar: Extracting \"lib/xlib/examples/picture\" \(2425 characters\)
sed "s/^X//" >lib/xlib/examples/picture <<'END_OF_lib/xlib/examples/picture'
X;;; -*-Scheme-*-
X
X;;; -*- Mode:Lisp; Package:XLIB; Syntax:COMMON-LISP; Base:10; Lowercase:T -*-
X
X;;; CLX - Point Graphing demo program
X
X;;; Copyright (C) 1988 Michael O. Newton (newton@csvax.caltech.edu)
X
X;;; Permission is granted to any individual or institution to use, copy,
X;;; modify, and distribute this software, provided that this complete
X;;; copyright and permission notice is maintained, intact, in all copies and
X;;; supporting documentation.
X
X;;; The author provides this software "as is" without express or
X;;; implied warranty.
X
X;;; This routine plots the recurrance
X;;; x <- y(1+sin(0.7x)) - 1.2(|x|)^.5
X;;; y <- .21 - x
X;;; As described in a ?? 1983 issue of the Mathematical Intelligencer
X;;; It has ONLY been tested under X.V11R2 on a Sun3 running KCL
X
X(require 'xlib)
X
X(define (picture point-count)
X (let* ((dpy (open-display))
X (width 600)
X (height 600)
X (black (black-pixel dpy))
X (white (white-pixel dpy))
X (root (display-root-window dpy))
X (win (make-window (parent root) (background-pixel white)
X (event-mask '(exposure button-press))
X (width width) (height height)))
X (gc (make-gcontext (window win)
X (background white) (foreground black))))
X (map-window win)
X (unwind-protect
X (handle-events dpy
X (expose
X (lambda ignore
X (clear-window win)
X (draw-points win gc point-count 0.0 0.0 (* width 0.5) (* height 0.5))
X (draw-poly-text win gc 10 10 (translate "Click a button to exit")
X '1-byte)
X #f))
X (else (lambda ignore #t)))
X (close-display dpy))))
X
X;;; Draw points. These should maybe be put into a an array so that they do
X;;; not have to be recomputed on exposure. X assumes points are in the range
X;;; of width x height, with 0,0 being upper left and 0,H being lower left.
X;;; x <- y(1+sin(0.7x)) - 1.2(|x|)^.5
X;;; y <- .21 - x
X;;; hw and hh are half-width and half-height of screen
X
X(define (draw-points win gc count x y hw hh)
X (if (zero? (modulo count 100))
X (display-flush-output (window-display win)))
X (if (not (zero? count))
X (let ((xf (floor (* (+ 1.2 x) hw ))) ; These lines center the picture
X (yf (floor (* (+ 0.5 y) hh ))))
X (draw-point win gc xf yf)
X (draw-points win gc (1- count)
X (- (* y (1+ (sin (* 0.7 x)))) (* 1.2 (sqrt (abs x))))
X (- 0.21 x)
X hw hh))))
X
X(define (translate string)
X (list->vector (map char->integer (string->list string))))
X
X(picture 10000)
END_OF_lib/xlib/examples/picture
if test 2425 -ne `wc -c <lib/xlib/examples/picture`; then
echo shar: \"lib/xlib/examples/picture\" unpacked with wrong size!
fi
# end of overwriting check
fi
if test -f lib/xlib/examples/useful -a "${1}" != "-c" ; then
echo shar: Will not over-write existing file \"lib/xlib/examples/useful\"
else
echo shar: Extracting \"lib/xlib/examples/useful\" \(567 characters\)
sed "s/^X//" >lib/xlib/examples/useful <<'END_OF_lib/xlib/examples/useful'
X;;; -*-Scheme-*-
X
X(require 'xlib)
X
X(define dpy
X (open-display))
X
X(define (f)
X (display-wait-output dpy #t))
X
X(define root
X (display-root-window dpy))
X
X(define cmap
X (display-colormap dpy))
X
X(define white (white-pixel dpy))
X(define black (black-pixel dpy))
X
X(define rgb-white (query-color cmap white))
X(define rgb-black (query-color cmap black))
X
X(define win
X (make-window (parent root)
X (width 300) (height 300)
X (background-pixel white)))
X
X(define gc (make-gcontext
X (window win)
X (background white) (foreground black)))
X
X(map-window win)
END_OF_lib/xlib/examples/useful
if test 567 -ne `wc -c <lib/xlib/examples/useful`; then
echo shar: \"lib/xlib/examples/useful\" unpacked with wrong size!
fi
# end of overwriting check
fi
if test -f lib/xlib/pixel.c -a "${1}" != "-c" ; then
echo shar: Will not over-write existing file \"lib/xlib/pixel.c\"
else
echo shar: Extracting \"lib/xlib/pixel.c\" \(1332 characters\)
sed "s/^X//" >lib/xlib/pixel.c <<'END_OF_lib/xlib/pixel.c'
X#include "xlib.h"
X
XGeneric_Predicate (Pixel);
X
XGeneric_Simple_Equal (Pixel, PIXEL, pix);
X
XGeneric_Print (Pixel, "#[pixel 0x%lx]", PIXEL(x)->pix);
X
XObject Make_Pixel (val) unsigned long val; {
X register char *p;
X Object pix;
X
X pix = Find_Object (T_Pixel, (GENERIC)0, Match_X_Obj, val);
X if (Nullp (pix)) {
X p = Get_Bytes (sizeof (struct S_Pixel));
X SET (pix, T_Pixel, (struct S_Pixel *)p);
X PIXEL(pix)->tag = Null;
X PIXEL(pix)->pix = val;
X Register_Object (pix, (GENERIC)0, (PFO)0, 0);
X }
X return pix;
X}
X
Xunsigned long Get_Pixel (p) Object p; {
X Check_Type (p, T_Pixel);
X return PIXEL(p)->pix;
X}
X
Xstatic Object P_Pixel_Value (p) Object p; {
X return Make_Unsigned ((unsigned)Get_Pixel (p));
X}
X
Xstatic Object P_Black_Pixel (d) Object d; {
X Check_Type (d, T_Display);
X return Make_Pixel (BlackPixel (DISPLAY(d)->dpy,
X DefaultScreen (DISPLAY(d)->dpy)));
X}
X
Xstatic Object P_White_Pixel (d) Object d; {
X Check_Type (d, T_Display);
X return Make_Pixel (WhitePixel (DISPLAY(d)->dpy,
X DefaultScreen (DISPLAY(d)->dpy)));
X}
X
Xinit_xlib_pixel () {
X Generic_Define (Pixel, "pixel", "pixel?");
X Define_Primitive (P_Pixel_Value, "pixel-value", 1, 1, EVAL);
X Define_Primitive (P_Black_Pixel, "black-pixel", 1, 1, EVAL);
X Define_Primitive (P_White_Pixel, "white-pixel", 1, 1, EVAL);
X}
END_OF_lib/xlib/pixel.c
if test 1332 -ne `wc -c <lib/xlib/pixel.c`; then
echo shar: \"lib/xlib/pixel.c\" unpacked with wrong size!
fi
# end of overwriting check
fi
echo shar: End of archive 9 \(of 14\).
cp /dev/null ark9isdone
MISSING=""
for I in 1 2 3 4 5 6 7 8 9 10 11 12 13 14 ; do
if test ! -f ark${I}isdone ; then
MISSING="${MISSING} ${I}"
fi
done
if test "${MISSING}" = "" ; then
echo You have unpacked all 14 archives.
rm -f ark[1-9]isdone ark[1-9][0-9]isdone
else
echo You still need to unpack the following archives:
echo " " ${MISSING}
fi
## End of shell archive.
exit 0