CountPhysicsBodyEvents ( world )

Parameters

world - world handle

Description

Returns how many body movement and sleep events the last step captured.

Returns the number of copied body movement/sleep events from the most recent step, or zero while disabled or before the first captured step. Body event capture is opt-in per world. The copied batch is replaced after each StepPhysics; it is independent of held query snapshots. Awake dynamic and kinematic bodies can emit entries, including zero-motion awake bodies; static bodies do not. A fell-asleep entry marks that transition, and sleeping bodies normally leave the stream. Entries are sorted by wrapper body handle, not creation order. Tags and native world poses are copied; after deletion live body/entity getters return zero. Event indices belong to one step. A kinematic native pose can differ from its authored entity target while integration approaches it.

Invalid/stale/wrong-kind handles, invalid indices or unavailable payload fields raise runtime errors.

Requires Extended mode.

See also: QueryPhysicsBodyContacts, QueryPhysicsShapeContacts, QueryPhysicsSensor, CountPhysicsQueryManifolds, PhysicsBodyEvents.

Example

; CountPhysicsBodyEvents Example
; ------------------------------
; Requires Extended mode.

Graphics3D 640,480,0,2
SetBuffer BackBuffer()

Const PHYSICS_STATIC=0
Const PHYSICS_DYNAMIC=2
Const CRATE_COUNT=12

SeedRnd MilliSecs()

camera=CreateCamera()
PositionEntity camera,0,6,-12
RotateEntity camera,20,0,0

light=CreateLight()
RotateEntity light,45,-30,0
AmbientLight 60,60,60

; An independent Box3D world with standard gravity
world=CreatePhysicsWorld()

; Blue static floor
ground=CreateCube()
ScaleEntity ground,6,0.5,6
PositionEntity ground,0,-0.5,0
EntityColor ground,80,160,255
ground_body=CreatePhysicsBody(world,ground,PHYSICS_STATIC)
ground_shape=PhysicsBodyBox(ground_body,12,1,12)

; A pile of crates, dropped from random heights
Dim crates(CRATE_COUNT)
Dim crate_bodies(CRATE_COUNT)
For i=1 To CRATE_COUNT
    crates(i)=CreateCube()
    ScaleEntity crates(i),0.5,0.5,0.5
    crate_bodies(i)=CreatePhysicsBody(world,crates(i),PHYSICS_DYNAMIC)
    crate_shape=PhysicsBodyBox(crate_bodies(i),1,1,1)
Next
DropPile()

; Copy body movement and sleep events after every step
PhysicsBodyEvents world,True

While Not KeyDown(1)

    ; R drops the pile again
    If KeyHit(19) Then DropPile()

    StepPhysics world,1.0/60.0,4

    ; One event for each body the last step moved or put to sleep
    moved=CountPhysicsBodyEvents(world)

    ; Orange crates are awake, grey crates are asleep
    For i=1 To CRATE_COUNT
        If PhysicsBodyIsAwake(crate_bodies(i))
            EntityColor crates(i),255,120,70
        Else
            EntityColor crates(i),150,150,150
        EndIf
    Next

    ; Arrow keys move the camera
    If KeyDown(200) Then MoveEntity camera,0,0,0.1
    If KeyDown(208) Then MoveEntity camera,0,0,-0.1
    If KeyDown(203) Then TurnEntity camera,0,1,0
    If KeyDown(205) Then TurnEntity camera,0,-1,0

    RenderWorld

    Text 0,0,"Arrow keys: move camera   R: drop again   Esc: exit"
    Text 0,20,"CountPhysicsBodyEvents(world) = "+moved
    Text 0,40,"Static and sleeping bodies send no events"

    Flip

Wend

FreePhysicsWorld world
End

Function DropPile()
    For i=1 To CRATE_COUNT
        ResetPhysicsBody crate_bodies(i),Rnd(-1.5,1.5),2+i*0.8,Rnd(-1.5,1.5),0,Rnd(Pi),0
    Next
End Function

Index

Blitz3D+ Command Reference

CountPhysicsBodyEvents ( world )

Parameters

Description

Example