PhysicsQueryValid ( query )

Parameters

query - query handle

Description

Returns True for a current query handle and False for zero, wrong-kind, freed or stale handles.

This validity probe does not raise an error for invalid handles.

Query handles are invalidated by FreePhysicsQuery, owning-world destruction, and runtime reset.

Requires Extended mode.

See also: CreatePhysicsQuery, PhysicsQueryFilter, PhysicsQueryTarget, QueryPhysicsRay, QueryPhysicsSphere, PhysicsQueryLimit.

Example

; PhysicsQueryValid Example
; -------------------------
; Requires Extended mode.

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

Const PHYSICS_STATIC=0
Const PHYSICS_DYNAMIC=2

camera=CreateCamera()
PositionEntity camera,0,7,-8
RotateEntity camera,40,0,0

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 ring of crates to aim at
For i=1 To 8
    crate=CreateCube()
    ScaleEntity crate,0.5,0.5,0.5
    PositionEntity crate,Cos(i*45)*4,0.5,Sin(i*45)*4
    EntityColor crate,255,120,70
    crate_body=CreatePhysicsBody(world,crate,PHYSICS_STATIC)
    crate_shape=PhysicsBodyBox(crate_body,1,1,1)
Next

; A query object runs searches and keeps a copy of their results
query=CreatePhysicsQuery(world)

; Start aimed at a crate
angle#=45

While Not KeyDown(1)

    ; A and D sweep the ray around the centre
    If KeyDown(30) Then angle=angle+1.5
    If KeyDown(32) Then angle=angle-1.5
    dx#=Cos(angle)*6
    dz#=Sin(angle)*6

    ; Q frees the query, or creates a new one
    If KeyHit(16)
        If PhysicsQueryValid(query)
            FreePhysicsQuery query
        Else
            query=CreatePhysicsQuery(world)
        EndIf
    EndIf

    StepPhysics world,1.0/60.0,4

    ; Only search with a live query
    hits=0
    If PhysicsQueryValid(query) Then hits=QueryPhysicsRay(query,0,0.5,0,dx,0,dz)

    ; 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

    ; Draw the ray from the centre to the first hit, or to its full length
    CameraProject camera,0,0.5,0
    start_x=ProjectedX()
    start_y=ProjectedY()
    If hits>0
        CameraProject camera,PhysicsQueryX(query,1),PhysicsQueryY(query,1),PhysicsQueryZ(query,1)
    Else
        CameraProject camera,dx,0.5,dz
    EndIf
    Line start_x,start_y,ProjectedX(),ProjectedY()

    Text 0,0,"Arrow keys: move camera   A / D: sweep the ray   Q: free / create   Esc: exit"
    Text 0,20,"PhysicsQueryValid(query) = "+PhysicsQueryValid(query)

    Flip

Wend

FreePhysicsWorld world
End

Index

Blitz3D+ Command Reference

PhysicsQueryValid ( query )

Parameters

Description

Example