StopPhysicsRecording ( world,file$ )

Parameters

world - physics-world handle returned by CreatePhysicsWorld; must currently be recording

file$ - name of the file to save the recording to

Description

Stops recording and saves the physics recording to a file.

Ends the session begun by StartPhysicsRecording and writes everything - the starting snapshot, every recorded operation and the state hashes used for verification - into one self-contained file. Returns True.

Note that failures do not return False: stopping a world that is not recording, or a file that cannot be written, raises a runtime error instead.

Feed the saved file to ValidatePhysicsRecording to confirm a replay reproduces the recorded simulation exactly.

Requires Extended mode.

See also: StartPhysicsRecording, ValidatePhysicsRecording, StepPhysics.

Example

; StopPhysicsRecording Example
; ----------------------------
; Requires Extended mode.

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

Const PHYSICS_STATIC=0
Const PHYSICS_DYNAMIC=2

camera=CreateCamera()
PositionEntity camera,0,3,-6

light=CreateLight()
RotateEntity light,45,-30,0
AmbientLight 50,50,50

world=CreatePhysicsWorld()
PhysicsGravity world,0,-9.81,0

; Static ground slab
ground=CreateCube()
ScaleEntity ground,4,0.5,4
PositionEntity ground,0,-0.5,5,True
EntityColor ground,80,160,255
ground_body=CreatePhysicsBody(world,ground,PHYSICS_STATIC)
ground_shape=PhysicsBodyBox(ground_body,8,1,8,0)

; A bouncy ball gives the recording something to capture
ball=CreateSphere(16)
ScaleEntity ball,0.5,0.5,0.5
PositionEntity ball,0,4,5,True
EntityColor ball,255,120,70
ball_body=CreatePhysicsBody(world,ball,PHYSICS_DYNAMIC)
ball_shape=PhysicsBodySphere(ball_body,1,1)
PhysicsShapeRestitution ball_shape,0.7

recording_file$="physics_example.b3rec"

; Begin capturing a deterministic recording of the simulation
StartPhysicsRecording world
recording=1
frames=0
saved=0
valid=0

While Not KeyDown(1)

    If recording
        frames=frames+1
        ; Space (or 300 recorded frames) stops and validates the recording
        If KeyHit(57) Or frames>=300
            saved=StopPhysicsRecording(world,recording_file)
            valid=ValidatePhysicsRecording(recording_file,1)
            recording=0
        EndIf
    Else
        ; Space re-drops the ball and starts a fresh recording
        If KeyHit(57)
            FreePhysicsBody ball_body
            PositionEntity ball,0,4,5,True
            ball_body=CreatePhysicsBody(world,ball,PHYSICS_DYNAMIC)
            ball_shape=PhysicsBodySphere(ball_body,1,1)
            PhysicsShapeRestitution ball_shape,0.7
            StartPhysicsRecording world
            recording=1
            frames=0
        EndIf
    EndIf

    StepPhysics world,1.0/60.0,4

    ; 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

    If recording
        Text 0,0,"Space: stop and validate   Arrow keys: move camera   Esc: exit"
        Text 0,20,"Recording frame "+frames+"   (Space calls StopPhysicsRecording)"
    Else
        Text 0,0,"Space: record again   Arrow keys: move camera   Esc: exit"
        Text 0,20,"StopPhysicsRecording(world,recording_file$) = "+saved+"   Validated: "+valid
    EndIf

    Flip

Wend

; Tidy up the recording file the example created
If FileType(recording_file)=1 Then DeleteFile recording_file
FreePhysicsWorld world
End

Index

Blitz3D+ Command Reference

StopPhysicsRecording ( world,file$ )

Parameters

Description

Example