Track AI Function

Track functions

Author: Giano

;TRACK_SMOOTH TRACK_YR TRACK_SMOOTH_YR SAMPLE DEMO
;WRITTEN By Bitmaniak
;Tracking Functions idea and specs By DoctorZ
;Tracking Functions code by Bitmaniak
;*********************************************************************************
;*** Thi is a real shared pivot...
;*********************************************************************************
Global gPivot1,gPivot2,gCube

;*********************************************************************************
;*** Slow PointEntity on xz axe
;*********************************************************************************
Function  track_YR_Smooth(e1,e2,smothness#=1.0)
    PositionEntity gPivot1,EntityX(e1),EntityY(e1),EntityZ(e1)
    PointEntity gPivot1,e2  
    RotateEntity e1, 0,curveAngle#(EntityYaw(gPivot1),EntityYaw(e1),smothness#),0
End Function

;*********************************************************************************
;*** Fast PointEntity on xz axe
;*********************************************************************************
Function  track_YR(e1,e2)
    PositionEntity gPivot1,EntityX(e1),EntityY(e1),EntityZ(e1)
    PointEntity gPivot1,e2  
    RotateEntity e1, 0,EntityYaw(gPivot1),0
End Function

;*********************************************************************************
;*** Slow PointEntity on all axes
;*********************************************************************************
Function  track_Smooth(e1,e2,smothness#)
    PositionEntity gPivot1,EntityX(e1),EntityY(e1),EntityZ(e1)
    PointEntity gPivot1,e2  
    RotateEntity e1, curveAngle#(EntityPitch(gPivot1),EntityPitch(e1),smothness#),curveAngle#(EntityYaw(gPivot1),EntityYaw(e1),smothness#),0
End Function
;*********************************************************************************
;*** Fast PointEntity on all axes...so...pointEntity...just for fun!
;*********************************************************************************
Function  track(e1,e2)
    PointEntity e1,e2
End Function

;*********************************************************************************
;*** This calculate the 2d distance*distance on y axes 
;*** The exact distance is the sqr( EntityDistance_YR_Power2(e1,e2))
;*********************************************************************************
Function EntityDistance_YR_Power2(e1,e2)
    p#=EntityX(e2)-EntityX(e1)
    q#=EntityZ(e2)-EntityZ(e1)
    Return (p*p)+(q*q)
End Function

;*********************************************************************************
;*** Anyone knows this! Calculate the incremental steps
;*********************************************************************************
Function curveangle#( newangle#,oldangle#,increments#)
    If increments>1
        If (oldangle+360)-newangle<newangle-oldangle 
            oldangle=360+oldangle
        End If
        If (newangle+360)-oldangle<oldangle-newangle 
            newangle=360+newangle
        End If
        oldangle=oldangle-(oldangle-newangle)/increments
    End If
    If increments<=1 
        Return newangle
    End If
    Return oldangle

End Function

;*********************************************************************************
;*** Same of above but with points
;*********************************************************************************
;Global gPivot2
Function track_SmoothPoint(entity, x#,y#,z#, turnspeed#=1.0, useRoll%=0)
    PositionEntity gPivot2,x,y,z
    PositionEntity gPivot1,EntityX(entity),EntityY(entity),EntityZ(entity)
    PointEntity gPivot1,gPivot2 
    temp_pitch# = curveAngle#(EntityPitch(gPivot1),EntityPitch(entity),turnspeed#*2)
    temp_yaw# = curveAngle#(EntityYaw(gPivot1),EntityYaw(entity),turnspeed#)
    If useRoll
        temp_roll# = curveAngle#(EntityRoll(gPivot1),EntityRoll(entity),turnspeed#)
        RotateEntity entity, temp_pitch, temp_yaw, temp_roll
    Else
        RotateEntity entity, temp_pitch, temp_yaw, 0
    End If
End Function

;*********************************************************************************
;*** Create a squared texure
;*********************************************************************************
Function defaultTextureEntity(mesh, colr1=32,colg1=128,colb1=192, colr2=255,colg2=255,colb2=160)
    tex=CreateTexture( 64,64 )
    ScaleTexture tex,.125,.125
    SetBuffer TextureBuffer( tex )
    Color colr1,colg1,colb1:Rect 32,0,32,32:Rect 0,32,32,32
    Color colr2,colg2,colb2:Rect 0,0,32,32:Rect 32,32,32,32
    SetBuffer BackBuffer()
    Color 255,255,255

    brush=CreateBrush()
    BrushTexture brush,tex
    EntityTexture mesh,tex

    FreeBrush brush
    FreeTexture tex
End Function

;*********************************************************************************
;*** Draws Lines
;*********************************************************************************
Function drawpivot(e,camera,length)
    ;Get initial position
    CameraProject camera,EntityX(e,1),EntityY(e,1),EntityZ(e,1)
    x=ProjectedX()
    y=ProjectedY()

    ;Draw X axis
    Color 255,0,0
    MoveEntity e,length,0,0
    CameraProject camera,EntityX(e,1),EntityY(e,1),EntityZ(e,1)
    Line x,y,ProjectedX(),ProjectedY()
    MoveEntity e,-length,0,0

    ;Draw Y axis
    Color 0,255,0
    MoveEntity e,0,length,0
    CameraProject camera,EntityX(e,1),EntityY(e,1),EntityZ(e,1)
    Line x,y,ProjectedX(),ProjectedY()
    MoveEntity e,0,-length,0

    ;Draw Z axis
    Color 0,0,255
    MoveEntity e,0,0,length
    CameraProject camera,EntityX(e,1),EntityY(e,1),EntityZ(e,1)
    Line x,y,ProjectedX(),ProjectedY()
    MoveEntity e,0,0,-length
End Function

;*********************************************************************************
;*** The test!
;*********************************************************************************

Graphics3D 800,600
SetBuffer BackBuffer()

camera=CreateCamera()
light=CreateLight()

PositionEntity camera,0,0,-10

;*** create some entities
cone=CreateCone()
PositionEntity cone,-2,0,-5
RotateMesh cone,90,0,0
defaultTextureEntity(cone)

cone1=CopyEntity(cone)
PositionEntity cone1,-1,0,0
EntityColor cone1,255,0,0

cone2=CopyEntity(cone)
PositionEntity cone2,1,2,0
EntityColor cone2,0,255,0

cone3=CopyEntity(cone)
PositionEntity cone3,0,0,0
EntityColor cone3,0,255,255

cone4=CopyEntity(cone)
PositionEntity cone4,0,0,0
EntityColor cone4,255,255,0

cube=CreateCube()
PositionEntity cube,0,0,8
defaultTextureEntity(cube)

plane = CreatePlane()
defaultTextureEntity(plane)
PositionEntity plane,0,-.5,0
EntityAlpha plane,.5

gPivot1 = CreatePivot()
gPivot2 = CreatePivot()
gCube = CreatePivot()

gfxMiddleWidth = GraphicsWidth()/2
gfxMiddleHeight = GraphicsHeight()/2

;*********************************************************************************

While Not KeyDown( 1 )
;*** Cube rotation
    my = -MouseYSpeed()/5
    mx = MouseXSpeed()/5

    MoveMouse gfxMiddleWidth,gfxMiddleHeight
;   PositionEntity gPivot1,EntityX(cone),EntityY(cone),EntityZ(cone)
    PositionEntity gPivot1,0,0,0

    EntityParent cube,gCube
    TurnEntity gCube,my,mx,0
    EntityParent cube,0

;*** The routines
;*** Before you used to call a pointEntity(e1,e2)...now you'll call a track_Smooth(e1,e2,smooth)

    track_Smooth(cone,cube,20.0)
    track_Smooth(cone1,cube,100.0)  
    track(cone2,cube)   

    d#=EntityDistance_YR_Power2(cone3,cube)
    If d>1
        track_YR_Smooth(cone3,cube,10.0)    
        MoveEntity cone3,0,0,.1
    End If

    track_Smooth(cone4,cube,EntityDistance(cone4,cube)*2)   
    MoveEntity cone4,0,0,EntityDistance(cone4,cube)/200.0

    RenderWorld

    drawpivot(cone,camera,1)
    drawpivot(cone1,camera,1)
    drawpivot(cone2,camera,1)
    drawpivot(cone3,camera,1)
    drawpivot(cone4,camera,1)

    Text 0,0,d
    Flip
Wend

End

'wend' without 'while'

Thanks for pointing that out. For some reason, the complete code is being cut off and now hosted externally.

thats cool