; Invisible slack constraints engage only at the end of a pin's free travel.
BowlingPlayTether3D PROC uses ebx esi pin:DWORD
    local deltaX:DWORD,deltaY:DWORD,length8:DWORD,nx:DWORD,ny:DWORD,outward:DWORD
    mov esi,pin
    mov eax,bpPinX3D[esi*4]
    sub eax,bwPinX3D[esi*4]
    mov deltaX,eax
    sar eax,8
    imul eax,eax
    mov ebx,eax
    mov eax,bpPinY3D[esi*4]
    sub eax,bwPinY3D[esi*4]
    mov deltaY,eax
    sar eax,8
    imul eax,eax
    add eax,ebx
    cmp eax,128*128
    jbe bp_tether_done
    invoke PoolSqrt3D,eax
    mov length8,eax
    mov eax,deltaX
    imul eax,256
    cdq
    idiv length8
    mov nx,eax
    mov eax,deltaY
    imul eax,256
    cdq
    idiv length8
    mov ny,eax
    mov eax,nx
    imul eax,128
    sar eax,8
    add eax,bwPinX3D[esi*4]
    mov bpPinX3D[esi*4],eax
    mov eax,ny
    imul eax,128
    sar eax,8
    add eax,bwPinY3D[esi*4]
    mov bpPinY3D[esi*4],eax
    mov eax,bpPinVX3D[esi*4]
    imul nx
    shrd eax,edx,16
    mov ebx,eax
    mov eax,bpPinVY3D[esi*4]
    imul ny
    shrd eax,edx,16
    add eax,ebx
    test eax,eax
    jle bp_tether_done
    imul eax,4
    cdq
    mov ecx,5
    idiv ecx
    mov outward,eax
    imul nx
    shrd eax,edx,16
    sub bpPinVX3D[esi*4],eax
    mov eax,outward
    imul ny
    shrd eax,edx,16
    sub bpPinVY3D[esi*4],eax
bp_tether_done:
    ret
BowlingPlayTether3D ENDP

; Bound the complete pin silhouette, including its horizontal neck/head.
BowlingPlayDeckBounds3D PROC uses ebx esi pin:DWORD
    local extension:DWORD,lo:DWORD,hi:DWORD
    mov esi,pin
    mov ecx,bpPinTilt3D[esi*4]
    shr ecx,8
    mov eax,tableSin[ecx*4]
    imul eax,35
    cdq
    mov ecx,100
    idiv ecx
    mov extension,eax
    imul bpPinAxisX3D[esi*4]
    shrd eax,edx,16
    mov lo,-FP_1*82/100
    mov hi,FP_1*82/100
    test eax,eax
    js bp_deck_left_extent
    sub hi,eax
    jmp bp_deck_x
bp_deck_left_extent:
    sub lo,eax
bp_deck_x:
    mov eax,bpPinX3D[esi*4]
    cmp eax,lo
    jge bp_deck_right
    mov eax,lo
    mov bpPinX3D[esi*4],eax
    cmp bpPinVX3D[esi*4],0
    jge bp_deck_y_extent
    jmp bp_deck_bounce_x
bp_deck_right:
    cmp eax,hi
    jle bp_deck_y_extent
    mov eax,hi
    mov bpPinX3D[esi*4],eax
    cmp bpPinVX3D[esi*4],0
    jle bp_deck_y_extent
bp_deck_bounce_x:
    mov eax,bpPinVX3D[esi*4]
    neg eax
    cdq
    mov ecx,5
    idiv ecx
    mov bpPinVX3D[esi*4],eax
bp_deck_y_extent:
    mov eax,extension
    imul bpPinAxisY3D[esi*4]
    shrd eax,edx,16
    mov lo,FP_1*308/100
    mov hi,FP_1*547/100
    test eax,eax
    js bp_deck_back_extent
    sub hi,eax
    jmp bp_deck_y
bp_deck_back_extent:
    sub lo,eax
bp_deck_y:
    mov eax,bpPinY3D[esi*4]
    cmp eax,lo
    jge bp_deck_front
    mov eax,lo
    mov bpPinY3D[esi*4],eax
    cmp bpPinVY3D[esi*4],0
    jge bp_deck_done
    jmp bp_deck_bounce_y
bp_deck_front:
    cmp eax,hi
    jle bp_deck_done
    mov eax,hi
    mov bpPinY3D[esi*4],eax
    cmp bpPinVY3D[esi*4],0
    jle bp_deck_done
bp_deck_bounce_y:
    mov eax,bpPinVY3D[esi*4]
    neg eax
    cdq
    mov ecx,5
    idiv ecx
    mov bpPinVY3D[esi*4],eax
bp_deck_done:
    ret
BowlingPlayDeckBounds3D ENDP