; The visible people and the user's personality records share the same positions.
InitNpcLife3D PROC uses ebx esi edi
    xor esi,esi
    mov npcLifeClock3D,0
    mov npcSelected3D,-1
npc_life_init:
    imul ebx,esi,SIZEOF NpcLife3D
    mov npcLife3D[ebx].identity,esi
    mov npcLife3D[ebx].state,NPC_STAND
    mov eax,esi
    imul eax,900
    add eax,1800
    mov npcLife3D[ebx].remaining,eax
    mov npcLife3D[ebx].routeStep,esi
    mov npcLife3D[ebx].pathCount,0
    mov npcLife3D[ebx].remainder,0
    mov npcLife3D[ebx].poseClock,0
    mov npcWalkDistance3D[esi*4],0
    mov npcWalkVelocityX3D[esi*4],0
    mov npcWalkVelocityY3D[esi*4],0
    mov eax,npcStartDest3D[esi*4]
    mov npcLife3D[ebx].destination,eax
    imul edi,esi,SIZEOF NpcMindEntity
    mov ecx,npcDestX3D[eax*4]
    mov casinoNpcs3D[edi].posX,ecx
    mov ecx,npcDestY3D[eax*4]
    mov casinoNpcs3D[edi].posY,ecx
    cmp eax,7
    je @F
    cmp eax,8
    jne npc_life_init_next
@@:
    mov npcLife3D[ebx].state,NPC_SIT
npc_life_init_next:
    inc esi
    cmp esi,NPC_LIFE_COUNT
    jb npc_life_init
    mov npcLifeReady3D,1
    ret
InitNpcLife3D ENDP

; BFS visits each tile at most once. Body clearance includes furniture and the stage.
NpcTryCell3D PROC uses ebx esi cell:DWORD,parent:DWORD
    mov esi,cell
    cmp esi,NPC_PATH_CAP
    jae npc_cell_done
    cmp npcParents3D[esi*4],-1
    jne npc_cell_done
    mov eax,esi
    and eax,31
    shl eax,16
    add eax,FP_HALF
    mov edx,esi
    shr edx,5
    shl edx,16
    add edx,FP_HALF
    invoke CanWalk3D,eax,edx
    test eax,eax
    jz npc_cell_done
    mov eax,parent
    mov npcParents3D[esi*4],eax
    mov ebx,npcSearchTail3D
    cmp ebx,NPC_PATH_CAP
    jae npc_cell_done
    mov npcQueue3D[ebx*4],esi
    inc npcSearchTail3D
npc_cell_done:
    ret
NpcTryCell3D ENDP

NpcPlanPath3D PROC uses ebx esi edi slot:DWORD,destination:DWORD
    local firstCell:DWORD,currentCell:DWORD,pathBase:DWORD
    cmp slot,NPC_LIFE_COUNT
    jae npc_plan_fail
    cmp destination,NPC_DEST_COUNT
    jae npc_plan_fail
    imul ebx,slot,SIZEOF NpcLife3D
    mov npcLife3D[ebx].pathCount,0
    imul esi,slot,SIZEOF NpcMindEntity
    mov eax,casinoNpcs3D[esi].posY
    sar eax,16
    shl eax,5
    mov ecx,casinoNpcs3D[esi].posX
    sar ecx,16
    add eax,ecx
    cmp eax,NPC_PATH_CAP
    jae npc_plan_fail
    mov firstCell,eax
    mov ecx,destination
    mov eax,npcDestY3D[ecx*4]
    sar eax,16
    shl eax,5
    mov edx,npcDestX3D[ecx*4]
    sar edx,16
    add eax,edx
    mov npcSearchGoal3D,eax
    lea edi,npcParents3D
    mov ecx,NPC_PATH_CAP
    mov eax,-1
    rep stosd
    mov eax,firstCell
    mov npcParents3D[eax*4],eax
    mov npcQueue3D,eax
    mov npcSearchHead3D,0
    mov npcSearchTail3D,1
npc_plan_search:
    mov eax,npcSearchHead3D
    cmp eax,npcSearchTail3D
    jae npc_plan_fail
    mov esi,npcQueue3D[eax*4]
    inc npcSearchHead3D
    cmp esi,npcSearchGoal3D
    je npc_plan_found
    mov eax,esi
    and eax,31
    test eax,eax
    jz @F
    lea eax,[esi-1]
    invoke NpcTryCell3D,eax,esi
@@:
    mov eax,esi
    and eax,31
    cmp eax,31
    je @F
    lea eax,[esi+1]
    invoke NpcTryCell3D,eax,esi
@@:
    cmp esi,32
    jb @F
    lea eax,[esi-32]
    invoke NpcTryCell3D,eax,esi
@@:
    cmp esi,NPC_PATH_CAP-32
    jae npc_plan_search
    lea eax,[esi+32]
    invoke NpcTryCell3D,eax,esi
    jmp npc_plan_search
npc_plan_found:
    mov eax,slot
    imul eax,NPC_PATH_CAP*4
    add eax,OFFSET npcPaths3D
    mov pathBase,eax
    xor edi,edi
npc_plan_reverse:
    cmp esi,firstCell
    je npc_plan_success
    cmp edi,NPC_PATH_CAP
    jae npc_plan_fail
    mov edx,pathBase
    mov [edx+edi*4],esi
    inc edi
    mov esi,npcParents3D[esi*4]
    jmp npc_plan_reverse
npc_plan_success:
    mov npcLife3D[ebx].pathCount,edi
    mov eax,destination
    mov npcLife3D[ebx].destination,eax
    mov eax,1
    ret
npc_plan_fail:
    xor eax,eax
    ret
NpcPlanPath3D ENDP

NpcCanStep3D PROC uses ebx esi slot:DWORD,px:DWORD,py:DWORD
    invoke CanWalk3D,px,py
    test eax,eax
    jz npc_space_done
    mov eax,px
    sub eax,playerX
    jns @F
    neg eax
@@:
    cmp eax,FP_1*3/10
    jae npc_space_people
    mov eax,py
    sub eax,playerY
    jns @F
    neg eax
@@:
    cmp eax,FP_1*3/10
    jb npc_space_blocked
npc_space_people:
    xor esi,esi
npc_space_person:
    cmp esi,slot
    je npc_space_next
    imul ebx,esi,SIZEOF NpcLife3D
    cmp npcLife3D[ebx].state,NPC_AWAY
    je npc_space_next
    imul ebx,esi,SIZEOF NpcMindEntity
    mov eax,px
    sub eax,casinoNpcs3D[ebx].posX
    jns @F
    neg eax
@@:
    cmp eax,FP_1*2/5
    jae npc_space_next
    mov eax,py
    sub eax,casinoNpcs3D[ebx].posY
    jns @F
    neg eax
@@:
    cmp eax,FP_1*2/5
    jb npc_space_blocked
npc_space_next:
    inc esi
    cmp esi,NPC_LIFE_COUNT
    jb npc_space_person
    mov eax,1
    ret
npc_space_blocked:
    xor eax,eax
npc_space_done:
    ret
NpcCanStep3D ENDP

; Millisecond movement, carrying the remainder and consuming whole route cells.
NpcMove3D PROC uses ebx esi edi slot:DWORD,milliseconds:DWORD
    local budget:DWORD,wx:DWORD,wy:DWORD,mind:DWORD,pathBase:DWORD
    local oldX:DWORD,oldY:DWORD
    imul ebx,slot,SIZEOF NpcLife3D
    imul eax,slot,SIZEOF NpcMindEntity
    lea esi,casinoNpcs3D[eax]
    mov mind,esi
    mov eax,[esi].NpcMindEntity.posX
    mov oldX,eax
    mov eax,[esi].NpcMindEntity.posY
    mov oldY,eax
    mov eax,slot
    imul eax,NPC_PATH_CAP*4
    add eax,OFFSET npcPaths3D
    mov pathBase,eax
    mov eax,milliseconds
    mov ecx,55000
    mul ecx
    add eax,npcLife3D[ebx].remainder
    adc edx,0
    mov ecx,1000
    div ecx
    mov npcLife3D[ebx].remainder,edx
    mov budget,eax
npc_move_cell:
    mov eax,npcLife3D[ebx].pathCount
    test eax,eax
    jz npc_move_arrived
    dec eax
    mov edx,pathBase
    mov edi,[edx+eax*4]
    mov eax,edi
    and eax,31
    shl eax,16
    add eax,FP_HALF
    mov wx,eax
    mov eax,edi
    shr eax,5
    shl eax,16
    add eax,FP_HALF
    mov wy,eax
    mov esi,mind
    mov eax,wx
    sub eax,[esi].NpcMindEntity.posX
    mov edi,1
    test eax,eax
    jns @F
    neg eax
    mov edi,-1
@@:
    test eax,eax
    jz npc_move_y
    cmp eax,budget
    jbe @F
    mov eax,budget
@@:
    sub budget,eax
    imul eax,edi
    add eax,[esi].NpcMindEntity.posX
    mov wx,eax
    invoke NpcCanStep3D,slot,wx,[esi].NpcMindEntity.posY
    test eax,eax
    jz npc_move_blocked
    mov eax,wx
    mov [esi].NpcMindEntity.posX,eax
npc_move_y:
    mov eax,wy
    sub eax,[esi].NpcMindEntity.posY
    mov edi,1
    test eax,eax
    jns @F
    neg eax
    mov edi,-1
@@:
    cmp eax,budget
    jbe @F
    mov eax,budget
@@:
    sub budget,eax
    imul eax,edi
    add eax,[esi].NpcMindEntity.posY
    mov wy,eax
    invoke NpcCanStep3D,slot,[esi].NpcMindEntity.posX,wy
    test eax,eax
    jz npc_move_blocked
    mov eax,wy
    mov [esi].NpcMindEntity.posY,eax
    mov edx,pathBase
    mov eax,npcLife3D[ebx].pathCount
    dec eax
    mov edi,[edx+eax*4]
    mov eax,[esi].NpcMindEntity.posX
    sub eax,FP_HALF
    sar eax,16
    mov edx,[esi].NpcMindEntity.posY
    sub edx,FP_HALF
    sar edx,16
    shl edx,5
    add eax,edx
    cmp eax,edi
    jne npc_move_done
    ; Integer cell membership is insufficient: finish at the exact cell centre.
    mov eax,edi
    and eax,31
    shl eax,16
    add eax,FP_HALF
    cmp eax,[esi].NpcMindEntity.posX
    jne npc_move_done
    mov eax,edi
    shr eax,5
    shl eax,16
    add eax,FP_HALF
    cmp eax,[esi].NpcMindEntity.posY
    jne npc_move_done
    dec npcLife3D[ebx].pathCount
    cmp budget,0
    jne npc_move_cell
    cmp npcLife3D[ebx].pathCount,0
    jne npc_move_done
npc_move_arrived:
    mov eax,npcLife3D[ebx].destination
    mov npcLife3D[ebx].state,NPC_STAND
    mov npcLife3D[ebx].remaining,3500
    cmp eax,0
    jne @F
    mov npcLife3D[ebx].state,NPC_AWAY
    mov npcLife3D[ebx].remaining,4500
    jmp npc_move_done
@@:
    cmp eax,7
    je @F
    cmp eax,8
    jne npc_move_done
@@:
    mov npcLife3D[ebx].state,NPC_SIT
    mov npcLife3D[ebx].remaining,12000
    jmp npc_move_done
npc_move_blocked:
    mov npcLife3D[ebx].state,NPC_STAND
    mov npcLife3D[ebx].remaining,1000
    mov npcLife3D[ebx].pathCount,0
npc_move_done:
    ; Advance gait by successful displacement only, including partial blocked steps.
    mov esi,mind
    mov ebx,slot
    mov eax,[esi].NpcMindEntity.posX
    sub eax,oldX
    mov ecx,eax
    mov eax,[esi].NpcMindEntity.posY
    sub eax,oldY
    mov edi,eax
    or eax,ecx
    jz npc_move_no_stride
    mov npcWalkVelocityX3D[ebx*4],ecx
    mov npcWalkVelocityY3D[ebx*4],edi
    mov eax,ecx
    cdq
    xor eax,edx
    sub eax,edx
    mov ecx,eax
    mov eax,edi
    cdq
    xor eax,edx
    sub eax,edx
    add eax,ecx
    add eax,npcWalkDistance3D[ebx*4]
    xor edx,edx
    mov ecx,FP_1*3/4
    div ecx
    mov npcWalkDistance3D[ebx*4],edx
npc_move_no_stride:
    ret
NpcMove3D ENDP

UpdateNpcLife3D PROC uses ebx esi edi
    local milliseconds:DWORD,destination:DWORD
    cmp npcLifeReady3D,1
    jne npc_update_done
    cmp hallLevel3D,0
    jne npc_update_done
    mov eax,deltaTime3D
    cmp eax,250
    jbe @F
    mov eax,250
@@:
    mov milliseconds,eax
    add npcLifeClock3D,eax
    xor esi,esi
npc_update_person:
    imul ebx,esi,SIZEOF NpcLife3D
    mov eax,milliseconds
    add npcLife3D[ebx].poseClock,eax
    cmp npcLife3D[ebx].state,NPC_WALK
    jne npc_update_wait
    invoke NpcMove3D,esi,milliseconds
    jmp npc_update_sync
npc_update_wait:
    sub npcLife3D[ebx].remaining,eax
    ja npc_update_sync
    cmp npcLife3D[ebx].state,NPC_AWAY
    jne npc_update_choose
    mov eax,npcLife3D[ebx].identity
    add eax,6
    cmp eax,NPC_IDENTITY_COUNT
    jb @F
    sub eax,NPC_IDENTITY_COUNT
@@:
    mov npcLife3D[ebx].identity,eax
    mov npcLife3D[ebx].state,NPC_STAND
npc_update_choose:
    mov eax,npcLife3D[ebx].routeStep
    xor edx,edx
    mov ecx,NPC_DEST_COUNT
    div ecx
    mov eax,npcVisitRoute3D[edx*4]
    mov destination,eax
    inc npcLife3D[ebx].routeStep
    invoke NpcPlanPath3D,esi,destination
    test eax,eax
    jz npc_update_retry
    mov npcLife3D[ebx].state,NPC_WALK
    jmp npc_update_sync
npc_update_retry:
    mov npcLife3D[ebx].state,NPC_STAND
    mov npcLife3D[ebx].remaining,1000
npc_update_sync:
    imul edi,esi,SIZEOF NpcMindEntity
    mov eax,npcLife3D[ebx].state
    mov casinoNpcs3D[edi].state,eax
    mov eax,npcLife3D[ebx].remaining
    mov casinoNpcs3D[edi].stateTimer,eax
    ; Keep the old public position array coherent for existing world checks.
    imul ecx,esi,SIZEOF CityProp3D
    mov eax,casinoNpcs3D[edi].posX
    mov hallGuests3D[ecx].posX,eax
    mov eax,casinoNpcs3D[edi].posY
    mov hallGuests3D[ecx].posY,eax
    inc esi
    cmp esi,NPC_LIFE_COUNT
    jb npc_update_person
npc_update_done:
    ret
UpdateNpcLife3D ENDP

RenderNpcLife3D PROC uses ebx esi edi
    cmp npcLifeReady3D,1
    jne npc_draw_done
    xor esi,esi
npc_draw_depth:
    imul ebx,esi,SIZEOF NpcMindEntity
    invoke ProjectCityPoint3D,casinoNpcs3D[ebx].posX,casinoNpcs3D[ebx].posY
    mov npcDrawDepth3D[esi*4],edx
    mov npcDrawOrder3D[esi*4],esi
    inc esi
    cmp esi,NPC_LIFE_COUNT
    jb npc_draw_depth
    xor esi,esi
npc_draw_sort:
    lea edi,[esi+1]
npc_draw_compare:
    mov eax,npcDrawOrder3D[esi*4]
    mov ebx,npcDrawDepth3D[eax*4]
    mov ecx,npcDrawOrder3D[edi*4]
    cmp ebx,npcDrawDepth3D[ecx*4]
    jge @F
    mov npcDrawOrder3D[esi*4],ecx
    mov npcDrawOrder3D[edi*4],eax
@@:
    inc edi
    cmp edi,NPC_LIFE_COUNT
    jb npc_draw_compare
    inc esi
    cmp esi,NPC_LIFE_COUNT-1
    jb npc_draw_sort
    xor esi,esi
npc_draw_person:
    mov eax,npcDrawOrder3D[esi*4]
    imul ebx,eax,SIZEOF NpcLife3D
    cmp npcLife3D[ebx].state,NPC_AWAY
    je npc_draw_next
    imul edi,eax,SIZEOF NpcMindEntity
    mov eax,casinoNpcs3D[edi].posX
    mov npcSprite3D.posX,eax
    mov eax,casinoNpcs3D[edi].posY
    mov npcSprite3D.posY,eax
    mov npcSprite3D.worldW,FP_1*3/5
    mov npcSprite3D.worldH,FP_1*6/5
    mov npcSprite3D.groundZ,-FP_1*6/5*4/224
    mov npcSprite3D.asset,OFFSET npcGuestArt3D
    cmp npcGuestArt3D.pixels,0
    je npc_draw_next
    mov eax,npcLife3D[ebx].identity
    mov eax,npcGuestAppearance3D[eax*4]
    imul eax,6
    mov npcSprite3D.frame,eax
    cmp npcLife3D[ebx].state,NPC_SIT
    jne npc_draw_walk
    add npcSprite3D.frame,5
    ; Seated pose is already shorter within the same foot-anchored canvas.
    mov npcSprite3D.worldW,FP_1*3/5
    mov npcSprite3D.worldH,FP_1*6/5
    jmp npc_draw_sprite
npc_draw_walk:
    cmp npcLife3D[ebx].state,NPC_WALK
    jne npc_draw_sprite
    cmp npcWalkArt3D.pixels,0
    je npc_draw_sprite
    mov npcSprite3D.asset,OFFSET npcWalkArt3D
    mov npcSprite3D.groundZ,0
    mov eax,npcLife3D[ebx].identity
    mov eax,npcGuestAppearance3D[eax*4]
    shl eax,3
    mov npcSprite3D.frame,eax
    mov ebx,npcDrawOrder3D[esi*4]
    mov eax,npcWalkDistance3D[ebx*4]
    xor edx,edx
    mov ecx,FP_1*3/32
    div ecx
    and eax,7
    add npcSprite3D.frame,eax
    ; Match the drawn facing to the actual camera-relative direction of travel.
    mov eax,npcWalkVelocityY3D[ebx*4]
    imul playerDirX
    shrd eax,edx,16
    mov edi,eax
    mov eax,npcWalkVelocityX3D[ebx*4]
    imul playerDirY
    shrd eax,edx,16
    sub edi,eax
    jns npc_draw_sprite
    cmp npcWalkLeftArt3D.pixels,0
    je npc_draw_sprite
    mov npcSprite3D.asset,OFFSET npcWalkLeftArt3D
npc_draw_sprite:
    invoke DrawCityObject3D,OFFSET npcSprite3D,0
npc_draw_next:
    inc esi
    cmp esi,NPC_LIFE_COUNT
    jb npc_draw_person
npc_draw_done:
    ret
RenderNpcLife3D ENDP

CheckNpcInteractions3D PROC uses ebx esi edi
    local distance:DWORD,nearest:DWORD,deltaX:DWORD,deltaY:DWORD
    cmp npcLifeReady3D,1
    jne npc_interact_done
    cmp hallLevel3D,0
    jne npc_interact_done
    cmp interactTargetId,0
    jne npc_interact_done
    mov npcSelected3D,-1
    mov nearest,165000
    xor esi,esi
npc_interact_person:
    imul ebx,esi,SIZEOF NpcLife3D
    cmp npcLife3D[ebx].state,NPC_AWAY
    je npc_interact_next
    imul edi,esi,SIZEOF NpcMindEntity
    mov eax,casinoNpcs3D[edi].posX
    sub eax,playerX
    sar eax,8
    mov deltaX,eax
    imul eax,eax
    mov distance,eax
    mov eax,casinoNpcs3D[edi].posY
    sub eax,playerY
    sar eax,8
    mov deltaY,eax
    imul eax,eax
    add eax,distance
    cmp eax,nearest
    jae npc_interact_next
    mov distance,eax
    mov eax,playerDirX
    sar eax,8
    imul eax,deltaX
    mov edx,playerDirY
    sar edx,8
    imul edx,deltaY
    add eax,edx
    cmp eax,6000
    jl npc_interact_next
    ; Short, bounded line-of-sight test prevents talking through a wall.
    mov ebx,1
npc_interact_ray:
    mov eax,deltaX
    imul eax,ebx
    shl eax,5
    add eax,playerX
    sar eax,16
    mov edx,deltaY
    imul edx,ebx
    shl edx,5
    add edx,playerY
    sar edx,16
    cmp eax,32
    jae npc_interact_next
    cmp edx,32
    jae npc_interact_next
    shl edx,5
    add edx,eax
    mov ecx,worldMap3D
    cmp BYTE PTR [ecx+edx],0
    jne npc_interact_next
    inc ebx
    cmp ebx,8
    jb npc_interact_ray
    mov eax,distance
    mov nearest,eax
    mov npcSelected3D,esi
npc_interact_next:
    inc esi
    cmp esi,NPC_LIFE_COUNT
    jb npc_interact_person
    cmp npcSelected3D,-1
    je npc_interact_done
    mov interactTargetId,INTERACT_NPC
    mov interactPromptPtr,OFFSET npcTalkPrompt3D
npc_interact_done:
    ret
CheckNpcInteractions3D ENDP