; Native ray/ellipsoid intersection supplies rounded cushions and copper domes.
DrawRoofEllipsoid3D PROC uses ebx esi edi centreX:DWORD,centreY:DWORD,centreZ:DWORD,radiusX:DWORD,radiusY:DWORD,radiusZ:DWORD,material:DWORD
    local leftPx:DWORD,rightPx:DWORD,topPx:DWORD,bottomPx:DWORD,column:DWORD,row:DWORD
    local centrePx:DWORD,centreDepth:DWORD,pixelDepth:DWORD,temp:DWORD,texU:DWORD,texV:DWORD
    local texture:DWORD,texWidth:DWORD,texHeight:DWORD,shade:DWORD,color:DWORD
    local ox:REAL4,oy:REAL4,oz:REAL4,rayX:REAL4,rayY:REAL4,rayZ:REAL4
    local quadraticC:REAL4,quadraticA:REAL4,quadraticB:REAL4,discriminant:REAL4,hitTime:REAL4
    invoke ResolveCitySurface3D,material
    test eax,eax
    jz roof_round_done
    mov texture,eax
    mov texWidth,ecx
    mov texHeight,edx
    invoke ProjectCityPoint3D,centreX,centreY
    cmp edx,FP_1/8
    jle roof_round_done
    mov centrePx,eax
    mov centreDepth,edx
    mov eax,radiusX
    add eax,radiusY
    imul eax,SCREEN_H
    cdq
    idiv centreDepth
    mov ecx,centrePx
    sub ecx,eax
    mov leftPx,ecx
    add eax,centrePx
    mov rightPx,eax
    mov eax,viewEye3D
    sub eax,centreZ
    sub eax,radiusZ
    imul eax,SCREEN_H
    cdq
    idiv centreDepth
    add eax,viewHorizon3D
    sub eax,4
    mov topPx,eax
    mov eax,viewEye3D
    sub eax,centreZ
    add eax,radiusZ
    imul eax,SCREEN_H
    cdq
    idiv centreDepth
    add eax,viewHorizon3D
    add eax,4
    mov bottomPx,eax
    cmp leftPx,0
    jge @F
    mov leftPx,0
@@:
    cmp rightPx,SCREEN_W-1
    jle @F
    mov rightPx,SCREEN_W-1
@@:
    cmp topPx,0
    jge @F
    mov topPx,0
@@:
    cmp bottomPx,SCREEN_H-1
    jle @F
    mov bottomPx,SCREEN_H-1
@@:
    mov eax,leftPx
    cmp eax,rightPx
    jge roof_round_done
    mov eax,topPx
    cmp eax,bottomPx
    jge roof_round_done
    mov eax,playerX
    sub eax,centreX
    mov temp,eax
    fild temp
    fidiv radiusX
    fstp ox
    mov eax,playerY
    sub eax,centreY
    mov temp,eax
    fild temp
    fidiv radiusY
    fstp oy
    mov eax,viewEye3D
    sub eax,centreZ
    mov temp,eax
    fild temp
    fidiv radiusZ
    fstp oz
    fld ox
    fmul st,st
    fld oy
    fmul st,st
    faddp st(1),st
    fld oz
    fmul st,st
    faddp st(1),st
    fld1
    fsubp st(1),st
    fstp quadraticC
    mov eax,topPx
    mov row,eax
roof_round_row:
    mov eax,viewHorizon3D
    sub eax,row
    mov temp,eax
    fild temp
    fmul roofFloatFP3D
    fdiv roofFloat4803D
    fidiv radiusZ
    fstp rayZ
    mov eax,row
    imul eax,SCREEN_W*4
    mov ebx,leftPx
    lea edi,[eax+ebx*4]
    mov column,ebx
roof_round_pixel:
    mov ebx,column
    fild cityRayX3D[ebx*4]
    fidiv radiusX
    fstp rayX
    fild cityRayY3D[ebx*4]
    fidiv radiusY
    fstp rayY
    fld rayX
    fmul st,st
    fld rayY
    fmul st,st
    faddp st(1),st
    fld rayZ
    fmul st,st
    faddp st(1),st
    fstp quadraticA
    fld rayX
    fmul ox
    fld rayY
    fmul oy
    faddp st(1),st
    fld rayZ
    fmul oz
    faddp st(1),st
    fstp quadraticB
    fld quadraticB
    fmul st,st
    fld quadraticA
    fmul quadraticC
    fsubp st(1),st
    fst discriminant
    ftst
    fnstsw ax
    sahf
    fstp st(0)
    jb roof_round_next
    fld discriminant
    fsqrt
    fadd quadraticB
    fchs
    fdiv quadraticA
    fst hitTime
    fmul roofFloatFP3D
    fistp pixelDepth
    mov eax,pixelDepth
    cmp eax,4096
    jle roof_round_next
    cmp eax,cityDepthBuffer3D[edi]
    jae roof_round_next
    fld hitTime
    fmul rayX
    fadd ox
    fld1
    faddp st(1),st
    fmul roofFloatHalfTex3D
    fistp texU
    fld hitTime
    fmul rayZ
    fadd oz
    fchs
    fld1
    faddp st(1),st
    fmul roofFloatHalfTex3D
    fistp texV
    fld hitTime
    fmul rayZ
    fadd oz
    fmul roofFloatShade3D
    fadd roofFloatAmbient3D
    fistp shade
    mov eax,texV
    and eax,255
    mov ecx,texHeight
    imul eax,ecx
    shr eax,8
    imul eax,texWidth
    mov edx,texU
    and edx,255
    imul edx,texWidth
    shr edx,8
    add eax,edx
    mov esi,texture
    mov eax,[esi+eax*4]
    mov color,eax
    movzx eax,al
    imul eax,shade
    shr eax,8
    mov ebx,eax
    mov eax,color
    shr eax,8
    and eax,255
    imul eax,shade
    and eax,0FF00h
    or ebx,eax
    mov eax,color
    shr eax,16
    and eax,255
    imul eax,shade
    and eax,0FF00h
    shl eax,8
    or eax,ebx
    cmp roofCityPass3D,0
    je roof_round_color_ready
    invoke ShadeRoofCityPixel3D,eax,pixelDepth,256,material
    mov ecx,edi
    shr ecx,2
    mov edx,roofPixelGlow3D
    mov roofGlowMask3D[ecx],dl
roof_round_color_ready:
    mov screenBuffer[edi],eax
    cmp hallLevel3D,HALL_ROOF
    jne @F
    mov ecx,edi
    shr ecx,2
    mov edx,roofCityPass3D
    mov roofCityMask3D[ecx],dl
@@:
    mov eax,pixelDepth
    mov cityDepthBuffer3D[edi],eax
roof_round_next:
    add edi,4
    inc column
    mov eax,column
    cmp eax,rightPx
    jbe roof_round_pixel
    inc row
    mov eax,row
    cmp eax,bottomPx
    jbe roof_round_row
roof_round_done:
    ret
DrawRoofEllipsoid3D ENDP

; Closed furniture parts use material surfaces, never pictures of whole chairs.
DrawRoofSolid3D PROC uses ebx esi x0:DWORD,x1:DWORD,y0:DWORD,y1:DWORD,z0:DWORD,z1:DWORD,mat:DWORD
    mov eax,x0
    cmp playerX,eax
    jge @F
    invoke DrawCityVertical3D,0,x0,y0,y1,z0,z1,mat
@@:
    mov eax,x1
    cmp playerX,eax
    jle @F
    invoke DrawCityVertical3D,0,x1,y0,y1,z0,z1,mat
@@:
    mov eax,y0
    cmp playerY,eax
    jge @F
    invoke DrawCityVertical3D,1,y0,x0,x1,z0,z1,mat
@@:
    mov eax,y1
    cmp playerY,eax
    jle @F
    invoke DrawCityVertical3D,1,y1,x0,x1,z0,z1,mat
@@:
    mov eax,z1
    cmp viewEye3D,eax
    jle @F
    invoke DrawCityHorizontal3D,x0,x1,y0,y1,z1,mat
@@:
    ret
DrawRoofSolid3D ENDP

DrawRoofPadding3D PROC uses ebx esi edi centreX:DWORD,centreY:DWORD,centreZ:DWORD,rx:DWORD,ry:DWORD,rz:DWORD,mat:DWORD
    local x0:DWORD,x1:DWORD,y0:DWORD,y1:DWORD,z0:DWORD,z1:DWORD
    local insetX0:DWORD,insetX1:DWORD,insetY0:DWORD,insetY1:DWORD,loZ:DWORD,hiZ:DWORD
    mov eax,centreX
    sub eax,rx
    mov x0,eax
    add eax,FP_1*35/1000
    mov insetX0,eax
    mov eax,centreX
    add eax,rx
    mov x1,eax
    sub eax,FP_1*35/1000
    mov insetX1,eax
    mov eax,centreY
    sub eax,ry
    mov y0,eax
    add eax,FP_1*35/1000
    mov insetY0,eax
    mov eax,centreY
    add eax,ry
    mov y1,eax
    sub eax,FP_1*35/1000
    mov insetY1,eax
    mov eax,centreZ
    sub eax,rz
    mov z0,eax
    add eax,FP_1*35/1000
    mov loZ,eax
    mov eax,centreZ
    add eax,rz
    mov z1,eax
    sub eax,FP_1*35/1000
    mov hiZ,eax
    invoke DrawRoofSolid3D,insetX0,insetX1,insetY0,insetY1,z0,z1,mat
    invoke DrawRoofSolid3D,x0,x1,insetY0,insetY1,loZ,hiZ,mat
    invoke DrawRoofSolid3D,insetX0,insetX1,y0,y1,loZ,hiZ,mat
    ret
DrawRoofPadding3D ENDP

DrawRoofUpholstery3D PROC uses ebx esi edi centreX:DWORD,frontY:DWORD,kind:DWORD
    local x0:DWORD,x1:DWORD,y1:DWORD,halfWidth:DWORD,count:DWORD,seatZ:DWORD,backZ:DWORD
    local xa:DWORD,xb:DWORD,ya:DWORD,yb:DWORD,za:DWORD,zb:DWORD
    mov halfWidth,FP_1*120/100
    mov count,3
    mov seatZ,FP_1*45/100
    mov backZ,FP_1*92/100
    mov ecx,FP_1*90/100
    cmp kind,0
    je @F
    mov halfWidth,FP_1*46/100
    mov count,1
    mov ecx,FP_1*86/100
    cmp kind,2
    jb @F
    mov halfWidth,FP_1*27/100
    mov seatZ,FP_1*78/100
    mov backZ,FP_1*108/100
    mov ecx,FP_1*48/100
@@:
    mov eax,centreX
    sub eax,halfWidth
    mov x0,eax
    mov eax,centreX
    add eax,halfWidth
    mov x1,eax
    mov eax,frontY
    add eax,ecx
    mov y1,eax
    ; Four metal feet, solid armrests, a seat base and separate upholstered pads.
    xor esi,esi
roof_furniture_foot:
    mov eax,x0
    add eax,FP_1*8/100
    test esi,1
    jz @F
    mov eax,x1
    sub eax,FP_1*12/100
@@:
    mov xa,eax
    add eax,FP_1*4/100
    mov xb,eax
    mov eax,frontY
    add eax,FP_1*8/100
    test esi,2
    jz @F
    mov eax,y1
    sub eax,FP_1*12/100
@@:
    mov ya,eax
    add eax,FP_1*4/100
    mov yb,eax
    mov eax,seatZ
    sub eax,FP_1*12/100
    invoke DrawRoofSolid3D,xa,xb,ya,yb,0,eax,ROOF_METAL
    inc esi
    cmp esi,4
    jb roof_furniture_foot
    mov eax,seatZ
    sub eax,FP_1*14/100
    mov za,eax
    add eax,FP_1*5/100
    invoke DrawRoofSolid3D,x0,x1,frontY,y1,za,eax,ROOF_TEAL
    mov eax,y1
    sub eax,FP_1*14/100
    mov ya,eax
    invoke DrawRoofSolid3D,x0,x1,ya,y1,seatZ,backZ,ROOF_TEAL
    mov eax,x0
    add eax,FP_1*12/100
    mov xa,eax
    mov eax,x1
    sub eax,FP_1*12/100
    mov xb,eax
    ; Soft rectangular cushion edges are inset in three shallow bands.
    xor esi,esi
roof_furniture_pad:
    mov eax,xb
    sub eax,xa
    xor edx,edx
    div count
    mov edi,eax
    imul eax,esi
    add eax,xa
    add eax,FP_1/100
    mov ebx,eax
    add ebx,edi
    sub ebx,FP_1*2/100
    mov ecx,frontY
    add ecx,FP_1*5/100
    mov edx,y1
    sub edx,FP_1*16/100
    mov za,eax
    mov zb,ebx
    mov ya,ecx
    mov yb,edx
    mov eax,seatZ
    sub eax,FP_1*9/100
    mov eax,za
    add eax,zb
    sar eax,1
    mov ebx,zb
    sub ebx,za
    sar ebx,1
    mov ecx,ya
    add ecx,yb
    sar ecx,1
    mov edx,yb
    sub edx,ya
    sar edx,1
    mov edi,seatZ
    sub edi,FP_1*4/100
    invoke DrawRoofPadding3D,eax,ecx,edi,ebx,edx,FP_1*8/100,ROOF_IVORY
    mov eax,za
    add eax,FP_1*2/100
    mov ebx,zb
    sub ebx,FP_1*2/100
    mov ecx,ya
    add ecx,FP_1*2/100
    mov edx,yb
    sub edx,FP_1*2/100
    mov ya,ecx
    mov yb,edx
    mov ecx,seatZ
    add ecx,FP_1*2/100
    ; Back cushions are real thin volumes, not alpha views pasted on each side.
    mov eax,y1
    sub eax,FP_1*22/100
    mov ya,eax
    add eax,FP_1*9/100
    mov yb,eax
    mov eax,seatZ
    add eax,FP_1*2/100
    mov ecx,backZ
    sub ecx,FP_1*3/100
    add eax,ecx
    sar eax,1
    mov edi,eax
    mov eax,za
    add eax,zb
    sar eax,1
    mov ebx,zb
    sub ebx,za
    sar ebx,1
    mov ecx,ya
    add ecx,yb
    sar ecx,1
    invoke DrawRoofPadding3D,eax,ecx,edi,ebx,FP_1*9/100,FP_1*23/100,ROOF_IVORY
    inc esi
    cmp esi,count
    jb roof_furniture_pad
    cmp kind,2
    jae roof_furniture_done
    mov eax,seatZ
    add eax,FP_1*17/100
    mov zb,eax
    mov eax,x0
    add eax,FP_1*11/100
    invoke DrawRoofSolid3D,x0,eax,frontY,y1,seatZ,zb,ROOF_TEAL
    mov eax,x1
    sub eax,FP_1*11/100
    invoke DrawRoofSolid3D,eax,x1,frontY,y1,seatZ,zb,ROOF_TEAL
roof_furniture_done:
    ret
DrawRoofUpholstery3D ENDP

DrawRoofPlanter3D PROC uses ebx esi x0:DWORD,x1:DWORD,y0:DWORD,y1:DWORD
    local xa:DWORD,xb:DWORD,ya:DWORD,yb:DWORD
    invoke DrawRoofSolid3D,x0,x1,y0,y1,0,FP_1*42/100,ROOF_STONE
    mov eax,x0
    add eax,FP_1*4/100
    mov xa,eax
    mov eax,x1
    sub eax,FP_1*4/100
    mov xb,eax
    mov eax,y0
    add eax,FP_1*4/100
    mov ya,eax
    mov eax,y1
    sub eax,FP_1*4/100
    mov yb,eax
    invoke DrawCityHorizontal3D,xa,xb,ya,yb,FP_1*425/1000,ROOF_EARTH
    ; Several separated foliage tufts give the bed depth from either end.
    mov esi,xa
roof_planter_tuft:
    mov ebx,esi
    add ebx,FP_1*34/100
    cmp ebx,xb
    jae roof_planter_done
    mov eax,ya
    add eax,FP_1*10/100
    invoke DrawCityVertical3D,1,eax,esi,ebx,FP_1*43/100,FP_1*85/100,ROOF_FOLIAGE
    mov eax,yb
    sub eax,FP_1*10/100
    invoke DrawCityVertical3D,1,eax,esi,ebx,FP_1*43/100,FP_1*78/100,ROOF_FOLIAGE
    mov eax,esi
    add eax,FP_1*17/100
    invoke DrawCityVertical3D,0,eax,ya,yb,FP_1*43/100,FP_1*85/100,ROOF_FOLIAGE
    add esi,FP_1*38/100
    jmp roof_planter_tuft
roof_planter_done:
    ret
DrawRoofPlanter3D ENDP

UpdateRoofGuests3D PROC uses ebx esi edi milliseconds:DWORD
    local px:DWORD,py:DWORD,stepSize:DWORD,savedSeat:DWORD,savedLean:DWORD
    mov eax,milliseconds
    add roofGuestClock3D,eax
    imul eax,38
    mov stepSize,eax
    mov eax,roofSeat3D
    mov savedSeat,eax
    mov eax,roofLean3D
    mov savedLean,eax
    mov roofSeat3D,0
    mov roofLean3D,0
    xor esi,esi
roof_person_update:
    mov roofGuestMoving3D[esi*4],0
    mov eax,milliseconds
    cmp roofGuestWait3D[esi*4],eax
    jbe roof_person_step
    sub roofGuestWait3D[esi*4],eax
    jmp roof_person_next
roof_person_step:
    mov roofGuestWait3D[esi*4],0
    mov eax,roofGuestX3D[esi*4]
    mov px,eax
    mov eax,roofGuestY3D[esi*4]
    mov py,eax
    mov eax,roofGuestDir3D[esi*4]
    mov ebx,stepSize
    cmp eax,0
    jne @F
    add px,ebx
    jmp roof_person_check
@@:
    cmp eax,1
    jne @F
    sub px,ebx
    jmp roof_person_check
@@:
    cmp eax,2
    jne @F
    add py,ebx
    jmp roof_person_check
@@:
    sub py,ebx
roof_person_check:
    invoke RoofCanWalk3D,px,py
    test eax,eax
    jz roof_person_turn
    mov eax,px
    sub eax,playerX
    cdq
    xor eax,edx
    sub eax,edx
    mov ebx,eax
    mov eax,py
    sub eax,playerY
    cdq
    xor eax,edx
    sub eax,edx
    add eax,ebx
    cmp eax,FP_1*7/10
    jb roof_person_turn
    mov eax,px
    mov roofGuestX3D[esi*4],eax
    mov eax,py
    mov roofGuestY3D[esi*4],eax
    mov roofGuestMoving3D[esi*4],1
    mov eax,stepSize
    add roofGuestDistance3D[esi*4],eax
    add roofGuestStep3D[esi*4],eax
    cmp roofGuestStep3D[esi*4],FP_1*18/10
    jb roof_person_next
roof_person_turn:
    mov roofGuestStep3D[esi*4],0
    mov roofGuestWait3D[esi*4],1700
    inc roofGuestDir3D[esi*4]
    and roofGuestDir3D[esi*4],3
roof_person_next:
    inc esi
    cmp esi,ROOF_GUEST_COUNT
    jb roof_person_update
    mov eax,savedSeat
    mov roofSeat3D,eax
    mov eax,savedLean
    mov roofLean3D,eax
    ret
UpdateRoofGuests3D ENDP

CheckRoofRail3D PROC
    mov roofLeanSide3D,-1
    cmp playerY,FP_1*191/10
    jb @F
    cmp playerAngle,64
    jb @F
    cmp playerAngle,192
    ja @F
    mov roofLeanSide3D,0
@@:
    cmp playerX,FP_1*272/10
    jb @F
    mov eax,playerAngle
    add eax,64
    and eax,511
    cmp eax,128
    ja @F
    mov roofLeanSide3D,1
@@:
    cmp playerX,FP_1*128/10
    ja @F
    cmp playerAngle,192
    jb @F
    cmp playerAngle,320
    ja @F
    ; The western drinks counter is not a handrail approach.
    cmp playerY,11*FP_1
    jb roof_check_west_rail
    cmp playerY,17*FP_1
    jbe @F
roof_check_west_rail:
    mov roofLeanSide3D,2
@@:
    cmp roofLeanSide3D,-1
    je @F
    mov interactTargetId,INTERACT_ROOF_RAIL
    mov interactPromptPtr,OFFSET roofLeanPrompt3D
@@:
    ret
CheckRoofRail3D ENDP

StartRoofLean3D PROC
    mov eax,playerX
    mov roofReturnX3D,eax
    mov eax,playerY
    mov roofReturnY3D,eax
    mov eax,playerAngle
    mov roofReturnAngle3D,eax
    mov roofLeanAngle3D,128
    mov eax,playerX
    mov edx,FP_1*1975/100
    cmp roofLeanSide3D,0
    je roof_start_lean_check
    mov eax,FP_1*2775/100
    mov edx,playerY
    mov roofLeanAngle3D,0
    cmp roofLeanSide3D,1
    je roof_start_lean_check
    mov eax,FP_1*1225/100
    mov roofLeanAngle3D,256
roof_start_lean_check:
    push eax
    push edx
    invoke RoofCanWalk3D,eax,edx
    mov ecx,eax
    pop edx
    pop eax
    test ecx,ecx
    jz roof_start_lean_done
    mov playerX,eax
    mov playerY,edx
    mov eax,roofLeanAngle3D
    mov playerAngle,eax
    mov roofLean3D,1
    mov roofLeanTime3D,0
    call UpdateCamera3D
roof_start_lean_done:
    ret
StartRoofLean3D ENDP

UpdateRoofLook3D PROC
    cmp roofLean3D,0
    je roof_look_done
    mov eax,playerAngle
    sub eax,roofLeanAngle3D
    add eax,256
    and eax,511
    sub eax,256
    cmp eax,104
    jle @F
    mov eax,104
@@:
    cmp eax,-104
    jge @F
    mov eax,-104
@@:
    add eax,roofLeanAngle3D
    and eax,511
    mov playerAngle,eax
    call UpdateCamera3D
roof_look_done:
    ret
UpdateRoofLook3D ENDP

RenderRoofLean3D PROC uses ebx esi
    local anchorX:DWORD,anchorY:DWORD,depth:DWORD,left:DWORD,widthPx:DWORD,heightPx:DWORD
    cmp roofLean3D,0
    je roof_hands_done
    cmp engineMode,MODE_WALK
    jne roof_hands_done
    mov eax,roofLeanTime3D
    imul eax,31
    xor edx,edx
    mov ecx,1100
    div ecx
    mov esi,eax
    ; Project the fixed rail contact instead of rotating the hands with the head.
    mov ebx,roofLeanAngle3D
    and ebx,511
    mov eax,tableCos[ebx*4]
    mov ecx,FP_1*115/100
    imul ecx
    shrd eax,edx,16
    add eax,playerX
    mov anchorX,eax
    mov eax,tableSin[ebx*4]
    imul ecx
    shrd eax,edx,16
    add eax,playerY
    mov anchorY,eax
    invoke ProjectCityPoint3D,anchorX,anchorY
    cmp edx,FP_1/5
    jle roof_hands_done
    mov depth,edx
    mov left,eax
    mov roofHandsContactX3D,eax
    mov eax,640*FP_1*115/100
    cdq
    idiv depth
    mov widthPx,eax
    mov roofHandsWidth3D,eax
    shr eax,1
    sub left,eax
    mov eax,widthPx
    shr eax,1
    mov heightPx,eax
    mov eax,viewEye3D
    sub eax,ROOF_RAIL_HEIGHT
    imul eax,480
    cdq
    idiv depth
    add eax,viewHorizon3D
    mov ebx,eax
    mov eax,widthPx
    imul eax,166
    xor edx,edx
    mov ecx,640
    div ecx
    sub ebx,eax
    invoke DrawRoofHandsPlane3D,esi,left,widthPx
roof_hands_done:
    ret
RenderRoofLean3D ENDP

; Keep the forearms in the first-person view; shear their contact line onto the rail.
DrawRoofHandsPlane3D PROC uses ebx esi edi frame:DWORD,left:DWORD,scaleW:DWORD
    local source:DWORD,col:DWORD,normalX:DWORD,normalY:DWORD,denom:DWORD
    local depth:DWORD,srcX:DWORD,srcY:DWORD,stepY:DWORD,row:DWORD,lastRow:DWORD
    local extension:DWORD,shiftDown:DWORD
    cmp roofHandsArt3D.pixels,0
    je roof_hands_plane_done
    mov eax,frame
    cmp eax,roofHandsArt3D.frames
    jae roof_hands_plane_done
    imul eax,640*320*4
    add eax,roofHandsArt3D.pixels
    mov source,eax
    mov eax,roofLeanAngle3D
    and eax,511
    mov ecx,tableCos[eax*4]
    mov normalX,ecx
    mov ecx,tableSin[eax*4]
    mov normalY,ecx
    mov eax,FP_1*640
    cdq
    idiv scaleW
    mov stepY,eax
    mov col,0
roof_hands_plane_column:
    cmp col,640
    jge roof_hands_plane_done
    mov esi,col
    mov eax,cityRayX3D[esi*4]
    imul normalX
    shrd eax,edx,16
    mov ebx,eax
    mov eax,cityRayY3D[esi*4]
    imul normalY
    shrd eax,edx,16
    add eax,ebx
    cmp eax,FP_1/12
    jle roof_hands_plane_next
    mov denom,eax
    mov eax,FP_1*115/100
    mov ecx,FP_1
    imul ecx
    idiv denom
    cmp eax,16*FP_1
    jge roof_hands_plane_next
    mov depth,eax
    mov eax,col
    sub eax,left
    imul eax,640
    cdq
    idiv scaleW
    mov extension,0
    mov shiftDown,0
    cmp eax,8
    jge roof_hands_check_right_edge
    mov eax,scaleW
    xor edx,edx
    mov ecx,80
    div ecx
    add eax,left
    sub eax,col
    mov shiftDown,eax
    mov extension,1
    mov eax,8
    jmp roof_hands_source_column
roof_hands_check_right_edge:
    cmp eax,632
    jl roof_hands_source_column
    mov eax,scaleW
    imul eax,632
    xor edx,edx
    mov ecx,640
    div ecx
    add eax,left
    mov ecx,col
    sub ecx,eax
    mov shiftDown,ecx
    mov extension,1
    mov eax,631
roof_hands_source_column:
    mov srcX,eax
    mov eax,viewEye3D
    sub eax,ROOF_RAIL_HEIGHT
    imul eax,480
    cdq
    idiv depth
    add eax,viewHorizon3D
    mov ebx,eax
    mov eax,scaleW
    imul eax,166
    xor edx,edx
    mov ecx,640
    div ecx
    sub ebx,eax
    mov eax,shiftDown
    add ebx,eax
    mov denom,ebx
    mov eax,ebx
    test eax,eax
    jns @F
    xor eax,eax
@@:
    cmp eax,480
    jge roof_hands_plane_next
    mov row,eax
    mov eax,scaleW
    shr eax,1
    add eax,denom
    cmp eax,480
    jle @F
    mov eax,480
@@:
    mov lastRow,eax
    cmp extension,0
    je @F
    mov lastRow,480
@@:
    mov eax,row
    sub eax,denom
    imul eax,stepY
    mov srcY,eax
    mov eax,row
    imul eax,640*4
    mov edi,col
    lea edi,[eax+edi*4]
    mov ebx,srcX
    shl ebx,2
    add ebx,source
roof_hands_plane_pixel:
    mov eax,row
    cmp eax,lastRow
    jge roof_hands_plane_next
    mov edx,srcY
    sar edx,16
    cmp extension,0
    je @F
    cmp edx,314
    jl @F
    mov edx,313
@@:
    cmp edx,320
    jae roof_hands_plane_advance
    imul edx,640*4
    mov eax,[ebx+edx]
    cmp eax,80000000h
    jb roof_hands_plane_advance
    and eax,00FFFFFFh
    mov screenBuffer[edi],eax
    mov eax,edi
    shr eax,2
    mov roofCityMask3D[eax],0
roof_hands_plane_advance:
    mov eax,stepY
    add srcY,eax
    add edi,640*4
    inc row
    jmp roof_hands_plane_pixel
roof_hands_plane_next:
    inc col
    cmp col,640
    jb roof_hands_plane_column
roof_hands_plane_done:
    ret
DrawRoofHandsPlane3D ENDP

ShadeRoofNight3D PROC uses ebx esi edi
    cmp roofNight3D,0
    je roof_night_done
    ; Sky is already night artwork. Only shade actual depth-tested world pixels.
    xor edi,edi
roof_night_pixel:
    mov eax,edi
    shr eax,2
    cmp roofCityMask3D[eax],0
    jne roof_night_next
    cmp cityDepthBuffer3D[edi],ROOF_FAR_DEPTH
    jae roof_night_next
    mov eax,screenBuffer[edi]
    mov edx,eax
    and edx,000000FFh
    cmp edx,90
    ja @F
    mov edx,eax
    shr edx,16
    cmp edx,110
    ja roof_night_next
@@:
    and eax,00FCFCFCh
    shr eax,2
    add eax,00070D1Dh
    mov screenBuffer[edi],eax
roof_night_next:
    add edi,4
    cmp edi,SCREEN_SIZE*4
    jb roof_night_pixel
roof_night_done:
    ret
ShadeRoofNight3D ENDP

PrepareRoofFloorDepth3D PROC uses ebx esi edi
    local row:DWORD,depth:DWORD,px:DWORD,py:DWORD,deltaX:DWORD,deltaY:DWORD
    mov eax,viewHorizon3D
    inc eax
    mov row,eax
roof_floor_depth_row:
    mov ecx,row
    sub ecx,viewHorizon3D
    mov eax,viewEye3D
    imul eax,SCREEN_H
    cdq
    idiv ecx
    mov depth,eax
    imul cityRayX3D[0]
    shrd eax,edx,16
    add eax,playerX
    mov px,eax
    mov eax,depth
    imul cityRayY3D[0]
    shrd eax,edx,16
    add eax,playerY
    mov py,eax
    mov eax,depth
    imul playerPlaneX
    shrd eax,edx,16
    shl eax,1
    cdq
    mov ecx,SCREEN_W
    idiv ecx
    mov deltaX,eax
    mov eax,depth
    imul playerPlaneY
    shrd eax,edx,16
    shl eax,1
    cdq
    idiv ecx
    mov deltaY,eax
    mov eax,row
    imul eax,SCREEN_W*4
    mov edi,eax
    xor ebx,ebx
roof_floor_depth_pixel:
    cmp px,FP_1*109/10
    jl roof_floor_depth_next
    cmp px,FP_1*291/10
    jge roof_floor_depth_next
    cmp py,FP_1*9/10
    jl roof_floor_depth_next
    cmp py,FP_1*211/10
    jge roof_floor_depth_next
    mov eax,depth
    mov cityDepthBuffer3D[edi],eax
    mov eax,edi
    shr eax,2
    mov roofCityMask3D[eax],0
    cmp roofHDReady3D,1
    jne roof_floor_depth_next
    cmp engineMode,MODE_WALK
    jne roof_floor_depth_next
    mov roofCityMask3D[eax],3
roof_floor_depth_next:
    mov eax,deltaX
    add px,eax
    mov eax,deltaY
    add py,eax
    add edi,4
    inc ebx
    cmp ebx,SCREEN_W
    jb roof_floor_depth_pixel
    inc row
    cmp row,SCREEN_H
    jb roof_floor_depth_row
    ret
PrepareRoofFloorDepth3D ENDP

RenderRoofDistrict3D PROC uses ebx esi edi
    local x0:DWORD,x1:DWORD,y0:DWORD,y1:DWORD,z:DWORD,mat:DWORD,roofZ:DWORD
    local screenX:DWORD,centreDepth:DWORD,middle:DWORD,ridgeZ:DWORD
    xor esi,esi
roof_district_building:
    imul edi,esi,28
    mov eax,roofDistrict3D[edi]
    mov x0,eax
    mov eax,roofDistrict3D[edi+4]
    mov x1,eax
    add eax,x0
    sar eax,1
    mov ebx,roofDistrict3D[edi+8]
    mov y0,ebx
    mov ecx,roofDistrict3D[edi+12]
    mov y1,ecx
    add ebx,ecx
    sar ebx,1
    invoke ProjectCityPoint3D,eax,ebx
    cmp edx,-12*FP_1
    jle roof_district_next
    mov centreDepth,edx
    mov screenX,eax
    cmp edx,12*FP_1
    jle roof_district_visible
    mov eax,x1
    sub eax,x0
    add eax,y1
    sub eax,y0
    imul eax,SCREEN_H
    cdq
    idiv centreDepth
    mov edx,screenX
    add edx,eax
    cmp edx,0
    jl roof_district_next
    neg eax
    add eax,screenX
    cmp eax,SCREEN_W
    jg roof_district_next
roof_district_visible:
    mov eax,roofDistrict3D[edi+16]
    mov z,eax
    mov eax,roofDistrict3D[edi+20]
    mov mat,eax
    invoke DrawCityBoxSides3D,x0,x1,y0,y1,ROOF_CITY_STREET_Z,z,mat
    mov eax,z
    add eax,FP_1/6
    mov roofZ,eax
    invoke DrawRoofSolid3D,x0,x1,y0,y1,z,eax,ROOF_PLASTER
    cmp mat,ROOF_MODERN_FACADE
    jae roof_city_flat_roof
    cmp centreDepth,100*FP_1
    jle @F
roof_city_flat_roof:
    mov eax,roofZ
    add eax,FP_1/20
    invoke DrawCityHorizontal3D,x0,x1,y0,y1,eax,ROOF_CITY_ROOF
    jmp roof_district_next
@@:
    ; Stepped low mansards, dormers and chimneys give the skyline real parallax.
    mov ebx,x0
    add ebx,FP_1*6/10
    mov ecx,x1
    sub ecx,FP_1*6/10
    mov edx,y0
    add edx,FP_1*6/10
    mov eax,y1
    sub eax,FP_1*6/10
    mov x0,ebx
    mov x1,ecx
    mov y0,edx
    mov y1,eax
    mov eax,roofZ
    add eax,FP_1*24/10
    mov ridgeZ,eax
    mov eax,x1
    sub eax,x0
    mov edx,y1
    sub edx,y0
    cmp eax,edx
    ja roof_mansard_ridge_x
    mov eax,x0
    add eax,x1
    sar eax,1
    mov middle,eax
    invoke DrawRoofSlope3D,0,x0,middle,y0,y1,roofZ,FP_1*24/10,ROOF_CITY_ROOF
    invoke DrawRoofSlope3D,0,middle,x1,y0,y1,ridgeZ,-FP_1*24/10,ROOF_CITY_ROOF
    jmp roof_mansard_chimney
roof_mansard_ridge_x:
    mov eax,y0
    add eax,y1
    sar eax,1
    mov middle,eax
    invoke DrawRoofSlope3D,1,x0,x1,y0,middle,roofZ,FP_1*24/10,ROOF_CITY_ROOF
    invoke DrawRoofSlope3D,1,x0,x1,middle,y1,ridgeZ,-FP_1*24/10,ROOF_CITY_ROOF
roof_mansard_chimney:
    mov eax,ridgeZ
    mov roofZ,eax
    mov eax,x0
    add eax,FP_1/2
    mov ebx,y0
    add ebx,FP_1/2
    mov ecx,z
    add ecx,FP_1*24/10
    invoke DrawRoofSolid3D,x0,eax,y0,ebx,roofZ,ecx,ROOF_STONE
roof_district_next:
    inc esi
    cmp esi,ROOF_BUILDING_COUNT
    jb roof_district_building
    ret
RenderRoofDistrict3D ENDP

RenderRoofCityGround3D PROC uses ebx esi edi
    local row:DWORD,depth:DWORD,px:DWORD,py:DWORD,deltaX:DWORD,deltaY:DWORD
    local road:DWORD,stone:DWORD,water:DWORD,tex:DWORD,ix:DWORD,iy:DWORD
    local sampleDepth:DWORD,planeHeight:DWORD,waterHeight:DWORD
    mov eax,viewEye3D
    sub eax,ROOF_CITY_STREET_Z
    mov planeHeight,eax
    add eax,2*FP_1
    mov waterHeight,eax
    invoke ResolveRoofSurface3D,ROOF_CITY_ROAD
    mov road,eax
    invoke ResolveRoofSurface3D,ROOF_CITY_WATER
    mov water,eax
    invoke ResolveRoofSurface3D,ROOF_STONE
    mov stone,eax
    cmp road,0
    jne @F
    mov road,0FFFFFFFFh
@@:
    cmp water,0
    jne @F
    mov water,0FFFFFFFDh
@@:
    cmp stone,0
    jne @F
    mov stone,0FFFFFFFEh
@@:
    mov roofGroundRoadPixels3D,0
    mov roofGroundWaterPixels3D,0
    mov eax,viewHorizon3D
    inc eax
    mov row,eax
roof_city_ground_row:
    mov ecx,row
    sub ecx,viewHorizon3D
    mov eax,viewEye3D
    sub eax,ROOF_CITY_STREET_Z
    imul eax,SCREEN_H
    cdq
    idiv ecx
    cmp eax,ROOF_FAR_DEPTH
    jae roof_city_ground_next_row
    mov depth,eax
    imul cityRayX3D[0]
    shrd eax,edx,16
    add eax,playerX
    mov px,eax
    mov eax,depth
    imul cityRayY3D[0]
    shrd eax,edx,16
    add eax,playerY
    mov py,eax
    mov eax,depth
    imul playerPlaneX
    shrd eax,edx,16
    shl eax,1
    cdq
    mov ecx,SCREEN_W
    idiv ecx
    mov deltaX,eax
    mov eax,depth
    imul playerPlaneY
    shrd eax,edx,16
    shl eax,1
    cdq
    idiv ecx
    mov deltaY,eax
    mov eax,row
    imul eax,SCREEN_W*4
    mov edi,eax
    xor ebx,ebx
roof_city_ground_pixel:
    mov eax,depth
    mov sampleDepth,eax
    cmp px,-600*FP_1
    jl roof_city_ground_advance
    cmp px,600*FP_1
    jg roof_city_ground_advance
    cmp py,-600*FP_1
    jl roof_city_ground_advance
    cmp py,600*FP_1
    jg roof_city_ground_advance
    mov eax,depth
    cmp eax,cityDepthBuffer3D[edi]
    jae roof_city_ground_advance
    mov eax,px
    sar eax,16
    sub eax,20
    cdq
    mov ecx,36
    idiv ecx
    test edx,edx
    jns @F
    add edx,36
@@:
    mov ix,edx
    mov eax,py
    sar eax,16
    sub eax,11
    cdq
    idiv ecx
    test edx,edx
    jns @F
    add edx,36
@@:
    mov iy,edx
    mov eax,road
    mov tex,eax
    ; Narrow stone pavements border the connected eight-metre carriageways.
    cmp ix,13
    jb roof_city_ground_y_street
    cmp ix,23
    ja roof_city_ground_y_street
    cmp ix,14
    jb roof_city_ground_pavement
    cmp ix,22
    ja roof_city_ground_pavement
    jmp roof_city_ground_canal
roof_city_ground_y_street:
    cmp iy,13
    jb roof_city_ground_pavement
    cmp iy,23
    ja roof_city_ground_pavement
    cmp iy,14
    jb roof_city_ground_pavement
    cmp iy,22
    jbe roof_city_ground_canal
roof_city_ground_pavement:
    mov eax,stone
    mov tex,eax
roof_city_ground_canal:
    cmp py,29*FP_1
    jl roof_city_ground_sample
    cmp py,76*FP_1
    jg roof_city_ground_sample
    cmp py,60*FP_1
    jge roof_city_old_channel
    cmp px,70*FP_1
    jl roof_city_ground_sample
    jmp roof_city_new_bridges
roof_city_old_channel:
    mov eax,px
    add eax,34*FP_1
    add eax,3*FP_1
    cmp eax,6*FP_1
    jbe roof_city_ground_sample
    mov eax,px
    sub eax,38*FP_1-3*FP_1
    cmp eax,6*FP_1
    jbe roof_city_ground_sample
roof_city_new_bridges:
    mov eax,px
    sub eax,110*FP_1-3*FP_1
    cmp eax,6*FP_1
    jbe roof_city_ground_sample
    mov eax,px
    sub eax,254*FP_1-3*FP_1
    cmp eax,6*FP_1
    jbe roof_city_ground_sample
    mov eax,px
    sub eax,398*FP_1-3*FP_1
    cmp eax,6*FP_1
    jbe roof_city_ground_sample
roof_city_ground_water:
    mov eax,water
    mov tex,eax
    mov eax,depth
    imul waterHeight
    idiv planeHeight
    mov sampleDepth,eax
roof_city_ground_sample:
    mov eax,py
    sar eax,9
    and eax,511
    shl eax,9
    mov edx,px
    sar edx,9
    and edx,511
    add eax,edx
    mov esi,tex
    cmp esi,stone
    jne @F
    shr eax,2
    and eax,65535
@@:
    cmp esi,0FFFFFFFDh
    jb roof_city_ground_texel
    mov eax,00343B42h
    cmp esi,0FFFFFFFFh
    je roof_city_ground_texel_ready
    mov eax,0063686Ah
    cmp esi,0FFFFFFFEh
    je roof_city_ground_texel_ready
    mov eax,00183848h
    jmp roof_city_ground_texel_ready
roof_city_ground_texel:
    mov eax,[esi+eax*4]
roof_city_ground_texel_ready:
    and eax,00FFFFFFh
    cmp esi,road
    jne @F
    inc roofGroundRoadPixels3D
@@:
    cmp esi,water
    jne roof_city_ground_lighting
    inc roofGroundWaterPixels3D
    cmp roofNight3D,0
    je @F
    mov eax,006E6E6Eh
    jmp roof_city_ground_lighting
@@:
    mov edx,px
    sar edx,11
    add edx,animationClock3D
    shr edx,4
    and edx,31
    cmp edx,3
    ja roof_city_ground_lighting
    add eax,0020160Ch
roof_city_ground_lighting:
    invoke SampleRoofGroundLight3D,eax,px,py
    invoke ShadeRoofCityPixel3D,eax,sampleDepth,225,ROOF_CITY_ROAD
    mov screenBuffer[edi],eax
    mov eax,edi
    shr eax,2
    mov roofCityMask3D[eax],1
    mov eax,sampleDepth
    mov cityDepthBuffer3D[edi],eax
roof_city_ground_advance:
    mov eax,deltaX
    add px,eax
    mov eax,deltaY
    add py,eax
    add edi,4
    inc ebx
    cmp ebx,SCREEN_W
    jb roof_city_ground_pixel
roof_city_ground_next_row:
    inc row
    cmp row,SCREEN_H
    jb roof_city_ground_row
    ; Continuous stone quays and three traversing bridge decks.
    invoke DrawCityBoxSides3D,-190*FP_1,230*FP_1,59*FP_1,60*FP_1,ROOF_CITY_STREET_Z-2*FP_1,ROOF_CITY_STREET_Z,ROOF_STONE
    invoke DrawCityBoxSides3D,-190*FP_1,230*FP_1,76*FP_1,77*FP_1,ROOF_CITY_STREET_Z-2*FP_1,ROOF_CITY_STREET_Z,ROOF_STONE
    mov esi,-34*FP_1
    mov ebx,3
roof_city_bridge:
    mov eax,esi
    sub eax,3*FP_1
    mov edx,esi
    add edx,3*FP_1
    invoke DrawCityHorizontal3D,eax,edx,59*FP_1,77*FP_1,ROOF_CITY_STREET_Z,ROOF_CITY_ROAD
    add esi,72*FP_1
    dec ebx
    jnz roof_city_bridge
roof_city_ground_done:
    ret
RenderRoofCityGround3D ENDP

RenderRoofLandmarks3D PROC uses ebx esi edi
    mov roofLandmarkLight3D,1
    lea esi,roofLandmarkParts3D
    mov ebx,ROOF_LANDMARK_PARTS
roof_landmark_piece:
    cmp DWORD PTR [esi],0
    jne roof_landmark_round
    invoke DrawRoofSolid3D,[esi+4],[esi+8],[esi+12],[esi+16],[esi+20],[esi+24],[esi+28]
    jmp roof_landmark_next
roof_landmark_round:
    cmp DWORD PTR [esi],2
    jne @F
    invoke DrawRoofPyramid3D,[esi+4],[esi+8],[esi+12],[esi+16],[esi+20],[esi+24],[esi+28]
    jmp roof_landmark_next
@@:
    invoke DrawRoofEllipsoid3D,[esi+4],[esi+8],[esi+12],[esi+16],[esi+20],[esi+24],[esi+28]
roof_landmark_next:
    add esi,32
    dec ebx
    jnz roof_landmark_piece
    mov roofLandmarkLight3D,0
    ret
RenderRoofLandmarks3D ENDP

RenderRoofCityParks3D PROC uses ebx esi edi
    local px:DWORD,py:DWORD,x0:DWORD,x1:DWORD,y0:DWORD,y1:DWORD,treeX:DWORD,treeY:DWORD
    xor esi,esi
roof_city_park:
    mov eax,roofCityParks3D[esi*8]
    mov px,eax
    sub eax,12*FP_1
    mov x0,eax
    add eax,24*FP_1
    mov x1,eax
    mov eax,roofCityParks3D[esi*8+4]
    mov py,eax
    sub eax,12*FP_1
    mov y0,eax
    add eax,24*FP_1
    mov y1,eax
    invoke DrawCityHorizontal3D,x0,x1,y0,y1,ROOF_CITY_STREET_Z+FP_1/20,ROOF_CITY_LAWN
    mov eax,px
    sub eax,FP_1
    mov edx,px
    add edx,FP_1
    invoke DrawCityHorizontal3D,eax,edx,y0,y1,ROOF_CITY_STREET_Z+FP_1/10,ROOF_STONE
    xor ebx,ebx
roof_city_park_tree:
    mov eax,px
    sub eax,8*FP_1
    test ebx,1
    jz @F
    add eax,16*FP_1
@@:
    mov treeX,eax
    mov eax,ebx
    shr eax,1
    imul eax,8*FP_1
    add eax,py
    sub eax,8*FP_1
    mov treeY,eax
    mov eax,treeX
    sub eax,FP_1/8
    mov edx,treeX
    add edx,FP_1/8
    mov ecx,treeY
    sub ecx,FP_1/8
    mov edi,treeY
    add edi,FP_1/8
    invoke DrawRoofSolid3D,eax,edx,ecx,edi,ROOF_CITY_STREET_Z,ROOF_CITY_STREET_Z+3*FP_1,ROOF_STONE
    invoke DrawRoofEllipsoid3D,treeX,treeY,ROOF_CITY_STREET_Z+4*FP_1,FP_1*18/10,FP_1*18/10,FP_1*22/10,ROOF_CITY_LAWN
    inc ebx
    cmp ebx,6
    jb roof_city_park_tree
    inc esi
    cmp esi,ROOF_PARK_COUNT
    jb roof_city_park
    ret
RenderRoofCityParks3D ENDP