; ========================================================================================

align 16
export D3D9_Startup:

  sub rsp, 48h
  
; ----- ENTER -----


; ----------------------------
;   zero the interface ptrs
; ----------------------------
  xor eax, eax
  mov [pp_D3D], rax
  mov [pp_Device], rax
  mov [pp_Texture], rax

; -----------------------------------------------------------------
; HRESULT  Direct3DCreate9Ex(UINT SDKVersion, IDirect3D9EX **ppD3D)
; -----------------------------------------------------------------
  mov ecx, D3D_SDK_VERSION              ; p1: UINT SDKVersion
  lea rdx, pp_D3D                       ; p2: IDirect3D9EX **ppD3D
  call Direct3DCreate9Ex
    test eax, eax
    jnz >> .d3d9LError

; --------------------------------------
; zero D3DPRESENT_PARAMETERS structure
; --------------------------------------
  lea edx, d3dpp
  xor eax, eax                          ; fillvalue = 0
  mov ecx, sizeof(D3DPRESENT_PARAMETERS / 8) ; size /8 bytes per fill

: mov [edx], rax
  add edx, 8
  dec ecx
  jnz <

; --------------------------------------
; fill D3DPRESENT_PARAMETERS structure
; --------------------------------------
  mov D[d3dpp.BackBufferWidth], SCREENWIDTH       ; 1920
  mov D[d3dpp.BackBufferHeight], SCREENHEIGHT     ; 1080
  mov D[d3dpp.BackBufferFormat], D3DFMT_X8R8G8B8  ; 22
  mov D[d3dpp.BackBufferCount], 1
  mov D[d3dpp.SwapEffect], D3DSWAPEFFECT_FLIPEX   ; 5
  mov rax, [hWindow]
  mov [d3dpp.hDeviceWindow], rax
  mov D[d3dpp.Windowed], TRUE
  mov D[d3dpp.PresentationInterval], D3DPRESENT_INTERVAL_IMMEDIATE

; ------------------
; create the device
; ------------------
; HRESULT CreateDeviceEx(
  mov rcx, [pp_D3D]           ; p1: *this
  xor edx, edx                ; p2: UINT Adapter = 0
  mov r8d, D3DDEVTYPE_HAL     ; p3: D3DDEVTYPE DeviceType (1)
  mov r9, [hWindow]      ; p4: HWND hFocusWindow
  mov D[rsp+20h], D3DCREATE_HARDWARE_VERTEXPROCESSING ; p5: DWORD BehaviorFlags (40h)
  lea rax, d3dpp
  mov [rsp+28h], rax          ; p6: D3DPRESENT_PARAMETERS *pPresentationParameters
  xor eax, eax
  mov [rsp+30h], rax          ; p7: D3DDISPLAYMODEEX *pFullscreenDisplayMode
  lea rax, pp_Device
  mov [rsp+38h], rax          ; p8: IDirect3DDevice9Ex **ppReturnedDeviceInterface

  mov rax, [rcx]
  add rax, IDirect3D9Ex_CreateDeviceEx 
  call [rax]
    test eax, eax
    jnz >> .d3d9LError

; ------------------
; create the texture
; ------------------

; HRESULT CreateTexture
  mov rcx, [pp_Device]                  ; p1: *this
  mov edx, 1920                         ; p2: UINT Width
  mov r8d, 1080                         ; p3: UINT Height
  mov r9d, 1                            ; p4: UINT Levels
  mov D[rsp+20h], D3DUSAGE_DYNAMIC      ; p5: DWORD Usage
  mov D[rsp+28h], D3DFMT_X8R8G8B8       ; p6: D3DFORMAT Format
  mov D[rsp+30h], D3DPOOL_DEFAULT       ; p7: D3DPOOL Pool
  lea rax, pp_Texture
  mov [rsp+38h], rax                    ; p8: IDirect3DTexture9 **ppTexture
  xor eax, eax
  mov [rsp+40h], rax                    ; p9: HANDLE *pSharedHandle

  mov rax, [rcx]
  add rax, IDirect3DDevice9Ex_CreateTexture 
  call [rax]
    test eax, eax
    jnz >> .d3d9LError


; ----- EXIT -----

  mov eax, TRUE               ; return 1 if successful
  jmp > .d3d9LExit

.d3d9LError:
  xor rax, rax               ; return 0 if error

.d3d9LExit:
  add rsp, 48h
  ret

; ========================================================================================

align 16
export D3D9_Shutdown:

  sub rsp, 28h

; ----- Enter -----

  mov eax, [pp_D3D]
  or eax, eax
  jz >> .d3d9uExit

; release back buffer interface
  mov rcx, [pp_Texture]
  mov rax, [rcx]
  add eax, IDirect3DTexture9_Release
  call [rax]
    or eax, eax
    jnz >> .d3d9uExit
  
; release front buffer interface
  mov rcx, [pp_Device]
  mov rax, [rcx]
  add eax, IDirect3DDevice9Ex_Release
  call [rax]
    or eax, eax
    jnz >> .d3d9uExit

; release DirectDraw 7 interface
  mov rcx, [pp_D3D]
  mov rax, [rcx]
  add eax, IDirect3D9Ex_Release
  call [rax]
    or eax, eax
    jnz >> .d3d9uExit

; zero the DDraw interface ptrs
  xor eax, eax
  mov [pp_Texture], rax
  mov [pp_Device], rax
  mov [pp_D3D], rax


; -----  Exit  -----

.d3d9uExit:
  add rsp, 28h
  ret

; ========================================================================================