DirectX I

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DirectX I
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Direct3D Interface IDirect3D9

• Header d3d9.h
• Import library d3d9.lib
• IDirect3D9
• Applications use the methods of the IDirect3D9
  interface to create Microsoft Direct3D objects
  and set up the environment. This interface
  includes methods for enumerating and retrieving
  capabilities of the device
• The IDirect3D9 interface is obtained by calling
  the Direct3DCreate9 function
• LPDIRECT3D9 is long pointer for IDirect3D9
• typedef struct IDirect3D9 LPDIRECT3D9
• Declare a variable LPDIRECT3D9 d3d NULL

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Direct3D Interface IDirect3DDevice9

• IDirect3DDevice9
• Applications use the methods of the
  IDirect3DDevice9 interface to perform
  DrawPrimitive-based rendering, create resources,
  work with system-level variables, adjust gamma
  ramp levels, work with palettes, and create
  shaders.
• The IDirect3DDevice9 interface is obtained by
  calling the IDirect3D9CreateDevice method
• LPDirect3DDevice9 is long pointer for
  IDirect3DDevice9
• typedef struct IDirect3DDevice9
  LPDIRECT3DDEVICE9
• Declare a variable LPDIRECT3DDEVICE9 d3ddev
  NULL

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Create the Direct3D Object

• Initialize the main Direct3D object
• D3d Direct3DCreate9(D3D_SDK_VERSION)
• D3D_SDK_VERSION ensure that the header file
  version match the runtime DLL version
• Create the device upon which Direct3D will
  display output
• d3d-gtCreateDevice(
• D3DADAPTER_DEFAULT, //use default video
  card
• D3DDEVTYPE_HAL, // use the
  hardware renderer
• hwnd, // window handle
• D3DCREATE_SOFTWARE_VERTEXPROCESSING,
• // do not use TL (for
  compatibility)
• d3dpp, // presentation
  parameters
• d3ddev) // pointer to the
  new device
• TL transform and lighting, is handled by video
  card itself (since 2002), offload that work from
  the CPU

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Set Direct3D presentation parameters

• D3DPRESENT_PARAMETERS d3dpp
• clear out the struct to zero all values before
  use ZeroMemory(d3dpp, sizeof(d3dpp))
• Fill in the d3dpp struct with a few values, for
  example
• d3dpp.Windowed TRUE
• d3dpp.SwapEffect D3DSWAPEFFECT_DISCARD
• d3dpp.BackBufferFormat D3DFMT_UNKNOWN

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Draw on the Direct3D display

• Clears one or more surfaces such as a render
  target before each rendering frame
  IDirect3DDevice9Clear
• Applications must call IDirect3DDevice9BeginScen
  e before performing any rendering and must call
  IDirect3DDevice9EndScene when rendering is
  complete
• Presents the contents of the next buffer in the
  sequence of back buffers owned by the device
  IDirect3DDevice9Present

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Release the Direct3D Object and other things from
memory

• release the Direct3D device
• d3ddev-gtRelease()
• release the Direct3D object
• d3d-gtRelease()
• If not released, Direct3D will keep running in
  the memory

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Direct3D in Fullscreen Mode

• hWnd CreateWindow(
• APPTITLE, //window class
• APPTITLE, //title bar
• WS_EX_TOPMOST WS_VISIBLE WS_POPUP,
  //window style
• CW_USEDEFAULT, //x position of
  window
• CW_USEDEFAULT, //y position of
  window
• SCREEN_WIDTH, //width of the
  window
• SCREEN_HEIGHT, //height of the
  window
• NULL, //parent window
• NULL, //menu
• hInstance, //application
  instance
• NULL) //window parameters
• WS_EX_TOPMOST cause the window to take
  precedence over all other windows
• WS_VISIBLE WS_POPUP ensure that the window has
  focus and no longer includes a border or title
  bar
• main changing the presentation parameters
• d3dpp.Windowed FALSE
• d3dpp.BackBufferFormat D3DFMT_X8R8G8B8

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Surface

• Surfaces are an integral part of DirectX
• Surfaces are areas within memory (residing on the
  video card) that are used for the storage of
  image information
• Surfaces store images and textures and are used
  to represent the display buffers
• We will use two specific types of surfaces
• Display buffers
• Front buffer is the surface that represents the
  viewable area of the game window
• Back buffer is where all the drawing is done and
  is used to eliminate flickering
• Offscreen surfaces
• Areas of video or system memory that hold the
  graphics that the game needs

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IDirect3DSurface9

• Applications use the methods of the
  IDirect3DSurface9 interface to query and prepare
  surfaces
• typedef struct IDirect3DSurface9
  LPDIRECT3DSURFACE9
• Create a surface
• LPDIRECT3DSURFACE9 surface NULL

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IDirect3DDevice9GetBackBuffer Method

• Retrieves a back buffer from the device's swap
  chain
• HRESULT GetBackBuffer(          UINT iSwapChain,
      
• UINT BackBuffer,     
• D3DBACKBUFFER_TYPE Type,     
• IDirect3DSurface9 ppBackBuffer )
• Parameters
• iSwapChain in An unsigned integer specifying
  the swap chain.
• BackBuffer in Index of the back buffer object
  to return. Back buffers are numbered from 0 to
  the total number of back buffers minus one. A
  value of 0 returns the first back buffer, not the
  front buffer. The front buffer is not accessible
  through this method. Use IDirect3DDevice9GetFron
  tBufferData to retrieve a copy of the front
  buffer.
• Type in Stereo view is not supported in
  Microsoft DirectX 9.0, so the only valid value
  for this parameter is D3DBACKBUFFER_TYPE_MONO.
• ppBackBuffer out, retval Address of a pointer
  to an IDirect3DSurface9 interface, representing
  the returned back buffer surface

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IDirect3DDevice9CreateOffscreenPlainSurface

• Create an off-screen surface
• HRESULT CreateOffscreenPlainSurface(
• UINT Width,
• UINT Height,
• D3DFORMAT Format,
• DWORD Pool,
• IDirect3DSurface9 ppSurface,
• HANDLE pSharedHandle )
• Parameters
• Width in Width of the surface
• Height in Height of the surface
• Format in Format of the surface
• Pool in Surface pool type
• ppSurface out, retval Pointer to the
  IDirect3DSurface9 interface created
• pSharedHandle in Reserved. Set this parameter
  to NULL

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IDirect3DDevice9StretchRect

• Copy the contents of the source rectangle to the
  destination rectangle. The source rectangle can
  be stretched and filtered by the copy. This
  function is often used to change the aspect ratio
  of a video stream
• HRESULT StretchRect(
• IDirect3DSurface9 pSourceSurface,
• CONST RECT pSourceRect,
• IDirect3DSurface9 pDestSurface,
• CONST RECT pDestRect,
• D3DTEXTUREFILTERTYPE Filter )
• Parameters
• pSourceSurface in Pointer to the source
  surface.
• pSourceRect in Pointer to the source
  rectangle. A NULL for this parameter causes the
  entire source surface to be used.
• pDestSurface in Pointer to the destination
  surface.
• pDestRect in Pointer to the destination
  rectangle. A NULL for this parameter causes the
  entire destination surface to be used.
• Filter in Filter type. Allowable values are
  D3DTEXF_NONE, D3DTEXF_POINT, or D3DTEXF_LINEAR.

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D3DXLoadSurfaceFromFile Function

• Loads a surface from a file
• HRESULT WINAPI D3DXLoadSurfaceFromFile(          
  LPDIRECT3DSURFACE9 pDestSurface,     
• CONST PALETTEENTRY pDestPalette,     
• CONST RECT pDestRect,     
• LPCTSTR pSrcFile,     
• CONST RECT pSrcRect,     
• DWORD Filter,     
• D3DCOLOR ColorKey,     
• D3DXIMAGE_INFO pSrcInfo )
• Header d3dx9tex.h or d3dx9.h
• Import library d3dx9.lib
• D3DX stands for Direct3D extensions

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D3DXLoadSurfaceFromFile Function cont.

• Parameters
• pDestSurface in Pointer to an
  IDirect3DSurface9 interface. Specifies the
  destination surface, which receives the image.
• pDestPalette in Pointer to a PALETTEENTRY
  structure, the destination palette of 256 colors
  or NULL.
• pDestRect in Pointer to a RECT structure.
  Specifies the destination rectangle. Set this
  parameter to NULL to specify the entire surface.
• pSrcFile in Pointer to a string that specifies
  the filename. If the compiler settings require
  Unicode, the data type LPCTSTR resolves to
  LPCWSTR. Otherwise, the string data type resolves
  to LPCSTR.
• pSrcRect in Pointer to a RECT structure.
  Specifies the source rectangle. Set this
  parameter to NULL to specify the entire image.
• Filter in Combination of one or more
  D3DX_FILTER controlling how the image is
  filtered. Specifying D3DX_DEFAULT for this
  parameter is the equivalent of specifying
  D3DX_FILTER_TRIANGLE D3DX_FILTER_DITHER.
• ColorKey in D3DCOLOR value to replace with
  transparent black, or 0 to disable the colorkey.
  This is always a 32-bit ARGB color, independent
  of the source image format. Alpha is significant
  and should usually be set to FF for opaque color
  keys Thus, for opaque black, the value would be
  equal to 0xFF000000.
• pSrcInfo in, out Pointer to a D3DXIMAGE_INFO
  structure to be filled with a description of the
  data in the source image file, or NULL.

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load surface from file into newly created surface
example

• result D3DXLoadSurfaceFromFile(
• surface, //destination
  surface
• NULL, //destination
  palette
• NULL, //destination
  rectangle
• "legotron.bmp", //source filename
• NULL, //source
  rectangle
• D3DX_DEFAULT, //controls how image is
  filtered
• 0, //for
  transparency (0 for none)
• NULL) //source image info
  (usually NULL)