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Category Archives: d3d

This is a very long, very long, very long tutorial about how to get started with D3D in C++.

Check it out!

//////////////////////////////////////////
//                                      //
// Direct3D basics                      //
//                                      //
// You found this at bobobobo's weblog, //
// https://bobobobo.wordpress.com        //
//                                      //
// Creation date:  July 1/09 (HAPPY CANADA DAY! ) //
// Last modified:  July 3/09            //
//                                      //
//////////////////////////////////////////

#include <windows.h>
#include <stdio.h>
#include <stdlib.h>
#include <math.h>

#include <d3d9.h>      // core direct3d
#include <d3dx9.h>     // aux libs

#include <dxerr9.h>    // detailed error messages

#pragma comment(lib, "d3d9.lib")
#pragma comment(lib, "d3dx9.lib")  // aux libs
#ifdef _DEBUG
#pragma comment(lib,"d3dx9d.lib")
#else
#pragma comment(lib,"d3dx9.lib")
#endif

#pragma comment(lib, "dxerr9.lib")


// Macros.
#define SAFE_RELEASE(ptr) if(ptr) { ptr->Release(); ptr = NULL; }
#define CAST_AS_DWORD(x) *((DWORD*)&x)
#define PI 3.14159

struct Globals
{
  // Wrapping the Win32-related variables up
  // together in their own struct so they don't
  // get in the way of the Direct3D ones
  struct _Win
  {
    HINSTANCE hInstance;    // window app instance
    HWND hwnd;              // handle for the window
    HWND hConsole ;         // handle for the console window
    
    int width, height;      // the desired width and
    // height of the CLIENT AREA
    // (DRAWABLE REGION in Window)
  } win ;

  #pragma region DIRECT3D9 stuff
  ////////////////////////////
  // Declare The IDirect3D9 INTERFACE!!
  // IDirect3D9 interface
  IDirect3D9 * d3d ;        // represents the BEAST
  // that is Direct3D9 itself.  What's it for?
  
  // MSDN SAYS about the IDirect3D9 interface:
  // "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."

  // IDirect3DDevice9
  IDirect3DDevice9 * gpu ;  // represents the GPU

  // MSDN SAYS about the 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 ABOVE TWO variables are
  // very important to this application.
  
  // For both of these, notice how they
  // are BOTH POINTERS to an INTERFACE.

  // What's an interface?  Well, in a few words,
  // an INTERFACE is something you "face" to
  // interact with something.  Thru means of
  // the "INTERFACE" you get information from
  // the underlying system, or send commands
  // to the underlying system, without really
  // having to understand the underlying system
  // at all to do it.  You just have to know what
  // types of commands it expects to get.

  // For example, your car.

  // The "interface" of your car is its steering wheel,
  // its dials on the dash telling you what speed
  // you're going and the RPM's you're at so you
  // don't blow the engine redlining, and also,
  // the gas and brakes, so you can send commands
  // to the car to stop and go.

  // Notice how you don't have to know a THING
  // about how an internal combustion engine works
  // to get the car to go.  Because the car's INTERFACE
  // is SO abstract (simply PUSH THE PEDAL TO GO),
  // working the car becomes incredibly simple.

  // If the car didn't have such an abstract
  // interface (like, if REALLY crummy engineers
  // made a car), then to drive that crummy car,
  // you might have to put your hands into
  // the engine and carefully push
  // vaporized gas underneath a piston, then
  // push down on the piston until it goes POP!
  // Then the car would be going!
  
  // Anyway, point is, working with a system
  // THROUGH ITS INTERFACE that the system defines
  // makes working with the system SO easy, and
  // the system itself is a black box -- its internal
  // workings are hidden from you.  Like, you
  // don't even have to know what an internal
  // combustion engine IS to be able to
  // work a modern car.  Heck, for all you know,
  // it might not even be an internal combustion
  // engine!  (It might be electric).  That's another
  // beauty about interfaces:  You can swap out
  // the nitty gritty details of the implementation
  // (e.g. software updates / patches, or the
  // difference between Direct3D9 June 2008 release
  // and March 2009 release) without affecting 
  // the programs that USE those interfaces, so long
  // as you have not CHANGED the interface itself.

  // IN the case of Direct3D9, an IDirect3DDevice9 *
  // is a pointer to, let's just say the "dashboard" ON TOP
  // OF the Direct3D9 RENDERING MACHINE.

  // Inside, the Direct3D 3D graphics "engine" is VERY complex!
  // Especially when you get to rendering textures in 3D..
  // (see this book if you want to learn that stuff!)
  
  // But with Direct3D9, you don't have to understand
  // HOW 3d graphics actually gets drawn.  You only have to
  // understand the format that D3D expects, and pass it
  // your data that you want drawn in that format.

  // OK?  So hopefully that made a little bit of sense.
  // To me Direct3D seems slightly more "centralized"
  // than OpenGL does.  With OpenGL, the "interface"
  // is a set of C-style functions that all begin
  // with gl*.  OpenGL doesn't have an "INTERFACE"
  // in the OOP sense (but that set of gl* C functions
  // is still an 'interface' though, its just a very
  // different way of creating one!)

  // Anyway, on with it.
  #pragma endregion
};

///////////////////////////
// GLOBALS
// declare one struct Globals called g;
Globals g;
//
///////////////////////////


///////////////////////////
// FUNCTION PROTOTYPES
// Windows app functions.  If need help
// understanding these, see MostBasicWindow
// and FastWindowsProgram
LRESULT CALLBACK WndProc( HWND hwnd, UINT message, WPARAM wparam, LPARAM lparam );
int WINAPI WinMain( HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR szCmdLine, int iCmdShow );

inline bool CHECK( HRESULT hr, char * msg, bool stop=true ) ;  // checks for errors on the HR passed.

bool initD3D() ;         // function to initialize the BEAST that is Direct3D9
void printSystemInfo() ; // function that prints some system info.  can ignore if not interested
void draw() ;            // drawing function containing Direct3D drawing calls

//
///////////////////////////


/// If there was an error, the ErrorString is printed out for you to see at the console.
inline bool CHECK( HRESULT hr, char * msg, bool stop )
{
  if( FAILED( hr ) )
  {
    printf( "%s. %s:  %s\n",
            msg, DXGetErrorString9A( hr ), DXGetErrorDescription9A( hr ) ) ;

    // Pause so we can see the error and deal with it.
    if( stop )  system("pause") ;

    return false ;
  }
  
  else
    return true ;


}

///////////////////////////
// FUNCTION IMPLEMENTATIONS
/// Initializes Direct3D9.  Returns true on success.
bool initD3D()
{
  // start by nulling out both pointers:
  g.d3d = 0 ;
  g.gpu = 0 ;
  
  // Create the IDirect3D9 (d3d) object now.  We need the d3d object
  // in order to be able to create the IDirect3DDevice9 interface.
  // We can also use the d3d object to find out additional information
  // about the system we are on (such as the number of displays it has, etc).

  // [[ I know, I know.  If you think its confusing/stupid to have
  // two separate Direct3D9 things both starting with I, 
  // just bear with it because you'll see that these two objects
  // will do VERY different things, and you'll see it does
  // make a whole lot of sense to separate them out into two things.
  // Granted, they could have been named a little more distinctly,
  // but whaddya gonna do... ]]
  
  // So, the IDirect3D9 object (variable 'd3d') is the "interface"
  // or means by which we will access the Direct3D9
  // beast
  
  // And the IDirect3DDevice9 (called 'gpu') is THE
  // variable that IS OUR PROGRAMMATIC HANDLE TO THE GPU and
  // we will use it A LOT to send down triangles and stuff to the
  // gpu to be drawn.

  // we'll be using 'gpu' a lot more than 'd3d'.

  // So now, to create our 'd3d' interface.
  // Remember, FROM this interface will come
  // our 'gpu' interface.

  // Direct3DCreate9
  g.d3d = Direct3DCreate9( D3D_SDK_VERSION ) ;  // Always use D3D_SDK_VERSION

  if( g.d3d == NULL )
  {
    // DEVICE CREATION FAILED!!!! OH NO!!!
    puts( "Oh.. PHOOEY!!!!!  Device creation FAILED!!! WHAT NOW???\n" ) ;
    return false ;
  }



  // Ok, if we get here without returning, it means device creation succeeded.
  puts( "Device creation SUCCESS!!!!\nWe're in business now, son..\n" ) ;
  
  // Next we'll just print a few details about the system
  // just because we can..
  // Note how we use PURELY the 'd3d' object
  // to do this (NOT the 'gpu' device, which hasn't
  // even been created yet!)
  ///// printf( "I will now tell you some \nthings ABOUT your system.\n" );
  ///// printSystemInfo(); // BOOOOORING.
  


  puts( "Ok, Now to CREATE the 'gpu' device!!" ) ;
  
  // First, create the D3DPRESENT_PARAMETERS structure.
  // This structure will basically "explain" to the
  // IDirect3D9 interface EXACTLY WHAT we want the
  // GPU rendering surface to look like once
  // it has been created.



  // D3DPRESENT_PARAMETERS structure
  D3DPRESENT_PARAMETERS pps = { 0 } ;  // Start structure all 0'd out.

  // We're using a windowed mode, NOT fullscreen in this
  // example.  Its really annoying to program little test
  // apps in fullscreen mode.  Also when using windowed mode
  // we don't have to (in fact, we should not) specify
  // some of the other parameters, such as the refresh rate.
  pps.Windowed = true ;

  // How many backbuffers do we want?  One.
  pps.BackBufferCount = 1 ;

  // This one's interesting
  // Backbuffering.  Imagine Leonardo Davinci doing
  // a live animation for you.

  // Imagine he stood in front of the canvas,
  // and blazingly quickly, painted a live scene for you.
  // Then to make the animation effect happen, he'd have
  // to erase the canvas (paint over it in all white?) then
  // paint over that white the next frame.

  // Not that great for watching an "animation!"  even if
  // he moved blazing fast, it'd still be "flickery" having
  // to "see" the canvas get all cleared out, then see each
  // shape get drawn on.

  // So instead, Davinci has a better idea.  He will
  // use TWO canvases.  He will draw to the canvas
  // in a HIDDEN place, where you can't see it.

  // When he's done painting hte first frame, BAM,
  // he slams it in your face and you can see it.
  // He then takes a SECOND canvas, and paints to it
  // blazing fast, what should be the next frame you see.
  // Then, BAM, he slams that second canvas right in your face,
  // where you can see it.  He then quietly pulls away
  // that first canvas that had the first frame on it
  // (which you can't see anymore, because you're looking
  // at the SECOND canvas he just slammed in your face),
  // and quickly paints the NEXT (3rd) frame onto it.
  // Then, BAM, he slams that first canvas in your face
  // again, but now it has the 3rd frame on it.  He then
  // takes the SECOND canvas, and draws the 4th frame on it...

  // Do you see what's happening here?  Read it again
  // if not... the whole point is to give a MUCH smoother
  // and continuous presentation of image frames.  If you
  // didn't use a backbuffer, then the animation presented
  // would look all awful and flickery and horrible because
  // you'd basically be WATCHING the gpu do its drawing work,
  // instead of looking at nice finished product painted scenes instead.

  // Swap chains
  pps.SwapEffect = D3DSWAPEFFECT_DISCARD ; // You start with
  // 2 buffers, one that displays what you're currently
  // looking at (the "frontbuffer") and
  // one that is hidden from you (the "backbuffer").
  
  // Basically FLIP means that
  // d3d should DRAW to the BACKBUFFER first, then
  // when its done doing that, it should BAM, slam
  // that backbuffer in your face, so you can see it.
  // The former front buffer, is then DISCARDED.

  // SO, the former "backbuffer" is NOW the FRONTBUFFER.
  // And the former front buffer, we will treat
  // as the NEW "backbuffer".

  // SO draw to the OTHER buffer now (which is considered
  // as the backbuffer at the moment), when you're done,
  // BAM, slam that backbuffer in the user's face
  // (so again, the former "backbuffer" has flipped
  // and become the frontbuffer).

  // The OTHER way to do this is to DRAW TO
  // the backbuffer, then to COPY OUT the backbuffer
  // in its entirety to the front buffer.  That's
  // less efficient though, for obvious reasons
  // (copying about 2,000,000 pixels has gotta take
  // at least some time!).  Discard is nice, but
  // using it REQUIRES that you completely update
  // ALL the pixels of the backbuffer before presenting it
  // (because there's NO TELLING what will happen to
  // the frontbuffer once you've "discarded" it!
  // Microsoft says "we might do anything to it..."
  // The Clear() operation is sufficient to touch every
  // pixel on the buffer, so as long as you're calling
  // Clear() every frame, there's nothing to worry about.
  // You'll see Clear() in use a bit later in this tutorial.)

  // Pixel format to use on the backbuffer.
  pps.BackBufferFormat = D3DFMT_UNKNOWN ;   // So, this doesn't mean
  // we don't KNOW the pixel format we want.. its more
  // like saying "D3DFMT_CHOOSE_IT_FOR_ME!"
  
  // What really happens is "color conversion is done by the hardware"

  // But you can think of it as D3D should picking
  // the appropriate pixel format to use.

  
  
  // Now, we WANT Direct3D to create and manage
  // a depth buffer for this surface.  That means
  // if we draw two triangles and one is "closer"
  // than the other, then the "closer" one should
  // be drawn on top of the "further" one.  That's
  // achieved using the depth buffer
  pps.EnableAutoDepthStencil = true ;
  // Now we have to say "how deep" is the depth buffer.
  // Kind of.  How precise are the depth values?
  // The more bits you use, the more "slots of depth"
  // your depth buffer can handle.  If your depth buffer
  // used 2 bits, it might be able to handle 4 levels
  // of depth.  With 16 bits, there's a lot more levels of
  // depth.  Having many different levels of depth is
  // really important because if two objects are
  // like thought by the gpu to be at the exact same
  // "depth", then there will be "z-fighting"
  // z-fighting sample1
  // Apparently some users experienced problems
  // with z-fighting when playing GTA 4 on ATI hardware.

  // We choose a fairly "deep" pixel format (16 bits)
  // Could also choose 24 bits.
  pps.AutoDepthStencilFormat = D3DFMT_D16 ;

  // Finally, make the gpu device.
  HRESULT hr = g.d3d->CreateDevice(
    
    D3DADAPTER_DEFAULT, // primary display adapter
    D3DDEVTYPE_HAL,     // use HARDWARE rendering (fast!)
    g.win.hwnd,
    D3DCREATE_HARDWARE_VERTEXPROCESSING,
    &pps,
    &g.gpu  // THIS IS where you get
    // the ACTUAL return value (the
    // GPU device!) from this function.
    // Because this function has its
    // return value as an HRESULT,
    // the return value is used to
    // indicate success or failure.

  ) ;


  if( !CHECK( hr, "OH NOS!! I could not initialize Direct3D!  Bailing...\n" ) )
  {
    return false ;
  }



  // Successfully created direct3d9 devices
  printf( "WHOO!  We SUCCESSFULLY created the Direct3D9 GPU device\n" ) ;
  


  return true ;
}


////////////////////////
// DRAWING FUNCTION
void draw()
{
  HRESULT hr ;

  #pragma region clear
  // First, we will clear the backbuffer.  This is a VERY general use
  // function and has way more capabilities than we care to use
  // at the moment.  For example, you can choose to clear little
  // sub-rectangles of the screen ONLY instead of clearing the whole
  // screen with the first 2 params.  we're not interested in that though,
  // we just wanna clear the whole screen.

  // IDirect3DDevice9::Clear()
  hr = g.gpu->Clear(

    0, // NUMBER of sub rectangles to clear.  We set to 0 because
       // we don't want to even clear any subrectangles.. we just
       // want to clear the WHOLE thing!

    0, // you can choose to clear only a sub-region of the
       // backbuffer.  But we wanna clear the WHOLE back buffer!
       // so we pass 0 here and d3d will automatically clear the WHOLE THING for us.

    // D3DCLEAR
    D3DCLEAR_TARGET | D3DCLEAR_ZBUFFER /* | D3DCLEAR_STENCIL */,  // next is weird, but
    // here we specify WHAT exactly we want cleared.  Because a 3d
    // buffer is actually made of several LAYERS (color layer,
    // and depth layer, and stencil layer), you choose
    // what exactly what you want cleared.  If you weren't
    // doing 3d graphics for example (you used direct3d9 to draw
    // 2d graphics, which you can!) you would have no need for
    // the depthbuffer.  So you could save a bit of time
    // (clearing a buffer is a relatively expensive operation)
    // by NOT clearing the buffers you aren't going to use.
    
    // In this example we are NOT using the stencil buffer,
    // but we ARE using the color BUFFER ITSELF (like color values)
    // hence specification of D3DCLEAR_TARGET,
    // and we ARE using the depth buffer (D3DCLEAR_ZBUFFER)
    // but we are NOT using the stencil buffer (hence me omitting
    // D3DCLEAR_STENCIL).  There's no sense in clearing out a
    // buffer that's not in use.  That's like vaccumming a room
    // that's just been vaccummed squeaky clean.
    // If you're not going to be picking up any extra dirt,
    // cleaning it again is really just a waste of time and energy.
    
    D3DCOLOR_ARGB( 255, 125, 25, 237 ),  // The color to clear
    // the backbuffer out to.
    
    1.0f, // value to clear the depth buffer to.  we clear
    // it to 1.0f because 1.0f means ("furthest away possible
    // before being out of range")

    // So we clear every value in the depth buffer to this
    // value so when something is rendered that is in view range,
    // it will definitely be closer than 1.0f!
    // (0.0f means right in our faces).
    
    0  // value to clear the stencil buffer to.  since we
    // chose NOT to clear the stencil buffer (omitted
    // D3DCLEAR_STENCIL from above), this value is
    // actually going to be ignored.
    
  ) ; 
  CHECK( hr, "Clear FAILED!" ) ;

  #pragma endregion

  #pragma region set up the camera

  // First we start by setting up the viewport.
  // the viewport "Defines the window dimensions of
  // a render-target surface onto which a 3D volume projects."
  D3DVIEWPORT9 viewport ;

  // Very clear explanations of each (and advice! :) )
  // of these members are on msdn.
  viewport.X = 0 ;
  viewport.Y = 0 ;
  viewport.Width = g.win.width ;
  viewport.Height = g.win.height ;
  viewport.MinZ = 0.0f ;
  viewport.MaxZ = 1.0f ;

  g.gpu->SetViewport( &viewport ) ;


  // Technically we don't need to set the viewport here
  // BUT you can use viewport setting to draw "picture in picture" -

  // Form the 

  // Set projection matrix
  D3DXMATRIX projx ;
  
  // Create a perspective matrix
  D3DXMatrixPerspectiveFovRH( &projx, PI/4, (float)g.win.width/g.win.height, 1.0f, 1000.0f ) ;
  
  // set
  g.gpu->SetTransform( D3DTS_PROJECTION, &projx ) ;

  // Create the view matrix
  D3DXMATRIX viewx ;

  D3DXVECTOR3 eye( 4, 2, 4 ) ;
  D3DXVECTOR3 look( 0, 0, 0 ) ;
  D3DXVECTOR3 up( 0, 1, 0 ) ;
  D3DXMatrixLookAtRH( &viewx, &eye, &look, &up ) ;
  g.gpu->SetTransform( D3DTS_VIEW, &viewx ) ;
  #pragma endregion

  // Preparing to draw
  // FVF.  WTF is an FVF?
  // MSDN:  "Flexible Vertex Format Constants, or FVF codes,
  //   are used to describe the contents of vertices
  //   interleaved in a single data stream that will
  //   be processed by the fixed-function pipeline."

  // FVF stands for "FLEXIBLE VERTEX FORMAT".  If you're familiar with
  // OpenGL, this is a completely (but some might say a little bit better..)
  // way of allowing a person to say WHAT data each vertex has tagged along
  // with it.

  // So let's tell Direct3D what data exactly each VERTEX 
  // will have.  A position?  A color?  A normal?  A texture
  // coordinate?  What do you WANT TO specify for each vertex.

  hr = g.gpu->SetFVF(
    
    D3DFVF_XYZ  // THe most OBVIOUS (and most important?) aspect of a VERTEX is
    // that it have a POSITION, XYZ.  Specifying that our vertex format
    // includes an XYZ position
    
    | D3DFVF_DIFFUSE // We also specify a diffuse color for each vertex.
    
  ) ;
  CHECK( hr, "SetFVF FAILED!" ) ;
  
  // So there we have it.  We just told d3d to expect
  // to get vertices that each have an XYZ coordinate
  // AND a color specified for them.

  

  // SO NOW, before DRAWING anything, we have to 
  // do 2 more things:
  //   #1)  Create a D3DVERTEXELEMENT9 structure
  //       which will represent our vertex format.

  //   #2)  Create an array of vertices to draw!
  
  //   #3)  Just draw it!

  // #1)  This part is a bit confusing at first,
  // but if you read through it carefully, it should
  // make sense.

  // What we need to do here is create a SPECIAL
  // kind of structure called a "VERTEX DECLARATION"
  // This VertexDeclaration will MATCH UP with
  // the "FVF" format that we set up just a couple
  // of lines ago.  Read on!

  // In the specification, we actually have to
  // obey the FVF mapping
  // on msdn.

  /////////////
  #pragma region // <position vertex element decl>
  // IDirect3DVertexDeclaration9
  
  // OK in the FVF above, we promised d3d that
  // EACH AND EVERY vertex would have a POSITION
  // and a COLOR.

  // So we declare and set up TWO D3DVERTEXELEMENT9
  // structures which explain to d3d the EXACT format
  // and nature of each vertex -

  // IS this a bit redundant?  Kind of, yes.  Getting
  // on with it.

  D3DVERTEXELEMENT9 pos ;
  
  // Here is where we say that this part
  // of the vertex will specify a POSITION
  // in space.
  pos.Usage = D3DDECLUSAGE_POSITION ;

  // This part makes sense if you understand
  // that sometimes, you want to send MORE THAN
  // one position coordinate for each vertex.
  // If that makes less sense, then think about
  // sending down more than one COLOR for each
  // vertex, for some type of funky color blending.
  pos.UsageIndex = 0 ;

  pos.Stream = 0 ; // Vertex shaders have a concept
  // of "stream".
  
  // So what's a "stream" you ask?
  // This really is QUITE an advanced topic, so my honest advice
  // to you is to completely ignore the below unless you 
  // REALLY want to know what streams are.

  // <streams>
  // There is a concept in GPU programming called "shader instancing".
  // Shader instancing is when you specify a model's geometry once,
  // then draw that same model like a million times.

  // 

  // So, you specify the model vertex data with POSITIONS on
  // channel 0, for example.  Then you specify a bunch of
  // positions on channel 1 (1,000,000 positions in your game world,
  // or something) that describe places to draw ALL the vertices
  // that are on channel 0.

  // So its really quite complicated and hard to understand.
  // Channels are like TV -- like the TV station sends like,
  // 500 channels down to your TV in parallel (hey, pretend
  // they do), the vertex data you send down to the GPU
  // all goes down to the GPU in parallel, work at drawing the same thing, kind of.
    
  // Your tv can tune into one channel at a time only, and the GPU
  // will actually tune into ALL the channels when drawing..
  // </streams>  See http://msdn.microsoft.com/en-us/library/bb147299(VS.85).aspx for more detail.
    
  // UH, where were we?  Next, we specify the actual data type of
  // the position data.

  pos.Type = D3DDECLTYPE_FLOAT3 ;  // "Vertices will use
  // 3 floats to specify their position in space".
  
  // If you are familiar with GPU datatypes and HLSL,
  // this would correspond directly with the "float3"
  // datatype in the vertex shader.
  
  // If you don't know what a vertex shader is,
  // just suffice it to say, that all this means
  // is 3 floats will be used for the POSITION
  // of the vertex.
  
  // Next we set the "offset":

  pos.Offset = 0 ;

  // In the Vertex STRUCT that WE defined,
  // this is the byte offset from the start
  // of the struct where D3D SHOULD expect
  // to find this data.
  
  // Using default method.
  pos.Method = D3DDECLMETHOD_DEFAULT ; // here's more info
  
  #pragma endregion // </position vertex element decl>
  /////////////


  /////////////
  #pragma region // <color vertex element decl>
  // Next we declare the vertex element that
  // will represent the DIFFUSE COLOR component.
  D3DVERTEXELEMENT9 col;
  
  col.Usage = D3DDECLUSAGE_COLOR ; // its a color
  col.UsageIndex = 0 ; // COLOR0
  col.Stream = 0 ;

  col.Type = D3DDECLTYPE_D3DCOLOR ; // UNFORTUNATELY you MUST
  // chose D3DDECLTYPE_D3DCOLOR when using COLOR0
  // or COLOR1.  If you write your own shader,
  // then you can use a FLOAT4 color.
  // If you try and do that, you will get
  // [5052] Direct3D9: Decl Validator: X254: (Element Error) (Decl Element [2])
  // Declaration can't map to fixed function FVF because color0/color1
  // cannot have type other than D3DDECLTYPE_D3DCOLOR
  // in the d3d extended debug output.

  
  // NEXT, the OFFSET.  The offset is
  // 3*sizeof(float) because the 'POSITION'
  // comes first and takes up 3 floats as we
  // specified above.
  col.Offset = 3*sizeof( float ) ;
  col.Method = D3DDECLMETHOD_DEFAULT ;
  #pragma endregion // </color vertex element decl>
  /////////////
  

  /////////////
  #pragma region create and set vertex declaration
  // Now put the two D3DVERTEXELEMENT9's into
  // an array and create the VertexDeclaration:
  D3DVERTEXELEMENT9 vertexElements[] =
  {
    pos,
    col,

    // VERY IMPORTANT!  D3D doesn't konw
    // HOW MANY elements you will be specifying
    // in advance, so you TELL IT by passing
    // this SPECIAL D3DVERTEXELEMENT9 object
    // which is basically just like the null
    // terminator at the end of C string.
    D3DDECL_END()
  } ;
  
  IDirect3DVertexDeclaration9 * Vdecl ;

  // Now register in the "vertexElements" array
  // we just created above into the decl
  hr = g.gpu->CreateVertexDeclaration( vertexElements, &Vdecl ) ;
  CHECK( hr, "CreateVertexDeclaration FAILED!" ) ;

  // Now SET IN that vertex declaration into the GPU
  hr = g.gpu->SetVertexDeclaration( Vdecl ) ;
  CHECK( hr, "SetVertexDeclaration FAILED!" ) ;
  #pragma endregion

  #pragma region set render states
  // FINALLY, last thing before drawing, we
  // have to set the renderstate to USE
  // the DIFFUSE component to determine the
  // color of each vertex
  // Per-Vertex Color State
  hr = g.gpu->SetRenderState( D3DRS_COLORVERTEX, TRUE ) ;
  CHECK( hr, "SetRenderState( COLORVERTEX ) FAILED!" ) ;

  
  // Turn LIGHTING off.  TRUE to enable Direct3D lighting,
  // or FALSE to disable it. The default value is TRUE.
  // __Only vertices that include a vertex normal are properly lit;
  // vertices that do not contain a normal ___employ a dot product of 0___
  // in all lighting calculations.__!

  // So if you don't disable lighting, what will actually happen is,
  // since we don't specify normals for any of our vertices,
  // they will all have a normal vertex of the 0 vector, so
  // the result is they will all be completely black.
  hr = g.gpu->SetRenderState( D3DRS_LIGHTING, FALSE ) ;
  CHECK( hr, "Lighting off" ) ;


  // Turn backface culling off.  Its good to turn this off
  // when starting out because triangles that you wind
  // ccw are discarded if this is on.
  // http://msdn.microsoft.com/en-us/library/bb204882(VS.85).aspx
  hr = g.gpu->SetRenderState( D3DRS_CULLMODE, D3DCULL_NONE ) ;
  CHECK( hr, "Culling off" ) ;

  #pragma endregion

  #pragma region declare a vertex structure, create verts
  // OK?? WHEW!!  THAT was a lot of work!
  // Now let's DRAW SOMETHING!!  First,
  // we have to create a STRUCT which
  // will match up the vertex declaration
  // we specified above.

  // Practically you'd probably want this struct
  // to be declared in global space, but its declared
  // inline here just to preserve the
  // flow of information for you.

  struct Vertex 
  {
    float x,y,z ;
    DWORD color ;

    // Ctor starts you at origin in black
    // with alpha (opacity) set to 100%
    Vertex()
    {
      x=y=z = 0.0f;
      color = D3DCOLOR_XRGB( 0,0,0 ) ;
    }

    // Ctor.
    Vertex( float ix, float iy, float iz,
      unsigned char ir, unsigned char ig, unsigned char ib )
    {
      x=ix;y=iy;z=iz;
      color = D3DCOLOR_XRGB( ir, ig, ib ) ;
    }

    // Ctor that lets you pick alpha
    Vertex( float ix, float iy, float iz,
      unsigned char ir, unsigned char ig, unsigned char ib, unsigned char ALPHA )
    {
      x=ix;y=iy;z=iz;
      color = D3DCOLOR_ARGB( ALPHA, ir, ig, ib ) ;
    }
  } ;

  // Now create an array full of vertices!
  Vertex verts[] = {

    // Red vertex @ ( -1, 0, 0 )
    Vertex( -1, 0, 0, 255, 19, 0 ),

    // Green vertex @ ( 0, 1, 0 )
    Vertex(  0, 1, 0, 0, 255, 0 ),

    // Blue vertex @ ( 1, 0, 0 )
    Vertex(  1, 0, 0, 0, 0, 255 )

  } ;

  float axisLen = 2.0f ;
  Vertex axis[] = {

    // x-axis is red
    Vertex( -axisLen, 0, 0, 255, 0, 0 ),
    Vertex( +axisLen, 0, 0, 255, 0, 0 ),

    // y-axis green
    Vertex( 0, -axisLen, 0, 0, 255, 0 ),
    Vertex( 0, +axisLen, 0, 0, 255, 0 ),

    // z-axis blue
    Vertex( 0, 0, -axisLen, 0, 0, 255 ),
    Vertex( 0, 0, +axisLen, 0, 0, 255 )

  } ;

  #pragma endregion

  #pragma region ACTUALLY __draw__
  // IDirect3DDevice9::BeginScene()
  // You must call BeginScene() before you start drawing anything.
  hr = g.gpu->BeginScene() ;
  CHECK( hr, "BeginScene FAILED!" ) ;

  hr = g.gpu->DrawPrimitiveUP( D3DPT_TRIANGLELIST, 1, verts, sizeof( Vertex ) ) ;
  CHECK( hr, "DrawPrimitiveUP FAILED!" ) ;

  hr = g.gpu->DrawPrimitiveUP( D3DPT_LINELIST, 3, axis, sizeof( Vertex ) ) ;
  CHECK( hr, "DrawPrimitiveUP FAILED!" ) ;

  float pointSize = 8.0f ;

  // A DWORD is 4 bytes (a WORD is 2 bytes).
  // So, what we need to do is basically cast
  // pointSize to (DWORD).  Its a bit complicated
  // about how you actually do it, so I made a macro for it.
  // The general idea is you need to "trick" SetRenderState
  // into taking your float value.. SetRenderState "thinks"
  // its a DWORD, while its actually a float.. and D3D
  // internally somehow gets it and knows to treat it as a float.
  // Kind of clunky, eh, but what can you do.
  g.gpu->SetRenderState( D3DRS_POINTSIZE, CAST_AS_DWORD( pointSize ) ) ;
  
  // Draw points at end of axis.
  Vertex points[] = {
    Vertex( axisLen, 0, 0, 255, 0, 0 ),
    Vertex( 0, axisLen, 0, 0, 255, 0 ),
    Vertex( 0, 0, axisLen, 0, 0, 255 ),
  } ;
  hr = g.gpu->DrawPrimitiveUP( D3DPT_POINTLIST, 3, points, sizeof( Vertex ) ) ;
  CHECK( hr, "DrawPrimitiveUP FAILED!" ) ;

  // endscene, and present
  // IDirect3DDevice9::EndScene()
  // You must call EndScene() to signify to the gpu that
  // you are finished drawing.  Must pair up with
  // a BeginScene() call that happened earlier.
  hr = g.gpu->EndScene() ;
  CHECK( hr, "EndScene FAILED!" ) ;

  // And finally, PRESENT what we drew to the backbuffer
  g.gpu->Present( 0, 0, 0, 0 ) ;
  #pragma endregion



}




// function that prints some system info.  can ignore this part
// if you are not interested in it.
void printSystemInfo()
{
  UINT numAdapters = g.d3d->GetAdapterCount() ;
  printf( "\n\n* * * * System information * * * *\n" ) ;
  printf( "Owner name:  Dorky Dorkinson (haha, just kidding, little easter egg there..)\n" ) ;
  printf( "Ok, the rest of this information IS real!\n" ) ;
  
  printf( "You have %d adapters\n  * (this number is bigger than 1 if you have dualview)\n", numAdapters ) ;

  // Scroll through all adapters and print some info about each
  for( int i = 0 ; i < numAdapters ; i++ )
  {
    printf( "\n\n-- ADAPTER #%d --\n", i ) ;
    printf( "On monitor #%d\n", g.d3d->GetAdapterMonitor( i ) ) ;

    // Object into which display mode info will be saved
    // by GetAdapterDisplayMode
    D3DDISPLAYMODE displayMode ;
    g.d3d->GetAdapterDisplayMode( i, &displayMode ) ;

    printf( "Has Format=%d Height=%d Width=%d RefreshRate=%d\n", displayMode.Format, displayMode.Height, displayMode.Width, displayMode.RefreshRate ) ;
    printf( "  * (format refers to the D3DFMT_ pixel mode.. e.g. 22=D3DFMT_X8R8G8B8 which is 24 bit color)\n" ) ;
    
    D3DADAPTER_IDENTIFIER9 id ; // Will hold info about the adapter
    // after call to GetAdapterIdentifier

    g.d3d->GetAdapterIdentifier( i, 0, &id ) ;
    // At this point you can see how WEIRD the API gets.
    // All I want is the adapter identifier, and here MSDN
    // says the API offers to "connect to the Internet
    // and download new MS Windows Hardware Quality Labs certificates."
    // Holy cow.  I don't want to do THAT.  So leave the flag at 0.
    
    // There's PLENTY of info here we don't care about,
    // but some of it is interesting!!  I've printed
    // only the most interesting members, leaving parts
    // like the GUID out.
    printf( "<device driver info>\n" ) ;
    printf( "  Description: %s\n  Device Id: %d\n  Device name: %s\n  Driver: %s\n",
      id.Description, id.DeviceId, id.DeviceName, id.Driver ) ;
    printf( "</device driver info>\n" ) ;
    

    UINT modeCount ;
    
    // I guess this next part just shows.. how FEW modes are
    // actually supported on a GPU.. I have an NVIDIA 8800GTS,
    // and it only supports 28 modes on D3DFMT_X8R8G8B8,
    // and 28 modes on D3DFMT_R5G6B5.  The rest, 0 modes are
    // reported as supported!

    modeCount = g.d3d->GetAdapterModeCount( i, D3DFMT_R8G8B8 ) ;
    printf( "D3DFMT_R8G8B8   %d modes supported\n", modeCount ) ;

    modeCount = g.d3d->GetAdapterModeCount( i, D3DFMT_A8R8G8B8 ) ;
    printf( "D3DFMT_A8R8G8B8 %d modes supported\n", modeCount ) ;

    modeCount = g.d3d->GetAdapterModeCount( i, D3DFMT_X8R8G8B8 ) ;
    printf( "D3DFMT_X8R8G8B8 %d modes supported\n", modeCount ) ;

    modeCount = g.d3d->GetAdapterModeCount( i, D3DFMT_R5G6B5 ) ;
    printf( "D3DFMT_R5G6B5   %d modes supported\n", modeCount ) ;

    modeCount = g.d3d->GetAdapterModeCount( i, D3DFMT_X1R5G5B5 ) ;
    printf( "D3DFMT_X1R5G5B5 %d modes supported\n", modeCount ) ;

    modeCount = g.d3d->GetAdapterModeCount( i, D3DFMT_A1R5G5B5 ) ;
    printf( "D3DFMT_A1R5G5B5 %d modes supported\n", modeCount ) ;

    modeCount = g.d3d->GetAdapterModeCount( i, D3DFMT_A4R4G4B4 ) ;
    printf( "D3DFMT_A4R4G4B4 %d modes supported\n", modeCount ) ;

    modeCount = g.d3d->GetAdapterModeCount( i, D3DFMT_R3G3B2 ) ;
    printf( "D3DFMT_R3G3B2   %d modes supported\n", modeCount ) ;

    modeCount = g.d3d->GetAdapterModeCount( i, D3DFMT_A8 ) ;
    printf( "D3DFMT_A8       %d modes supported\n", modeCount ) ;

    modeCount = g.d3d->GetAdapterModeCount( i, D3DFMT_A8R3G3B2 ) ;
    printf( "D3DFMT_A8R3G3B2 %d modes supported\n", modeCount ) ;

    modeCount = g.d3d->GetAdapterModeCount( i, D3DFMT_X4R4G4B4 ) ;
    printf( "D3DFMT_X4R4G4B4 %d modes supported\n", modeCount ) ;

    modeCount = g.d3d->GetAdapterModeCount( i, D3DFMT_A2B10G10R10 ) ;
    printf( "D3DFMT_A2B10G10R10 %d modes supported\n", modeCount ) ;

    modeCount = g.d3d->GetAdapterModeCount( i, D3DFMT_A8B8G8R8 ) ;
    printf( "D3DFMT_A8B8G8R8 %d modes supported\n", modeCount ) ;

    modeCount = g.d3d->GetAdapterModeCount( i, D3DFMT_X8B8G8R8 ) ;
    printf( "D3DFMT_X8B8G8R8 %d modes supported\n", modeCount ) ;

    modeCount = g.d3d->GetAdapterModeCount( i, D3DFMT_G16R16 ) ;
    printf( "D3DFMT_G16R16   %d modes supported\n", modeCount ) ;

    modeCount = g.d3d->GetAdapterModeCount( i, D3DFMT_A2R10G10B10 ) ;
    printf( "D3DFMT_A2R10G10B10 %d modes supported\n", modeCount ) ;

    modeCount = g.d3d->GetAdapterModeCount( i, D3DFMT_A16B16G16R16 ) ;
    printf( "D3DFMT_A16B16G16R16 %d modes supported\n", modeCount ) ;






    // This mode is the MOST LIKELY TO be supported on your machine.
    modeCount = g.d3d->GetAdapterModeCount( i, D3DFMT_X8R8G8B8 ) ;
    for( int j = 0 ; j < modeCount; j++ )
    {
      g.d3d->EnumAdapterModes( i, D3DFMT_X8R8G8B8, j, &displayMode ) ;

      printf( "For format=%d (D3DFMT_X8R8G8B8) Height=%d Width=%d RefreshRate=%d is SUPPORTED\n", displayMode.Format, displayMode.Height, displayMode.Width, displayMode.RefreshRate ) ;

    }


    // At this point you're thinking, "HEY!!  But i'm SURE my gpu supports
    // alpha blending!  Why are all the modes like A8R8G8B8 NOT supported!?"
    // My best stab at this is it makes no sense to DISPLAY something with
    // an alpha component still in it.  For the final image that gets displayed --
    // the alphas should already have been blended -- present day
    // monitors can only display RGB, they don't have the ability to
    // "go transparent".  Maybe one day when we work with those enormous
    // glass screens that people work with in the movies -- kinda like this one:
    // http://business.timesonline.co.uk/multimedia/archive/00339/screen-385_339034a.jpg
    // then having an ALPHA component on the display WOULD make sense.  But for
    // now, all monitors are completely opaque, and they only display colors
    // RGB.  So an alpha component makes no sense on the display itself.
    // That's why displays don't support that display mode.



    // K, FINALLY we get to the device's capabilities.
    // I love how DirectX lets you "reflect" on what
    // the hardware is in fact capable of.  Its nice.

    D3DCAPS9 caps ;
    g.d3d->GetDeviceCaps( i, D3DDEVTYPE_HAL, &caps ) ;

    // Now we have the capabilities of the device.
    // Printing all of them would be meaningless,
    // but if you want to inspect some of them, just
    // use the debugger.

  }
}





int WINAPI WinMain( HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR szCmdLine, int iCmdShow )
{
  //////////////////
  // First we'll start by saving a copy of
  // the hInstance parameter inside our
  // "glob" of globals "g":
  g.win.hInstance = hInstance;
  // In case we need it later, we'll have it
  // with firsthand easy access.

  #pragma region part 0 - attach a console
  // Attach a console
  AllocConsole();
  AttachConsole( GetCurrentProcessId() ) ;
  freopen( "CON", "w", stdout ) ; // redirect stdout to console
  freopen( "CON", "w", stderr ) ; // redirect stderr to console

  // Move the console over to the top left
  g.win.hConsole = GetConsoleWindow();
  MoveWindow( g.win.hConsole, 0, 0, 400, 400, true ) ;

  printf( "* * Computer Program Begin * *\n" ) ;
  #pragma endregion

  #pragma region part 1 - create a window
  // The next few lines you should already
  // be used to:  create a WNDCLASSEX
  // that describes the properties of
  // the window we're going to soon create.
  // A.  Create the WNDCLASSEX
  WNDCLASSEX wcx = { 0 } ;
  wcx.cbSize = sizeof( WNDCLASSEX );
  wcx.hbrBackground = (HBRUSH)GetStockObject( BLACK_BRUSH );
  wcx.hCursor = LoadCursor( NULL, IDC_ARROW );
  wcx.hIcon = LoadIcon( NULL, IDI_APPLICATION );
  wcx.hInstance = hInstance;
  wcx.lpfnWndProc = WndProc;
  wcx.lpszClassName = TEXT("Philip");
  wcx.lpszMenuName = 0;
  wcx.style = CS_HREDRAW | CS_VREDRAW | CS_OWNDC;

  // Register that class with the Windows O/S..
  RegisterClassEx( &wcx );

  /////////////////
  // Ok, AT THIS POINT, we'd normally
  // just go ahead and call CreateWindow().
  // And we WILL call CreateWindow(), but
  // there is something I must explain to
  // you first.  That thing is the RECT structure.

  /////////////////
  // RECT:
  //
  // A RECT is just a C struct meant to represent
  // a rectangle.
  //
  // The RECT structure WILL DESCRIBE EXACTLY WHERE
  // AND HOW WE WANT OUR WINDOW TO APPEAR WHEN WE
  // CREATE IT.
  //
  //         TOP
  //       --------
  //       |      |
  // LEFT  |      | RIGHT
  //       --------
  //        BOTTOM
  //
  // So, what we do is, we create the RECT
  // struct for our window as follows:
  RECT rect;
  SetRect( &rect, 420,  // left
    25,  // top
    420 + 800, // right
    25  + 600 ); // bottom

  // Save width and height off.
  g.win.width = rect.right - rect.left;
  g.win.height = rect.bottom - rect.top;

  // Adjust it.
  DWORD windowStyle = WS_OVERLAPPEDWINDOW ; // typical features of a normal window
  DWORD windowExStyle = WS_EX_TOPMOST ; // I want the window to be topmost

  AdjustWindowRectEx( &rect, windowStyle, false, windowExStyle );

  // AdjustWindowRect() expands the RECT
  // so that the CLIENT AREA (drawable region)
  // has EXACTLY the dimensions we specify
  // in the incoming RECT.

  // If you didn't just understand that, understand
  // this:  "you have to call AdjustWindowRect()",
  // and move on.  Its not THAT important, but its
  // good for the performance of your app.

  ///////////////////
  // NOW we call CreateWindow, using
  // that adjusted RECT structure to
  // specify the width and height of the window.
  g.win.hwnd = CreateWindowEx(
    windowExStyle,
    TEXT("Philip"),
    TEXT("TIGER-DIRECT3D WINDOW!"),
    windowStyle,
    rect.left, rect.top,  // adjusted x, y positions
    rect.right - rect.left, rect.bottom - rect.top,  // adjusted width and height
    NULL, NULL,
    hInstance, NULL);

  // check to see that the window
  // was created successfully!
  if( g.win.hwnd == NULL )
  {
    FatalAppExit( NULL, TEXT("CreateWindow() failed!") );
  }

  // and show.
  ShowWindow( g.win.hwnd, iCmdShow );
  #pragma endregion

  #pragma region part 2 - initialize direct3d9

  // JUMP to the initD3D() method.
  if( !initD3D() )
  {
    FatalAppExit( 0, TEXT("SORRY!!!  DEVICE CREATION FAILED!!! YOU LOSE, WITHOUT EVEN PLAYING THE GAME!!!" ) ) ;
  }
  
  #pragma endregion

  #pragma region message loop
  MSG msg;

  while( 1 )
  {
    if( PeekMessage( &msg, NULL, 0, 0, PM_REMOVE ) )
    {
      if( msg.message == WM_QUIT )
      {
        break;
      }
      else
      {
        TranslateMessage( &msg );
        DispatchMessage( &msg );
      }
    }

    // 3.  DRAW USING Direct3D.
    // This region right here is the
    // heart of our application.  THE MOST
    // execution time is spent just repeating
    // this draw() function.
    draw();

  }
  #pragma endregion

  //////////////
  // clean up
  #pragma region clean up

  // Release COM objects.  
  // What's SAFE_RELEASE()?  Well, lots of people use
  // if( pointer ) pointer->Release() ; to guard
  // against null pointer exceptions.
  
  // Like the MS examples do, I've defined
  // SAFE_RELEASE at the top of this file and
  // I'm using it here.  All it does is
  // make sure the pointer is not null before releasing it.
  SAFE_RELEASE( g.gpu ) ;
  SAFE_RELEASE( g.d3d ) ;

  #pragma endregion

  // and a cheesy fade exit
  AnimateWindow( g.win.hwnd, 200, AW_HIDE | AW_BLEND );

  printf( "* * This Computer Program Has Ended * *\n" ) ;
  
  return msg.wParam;
}

////////////////////////
// WNDPROC
// Notice that WndProc is very very neglected.
// We hardly do anything with it!  That's because
// we do all of our processing in the draw()
// function.
LRESULT CALLBACK WndProc(   HWND hwnd, UINT message, WPARAM wparam, LPARAM lparam )
{
  switch( message )
  {
  case WM_CREATE:
    Beep( 50, 10 );
    return 0;
    break;

  case WM_PAINT:
    {
      HDC hdc;
      PAINTSTRUCT ps;
      hdc = BeginPaint( hwnd, &ps );
      // don't draw here.  would be waaay too slow.
      // draw in the draw() function instead.
      EndPaint( hwnd, &ps );
    }
    return 0;
    break;

  case WM_KEYDOWN:
    switch( wparam )
    {
    case VK_ESCAPE:
      PostQuitMessage( 0 );
      break;
    default:
      break;
    }
    return 0;

  case WM_SIZE:
    {
      int width = LOWORD( lparam ) ;
      int height = HIWORD( lparam ) ;
      printf( "RESIZED TO width=%d height=%d\n", width, height ) ;
    }
    break;

  case WM_DESTROY:
    PostQuitMessage( 0 ) ;
    return 0;
    break;
  }

  return DefWindowProc( hwnd, message, wparam, lparam );
}


/*
    ____   __   __      __   __  ___
   / _  \ /  / /  /    /  /  \ \/  /
  / _/ / /  / /  /    /  /    \   /
 / _/ \ /  / /  /__  /  /__   /  /
/_____//__/ /______//______/ /__/

*/

Code package on esnips (thanks esnips!)

Follow this link for a great article on byte alignment.

The deal is the VC++ compiler will sometimes pad your data structures automatically so that different variables start on word boundaries.

In VC++, you can bypass the automatic compiler padding. An example follows.

#include <iostream>
using namespace std;

// In this example, the C++ compiler will actually pad
// the PaddedStruct structure definition with unnamed variables
// so that shorts start on word boundaries.
// So between c and d, an extra, unnamed 1 byte variable
// of type char will be added in automatically by the compiler.
// This is done so that application performance is better,
// but sometimes, you don't want that.

// To get your structures to be laid out in memory
// exactly as you'd like, with no padding, you have to change
// compiler behaviour with some #pragmas.  This example shows how.

// http://en.wikipedia.org/wiki/Data_structure_alignment

// Here is an example of a struct that gets AUTOMATICALLY
// padded out with an extra byte.
struct PaddedStruct
{
	char a;
	char b;
	char c;

 /* char PADDING; */ // the COMPILER will add in an extra byte here
                     // so the short gets started on a 2-byte boundary
	short d;
};


// Here is how you force the compiler to NOT add that extra PADDING char:
// Use the #pragma pack preprocessor directive to alter VC++ compiler behavior!
#pragma pack(push)  /* push current alignment to stack */
#pragma pack(1)     /* set alignment to 1 byte boundary */
struct UNPaddedStruct
{
	char a;
	char b;
	char c;
	short d;
};
#pragma pack(pop)   /* revert to default compiler behavior */


int main()
{
    cout << "sizeof(paddedStruct) " << sizeof(PaddedStruct) << endl;	    // should be 5, but its actually 6

    cout << "sizeof(UNpaddedStruct) " << sizeof(UNPaddedStruct) << endl;	// WILL be 5, b/c of #pragma
    
    return 0;
}

Note that there IS a huge difference between d3dx9.lib and d3d9.lib.

Getting error LNK2019: unresolved external symbol _D3DXVec3Normalize@8 referenced in function?

Do this

  1. In visual studio 2005, Go to TOOLS->OPTIONS.

    In that window that comes up, in the left hand side of the window, pick “PROJECTS AND SOLUTIONS” -> VC++ DIRECTORIES from the tree.

    d3d linker error fix

    ALSO do this:
    d3d include

  2. In every code file, include a line at the top that says:

    #pragma comment(lib, "d3dx9.lib")   // d3dx9.lib contains actual code for D3DX functions (like D3DXVec3Normalize)
    

Why?

Although d3dx9.h contains the function prototypes and signatures for the D3DX functions, it DOES NOT contain the actual implementation code.

The implementation code is provided IN “d3dx9.lib” which is why you have to LINK it to the executable at compile time.