DX SetFVF

自由顶点格式（flexible vertex format，FVF）

http://www.cnblogs.com/xmzyl/articles/1604096.html

if( SUCCEEDED( g_pd3dDevice->BeginScene() ) )
{
// Draw the triangles in the vertex buffer. This is broken into a few
// steps. We are passing the Vertices down a "stream", so first we need
// to specify the source of that stream, which is our vertex buffer. Then
// we need to let D3D know what vertex shader to use. Full, custom vertex
// shaders are an advanced topic, but in most cases the vertex shader is
// just the FVF, so that D3D knows what type of Vertices we are dealing
// with. Finally, we call DrawPrimitive() which does the actual rendering
// of our geometry (in this case, just one triangle).
g_pd3dDevice->SetStreamSource( 0, g_pVB, 0, sizeof( CUSTOMVERTEX ) );
g_pd3dDevice->SetFVF( D3DFVF_CUSTOMVERTEX );
g_pd3dDevice->DrawPrimitive( D3DPT_TRIANGLELIST, 0, 1 );

// End the scene
g_pd3dDevice->EndScene();
}

通过setFVF 按照我的理解 就是告诉shader 他要处理的vertices里面的格式

注释那段话已经说的很详细了 我们自己定义vertex buffer里的结构类型 ，比如D3DFVF_XYZ，D3DFVF_NORMAL，D3DFVF_TEX0.....

很眼熟吧，你规定的这些是可以在shader中使用的。

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因为很多链接会失效，我还是把那段抄过来吧 ，有关fvf的使用步骤

struct CustomerVertex
{
  FLOAT x,y,z,rhw;
  DWORD color; 
};

#define D3DFVF_CUSTOMVERTEX(D3DFVF_XYZRHW|D3DFVF_DIFFUSE)

g_pd3dDevice->CreateVertexBuffer(3*sizeof(CUSTOMVERTEX),
                                 0, 
                                 D3DFVF_CUSTOMVERTEX,
                                 D3DPOOL_DEFAULT, 
                                 &g_pVB, NULL )

CUSTOMVERTEX vertices[] =

{
  { 100.0f, 400.0f, 0.5f, 1.0f, 0xffff0000, },
  { 300.0f,  50.0f, 0.5f, 1.0f, 0xff00ff00, }, 
  { 500.0f, 400.0f, 0.5f, 1.0f, 0xff0000ff, },
};

然后将数据写入缓冲区：
 
 
VOID* pVertices;
if( FAILED( g_pVB->Lock( 0, sizeof(vertices), (void**)&pVertices, 0 ) ) )
  return E_FAIL;
memcpy( pVertices, vertices, sizeof(vertices) );
g_pVB->Unlock();
 
 
这里写入的过程用的是Lock函数得到的缓冲区的地址，然后用memcpy函数将自己写好的数据写进去。到这里，顶点就算是创建好了。