Microsoft DirectX 8.0 (C++)

LVertex Legacy Type

This topic shows the steps necessary to initialize and use vertices that have a position, diffuse color, specular color, and texture coordinates.

The first step is to define the custom vertex type and FVF as shown in the code example below.

struct LVertex
{
    FLOAT    x, y, z;
    D3DCOLOR specular, diffuse;
    FLOAT    tu, tv;
};

const DWORD VertexFVF = (D3DFVF_XYZ | D3DFVF_DIFFUSE |
                         D3DFVF_SPECULAR | D3DFVF_TEX1 );

The next step is to create a vertex buffer with enough room for four vertices by using the IDirect3DDevice8::CreateVertexBuffer method as shown in the code example below.

g_d3dDevice->CreateVertexBuffer(
                 4*sizeof(LVertex), VertexFVF, 
                 D3DUSAGE_WRITEONLY,
                 D3DPOOL_DEFAULT, &pBigSquareVB);

The next step is to manipulate the values for each vertex as shown in the code example below.

LVertex * v;
pBigSquareVB->Lock( 0, 0, (BYTE**)&v, 0 );

v[0].x  = 0.0f;  v[0].y  = 10.0;  v[0].z  = 10.0f;
v[0].diffuse  = 0xffff0000;
v[0].specular = 0xff00ff00;
v[0].tu = 0.0f;  v[0].tv = 0.0f;

v[1].x  = 0.0f;  v[1].y  = 0.0f;  v[1].z  = 10.0f;
v[1].diffuse  = 0xff00ff00;
v[1].specular = 0xff00ffff;
v[1].tu = 0.0f;  v[1].tv = 0.0f;

v[2].x  = 10.0f; v[2].y  = 10.0f; v[2].z  = 10.0f;
v[2].diffuse  = 0xffff00ff;
v[2].specular = 0xff000000;
v[2].tu = 0.0f;  v[2].tv = 0.0f;

v[3].x  = 0.0f; v[3].y  = 10.0f;  v[3].z = 10.0f;
v[3].diffuse  = 0xffffff00;
v[3].specular = 0xffff0000;
v[3].tu = 0.0f; v[3].tv = 0.0f;

pBigSquareVB->Unlock();

The vertex buffer has been initialized and is ready to render. The following code example shows how to use the legacy FVF to draw a square.

g_d3dDevice->SetVertexShader( VertexFVF );
g_d3dDevice->SetStreamSource( 0, pBigSquareVB, 4*sizeof(LVertex) );
g_d3dDevice->DrawPrimitive( D3DPT_TRIANGLESTRIP, 0 ,2);

Passing an FVF to the IDirect3DDevice8::SetVertexShader method tells Direct3D that a legacy FVF is being used and that stream 0 is the only valid stream.