Microsoft DirectX 8.1 (Visual Basic)

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.

Private Type LVertex
    x As Single
    y As Single
    z As Single
    diffuse As Long
    specular As Long
    tu As Single
    tv As Single
End Type

Const VertexFVF = (D3DFVF_XYZ Or D3DFVF_DIFFUSE Or _
                   D3DFVF_SPECULAR Or D3DFVF_TEX1)

The next step is to create a vertex with enough room for four vertices buffer by using the Direct3DDevice8.CreateVertexBuffer method as shown in the code example below.

Set BigSquareVB = m_D3DDevice.CreateVertexBuffer( _
                                  4*len(LVertex), VertexFVF, _
                                  D3DUSAGE_WRITEONLY, _
                                  D3DPOOL_DEFAULT)

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

Dim v(4) As LVertex
Call BigSquareVB.Lock(0, 0, v(), 0)

v(0).x  = 0.0: v(0).y  = 10.0: v(0).z  = 10.0
v(0).diffuse = &HFFFF0000;
v(0).specular = &HFF00FF00;
v(0).tu = 0.0: v(0).tv = 0.0

v(1).x  = 0.0: v(1).y  = 0.0:  v(1).z  = 10.0
v(1).diffuse  = &HFF00FF00;
v(1).specular = &HFF00FFFF;
v(1).tu = 0.0: v(1).tv = 0.0

v(2).x  = 10.0: v(2).y  = 10.0: v(2).z  = 10.0
v(2).diffuse  = &HFFFF00FF;
v(2).specular = &HFF000000;
v(2).tu = 0.0: v(2).tv = 0.0

v(3).x  = 0.0: v(3).y  = 10.0: v(3).z = 10.0
v(3).diffuse  = &HFFFFFF00;
v(3).specular = &HFFFF0000;
v(3).tu = 0.0: v(3).tv = 0.0

BigSquareVB.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.

Call m_D3DDevice.SetVertexShader(VertexFVF)
Call m_D3DDevice.SetStreamSource(0, BigSquareVB, 4*len(LVertex))
Call m_D3DDevice.DrawPrimitive(D3DPT_TRIANGLESTRIP, 0 ,2)

Passing an FVF to the Direct3DDevice8.SetVertexShader method tells Direct3D that a legacy FVF is being used and that stream 0 is the only valid stream.