Flexible Vertex Formats and Vertex Shaders

Microsoft® Direct3D® has a simplified programming model for using the fixed function vertex processing pipeline with a single input stream, providing functionality very similar to that of previous DirectX releases. In this case, the vertex shader consists of a flexible vertex format (FVF) code that is passed in place of a vertex shader handle when setting the current vertex shader. The handle space for vertex shaders is managed by the run-time library so that handles that are valid FVF codes are reserved for this usage.

Setting an FVF code as the current vertex shader causes the vertex processing to load from stream zero only, and to interpret the vertex elements as defined in the FVF code.

The following code example illustrates how to use an FVF code as a vertex shader in your C++ application.

First, define a structure for your custom vertex type and initialize the vertices. In this case, three vertices are initialized for rendering a triangle.

// This code example assumes that d3dDevice is a
// valid pointer to an IDirect3DDevice8 interface.

struct CUSTOMVERTEX
{
    FLOAT x, y, z, rhw; // The transformed position for the vertex
    DWORD color;        // The vertex color
};

#define D3DFVF_CUSTOMVERTEX (D3DFVF_XYZRHW|D3DFVF_DIFFUSE)

CUSTOMVERTEX g_Vertices[] =
{
    { 150.0f,  50.0f, 0.5f, 1.0f, 0xffff0000, }, // x, y, z, rhw, color
    { 250.0f, 250.0f, 0.5f, 1.0f, 0xff00ff00, },
    {  50.0f, 250.0f, 0.5f, 1.0f, 0xff00ffff, },
};

d3dDevice->SetStreamSource( 0, g_pVB, sizeof(CUSTOMVERTEX) );
d3dDevice->SetVertexShader( D3DFVF_CUSTOMVERTEX );
d3dDevice->DrawPrimitive( D3DPT_TRIANGLELIST, 0, 1 );

For more information, see Vertex Shaders.