If I create a vertex buffer with data like this (code from DirectX SDK Tutorial07):
SimpleVertex vertices[] =
{
{ XMFLOAT3( -1.0f, 1.0f, -1.0f ), XMFLOAT2( 0.0f, 0.0f ) },
{ XMFLOAT3( 1.0f, 1.0f, -1.0f ), XMFLOAT2( 1.0f, 0.0f ) },
{ XMFLOAT3( 1.0f, 1.0f, 1.0f ), XMFLOAT2( 1.0f, 1.0f ) },
{ XMFLOAT3( -1.0f, 1.0f, 1.0f ), XMFLOAT2( 0.0f, 1.0f ) },
// ... etc
};
Bind it with this input layout:
D3D11_INPUT_ELEMENT_DESC layout[] =
{
{ "POSITION", 0, DXGI_FORMAT_R32G32B32_FLOAT, 0, 0, D3D11_INPUT_PER_VERTEX_DATA, 0 },
{ "TEXCOORD", 0, DXGI_FORMAT_R32G32_FLOAT, 0, 12, D3D11_INPUT_PER_VERTEX_DATA, 0 },
};
To this vertex shader input in the shader:
struct VS_INPUT
{
float4 Pos : POSITION;
float2 Tex : TEXCOORD0;
};
Then is it guaranteed by D3D specification that the 4th component of the Pos attribute (Pos.w) in the shader will be 0.0 ?
I cannot find definitive information about it.
