Separating Different Types of Buffers in HLSL

Question

Is it possible to separate the different types of data being passed into HLSL shader?

For example, most tutorials that I have seen setup the buffer as

 struct vertin{
    float4 position: POSITION;
    float2 text    : TEXCOORD;
    float4 norm    : NORMAL:
 }

What I want to do is pass in each data separately without create a struct to hold everything together, thus separating the position vertices from texture from normal, and pass each in separately. Also how would the shader be able to tell which normal correspond to which vertices and texture?

I think what I am thinking about is very similar to how OPENGL can bind each vertex buffer, texture buffer, and normal buffer separately when passing to the shader. Can HLSL do the same, and how so?

Also I am working with DirectX 11.

Answer 1

Yes you can.

In DirectX app, define each variable as a struct

struct CBNeverChanges
{
    XMMATRIX mView;
};

struct CBChangeOnResize
{
    XMMATRIX mProjection;
};

in Shader file, define each variable as cbuffer

cbuffer cbNeverChanges : register( b0 )
{
    matrix View;
};

cbuffer cbChangeOnResize : register( b1 )
{
    matrix Projection;
};

Use CreateBuffer to create the contant buffer

D3D11_BUFFER_DESC bd;
ZeroMemory( &bd, sizeof(bd) );
bd.Usage = D3D11_USAGE_DEFAULT;
bd.ByteWidth = sizeof(CBNeverChanges);
bd.BindFlags = D3D11_BIND_CONSTANT_BUFFER;
bd.CPUAccessFlags = 0;
hr = g_pd3dDevice->CreateBuffer( &bd, NULL, &g_pCBNeverChanges );

Use UpdateSubresource to update the shader variables.

CBNeverChanges cbNeverChanges;
cbNeverChanges.mView = XMMatrixTranspose( g_View );
g_pImmediateContext->UpdateSubresource( g_pCBNeverChanges, 0, NULL, &cbNeverChanges, 0, 0 );

UPDATE: If you even don't want to use a struct, try below code.

// Shader variables
XMMATRIX mView;

// pointer to constant buffer
ID3D11Buffer* g_pCBChangeOnResize = NULL;

// Create constant buffer
D3D11_BUFFER_DESC bd;
ZeroMemory( &bd, sizeof(bd) );
bd.Usage = D3D11_USAGE_DEFAULT;
bd.ByteWidth = sizeof(XMMATRIX);
bd.BindFlags = D3D11_BIND_CONSTANT_BUFFER;
bd.CPUAccessFlags = 0;
hr = g_pd3dDevice->CreateBuffer( &bd, NULL, &g_pCBNeverChanges );

// Update shader variable
mView = XMMatrixTranspose( g_View );
g_pImmediateContext->UpdateSubresource( g_pCBNeverChanges, 0, NULL, &mView, 0, 0 );