Setting up the constant buffer using SlimDX

Question

I've been following the Microsoft Direct3D11 tutorials but using C# and SlimDX. I'm trying to set the constant buffer but am not sure how to either create or set it.

I'm simply trying to set three matrices (world, view and projection) using a constant buffer but I'm struggling at every stage, creation, data input and passing it to the shader.

The HLSL on MSDN (which I've essentially copied) is:

cbuffer ConstantBuffer : register( b0 )
{
    matrix World;
    matrix View;
    matrix Projection;
}

The C++ code on MSDN is:

ID3D11Buffer* g_pConstantBuffer = NULL;
XMMATRIX g_World;
XMMATRIX g_View;
XMMATRIX g_Projection;

//set up the constant buffer
D3D11_BUFFER_DESC bd;
ZeroMemory( &bd, sizeof(bd) );
bd.Usage = D3D11_USAGE_DEFAULT;
bd.ByteWidth = sizeof(ConstantBuffer);
bd.BindFlags = D3D11_BIND_CONSTANT_BUFFER;
bd.CPUAccessFlags = 0;
if( FAILED(g_pd3dDevice->CreateBuffer( &bd, NULL, &g_pConstantBuffer ) ) )
    return hr;


//
// Update variables
//
ConstantBuffer cb;
cb.mWorld = XMMatrixTranspose( g_World );
cb.mView = XMMatrixTranspose( g_View );
cb.mProjection = XMMatrixTranspose( g_Projection );
g_pImmediateContext->UpdateSubresource( g_pConstantBuffer, 0, NULL, &cb, 0, 0 );

Does anybody know how to translate this to SlimDX? Or if anybody knows any SlimDX tutorials or resources that would also be useful.

Thanks.

Answer 1

Something similar to this should work:

var buffer = new Buffer(device, new BufferDescription {
    Usage = ResourceUsage.Default,
    SizeInBytes = sizeof(ConstantBuffer),
    BindFlags = BindFlags.ConstantBuffer
});

var cb = new ConstantBuffer();
cb.World = Matrix.Transpose(world);
cb.View = Matrix.Transpose(view);
cb.Projection = Matrix.Transpose(projection);

var data = new DataStream(sizeof(ConstantBuffer), true, true);
data.Write(cb);
data.Position = 0;

context.UpdateSubresource(new DataBox(0, 0, data), buffer, 0);