Beginning Direct3D, simple triangle not rendering

Question

I've been playing around with making games for a little while now, using SDL at first and then SFML. It's been nice to have the basics done for me, but now I'd like to take another step and learn how to do the graphics from the ground up. So I'm trying to learn the ropes of Direct3D, and have been reading a couple of tutorials on D3D 11 to get started. I'm just trying to get the absolute basics going by drawing a white triangle on a dark background... but I can't get it to work.

I'm using the Visual Studio 2012 RC and the Windows 8 SDK, so there's some C++11 syntax in here, plus there's no D3DX. I've managed to set up the window and the initialization of Direct3D seems to go just fine. It runs the rendering part of the main loop, as it clears the screen in the color I specify. However, my fancy white triangle just won't show up. I've gone through my code several times, and with my lack of experience I can't tell what is wrong with it. I've cut out the window initialization/d3d shutdown and other irrelevant parts, but I'm afraid to cut off too much in case some of it is relevant to my problem, so... big-wall-of-code-warning.

I think I have all the required steps in place; I create the device, device context, swap chain and render target. Then I create a vertex shader+input layout and a pixel shader. After that I create a vertex buffer, add the vertices for my triangle and set the primitive topology to TRIANGLELIST, and that's it for the initialization. In my main loop, I point D3D to my vertex/pixel shaders, and tell it to draw the 3 vertices i inserted into the buffer. But only the dark blue background from the call to ClearRenderTargetView shows up; no triangle. Have I missed any steps, or done anything wrong on the way?

Here is the code I have (I'll shamefully admit to have slacked a bit with the code conventions on this one, so no p before pointer variables etc.):

Main loop:

while ( msg.message != WM_QUIT )
{
    if ( PeekMessage( &msg, 0, 0, 0, PM_REMOVE ))
    {
        TranslateMessage( &msg );
        DispatchMessage( &msg );
    }
    else
    {
        g_d3dContext->ClearRenderTargetView( g_renderTarget, clearColor );
        g_d3dContext->VSSetShader( g_vertexShader, nullptr, 0 );
        g_d3dContext->PSSetShader( g_pixelShader, nullptr, 0 );
        g_d3dContext->Draw( 3, 0 );
        g_swapChain->Present( 0, 0 );
    }
}

Direct3D init:

HRESULT hr = S_OK;

RECT rc;
GetClientRect( g_hWnd, &rc );
float width = static_cast<float>( rc.right - rc.left );
float height = static_cast<float>( rc.bottom - rc.top );

uint createDeviceFlags = 0;

const uint numDriverTypes = 3;
D3D_DRIVER_TYPE driverTypes[ numDriverTypes ] =
{
    D3D_DRIVER_TYPE_HARDWARE,
    D3D_DRIVER_TYPE_WARP,
    D3D_DRIVER_TYPE_REFERENCE
};

const uint numFeatureLevels = 3;
D3D_FEATURE_LEVEL featureLevels[ numFeatureLevels ] =
{
    D3D_FEATURE_LEVEL_11_0,
    D3D_FEATURE_LEVEL_10_1,
    D3D_FEATURE_LEVEL_10_0
};

DXGI_SWAP_CHAIN_DESC sd = { 0 };
sd.BufferCount                          = 1;
sd.BufferDesc.Width                     = static_cast<uint>( width );
sd.BufferDesc.Height                    = static_cast<uint>( height );
sd.BufferDesc.Format                    = DXGI_FORMAT_R8G8B8A8_UNORM;
sd.BufferDesc.RefreshRate.Numerator     = 60;
sd.BufferDesc.RefreshRate.Denominator   = 1;
sd.BufferUsage                          = DXGI_USAGE_RENDER_TARGET_OUTPUT;
sd.OutputWindow                         = g_hWnd;
sd.SampleDesc.Count                     = 1;
sd.SampleDesc.Quality                   = 0;
sd.Windowed                             = true;

for( uint driverTypeIndex : driverTypes )
{
    g_driverType = driverTypes[ driverTypeIndex ];
    hr = D3D11CreateDeviceAndSwapChain( nullptr, g_driverType, nullptr, createDeviceFlags, featureLevels, numFeatureLevels,
                                        D3D11_SDK_VERSION, &sd, &g_swapChain, &g_d3d, &g_featureLevel, &g_d3dContext );
    if( SUCCEEDED( hr ))
        break;
}
if( FAILED( hr ))
    return hr;

// Create a render target view
ID3D11Texture2D* backBuffer = nullptr;
hr = g_swapChain->GetBuffer( 0, __uuidof( ID3D11Texture2D ), reinterpret_cast<void**>( &backBuffer ));
if( FAILED( hr ))
    return hr;

hr = g_d3d->CreateRenderTargetView( backBuffer, nullptr, &g_renderTarget );
backBuffer->Release();
if( FAILED( hr ))
    return hr;

g_d3dContext->OMSetRenderTargets( 1, &g_renderTarget, nullptr );

// Setup the viewport
D3D11_VIEWPORT vp = { 0 };
vp.Width    = width;
vp.Height   = height;
vp.MinDepth = 0.0f;
vp.MaxDepth = 1.0f;
vp.TopLeftX = 0;
vp.TopLeftY = 0;
g_d3dContext->RSSetViewports( 1, &vp );

// Create vertex shader and input layout
ID3DBlob* vsBlob = nullptr;
ID3DBlob* errorBlob = nullptr;
hr = D3DCompileFromFile( L"VertexShader.hlsl", nullptr, nullptr, "main", "vs_4_0", 0, 0, &vsBlob, &errorBlob );
if ( FAILED( hr ))
    return hr;

hr = g_d3d->CreateVertexShader( vsBlob->GetBufferPointer(), vsBlob->GetBufferSize(), nullptr, &g_vertexShader );
if ( FAILED( hr ))
{
    vsBlob->Release();
    return hr;
}

D3D11_INPUT_ELEMENT_DESC ied = { 0 };
ied.AlignedByteOffset       = 0;
ied.Format                  = DXGI_FORMAT_R32G32B32_FLOAT;
ied.InputSlotClass          = D3D11_INPUT_PER_VERTEX_DATA;
ied.InputSlot               = 0;
ied.InstanceDataStepRate    = 0;
ied.SemanticIndex           = 0;
ied.SemanticName            = "POSITION";

hr = g_d3d->CreateInputLayout( &ied, 1, vsBlob->GetBufferPointer(), vsBlob->GetBufferSize(), &g_inputLayout );
vsBlob->Release();
if ( FAILED ( hr ))
    return hr;

g_d3dContext->IASetInputLayout( g_inputLayout );

// Create pixel shader
ID3DBlob* psBlob = nullptr;
errorBlob = nullptr;
hr = D3DCompileFromFile( L"PixelShader.hlsl", nullptr, nullptr, "main", "ps_4_0", 0, 0, &psBlob, &errorBlob );
if ( FAILED( hr ))
    return hr;

hr = g_d3d->CreatePixelShader( psBlob->GetBufferPointer(), psBlob->GetBufferSize(), nullptr, &g_pixelShader );
psBlob->Release();
if ( FAILED( hr ))
    return hr;

// Put some vertices up in this bitch
Vector3f vertices[] =
{
    Vector3f( 0.5f, -0.5f, 0.5f ),
    Vector3f( 0.5f, -0.5f, 0.5f ),
    Vector3f( -0.5f, -0.5f, 0.5f )
};

D3D11_BUFFER_DESC bd = { 0 };
bd.BindFlags            = D3D11_BIND_VERTEX_BUFFER;
bd.ByteWidth            = sizeof( Vector3f ) * 3;
bd.CPUAccessFlags       = 0;
bd.MiscFlags            = 0;
bd.StructureByteStride  = 0;
bd.Usage                = D3D11_USAGE_DEFAULT;

D3D11_SUBRESOURCE_DATA initData = { 0 };
initData.pSysMem            = vertices;
initData.SysMemPitch        = 0;
initData.SysMemSlicePitch   = 0;

hr = g_d3d->CreateBuffer( &bd, &initData, &g_vertexBuffer );
if ( FAILED( hr ))
    return hr;

uint stride = sizeof( Vector3f );
uint offset = 0;

g_d3dContext->IASetVertexBuffers( 0, 1, &g_vertexBuffer, &stride, &offset );
g_d3dContext->IASetPrimitiveTopology( D3D_PRIMITIVE_TOPOLOGY_TRIANGLELIST );

return S_OK;

My vertex type:

struct Vector3f
{
    Vector3f( float ix, float iy, float iz )
        : x( ix ), y( iy ), z( iz ) {}

    float x;
    float y;
    float z;
};

My vertex shader:

float4 main( float4 pos : POSITION ) : SV_POSITION
{
    return pos;
}

My pixel shader:

float4 main() : SV_TARGET
{
    return float4( 1.0f, 1.0f, 1.0f, 1.0f );
}

Martin Wedvich Martin Wedvich · Accepted Answer · 2012-06-11T18:08:56

Of course it was an incredibly stupid oversight. I simply entered bad vertex data - all the vertices were in the same Y dimension; the two first were even identical.

Changed to this:

Vector3f( -0.5f, 0.5f, 0.5f ),
Vector3f( 0.5f, 0.5f, 0.5f ),
Vector3f( -0.5f, -0.5f, 0.5f )

And there was much song and dance and happiness.

Beginning Direct3D, simple triangle not rendering

1 Answers