BufferHelpers

Helpers functions for creating Direct3D resources from CPU data.

Header

#include <BufferHelpers.h>

Creating vertex/index buffers

The CreateStaticBuffer helper is used to create Direct3D buffer type resources such as vertex buffers or index buffers.

HRESULT CreateStaticBuffer(ID3D11Device* device,
    const void* ptr, size_t count, size_t stride,
    D3D11_BIND_FLAG bindFlags,
    ID3D11Buffer** pBuffer);

template<typename T>
HRESULT CreateStaticBuffer(ID3D11Device* device,
    T const* data,
    size_t count,
    D3D11_BIND_FLAG bindFlags,
    ID3D11Buffer** pBuffer);

template<typename T>
HRESULT CreateStaticBuffer(ID3D11Device* device,
    T const& data,
    D3D11_BIND_FLAG bindFlags,
    ID3D11Buffer** pBuffer);

Examples

static const VertexPositionColor s_vertexData[3] =
{
    { XMFLOAT3{ 0.0f,   0.5f,  0.5f }, XMFLOAT4{ 1.0f, 0.0f, 0.0f, 1.0f } },  // Top / Red
    { XMFLOAT3{ 0.5f,  -0.5f,  0.5f }, XMFLOAT4{ 0.0f, 1.0f, 0.0f, 1.0f } },  // Right / Green
    { XMFLOAT3{ -0.5f, -0.5f,  0.5f }, XMFLOAT4{ 0.0f, 0.0f, 1.0f, 1.0f } }   // Left / Blue
};

ComPtr<ID3D11Buffer> vb;
DX::ThrowIfFailed(
  CreateStaticBuffer(device,
    s_vertexData,                // const void *ptr
    _countof(s_vertexData),      // size_t count
    sizeof(VertexPositionColor), // size_t stride
    D3D11_BIND_VERTEX_BUFFER, &vb)
  );

When creating from an array using VertexTypes, a template simplifies this to:

ComPtr<ID3D11Buffer> vb;
DX::ThrowIfFailed(
  CreateStaticBuffer(device, s_vertexData, _countof(s_vertexData),
    D3D11_BIND_VERTEX_BUFFER, &vb)
  );

Finally, you can create from C++ containers like std::vector:

std::vector<uint16_t> indices;

...

ComPtr<ID3D11Buffer> ib;
DX::ThrowIfFailed(
  CreateStaticBuffer(device, indices, D3D11_BIND_INDEX_BUFFER, &ib)
  );

See Model for creating vertex buffers/index buffers from disk files.

Creating textures

The CreateTextureFromMemory helpers can be used to create 1D, 2D, or 3D Direct3D texture resources. For the 2D version, you can enable auto-generation of mipmaps.

HRESULT CreateTextureFromMemory(ID3D11Device* device,
    size_t width,
    DXGI_FORMAT format,
    const D3D11_SUBRESOURCE_DATA& initData,
    ID3D11Texture1D** texture,
    ID3D11ShaderResourceView** textureView,
    D3D11_BIND_FLAG bindFlags = D3D11_BIND_SHADER_RESOURCE);

HRESULT CreateTextureFromMemory(ID3D11Device* device,
    size_t width, size_t height,
    DXGI_FORMAT format,
    const D3D11_SUBRESOURCE_DATA& initData,
    ID3D11Texture2D** texture,
    ID3D11ShaderResourceView** textureView,
    D3D11_BIND_FLAG bindFlags = D3D11_BIND_SHADER_RESOURCE);

HRESULT  CreateTextureFromMemory(ID3D11Device* device,
    ID3D11DeviceContext* d3dContext,
    size_t width, size_t height,
    DXGI_FORMAT format,
    const D3D11_SUBRESOURCE_DATA& initData,
    ID3D11Texture2D** texture,
    ID3D11ShaderResourceView** textureView);

HRESULT CreateTextureFromMemory(ID3D11Device* device,
    size_t width, size_t height, size_t depth,
    DXGI_FORMAT format,
    const D3D11_SUBRESOURCE_DATA& initData,
    ID3D11Texture3D** texture,
    ID3D11ShaderResourceView** textureView,
    D3D11_BIND_FLAG bindFlags = D3D11_BIND_SHADER_RESOURCE);

Examples

To create a 'default' texture (i.e. a 1x1 white pixel):

const uint32_t s_pixel = 0xffffffff;

D3D11_SUBRESOURCE_DATA initData = { &s_pixels, sizeof(uint32_t), 0 };

ComPtr<ID3D11ShaderResourceView> defaultTex;
DX::ThrowIfFailed(
    CreateTextureFromMemory(device, 1u, 1u, DXGI_FORMAT_R8G8B8A8_UNORM, initData,
        nullptr, &defaultTex)
    );

See DDSTextureLoader and WICTextureLoader for creating textures from disk files.

Constant buffers

The ConstantBuffer template class is a strongly-typed helper for managing constant buffers.

struct MyCB
{
    XMMATRIX world;
};

static_assert((sizeof(MyCB) % 16) == 0, "CB size not padded correctly");

ConstantBuffer<MyCB> cbuffer;

...

cbuffer.Create(device);

...


MyCB updates = { ... };
cbuffer.SetData(deviceContext, updates);

auto buffer = cbuffer.GetBuffer();

deviceContext->VSSetConstantBuffers(0, 1, &buffer);
deviceContext->PSSetConstantBuffers(0, 1, &buffer);