在 Direct3D9 中启用抗锯齿（多样本渲染目标）

Question

我正在尝试在 D3D9 应用程序中启用 AA，但不确定如何正确设置曲面。到目前为止，我有：

IDirect3DDevice9* m_pd3dDevice;
IDirect3DSurface9* screen;
IDirect3DSurface9* msaasurf;
D3DPRESENT_PARAMETERS m_presentationParameters;

初始化：

m_presentationParameters.Windowed = TRUE;
m_presentationParameters.SwapEffect = D3DSWAPEFFECT_DISCARD;
m_presentationParameters.MultiSampleType = D3DMULTISAMPLE_2_SAMPLES;
m_presentationParameters.MultiSampleQuality = 0;
m_presentationParameters.BackBufferFormat = D3DFMT_UNKNOWN;
m_presentationParameters.EnableAutoDepthStencil = TRUE;
m_presentationParameters.AutoDepthStencilFormat = D3DFMT_D16;
m_presentationParameters.PresentationInterval = D3DPRESENT_INTERVAL_IMMEDIATE;

// create d3d device
m_pD3D->CreateDevice(
  D3DADAPTER_DEFAULT, 
  D3DDEVTYPE_HAL, 
  hWnd,
  D3DCREATE_HARDWARE_VERTEXPROCESSING,
  &m_presentationParameters, &m_pd3dDevice 
)


// save screen surface
m_pd3dDevice->GetRenderTarget(0, &screen);
D3DSURFACE_DESC desc;
screen->GetDesc(&desc);

// Create multisample render target
m_pd3dDevice->CreateRenderTarget(
    800, 600, 
    D3DFMT_A8R8G8B8,
    desc.MultiSampleType, desc.MultiSampleQuality,
    false,
    &msaasurf,
    NULL
  );

然后，对于每一帧：

// render to multisample surface
m_pd3dDevice->SetRenderTarget(0, msaasurf);

m_pd3dDevice->Clear(0, NULL, D3DCLEAR_TARGET | D3DCLEAR_ZBUFFER, D3DCOLOR_XRGB( 0, 0, 0 ), 1.0f, 0 );
m_pd3dDevice->BeginScene();

// render stuff here

m_pd3dDevice->EndScene();

m_pd3dDevice->SetRenderTarget(0, screen);

// get back buffer
IDirect3DSurface9* backBuffer = NULL;
m_pd3dDevice->GetBackBuffer(0, 0, D3DBACKBUFFER_TYPE_MONO, &backBuffer);

// copy rendertarget to backbuffer
m_pd3dDevice->StretchRect(msaasurf, NULL, backBuffer, NULL, D3DTEXF_NONE);
backBuffer->Release();

// Present the backbuffer contents to the display
m_pd3dDevice->Present(NULL, NULL, NULL, NULL);

但是，我的屏幕上没有出现任何内容（全黑）。没有发生错误（我检查所有 d3d 调用的返回值）。我做错了什么？

Answer 1

您不需要额外的表面，可以直接渲染到多重采样后缓冲区。对我来说，像这样使用 StretchRect() 的唯一原因是获取场景的非多重采样副本以用于后处理（因为多重采样渲染目标是不良纹理，因此您需要场景数据在已解析的纹理中）。如果您想这样做，则无需为后缓冲区指定多重采样。那么用于渲染场景的多重采样渲染目标就足够了。