IDirect3DDevice9::SetViewport method (d3d9helper.h)

Sets the viewport parameters for the device.

HRESULT SetViewport(
  [in] const D3DVIEWPORT9 *pViewport
);

[in] pViewport

Type: const D3DVIEWPORT9*

Pointer to a D3DVIEWPORT9 structure, specifying the viewport parameters to set.

Type: HRESULT

If the method succeeds, the return value is D3D_OK. If the method fails, it will return D3DERR_INVALIDCALL. This will happen if pViewport is invalid, or if pViewport describes a region that cannot exist within the render target surface.

Direct3D sets the following default values for the viewport.

D3DVIEWPORT9 vp;
vp.X      = 0;
vp.Y      = 0;
vp.Width  = RenderTarget.Width;
vp.Height = RenderTarget.Height;
vp.MinZ   = 0.0f;
vp.MaxZ   = 1.0f;

IDirect3DDevice9::SetViewport can be used to draw on part of the screen. Make sure to call it before any geometry is drawn so the viewport settings will take effect.

To draw multiple views within a scene, repeat the IDirect3DDevice9::SetViewport and draw geometry sequence for each view.

IDirect3DDevice9

IDirect3DDevice9::GetViewport