IDirect3DDevice9::GetLight method (d3d9.h)
Retrieves a set of lighting properties that this device uses.
Syntax
HRESULT GetLight(
[in] DWORD Index,
[out] D3DLIGHT9 *unnamedParam2
);
Parameters
[in] Index
Type: DWORD
Zero-based index of the lighting property set to retrieve. This method will fail if a lighting property has not been set for this index by calling the IDirect3DDevice9::SetLight method.
[out] unnamedParam2
Type: D3DLight9*
Pointer to a D3DLIGHT9 structure that is filled with the retrieved lighting-parameter set.
Return value
Type: HRESULT
If the method succeeds, the return value is D3D_OK. If the method fails, the return value can be D3DERR_INVALIDCALL.
Remarks
This method will not return device state for a device that is created using D3DCREATE_PUREDEVICE. If you want to use this method, you must create your device with any of the other values in D3DCREATE.
Retrieve all the properties for an existing light source by calling the IDirect3DDevice9::GetLight method for the device. When calling the IDirect3DDevice9::GetLight method, pass the zero-based index of the light source for which the properties will be retrieved as the first parameter, and supply the address of a D3DLIGHT9 structure as the second parameter. The device fills the D3DLIGHT9 structure to describe the lighting properties it uses for the light source at that index.
// Assume d3dDevice is a valid pointer to an IDirect3DDevice9 interface.
HRESULT hr;
D3DLight9 light;
// Get the property information for the first light.
hr = pd3dDevice->GetLight(0, &light);
if (SUCCEEDED(hr))
// Handle Success
else
// Handle failure
If you supply an index outside the range of the light sources assigned in the device, the IDirect3DDevice9::GetLight method fails, returning D3DERR_INVALIDCALL.
When you assign a set of light properties for a light source in a scene, the light source can be activated by calling the IDirect3DDevice9::LightEnable method for the device. New light sources are disabled by default. The IDirect3DDevice9::LightEnable method accepts two parameters. Set the first parameter to the zero-based index of the light source to be affected by the method, and set the second parameter to TRUE to enable the light or FALSE to disable it. The following code example illustrates the use of this method by enabling the first light source in the device's list of light source properties.
// Assume d3dDevice is a valid pointer to an IDirect3DDevice9 interface.
HRESULT hr;
hr = pd3dDevice->LightEnable(0, TRUE);
if (SUCCEEDED(hr))
// Handle Success
else
// Handle failure
Check the MaxActiveLights member of the D3DCAPS9 structure when you retrieve device capabilities to determine the maximum number of active lights supported by that device.
If you enable or disable a light that has no properties that are set with IDirect3DDevice9::SetLight, the IDirect3DDevice9::LightEnable method creates a light source with the properties listed in following table and enables or disables it.
Requirements
| Requirement | Value |
|---|---|
| Target Platform | Windows |
| Header | d3d9.h (include D3D9.h) |
| Library | D3D9.lib |