IDirect3DDevice3::ComputeSphereVisibility

The IDirect3DDevice3::ComputeSphereVisibility method calculates the visibility (complete, partial, or no visibility) of an array spheres within the current viewport for this device.

HRESULT ComputeSphereVisibility( 
  LPD3DVECTOR lpCenters,         
  LPD3DVALUE  lpRadii,           
  DWORD       dwNumSpheres,      
  DWORD       dwFlags,           
  LPDWORD     lpdwReturnValues   
); 
 

Parameters

lpCenters

Array of D3DVECTOR structures describing the center point for each sphere, in world-space coordinates.

lpRadii

Array of D3DVALUE variables that represent the radius for each sphere.

dwNumSpheres

Number of spheres. This value must be greater than zero.

dwFlags

Not currently used; set to zero.

lpdwReturnValues

Array of DWORD values. The array need not be initialized, but it must be large enough to contain a DWORD for each sphere being tested. When the method returns, each element in the array contains a combination of the following flags that describe the visibility of that sphere within the current viewport for this device:

Inside flags

D3DVIS_INSIDE_BOTTOM, D3DVIS_INSIDE_FAR, D3DVIS_INSIDE_FRUSTUM, D3DVIS_INSIDE_LEFT

D3DVIS_INSIDE_NEAR, D3DVIS_INSIDE_RIGHT, D3DVIS_INSIDE_TOP

The sphere is inside the viewing frustum of the current viewport.

Intersection flags

D3DVIS_INTERSECT_BOTTOM or D3DVIS_INTERSECT_TOP

The sphere intersects the bottom or top plane of the viewing frustum for the current viewport, depending on which flag is present.

D3DVIS_INTERSECT_FAR or D3DVIS_INTERSECT_NEAR

The sphere intersects the far or near plane of the viewing frustum for the current viewport, depending on which flag is present.

D3DVIS_INTERSECT_FRUSTUM

The sphere intersects some part of the viewing frustum for the current viewport.

D3DVIS_INTERSECT_LEFT or D3DVIS_INTERSECT_RIGHT

The sphere intersects the left or right plane of the viewing frustum for the current viewport, depending on which flag is present.

Outside flags

D3DVIS_OUTSIDE_BOTTOM or D3DVIS_OUTSIDE_TOP

The sphere is outside the bottom or top plane of the viewing frustum for the current viewport, depending on which flag is present.

D3DVIS_OUTSIDE_FAR or D3DVIS_OUTSIDE_NEAR

The sphere is outside the far or near plane of the viewing frustum for the current viewport, depending on which flag is present.

D3DVIS_OUTSIDE_FRUSTUM

The sphere is somewhere outside the viewing frustum for the current viewport.

D3DVIS_OUTSIDE_LEFT or D3DVIS_OUTSIDE_RIGHT

The sphere is outside the left or right plane of the viewing frustum for the current viewport, depending on which flag is present.

Return Values

If the method succeeds, the return value is D3D_OK.

If the method fails, the return value may be one of the following values:

Remarks

Sphere visibility is computed by back transforming the viewing frustum to the model space, using the inverse of the combined world, view or projection matrices. If the combined matrix can not be inverted (if the determinant is zero), the method fails, returning D3DERR_INVALIDMATRIX.

QuickInfo

  Windows NT/2000: Requires Windows 2000.
  Windows 95/98: Requires Windows 95 or later. Available as a redistributable for Windows 95.
  Header: Declared in d3d.h.
  Import Library: Use ddraw.lib.