GPU Pro 6

440 VI Compute

1 // Plane equation from three points , simplified

2 // for the case where the f i rst point is the origin .

3 // N is normalized so that the plane equation can

4 // be used to compute signed distance .

5 float4 CreatePlaneEquation ( float3 Q , float3 R)

6 {

7 // N = normalize(cross(Q−P,R−P) ) ,

8 // except we know P is the origin

9 float3 N = normalize( cross ( Q , R ));

10 // D = −(N dot P) , except we know P is the origin

11 return float4( N ,0) ;

12 }

13

14 // Convert a point from postprojection space into view space

15 float3 ConvertProjToView ( float4 p)

16 {

17 p = mul ( p , g_mProjectionInv );

18 return ( p / p . w ).xyz ;

19 }

20

21 void ...