Dynamic Tessellation - Practical Rendering and Computation with Direct3D 11 - page 453

{

float Edges[3] : SV_TessFactor;

float Inside : SV_InsideTessFactor;

}',
HS__CONSTANT_DATA_OUTPUT hsConstantFunc( InputPatch<VS_OUTPUT, 3> ip, uint
PatchID : SV_PrimitiveID )
{

HS_CONSTANT_DATA_OUTPUT output;

output. Edges[0] = EdgeFactors.x;
output.Edges[l] = EdgeFactors.y;
output.Edges[2] = EdgeFactors .z;

output.Inside = EdgeFactors. w;

return output;

}

[domain ("tri")]
[partitioning("f ractional_even")]
[outputtopology ("triangle_cw") ]
[outputcontrolpoints(13) ]
[patchconstantfunc("hsConstantFunc")]
HS_OUTPUT hsDefault( InputPatch<VS_OUTPUT., 3> ip, uint i : SV_
OutputControlPointID, uint PatchID : SV_PrimitiveID )
{

HS_OUTPUT output;

// Must provide a default definition just in
// case we don J t match any branch below
output.position = float3(0.0f, 0.0f, 0.0f);
output.normal = float3(0.0f, 0.0f, 0.0f);
switch(i)

{

// Three actual vertices:

// b(306)
case 0:
// b(030)
case 1:
// b(003)
case 2:

output.position = ip[i] .position;
output.normal = ip[i] .normal;
break;

// Edge between v0 and vl

// b(210)
case 3:
output.position = ComputeEdgePosition(ip, 0, 1);
break;