Can't compile HLSL Hull shader code - c++

Question

Here's a simple hull shader code that i made, to try to understand tessellation.
I just can't find anything wrong with this code, but the compile function always return false. Here's my code:
My input and output structures:
[domain("tri")] // indicates a triangle patch (3 verts)
[partitioning("fractional_odd")] // fractional avoids popping
// vertex ordering for the output triangles
[outputtopology("triangle_cw")]
[outputcontrolpoints(3)]
// name of the patch constant hull shader
[patchconstantfunc("ConstantsHS")]
//[maxtessfactor(7.0)]
cbuffer TessellationBuffer
{
float tessellationAmount;
float3 padding;
};
struct VS_CONTROL_POINT_OUTPUT
{
float3 vWorldPos : POSITION;
float2 vTexCoord : TEXCOORD0;
float3 vNormal : NORMAL0;
};
struct HS_CONTROL_POINT_OUTPUT
{
float3 vWorldPos : POSITION;
float2 vTexCoord : TEXCOORD0;
float3 vNormal : NORMAL0;
};
struct HS_CONSTANT_DATA_OUTPUT
{
float Edges[3] : SV_TessFactor;
float Inside : SV_InsideTessFactor;
};
My functions:
HS_CONTROL_POINT_OUTPUT HS(InputPatch<VS_CONTROL_POINT_OUTPUT, 3> inputPatch, uint uCPID : SV_OutputControlPointID, uint patchId : SV_PrimitiveID )
{
HS_CONTROL_POINT_OUTPUT Output;
Output.vWorldPos = inputPatch[uCPID].vWorldPos;
Output.vTexCoord = inputPatch[uCPID].vTexCoord;
Output.vNormal = inputPatch[uCPID].vNormal;
return Output;
};
HS_CONSTANT_DATA_OUTPUT ConstantsHS(InputPatch<VS_CONTROL_POINT_OUTPUT, 3> inputPatch, uint PatchID : SV_PrimitiveID )
{
HS_CONSTANT_DATA_OUTPUT Output;
Output.Edges[0] = tessellationAmount;
Output.Edges[1] = tessellationAmount;
Output.Edges[2] = tessellationAmount;
Output.Inside = tessellationAmount;
return Output;
};
Thanks for any help.

Answer 1

The attributes have to be set on the entry point like below, then your hull shader is valid :
[domain("tri")] // indicates a triangle patch (3 verts)
[partitioning("fractional_odd")] // fractional avoids popping
// vertex ordering for the output triangles
[outputtopology("triangle_cw")]
[outputcontrolpoints(3)]
// name of the patch constant hull shader
[patchconstantfunc("ConstantsHS")]
//[maxtessfactor(7.0)]
HS_CONTROL_POINT_OUTPUT HS(InputPatch<VS_CONTROL_POINT_OUTPUT, 3> inputPatch, uint uCPID : SV_OutputControlPointID, uint patchId : SV_PrimitiveID )
On a side note, The command line tool FXC.exe would have print an error message that would have put you in the right direction : error X3000: syntax error: unexpected token 'cbuffer'
And i am unsure of what function you are referring to, D3DCompile return a HRESULT, not a boolean, and it also output a blob for you with the error messages in case of failure.