// Unity built-in shader source. Copyright (c) 2016 Unity Technologies. MIT license (see license.txt)

#pragma kernel main
#pragma kernel main SKIN_NORM
#pragma kernel main SKIN_NORM SKIN_TANG

#include "HLSLSupport.cginc"
#include "Internal-Skinning-Util.cginc"


uint g_FirstVert; // First vertex from blend shape buffer to use
uint g_VertCount; // Sparse vertex count, not the full amount of vertices in mesh
float g_Weight;

SKINNING_GENERIC_VERTEX_RWBUFFER inOutMeshVertices;
SKINNING_GENERIC_SKIN_BUFFER_BLENDSHAPE inBlendShapeVertices;

[numthreads(64, 1, 1)]
void main(uint3 threadID : SV_DispatchThreadID)
{
    const uint t = threadID.x;

    if (t >= g_VertCount)
    {
        return;
    }

    BlendShapeVertex blendShapeVert = FetchBlendShape(inBlendShapeVertices, t + g_FirstVert);

    const uint vertIndex = blendShapeVert.index;

    MeshVertex vertex = FetchVert(inOutMeshVertices, vertIndex);

    vertex.pos += blendShapeVert.pos * g_Weight;
#if SKIN_NORM
    vertex.norm += blendShapeVert.norm * g_Weight;
#endif
#if SKIN_TANG
    vertex.tang.xyz += blendShapeVert.tang * g_Weight;
#endif

    StoreVert(inOutMeshVertices, vertex, vertIndex);
}