/******************************************************************************/
/*
  Project   - MudBun
  Publisher - Long Bunny Labs
              http://LongBunnyLabs.com
  Author    - Ming-Lun "Allen" Chou
              http://AllenChou.net
*/
/******************************************************************************/

#pragma kernel bake_splat_verts
#pragma kernel rig_bones

#define kThreadGroupExtent (4)
#define kThreadGroupSize (kThreadGroupExtent * kThreadGroupExtent * kThreadGroupExtent)

#define MUDBUN_IS_COMPUTE_SHADER (1)

#include "../../Shader/BoneFuncs.cginc"
#include "../../Shader/GenPointDefs.cginc"
#include "../../Shader/Render/MeshCommon.cginc"
#include "../../Shader/Render/SplatCommon.cginc"

RWStructuredBuffer<int> indirectDrawArgs;

[numthreads(kThreadGroupSize, 1, 1)]
void bake_splat_verts(uint3 id : SV_DispatchThreadID)
{
  if (int(id.x) >= indirectDrawArgs[0])
    return;

  uint iGenPoint = id.x;

  float4 vertexWs;
  float3 vertexLs;
  float3 normalWs;
  float3 normalLs;
  float3 tangentWs;
  float3 tangentLs;
  float3 centerWs;
  float3 centerLs;
  float4 color;
  float4 emissionHash;
  float2 metallicSmoothness;
  float2 tex;
  float4 textureWeight;
  float sdfValue;
  float3 normal2dLs;
  float3 normal2dWs;
  mudbun_splat_vert(iGenPoint, vertexWs, vertexLs, normalWs, normalLs, tangentWs, tangentLs, centerWs, centerLs, color, emissionHash, metallicSmoothness, tex, textureWeight, sdfValue, normal2dLs, normal2dWs);

  // TODO: we actually need a second gen point buffer...otherwise we'll have a race condition

  aGenPoint[iGenPoint].posNorm.xyz = vertexLs;
  aGenPoint[iGenPoint].posNorm.w = pack_normal(normalLs);
  aGenPoint[iGenPoint].uv = tex + 0.5f;
}

[numthreads(kThreadGroupSize, 1, 1)]
void rig_bones(uint3 id : SV_DispatchThreadID)
{
  if (int(id.x) >= indirectDrawArgs[0])
    return;

  uint iGenPoint = id.x;
  
  float4 boneWeight;
  compute_brush_bone_weights(aGenPoint[iGenPoint].posNorm.xyz, aGenPoint[iGenPoint].boneIndex, boneWeight);
  aGenPoint[iGenPoint].boneWeight = pack_rgba(boneWeight);
}