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

#pragma kernel generate_sdf

#include "../../Shader/ComputeCommon.cginc"

#include "../../Shader/AabbTreeFuncs.cginc"
#include "../../Shader/BrushFuncs.cginc"
#include "../../Shader/Math/MathConst.cginc"
#include "../../Shader/SDF/Util.cginc"

RWTexture3D<half> sdfOutput;
int3 sdfOutputSize;  // size of SDF texture
float4 sdfCenter;    // point in SDF mapped to center of SDF texture
float4 sdfDimension; // dimension in SDF mapped to size of SDF texture

[numthreads(kThreadGroupExtent, kThreadGroupExtent, kThreadGroupExtent)]
void generate_sdf(int3 id : SV_DispatchThreadID)
{
  if (any(id > sdfOutputSize.xyz))
    return;

  float3 p = sdfCenter.xyz + sdfDimension.xyz * (((float3) id) / max(1, sdfOutputSize.xyz - 1) - 0.5f);

  BRUSH_MASK(brushMask);
  BRUSH_MASK_CLEAR_ALL(brushMask);

  AABB_TREE_QUERY_POINT(aabbTree, aabbRoot, p,
    BRUSH_MASK_SET(brushMask, iData);
  );

  SdfBrushMaterial mat;
  float d = kInfinity;
  SDF_SAMPLE_MASKED_BRUSHES(d, p, brushMask, mat);

  sdfOutput[id] = d;
}