UpkManager.Dds.Compression.ClusterFit.Compress4 C# (CSharp) Метод

    protected override unsafe void Compress4(byte *block) {
      //
      // cache some values
      //
      int count = colours.Count;

      Vec3[] values = colours.Points;
      //
      // create a codebook
      //
      Vec3[] codes = new Vec3[4];

      codes[0] = start;
      codes[1] = end;
      codes[2] = 2.0f / 3.0f * start + 1.0f / 3.0f * end;
      codes[3] = 1.0f / 3.0f * start + 2.0f / 3.0f * end;
      //
      // match each point to the closest code
      //
      byte[] closest = new byte[16];

      float error = 0.0f;

      for(int i = 0; i < count; ++i) {
        //
        // find the closest code
        //
        float dist = Single.MaxValue;

        int idx = 0;

        for(int j = 0; j < 4; ++j) {
          float d = Vec3.LengthSquared(metric * (values[i] - codes[j]));

          if (d < dist) {
            dist = d;

            idx = j;
          }
        }
        //
        // save the index
        //
        closest[i] = (byte)idx;
        //
        // accumulate the error
        //
        error += dist;
      }
      //
      // save this scheme if it wins
      //
      if (error < bestError) {
        //
        // remap the indices
        //
        byte[] indices = new byte[16];

        colours.RemapIndices(closest, indices);
        //
        // save the block
        //
        ColourBlock.WriteColourBlock4(start, end, indices, block);
        //
        // save the error
        //
        bestError = error;
      }
    }