internal float GetInterpolatedHeight(ChunkCoord chunkCoord, PointX2D coord, HeightMapFraction heightMapFraction)
{
// Height stored as: h5 - its v8 grid, h1-h4 - its v9 grid
// +--------------> X
// | h1--------h2 Coordinates are:
// | | | | h1 0,0
// | | 1 | 2 | h2 0,1
// | |----h5---| h3 1,0
// | | 3 | 4 | h4 1,1
// | | | | h5 1/2,1/2
// | h3--------h4
// V Y
if (HeightMaps == null) return float.NaN;
var heightMap = HeightMaps[chunkCoord.ChunkX, chunkCoord.ChunkY];
if (heightMap == null) return float.NaN;
var medianHeight = HalfUtils.Unpack(heightMap.MedianHeight);
if (heightMap.IsFlat) return medianHeight;
// Fixme: Indexing is backwards.
var heightX = (coord.Y == TerrainConstants.UnitsPerChunkSide)
? (TerrainConstants.UnitsPerChunkSide - 1)
: coord.Y;
var heightY = (coord.X == TerrainConstants.UnitsPerChunkSide)
? (TerrainConstants.UnitsPerChunkSide - 1)
: coord.X;
// Determine what quad we're in
var xf = heightMapFraction.FractionX;
var yf = heightMapFraction.FractionY;
float topLeft, topRight, bottomLeft, bottomRight;
if (xf < 0.5f)
{
if (yf < 0.5)
{
// Calc the #1 quad
// +--------------> X
// | h1--------h2 Coordinates are:
// | | | | h1 0,0
// | | 1 | | h2 0,1
// | |----h5---| h3 1,0
// | | | | h4 1,1
// | | | | h5 1/2,1/2
// | h3--------h4
// V Y
var packed1 = heightMap.OuterHeightDiff[heightX, heightY];
var packed2 = heightMap.OuterHeightDiff[heightX, heightY + 1];
var packed3 = heightMap.OuterHeightDiff[heightX + 1, heightY];
var packed5 = heightMap.InnerHeightDiff[heightX, heightY];
var h1 = HalfUtils.Unpack(packed1);
var h2 = HalfUtils.Unpack(packed2);
var h3 = HalfUtils.Unpack(packed3);
var h5 = HalfUtils.Unpack(packed5);
topLeft = h1;
topRight = (h1 + h2)/2.0f;
bottomLeft = (h1 + h3)/2.0f;
bottomRight = h5;
}
else
{
// Calc the #3 quad
// +--------------> X
// | h1--------h2 Coordinates are:
// | | | | h1 0,0
// | | | | h2 0,1
// | |----h5---| h3 1,0
// | | 3 | | h4 1,1
// | | | | h5 1/2,1/2
// | h3--------h4
// V Y
var packed1 = heightMap.OuterHeightDiff[heightX, heightY];
var packed3 = heightMap.OuterHeightDiff[heightX + 1, heightY];
var packed4 = heightMap.OuterHeightDiff[heightX + 1, heightY + 1];
var packed5 = heightMap.InnerHeightDiff[heightX, heightY];
var h1 = HalfUtils.Unpack(packed1);
var h3 = HalfUtils.Unpack(packed3);
var h4 = HalfUtils.Unpack(packed4);
var h5 = HalfUtils.Unpack(packed5);
topLeft = (h1 + h3) / 2.0f;
topRight = h5;
bottomLeft = h3;
bottomRight = (h3 + h4) / 2.0f;
yf -= 0.5f;
}
}
else
{
if (yf < 0.5)
{
// Calc the #2 quad
// +--------------> X
// | h1--------h2 Coordinates are:
// | | | | h1 0,0
// | | | 2 | h2 0,1
// | |----h5---| h3 1,0
// | | | | h4 1,1
// | | | | h5 1/2,1/2
// | h3--------h4
// V Y
var packed1 = heightMap.OuterHeightDiff[heightX, heightY];
var packed2 = heightMap.OuterHeightDiff[heightX, heightY + 1];
var packed4 = heightMap.OuterHeightDiff[heightX + 1, heightY + 1];
var packed5 = heightMap.InnerHeightDiff[heightX, heightY];
var h1 = HalfUtils.Unpack(packed1);
var h2 = HalfUtils.Unpack(packed2);
var h4 = HalfUtils.Unpack(packed4);
var h5 = HalfUtils.Unpack(packed5);
topLeft = (h1 + h2) / 2.0f;
topRight = h2;
bottomLeft = h5;
bottomRight = (h2 + h4) / 2.0f;
xf -= 0.5f;
}
else
{
// Calc the #4 quad
// +--------------> X
// | h1--------h2 Coordinates are:
// | | | | h1 0,0
// | | | | h2 0,1
// | |----h5---| h3 1,0
// | | | 4 | h4 1,1
// | | | | h5 1/2,1/2
// | h3--------h4
// V Y
var packed2 = heightMap.OuterHeightDiff[heightX, heightY + 1];
var packed3 = heightMap.OuterHeightDiff[heightX + 1, heightY];
var packed4 = heightMap.OuterHeightDiff[heightX + 1, heightY + 1];
var packed5 = heightMap.InnerHeightDiff[heightX, heightY];
var h2 = HalfUtils.Unpack(packed2);
var h3 = HalfUtils.Unpack(packed3);
var h4 = HalfUtils.Unpack(packed4);
var h5 = HalfUtils.Unpack(packed5);
topLeft = h5;
topRight = (h2 + h4) / 2.0f;
bottomLeft = (h3 + h4) / 2.0f;
bottomRight = h4;
xf -= 0.5f;
yf -= 0.5f;
}
}
//var heightDiff = InterpolateTriangle(ref vec1, ref vec2, ref vec3, heightMapFraction);
var heightDiff = BilinearInterpolate(ref topLeft, ref topRight, ref bottomLeft, ref bottomRight, ref xf,
ref yf);
return medianHeight + heightDiff;
}
internal float GetLiquidHeight(ChunkCoord chunkCoord, PointX2D pointX2D)
{
if (!LiquidProfile[chunkCoord.ChunkX, chunkCoord.ChunkY])
return float.MinValue;
var heightMap = HeightMaps[chunkCoord.ChunkX, chunkCoord.ChunkY];
var liquidHeights = heightMap.LiquidHeight;
return (liquidHeights == null)
? float.MinValue
: liquidHeights[pointX2D.X, pointX2D.Y];
}
