public Vector3 GetSurfaceNormal(Point2D chunkCoord, Point2D unitCoord, HeightMapFraction heightMapFraction)
{
if (Chunks == null)
{
return(Vector3.Zero);
}
var chunk = Chunks[chunkCoord.X, chunkCoord.Y];
if (chunk == null)
{
return(Vector3.Zero);
}
if (chunk.HolesMap[unitCoord.X / 2, unitCoord.Y / 2])
{
return(Vector3.Zero);
}
if (chunk.IsFlat)
{
return(Vector3.Up);
}
var outerHeights = chunk.Heights.GetLowResMapMatrix();
var innerHeights = chunk.Heights.GetHighResMapMatrix();
var v12 = new Vector3(0.5f, 0.5f, innerHeights[unitCoord.X, unitCoord.Y]);
var x = heightMapFraction.FractionX;
var y = heightMapFraction.FractionY;
Vector3 a, b;
if (y < x)
{
if (y < (1.0f - x))
{
// Upper triangle <h00, h01, h12>
var v00 = new Vector3(0.0f, 0.0f, outerHeights[unitCoord.X, unitCoord.Y]);
var v01 = new Vector3(0.0f, 1.0f, outerHeights[unitCoord.X + 1, unitCoord.Y]);
a = v00 - v12;
b = v01 - v12;
}
else
{
// Right triangle <h01, h11, h12>
var v01 = new Vector3(0.0f, 1.0f, outerHeights[unitCoord.X + 1, unitCoord.Y]);
var v11 = new Vector3(1.0f, 1.0f, outerHeights[unitCoord.X + 1, unitCoord.Y + 1]);
a = v01 - v12;
b = v11 - v12;
}
}
else
{
if (y < (1.0f - x))
{
// Left triangle <h10, h00, h12>
var v10 = new Vector3(1.0f, 0.0f, outerHeights[unitCoord.X + 1, unitCoord.Y]);
var v00 = new Vector3(0.0f, 0.0f, outerHeights[unitCoord.Y, unitCoord.Y]);
a = v10 - v12;
b = v00 - v12;
}
else
{
// Bottom triangle <h11, h10, h12>
var v11 = new Vector3(1.0f, 1.0f, outerHeights[unitCoord.Y + 1, unitCoord.Y + 1]);
var v10 = new Vector3(1.0f, 0.0f, outerHeights[unitCoord.X + 1, unitCoord.Y]);
a = v11 - v12;
b = v10 - v12;
}
}
var nml = Vector3.Cross(b, a);
nml.Normalize();
return(nml);
}
public float GetInterpolatedHeight(Point2D chunkCoord, Point2D unitCoord, HeightMapFraction heightMapFraction)
{
// Height stored as: h5 - its v8 grid, h1-h4 - its v9 grid
// h00------h01 Coordinates are:
// | \ / | h00 0,0
// | \ 1 / | h01 0,1
// | \ / |
// | 4 h12 2 | h10 1,0
// | / \ | h11 1,1
// | / 3 \ | h12 1/2,1/2
// | / \ |
// h10------h11
if (Chunks == null)
{
return(float.NaN);
}
var chunk = Chunks[chunkCoord.X, chunkCoord.Y];
if (chunk == null)
{
return(float.NaN);
}
if (chunk.HolesMap[unitCoord.X / 2, unitCoord.Y / 2])
{
return(float.NaN);
}
var medianHeight = chunk.MedianHeight;
if (chunk.IsFlat)
{
return(medianHeight);
}
// Using simplified Barycentric Coordinate coordinates, this actually becomes quite simple.
var outerHeights = chunk.Heights.GetLowResMapMatrix();
var innerHeights = chunk.Heights.GetHighResMapMatrix();
var h12 = innerHeights[unitCoord.X, unitCoord.Y];
var x = heightMapFraction.FractionX;
var y = heightMapFraction.FractionY;
float heightOffset;
if (y < x)
{
if (y < (1.0f - x))
{
// Upper triangle <h00, h01, h12>
var h00 = outerHeights[unitCoord.X, unitCoord.Y];
var h01 = outerHeights[unitCoord.X + 1, unitCoord.Y];
var alpha = 1 - x - y;
var beta = (y - x);
var gamma = 1.0f - alpha - beta;
heightOffset = (alpha * h00 + beta * h01 + gamma * h12);
}
else
{
// Right triangle <h01, h11, h12>
var h01 = outerHeights[unitCoord.X + 1, unitCoord.Y];
var h11 = outerHeights[unitCoord.X + 1, unitCoord.Y + 1];
var alpha = (y - x);
var beta = (x + y - 1.0f);
var gamma = 1.0f - alpha - beta;
heightOffset = (alpha * h01 + beta * h11 + gamma * h12);
}
}
else
{
if (y < (1.0f - x))
{
// Left triangle <h10, h00, h12>
var h10 = outerHeights[unitCoord.X + 1, unitCoord.Y];
var h00 = outerHeights[unitCoord.X, unitCoord.Y];
var alpha = x - y;
var beta = 1.0f - x - y;
var gamma = 1.0f - alpha - beta;
heightOffset = (alpha * h10 + beta * h00 + gamma * h12);
}
else
{
// Bottom triangle <h11, h10, h12>
var h11 = outerHeights[unitCoord.X + 1, unitCoord.Y + 1];
var h10 = outerHeights[unitCoord.X + 1, unitCoord.Y];
var alpha = (x + y - 1.0f);
var beta = x - y;
var gamma = 1.0f - alpha - beta;
heightOffset = (alpha * h11 + beta * h10 + gamma * h12);
}
}
return(medianHeight + heightOffset);
//// Fixme: Indexing is backwards.
//var heightX = (unitCoord.Y == TerrainConstants.UnitsPerChunkSide)
// ? (TerrainConstants.UnitsPerChunkSide - 1)
// : unitCoord.Y;
//var heightY = (unitCoord.X == TerrainConstants.UnitsPerChunkSide)
// ? (TerrainConstants.UnitsPerChunkSide - 1)
// : unitCoord.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 h1 = chunk.OuterHeightDiff[heightX, heightY];
// var h2 = chunk.OuterHeightDiff[heightX, heightY + 1];
// var h3 = chunk.OuterHeightDiff[heightX + 1, heightY];
// var h5 = chunk.InnerHeightDiff[heightX, heightY];
// 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 h1 = chunk.OuterHeightDiff[heightX, heightY];
// var h3 = chunk.OuterHeightDiff[heightX + 1, heightY];
// var h4 = chunk.OuterHeightDiff[heightX + 1, heightY + 1];
// var h5 = chunk.InnerHeightDiff[heightX, heightY];
// 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 h1 = chunk.OuterHeightDiff[heightX, heightY];
// var h2 = chunk.OuterHeightDiff[heightX, heightY + 1];
// var h4 = chunk.OuterHeightDiff[heightX + 1, heightY + 1];
// var h5 = chunk.InnerHeightDiff[heightX, heightY];
// 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 h2 = chunk.OuterHeightDiff[heightX, heightY + 1];
// var h3 = chunk.OuterHeightDiff[heightX + 1, heightY];
// var h4 = chunk.OuterHeightDiff[heightX + 1, heightY + 1];
// var h5 = chunk.InnerHeightDiff[heightX, heightY];
// 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;
}
public float GetInterpolatedHeight(Point2D chunkCoord, Point2D unitCoord, HeightMapFraction heightMapFraction)
{
// Height stored as: h5 - its v8 grid, h1-h4 - its v9 grid
// h00------h01 Coordinates are:
// | \ / | h00 0,0
// | \ 1 / | h01 0,1
// | \ / |
// | 4 h12 2 | h10 1,0
// | / \ | h11 1,1
// | / 3 \ | h12 1/2,1/2
// | / \ |
// h10------h11
if (Chunks == null) return float.NaN;
var chunk = Chunks[chunkCoord.X, chunkCoord.Y];
if (chunk == null) return float.NaN;
if (chunk.HolesMap[unitCoord.X / 2, unitCoord.Y / 2]) return float.NaN;
var medianHeight = chunk.MedianHeight;
if (chunk.IsFlat) return medianHeight;
// Using simplified Barycentric Coordinate coordinates, this actually becomes quite simple.
var outerHeights = chunk.Heights.GetLowResMapMatrix();
var innerHeights = chunk.Heights.GetHighResMapMatrix();
var h12 = innerHeights[unitCoord.X, unitCoord.Y];
var x = heightMapFraction.FractionX;
var y = heightMapFraction.FractionY;
float heightOffset;
if (y < x)
{
if (y < (1.0f - x))
{
// Upper triangle <h00, h01, h12>
var h00 = outerHeights[unitCoord.X, unitCoord.Y];
var h01 = outerHeights[unitCoord.X + 1, unitCoord.Y];
var alpha = 1 - x - y;
var beta = (y - x);
var gamma = 1.0f - alpha - beta;
heightOffset = (alpha*h00 + beta*h01 + gamma*h12);
}
else
{
// Right triangle <h01, h11, h12>
var h01 = outerHeights[unitCoord.X + 1, unitCoord.Y];
var h11 = outerHeights[unitCoord.X + 1, unitCoord.Y + 1];
var alpha = (y - x);
var beta = (x + y - 1.0f);
var gamma = 1.0f - alpha - beta;
heightOffset = (alpha*h01 + beta*h11 + gamma*h12);
}
}
else
{
if (y < (1.0f - x))
{
// Left triangle <h10, h00, h12>
var h10 = outerHeights[unitCoord.X + 1, unitCoord.Y];
var h00 = outerHeights[unitCoord.X, unitCoord.Y];
var alpha = x - y;
var beta = 1.0f - x - y;
var gamma = 1.0f - alpha - beta;
heightOffset = (alpha*h10 + beta*h00 + gamma*h12);
}
else
{
// Bottom triangle <h11, h10, h12>
var h11 = outerHeights[unitCoord.X + 1, unitCoord.Y + 1];
var h10 = outerHeights[unitCoord.X + 1, unitCoord.Y];
var alpha = (x + y - 1.0f);
var beta = x - y;
var gamma = 1.0f - alpha - beta;
heightOffset = (alpha*h11 + beta*h10 + gamma*h12);
}
}
return medianHeight + heightOffset;
//// Fixme: Indexing is backwards.
//var heightX = (unitCoord.Y == TerrainConstants.UnitsPerChunkSide)
// ? (TerrainConstants.UnitsPerChunkSide - 1)
// : unitCoord.Y;
//var heightY = (unitCoord.X == TerrainConstants.UnitsPerChunkSide)
// ? (TerrainConstants.UnitsPerChunkSide - 1)
// : unitCoord.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 h1 = chunk.OuterHeightDiff[heightX, heightY];
// var h2 = chunk.OuterHeightDiff[heightX, heightY + 1];
// var h3 = chunk.OuterHeightDiff[heightX + 1, heightY];
// var h5 = chunk.InnerHeightDiff[heightX, heightY];
// 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 h1 = chunk.OuterHeightDiff[heightX, heightY];
// var h3 = chunk.OuterHeightDiff[heightX + 1, heightY];
// var h4 = chunk.OuterHeightDiff[heightX + 1, heightY + 1];
// var h5 = chunk.InnerHeightDiff[heightX, heightY];
// 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 h1 = chunk.OuterHeightDiff[heightX, heightY];
// var h2 = chunk.OuterHeightDiff[heightX, heightY + 1];
// var h4 = chunk.OuterHeightDiff[heightX + 1, heightY + 1];
// var h5 = chunk.InnerHeightDiff[heightX, heightY];
// 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 h2 = chunk.OuterHeightDiff[heightX, heightY + 1];
// var h3 = chunk.OuterHeightDiff[heightX + 1, heightY];
// var h4 = chunk.OuterHeightDiff[heightX + 1, heightY + 1];
// var h5 = chunk.InnerHeightDiff[heightX, heightY];
// 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;
}
public Vector3 GetSurfaceNormal(Point2D chunkCoord, Point2D unitCoord, HeightMapFraction heightMapFraction)
{
if (Chunks == null) return Vector3.Zero;
var chunk = Chunks[chunkCoord.X, chunkCoord.Y];
if (chunk == null) return Vector3.Zero;
if (chunk.HolesMap[unitCoord.X / 2, unitCoord.Y / 2]) return Vector3.Zero;
if (chunk.IsFlat) return Vector3.Up;
var outerHeights = chunk.Heights.GetLowResMapMatrix();
var innerHeights = chunk.Heights.GetHighResMapMatrix();
var v12 = new Vector3(0.5f, 0.5f, innerHeights[unitCoord.X, unitCoord.Y]);
var x = heightMapFraction.FractionX;
var y = heightMapFraction.FractionY;
Vector3 a,b;
if (y < x)
{
if (y < (1.0f - x))
{
// Upper triangle <h00, h01, h12>
var v00 = new Vector3(0.0f, 0.0f, outerHeights[unitCoord.X, unitCoord.Y]);
var v01 = new Vector3(0.0f, 1.0f, outerHeights[unitCoord.X + 1, unitCoord.Y]);
a = v00 - v12;
b = v01 - v12;
}
else
{
// Right triangle <h01, h11, h12>
var v01 = new Vector3(0.0f, 1.0f, outerHeights[unitCoord.X + 1, unitCoord.Y]);
var v11 = new Vector3(1.0f, 1.0f, outerHeights[unitCoord.X + 1, unitCoord.Y + 1]);
a = v01 - v12;
b = v11 - v12;
}
}
else
{
if (y < (1.0f - x))
{
// Left triangle <h10, h00, h12>
var v10 = new Vector3(1.0f, 0.0f, outerHeights[unitCoord.X + 1, unitCoord.Y]);
var v00 = new Vector3(0.0f, 0.0f, outerHeights[unitCoord.Y, unitCoord.Y]);
a = v10 - v12;
b = v00 - v12;
}
else
{
// Bottom triangle <h11, h10, h12>
var v11 = new Vector3(1.0f, 1.0f, outerHeights[unitCoord.Y + 1, unitCoord.Y + 1]);
var v10 = new Vector3(1.0f, 0.0f, outerHeights[unitCoord.X + 1, unitCoord.Y]);
a = v11 - v12;
b = v10 - v12;
}
}
var nml = Vector3.Cross(b, a);
nml.Normalize();
return nml;
}
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;
}
private static float InterpolateTriangle(ref Vector3 point1, ref Vector3 point2, ref Vector3 point3, HeightMapFraction heightMapFraction)
{
var Ax = point2.X - point1.X;
var Ay = point2.Y - point1.Y;
var Az = point2.Z - point1.Z;
var Bx = point3.X - point1.X;
var By = point3.Y - point1.Y;
var Bz = point3.Z - point1.Z;
var Nnx = (Ay * Bz) - (Az * By);
var Nny = (Az * Bx) - (Ax * Bz);
var Nnz = (Ax * By) - (Ay * Bx);
var Nnsquared = ((Nnx * Nnx) + (Nny * Nny)) + (Nnz * Nnz);
var length = 1f / ((float)Math.Sqrt(Nnsquared));
var Nx = Nnx * length;
var Ny = Nny * length;
var Nz = Nnz * length;
var D = (Nx * point1.X) + (Ny * point1.Y) + (Nz * point1.Z);
var temp = D - (Nx * heightMapFraction.FractionX) - (Ny * heightMapFraction.FractionY);
return (temp / Nz);
}
public float GetInterpolatedHeight(Point2D chunkCoord, Point2D unitCoord, 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 (Chunks == null) return float.NaN;
var chunk = Chunks[chunkCoord.X, chunkCoord.Y];
if (chunk == null) return float.NaN;
var medianHeight = chunk.MedianHeight;
if (chunk.IsFlat) return medianHeight;
// TODO: Fix interpolated height
return medianHeight;
//// Fixme: Indexing is backwards.
//var heightX = (unitCoord.Y == TerrainConstants.UnitsPerChunkSide)
// ? (TerrainConstants.UnitsPerChunkSide - 1)
// : unitCoord.Y;
//var heightY = (unitCoord.X == TerrainConstants.UnitsPerChunkSide)
// ? (TerrainConstants.UnitsPerChunkSide - 1)
// : unitCoord.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 h1 = chunk.OuterHeightDiff[heightX, heightY];
// var h2 = chunk.OuterHeightDiff[heightX, heightY + 1];
// var h3 = chunk.OuterHeightDiff[heightX + 1, heightY];
// var h5 = chunk.InnerHeightDiff[heightX, heightY];
// 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 h1 = chunk.OuterHeightDiff[heightX, heightY];
// var h3 = chunk.OuterHeightDiff[heightX + 1, heightY];
// var h4 = chunk.OuterHeightDiff[heightX + 1, heightY + 1];
// var h5 = chunk.InnerHeightDiff[heightX, heightY];
// 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 h1 = chunk.OuterHeightDiff[heightX, heightY];
// var h2 = chunk.OuterHeightDiff[heightX, heightY + 1];
// var h4 = chunk.OuterHeightDiff[heightX + 1, heightY + 1];
// var h5 = chunk.InnerHeightDiff[heightX, heightY];
// 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 h2 = chunk.OuterHeightDiff[heightX, heightY + 1];
// var h3 = chunk.OuterHeightDiff[heightX + 1, heightY];
// var h4 = chunk.OuterHeightDiff[heightX + 1, heightY + 1];
// var h5 = chunk.InnerHeightDiff[heightX, heightY];
// 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;
}
