private float _Lerp4Height(uint x, uint y, float px, float py)
{
return(RMGUtility.LerpSquare(
_raster.SquareCorners[x, y], _cornerElevations[x, y],
_raster.SquareCorners[x + 1, y], _cornerElevations[x + 1, y],
_raster.SquareCorners[x + 1, y + 1], _cornerElevations[x + 1, y + 1],
_raster.SquareCorners[x, y + 1], _cornerElevations[x, y + 1],
px, py) - 1);
}
/// <summary>
/// 双线性插值
/// @---->*<--@
/// ↓
/// #
/// ↑
/// @---->*<--@
/// </summary>
/// <returns></returns>
private float _Lerp2D(uint x1, uint y1, uint x2, uint y2, float tx, float ty)
{
tx = RMGUtility.SmoothCurve(tx);
ty = RMGUtility.SmoothCurve(ty);
return(RMGUtility.Lerp(
RMGUtility.Lerp(_permutaion[x1, y1], _permutaion[x2, y1], tx),
RMGUtility.Lerp(_permutaion[x1, y2], _permutaion[x2, y2], tx),
ty));
}
/// <summary>
/// 1D coherent noise
/// </summary>
public float GetPixel(float x)
{
x = Mathf.Min(_to, x);
x = Mathf.Max(_from, x);
x -= _from;
x *= _scale;
// 整数
if ((ushort)x == x)
{
return(_permutation[(ushort)x]);
}
int left = Mathf.FloorToInt(x);
int right = Mathf.CeilToInt(x);
float t = RMGUtility.SmoothCurve(x - left);
return(RMGUtility.Lerp(_permutation[left], _permutation[right], t));
}
private void Test( )
{
Vector2 A = new Vector2(4, 3);
Vector2 B = new Vector2(22, 3);
Vector2 C = new Vector2(25, 30);
Vector2 D = new Vector2(5, 28);
Vector2 E = new Vector2(55, 2);
Vector2 F = new Vector2(50, 32);
float a = Random.value;
float b = Random.value;
float c = Random.value;
float d = Random.value;
float e = Random.value;
float f = Random.value;
print(a + " " + b + " " + c + " " + d);
print(RMGUtility.LerpSquare(A, a, B, b, C, c, D, d, B.x, B.y));
print(b + " " + e + " " + f + " " + c);
float[,] heights = new float[65, 65];
for (int i = 0; i < 65; i++)
{
for (int j = 0; j < 65; j++)
{
if (RMGUtility.PointInSquare(A, B, C, D, j, i))
{
heights[i, j] = RMGUtility.LerpSquare(A, a, B, b, C, c, D, d, j, i);
}
if (RMGUtility.PointInSquare(B, E, F, C, j, i))
{
heights[i, j] = RMGUtility.LerpSquare(B, b, E, e, F, f, C, c, j, i);
}
}
}
TerrainData trdata = new TerrainData();
trdata.heightmapResolution = 65;
trdata.size = new Vector3(100, 20, 100);
trdata.SetHeights(0, 0, heights);
GameObject tr = Terrain.CreateTerrainGameObject(trdata);
}
/// <summary>
/// 设置高度图
/// </summary>
/// <param name="terrainData">地形数据</param>
private void _SetHeight(TerrainData terrainData, float maxHeight)
{
int hmr = terrainData.heightmapResolution;
float[,] heights = new float[hmr, hmr];
// 每栅格采样点数
byte sample = (byte)((hmr - 1) / m);
float pixelSize = _squareSize / sample;
for (uint i = 0; i < hmr; i++)
{
for (uint j = 0; j < hmr; j++)
{
// 边界
if (i < sample || j < sample || i >= hmr - 1 - sample || j >= hmr - 1 - sample)
{
heights[i, j] = 0;
continue;
}
// 落到中心及周围8个栅格中的某一个，x、y是栅格的序号
uint x = j / sample;
uint y = i / sample;
// 坐标 = 序号 * 像素大小
float xPoint = (float)j * pixelSize;
float yPoint = (float)i * pixelSize;
// 落到哪里就用哪个的四个拐角插值
// 先判断是否在中间的栅格
if (RMGUtility.PointInSquare(
_raster.SquareCorners[x, y],
_raster.SquareCorners[x + 1, y],
_raster.SquareCorners[x + 1, y + 1],
_raster.SquareCorners[x, y + 1],
xPoint, yPoint))
{
if (_centerTypes[x, y] == CenterType.kLand)
{
heights[i, j] = _Lerp4Height(x, y, xPoint, yPoint) / maxHeight;
}
}
else
{
// 不在中间
// 退到左上角
x--;
y--;
for (byte p = 0; p < 3; p++)
{
for (byte q = 0; q < 3; q++)
{
// 中间的不用测试
if (p == 1 && q == 1)
{
continue;
}
uint xx = x + p;
uint yy = y + q;
// 判断是否在四边形内
if (RMGUtility.PointInSquare(
_raster.SquareCorners[xx, yy],
_raster.SquareCorners[xx + 1, yy],
_raster.SquareCorners[xx + 1, yy + 1],
_raster.SquareCorners[xx, yy + 1],
xPoint, yPoint))
{
if (_centerTypes[xx, yy] == CenterType.kOcean)
{
heights[i, j] = 0;
}
else
{
heights[i, j] = _Lerp4Height(xx, yy, xPoint, yPoint) / maxHeight;
}
continue;
}
}
}
}
}
}
terrain.terrainData.SetHeightsDelayLOD(0, 0, heights);
}