133 lines
5.1 KiB
C#
133 lines
5.1 KiB
C#
/*
|
|
* Copyright (c) Contributors, http://opensimulator.org/
|
|
* See CONTRIBUTORS.TXT for a full list of copyright holders.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions are met:
|
|
* * Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
* * Redistributions in binary form must reproduce the above copyright
|
|
* notice, this list of conditions and the following disclaimer in the
|
|
* documentation and/or other materials provided with the distribution.
|
|
* * Neither the name of the OpenSimulator Project nor the
|
|
* names of its contributors may be used to endorse or promote products
|
|
* derived from this software without specific prior written permission.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY
|
|
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
|
|
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
|
|
* DISCLAIMED. IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE FOR ANY
|
|
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
|
|
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
|
|
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
|
|
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
|
|
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
|
|
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
|
*/
|
|
|
|
using System;
|
|
using OpenSim.Region.Framework.Interfaces;
|
|
|
|
namespace OpenSim.Region.Framework.Scenes
|
|
{
|
|
public static class TerrainUtil
|
|
{
|
|
public static double MetersToSphericalStrength(double size)
|
|
{
|
|
//return Math.Pow(2, size);
|
|
return (size + 1) * 1.35; // MCP: a more useful brush size range
|
|
}
|
|
|
|
public static double SphericalFactor(double x, double y, double rx, double ry, double size)
|
|
{
|
|
return size * size - ((x - rx) * (x - rx) + (y - ry) * (y - ry));
|
|
}
|
|
|
|
public static double GetBilinearInterpolate(double x, double y, ITerrainChannel map)
|
|
{
|
|
int w = map.Width;
|
|
int h = map.Height;
|
|
|
|
if (x > w - 2.0)
|
|
x = w - 2.0;
|
|
if (y > h - 2.0)
|
|
y = h - 2.0;
|
|
if (x < 0.0)
|
|
x = 0.0;
|
|
if (y < 0.0)
|
|
y = 0.0;
|
|
|
|
const int stepSize = 1;
|
|
double h00 = map[(int) x, (int) y];
|
|
double h10 = map[(int) x + stepSize, (int) y];
|
|
double h01 = map[(int) x, (int) y + stepSize];
|
|
double h11 = map[(int) x + stepSize, (int) y + stepSize];
|
|
double h1 = h00;
|
|
double h2 = h10;
|
|
double h3 = h01;
|
|
double h4 = h11;
|
|
double a00 = h1;
|
|
double a10 = h2 - h1;
|
|
double a01 = h3 - h1;
|
|
double a11 = h1 - h2 - h3 + h4;
|
|
double partialx = x - (int) x;
|
|
double partialz = y - (int) y;
|
|
double hi = a00 + (a10 * partialx) + (a01 * partialz) + (a11 * partialx * partialz);
|
|
return hi;
|
|
}
|
|
|
|
private static double Noise(double x, double y)
|
|
{
|
|
int n = (int) x + (int) (y * 749);
|
|
n = (n << 13) ^ n;
|
|
return (1.0 - ((n * (n * n * 15731 + 789221) + 1376312589) & 0x7fffffff) / 1073741824.0);
|
|
}
|
|
|
|
private static double SmoothedNoise1(double x, double y)
|
|
{
|
|
double corners = (Noise(x - 1, y - 1) + Noise(x + 1, y - 1) + Noise(x - 1, y + 1) + Noise(x + 1, y + 1)) / 16;
|
|
double sides = (Noise(x - 1, y) + Noise(x + 1, y) + Noise(x, y - 1) + Noise(x, y + 1)) / 8;
|
|
double center = Noise(x, y) / 4;
|
|
return corners + sides + center;
|
|
}
|
|
|
|
private static double Interpolate(double x, double y, double z)
|
|
{
|
|
return (x * (1.0 - z)) + (y * z);
|
|
}
|
|
|
|
public static double InterpolatedNoise(double x, double y)
|
|
{
|
|
int integer_X = (int) (x);
|
|
double fractional_X = x - integer_X;
|
|
|
|
int integer_Y = (int) y;
|
|
double fractional_Y = y - integer_Y;
|
|
|
|
double v1 = SmoothedNoise1(integer_X, integer_Y);
|
|
double v2 = SmoothedNoise1(integer_X + 1, integer_Y);
|
|
double v3 = SmoothedNoise1(integer_X, integer_Y + 1);
|
|
double v4 = SmoothedNoise1(integer_X + 1, integer_Y + 1);
|
|
|
|
double i1 = Interpolate(v1, v2, fractional_X);
|
|
double i2 = Interpolate(v3, v4, fractional_X);
|
|
|
|
return Interpolate(i1, i2, fractional_Y);
|
|
}
|
|
|
|
public static double PerlinNoise2D(double x, double y, int octaves, double persistence)
|
|
{
|
|
double total = 0.0;
|
|
|
|
for (int i = 0; i < octaves; i++)
|
|
{
|
|
double frequency = Math.Pow(2, i);
|
|
double amplitude = Math.Pow(persistence, i);
|
|
|
|
total += InterpolatedNoise(x * frequency, y * frequency) * amplitude;
|
|
}
|
|
return total;
|
|
}
|
|
}
|
|
}
|