/* * 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 OpenSim 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 OpenSim.Region.Environment.Interfaces; using System; namespace OpenSim.Region.Environment.Modules.Terrain.PaintBrushes { ///

/// Hydraulic Erosion Brush ///

public class ErodeSphere : ITerrainPaintableEffect { NeighbourSystem type = NeighbourSystem.Moore; // Parameter double rainHeight = 1.0; int rounds = 10; double waterSaturation = 0.01; // Can carry 1% of water in height #region Supporting Functions private enum NeighbourSystem { Moore, VonNeumann } ; private int[] Neighbours(NeighbourSystem type, int index) { int[] coord = new int[2]; index++; switch (type) { case NeighbourSystem.Moore: switch (index) { case 1: coord[0] = -1; coord[1] = -1; break; case 2: coord[0] = -0; coord[1] = -1; break; case 3: coord[0] = +1; coord[1] = -1; break; case 4: coord[0] = -1; coord[1] = -0; break; case 5: coord[0] = -0; coord[1] = -0; break; case 6: coord[0] = +1; coord[1] = -0; break; case 7: coord[0] = -1; coord[1] = +1; break; case 8: coord[0] = -0; coord[1] = +1; break; case 9: coord[0] = +1; coord[1] = +1; break; default: break; } break; case NeighbourSystem.VonNeumann: switch (index) { case 1: coord[0] = 0; coord[1] = -1; break; case 2: coord[0] = -1; coord[1] = 0; break; case 3: coord[0] = +1; coord[1] = 0; break; case 4: coord[0] = 0; coord[1] = +1; break; case 5: coord[0] = -0; coord[1] = -0; break; default: break; } break; } return coord; } private double SphericalFactor(double x, double y, double rx, double ry, double size) { double z = size * size - ((x - rx) * (x - rx) + (y - ry) * (y - ry)); return z; } private 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; 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; } #endregion #region ITerrainPaintableEffect Members public void PaintEffect(ITerrainChannel map, double rx, double ry, double strength, double duration) { int x, y; // Using one 'rain' round for this, so skipping a useless loop // Will need to adapt back in for the Flood brush ITerrainChannel water = new TerrainChannel(map.Width, map.Height); ITerrainChannel sediment = new TerrainChannel(map.Width, map.Height); // Fill with rain for (x = 0; x < water.Width; x++) for (y = 0; y < water.Height; y++) water[x, y] = Math.Max(0.0, SphericalFactor(x, y, rx, ry, strength) * rainHeight * duration); for (int i = 0; i < rounds; i++) { // Erode underlying terrain for (x = 0; x < water.Width; x++) { for (y = 0; y < water.Height; y++) { double solConst = (1.0 / rounds); double sedDelta = water[x, y] * solConst; map[x, y] -= sedDelta; sediment[x, y] += sedDelta; } } // Move water for (x = 0; x < water.Width; x++) { for (y = 0; y < water.Height; y++) { if (water[x, y] <= 0) continue; // Step 1. Calculate average of neighbours int neighbours = 0; double altitudeTotal = 0.0; double altitudeMe = map[x, y] + water[x, y]; int NEIGHBOUR_ME = 4; int NEIGHBOUR_MAX = type == NeighbourSystem.Moore ? 9 : 5; for (int j = 0; j < NEIGHBOUR_MAX; j++) { if (j != NEIGHBOUR_ME) { int[] coords = Neighbours(type, j); coords[0] += x; coords[1] += y; if (coords[0] > map.Width - 1) continue; if (coords[1] > map.Height - 1) continue; if (coords[0] < 0) continue; if (coords[1] < 0) continue; // Calculate total height of this neighbour double altitudeNeighbour = water[coords[0], coords[1]] + map[coords[0], coords[1]]; // If it's greater than me... if (altitudeNeighbour - altitudeMe > 0) { // Add it to our calculations neighbours++; altitudeTotal += altitudeNeighbour; } } } if (neighbours == 0) continue; double altitudeAvg = altitudeTotal / neighbours; // Step 2. Allocate water to neighbours. for (int j = 0; j < NEIGHBOUR_MAX; j++) { if (j != NEIGHBOUR_ME) { int[] coords = Neighbours(type, j); coords[0] += x; coords[1] += y; if (coords[0] > map.Width - 1) continue; if (coords[1] > map.Height - 1) continue; if (coords[0] < 0) continue; if (coords[1] < 0) continue; // Calculate our delta average double altitudeDelta = altitudeMe - altitudeAvg; // Calculate how much water we can move double waterDelta = Math.Min(water[x, y], altitudeDelta) * (water[coords[0], coords[1]] + map[coords[0], coords[1]]) / altitudeTotal; double sedimentDelta = sediment[x, y] * (waterDelta / water[x, y]); if (sedimentDelta > 0) { sediment[x, y] -= sedimentDelta; sediment[coords[0], coords[1]] += sedimentDelta; } } } } } // Evaporate for (x = 0; x < water.Width; x++) { for (y = 0; y < water.Height; y++) { water[x, y] *= 1.0 - (rainHeight / rounds); double waterCapacity = waterSaturation * water[x, y]; double sedimentDeposit = Math.Max(0, sediment[x, y] - waterCapacity); sediment[x, y] -= sedimentDeposit; map[x, y] += sedimentDeposit; } } } // Deposit any remainder (should be minimal) for (x = 0; x < water.Width; x++) for (y = 0; y < water.Height; y++) if (sediment[x, y] > 0) map[x, y] += sediment[x, y]; } #endregion } }