/* * 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; using OpenSim.Region.Framework.Scenes; namespace OpenSim.Region.CoreModules.World.Terrain.PaintBrushes { ///

/// Hydraulic Erosion Brush ///

public class ErodeSphere : ITerrainPaintableEffect { private const double rainHeight = 0.2; private const int rounds = 10; private const NeighbourSystem type = NeighbourSystem.Moore; private const double waterSaturation = 0.30; #region Supporting Functions private static int[] Neighbours(NeighbourSystem neighbourType, int index) { int[] coord = new int[2]; index++; switch (neighbourType) { 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 enum NeighbourSystem { Moore, VonNeumann } ; #endregion #region ITerrainPaintableEffect Members public void PaintEffect(ITerrainChannel map, bool[,] mask, double rx, double ry, double rz, double strength, double duration) { strength = TerrainUtil.MetersToSphericalStrength(strength); 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, TerrainUtil.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++) { if (mask[x,y]) { const 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]; const int NEIGHBOUR_ME = 4; const int NEIGHBOUR_MAX = 9; 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; // Skip if we dont have water to begin with. if (water[x, y] < 0) continue; // Calculate our delta average double altitudeDelta = altitudeMe - altitudeAvg; if (altitudeDelta < 0) continue; // Calculate how much water we can move double waterMin = Math.Min(water[x, y], altitudeDelta); double waterDelta = waterMin * ((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 = sediment[x, y] - waterCapacity; if (sedimentDeposit > 0) { if (mask[x,y]) { 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 (mask[x,y] && sediment[x, y] > 0) map[x, y] += sediment[x, y]; } #endregion } }