fCraft.Noise.FindThreshold C# (CSharp) Method

FindThreshold() public static method

public static FindThreshold ( [ data, float desiredCoverage ) : float
data [
desiredCoverage float
return float
        public static unsafe float FindThreshold( [NotNull] float[,] data, float desiredCoverage )
        {
            if ( data == null )
                throw new ArgumentNullException( "data" );
            if ( desiredCoverage == 0 )
                return 0;
            if ( desiredCoverage == 1 )
                return 1;
            float threshold = 0.5f;
            fixed ( float* ptr = data ) {
                for ( int i = 0; i < ThresholdSearchPasses; i++ ) {
                    float coverage = CalculateCoverage( ptr, data.Length, threshold );
                    if ( coverage > desiredCoverage ) {
                        threshold = threshold - 1 / ( float )( 4 << i );
                    } else {
                        threshold = threshold + 1 / ( float )( 4 << i );
                    }
                }
            }
            return threshold;
        }

Usage Example

Example #1
0
        public Map GenerateMap()
        {
            Map map = new Map(null, args.MapWidth, args.MapLength, args.MapHeight, true);

            // Match water coverage
            float desiredWaterLevel = .5f;

            if (args.MatchWaterCoverage)
            {
                ReportProgress(2, "Heightmap Processing: Matching water coverage");
                desiredWaterLevel = Noise.FindThreshold(heightmap, args.WaterCoverage);
            }

            // Calculate above/below water multipliers
            float aboveWaterMultiplier = 0;

            if (desiredWaterLevel != 1)
            {
                aboveWaterMultiplier = (args.MaxHeight / (1 - desiredWaterLevel));
            }

            // Apply power functions to above/below water parts of the heightmap
            if (args.BelowFuncExponent != 1 || args.AboveFuncExponent != 1)
            {
                ReportProgress(5, "Heightmap Processing: Adjusting slope");
                for (int x = heightmap.GetLength(0) - 1; x >= 0; x--)
                {
                    for (int y = heightmap.GetLength(1) - 1; y >= 0; y--)
                    {
                        if (heightmap[x, y] < desiredWaterLevel)
                        {
                            float normalizedDepth = 1 - heightmap[x, y] / desiredWaterLevel;
                            heightmap[x, y] = desiredWaterLevel - ( float )Math.Pow(normalizedDepth, args.BelowFuncExponent) * desiredWaterLevel;
                        }
                        else
                        {
                            float normalizedHeight = (heightmap[x, y] - desiredWaterLevel) / (1 - desiredWaterLevel);
                            heightmap[x, y] = desiredWaterLevel + ( float )Math.Pow(normalizedHeight, args.AboveFuncExponent) * (1 - desiredWaterLevel);
                        }
                    }
                }
            }

            // Calculate the slope
            if (args.CliffSmoothing)
            {
                ReportProgress(2, "Heightmap Processing: Smoothing");
                slopemap = Noise.CalculateSlope(Noise.GaussianBlur5X5(heightmap));
            }
            else
            {
                slopemap = Noise.CalculateSlope(heightmap);
            }

            float[,] altmap = null;
            if (args.MaxHeightVariation != 0 || args.MaxDepthVariation != 0)
            {
                ReportProgress(5, "Heightmap Processing: Randomizing");
                altmap = new float[map.Width, map.Length];
                int blendmapDetailSize = ( int )Math.Log(Math.Max(args.MapWidth, args.MapLength), 2) - 2;
                new Noise(rand.Next(), NoiseInterpolationMode.Cosine).PerlinNoise(altmap, 3, blendmapDetailSize, 0.5f, 0, 0);
                Noise.Normalize(altmap, -1, 1);
            }

            int snowStartThreshold = args.SnowAltitude - args.SnowTransition;
            int snowThreshold      = args.SnowAltitude;

            ReportProgress(10, "Filling");
            for (int x = heightmap.GetLength(0) - 1; x >= 0; x--)
            {
                for (int y = heightmap.GetLength(1) - 1; y >= 0; y--)
                {
                    int   level;
                    float slope;
                    if (heightmap[x, y] < desiredWaterLevel)
                    {
                        float depth = args.MaxDepth;
                        if (altmap != null)
                        {
                            depth += altmap[x, y] * args.MaxDepthVariation;
                        }
                        slope = slopemap[x, y] * depth;
                        level = args.WaterLevel - ( int )Math.Round(Math.Pow(1 - heightmap[x, y] / desiredWaterLevel, args.BelowFuncExponent) * depth);

                        if (args.AddWater)
                        {
                            if (args.WaterLevel - level > 3)
                            {
                                map.SetBlock(x, y, args.WaterLevel, bDeepWaterSurface);
                            }
                            else
                            {
                                map.SetBlock(x, y, args.WaterLevel, bWaterSurface);
                            }
                            for (int i = args.WaterLevel; i > level; i--)
                            {
                                map.SetBlock(x, y, i, bWater);
                            }
                            for (int i = level; i >= 0; i--)
                            {
                                if (level - i < SeaFloorThickness)
                                {
                                    map.SetBlock(x, y, i, bSeaFloor);
                                }
                                else
                                {
                                    map.SetBlock(x, y, i, bBedrock);
                                }
                            }
                        }
                        else
                        {
                            if (blendmap != null && blendmap[x, y] > .25 && blendmap[x, y] < .75)
                            {
                                map.SetBlock(x, y, level, bCliff);
                            }
                            else
                            {
                                if (slope < args.CliffThreshold)
                                {
                                    map.SetBlock(x, y, level, bGroundSurface);
                                }
                                else
                                {
                                    map.SetBlock(x, y, level, bCliff);
                                }
                            }

                            for (int i = level - 1; i >= 0; i--)
                            {
                                if (level - i < groundThickness)
                                {
                                    if (blendmap != null && blendmap[x, y] > CliffsideBlockThreshold && blendmap[x, y] < (1 - CliffsideBlockThreshold))
                                    {
                                        map.SetBlock(x, y, i, bCliff);
                                    }
                                    else
                                    {
                                        if (slope < args.CliffThreshold)
                                        {
                                            map.SetBlock(x, y, i, bGround);
                                        }
                                        else
                                        {
                                            map.SetBlock(x, y, i, bCliff);
                                        }
                                    }
                                }
                                else
                                {
                                    map.SetBlock(x, y, i, bBedrock);
                                }
                            }
                        }
                    }
                    else
                    {
                        float height;
                        if (altmap != null)
                        {
                            height = args.MaxHeight + altmap[x, y] * args.MaxHeightVariation;
                        }
                        else
                        {
                            height = args.MaxHeight;
                        }
                        slope = slopemap[x, y] * height;
                        if (height != 0)
                        {
                            level = args.WaterLevel + ( int )Math.Round(Math.Pow(heightmap[x, y] - desiredWaterLevel, args.AboveFuncExponent) * aboveWaterMultiplier / args.MaxHeight * height);
                        }
                        else
                        {
                            level = args.WaterLevel;
                        }

                        bool snow = args.AddSnow &&
                                    (level > snowThreshold ||
                                     (level > snowStartThreshold && rand.NextDouble() < (level - snowStartThreshold) / ( double )(snowThreshold - snowStartThreshold)));

                        if (blendmap != null && blendmap[x, y] > .25 && blendmap[x, y] < .75)
                        {
                            map.SetBlock(x, y, level, bCliff);
                        }
                        else
                        {
                            if (slope < args.CliffThreshold)
                            {
                                map.SetBlock(x, y, level, (snow ? Block.White : bGroundSurface));
                            }
                            else
                            {
                                map.SetBlock(x, y, level, bCliff);
                            }
                        }

                        for (int i = level - 1; i >= 0; i--)
                        {
                            if (level - i < groundThickness)
                            {
                                if (blendmap != null && blendmap[x, y] > CliffsideBlockThreshold && blendmap[x, y] < (1 - CliffsideBlockThreshold))
                                {
                                    map.SetBlock(x, y, i, bCliff);
                                }
                                else
                                {
                                    if (slope < args.CliffThreshold)
                                    {
                                        if (snow)
                                        {
                                            map.SetBlock(x, y, i, Block.White);
                                        }
                                        else
                                        {
                                            map.SetBlock(x, y, i, bGround);
                                        }
                                    }
                                    else
                                    {
                                        map.SetBlock(x, y, i, bCliff);
                                    }
                                }
                            }
                            else
                            {
                                map.SetBlock(x, y, i, bBedrock);
                            }
                        }
                    }
                }
            }

            if (args.AddCaves || args.AddOre)
            {
                AddCaves(map);
            }

            if (args.AddBeaches)
            {
                ReportProgress(5, "Processing: Adding beaches");
                AddBeaches(map);
            }

            if (args.AddIgloos)
            {
                //GenerateIgloos( map );
            }

            if (args.AddTrees)
            {
                ReportProgress(5, "Processing: Planting trees");
                if (args.AddGiantTrees)
                {
                    Map outMap = new Map(null, map.Width, map.Length, map.Height, false)
                    {
                        Blocks = ( byte[] )map.Blocks.Clone()
                    };
                    var foresterArgs = new ForesterArgs {
                        Map       = map,
                        Rand      = rand,
                        TreeCount = ( int )(map.Width * map.Length * 4 / (1024f * (args.TreeSpacingMax + args.TreeSpacingMin) / 2)),
                        Operation = Forester.ForesterOperation.Add,
                        PlantOn   = bGroundSurface
                    };
                    foresterArgs.BlockPlacing += (sender, e) => outMap.SetBlock(e.Coordinate, e.Block);
                    Forester.Generate(foresterArgs);
                    map = outMap;
                }
                GenerateTrees(map);
            }

            ReportProgress(0, "Generation complete");

            map.Metadata["_Origin", "GeneratorName"]    = "fCraft";
            map.Metadata["_Origin", "GeneratorVersion"] = Updater.CurrentRelease.VersionString;
            map.Metadata["_Origin", "GeneratorParams"]  = args.Serialize().ToString(SaveOptions.DisableFormatting);
            return(map);
        }
All Usage Examples Of fCraft.Noise::FindThreshold