1 files changed, 122 insertions, 0 deletions
diff --git a/src/world/HeightmapGenHills.cs b/src/world/HeightmapGenHills.cs
new file mode 100644
index 0000000..12af005
--- /dev/null
+++ b/src/world/HeightmapGenHills.cs
@@ -0,0 +1,122 @@
+using System;
+namespace libsecondlife
+{
+    public class HeightmapGenHills
+    {
+        private Random Rand = new Random();
+        private int NumHills;
+        private float HillMin;
+        private float HillMax;
+        private bool Island;
+        private float[] heightmap;
+        public float[] GenerateHeightmap(int numHills, float hillMin, float hillMax, bool island)
+        {
+            NumHills = numHills;
+            HillMin = hillMin;
+            HillMax = hillMax;
+            Island = island;
+            heightmap = new float[256 * 256];
+            for (int i = 0; i < numHills; i++)
+            {
+                AddHill();
+            }
+            Normalize();
+            return heightmap;
+        }
+        private void AddHill()
+        {
+            float x, y;
+            float radius = RandomRange(HillMin, HillMax);
+            if (Island)
+            {
+                // Which direction from the center of the map the hill is placed
+                float theta = RandomRange(0, 6.28f);
+                // How far from the center of the map to place the hill. The radius
+                // is subtracted from the range to prevent any part of the hill from
+                // reaching the edge of the map
+                float distance = RandomRange(radius / 2.0f, 128.0f - radius);
+                x = 128.0f + (float)Math.Cos(theta) * distance;
+                y = 128.0f + (float)Math.Sin(theta) * distance;
+            }
+            else
+            {
+                x = RandomRange(-radius, 256.0f + radius);
+                y = RandomRange(-radius, 256.0f + radius);
+            }
+            float radiusSq = radius * radius;
+            float distSq;
+            float height;
+            int xMin = (int)(x - radius) - 1;
+            int xMax = (int)(x + radius) + 1;
+            if (xMin < 0) xMin = 0;
+            if (xMax > 255) xMax = 255;
+            int yMin = (int)(y - radius) - 1;
+            int yMax = (int)(y + radius) + 1;
+            if (yMin < 0) yMin = 0;
+            if (yMax > 255) yMax = 255;
+            // Loop through each affected cell and determine the height at that point
+            for (int v = yMin; v <= yMax; ++v)
+            {
+                float fv = (float)v;
+                for (int h = xMin; h <= xMax; ++h)
+                {
+                    float fh = (float)h;
+                    // Determine how far from the center of this hill this point is
+                    distSq = (x - fh) * (x - fh) + (y - fv) * (y - fv);
+                    height = radiusSq - distSq;
+                    // Don't add negative hill values
+                    if (height > 0.0f) heightmap[h + v * 256] += height;
+                }
+            }
+        }
+        private void Normalize()
+        {
+            float min = heightmap[0];
+            float max = heightmap[0];
+            for (int x = 0; x < 256; x++)
+            {
+                for (int y = 0; y < 256; y++)
+                {
+                    if (heightmap[x + y * 256] < min) min = heightmap[x + y * 256];
+                    if (heightmap[x + y * 256] > max) max = heightmap[x + y * 256];
+                }
+            }
+            // Avoid a rare divide by zero
+            if (min != max)
+            {
+                for (int x = 0; x < 256; x++)
+                {
+                    for (int y = 0; y < 256; y++)
+                    {
+                        heightmap[x + y * 256] = ((heightmap[x + y * 256] - min) / (max - min)) * (HillMax - HillMin);
+                    }
+                }
+            }
+        }
+        private float RandomRange(float min, float max)
+        {
+            return (float)Rand.NextDouble() * (max - min) + min;
+        }
+    }
+}

diff --git a/src/world/HeightmapGenHills.cs b/src/world/HeightmapGenHills.cs new file mode 100644 index 0000000..12af005 --- /dev/null +++ b/src/world/HeightmapGenHills.cs
@@ -0,0 +1,122 @@
	1	using System;
	2
	3	namespace libsecondlife
	4	{
	5	public class HeightmapGenHills
	6	{
	7	private Random Rand = new Random();
	8	private int NumHills;
	9	private float HillMin;
	10	private float HillMax;
	11	private bool Island;
	12	private float[] heightmap;
	13
	14	public float[] GenerateHeightmap(int numHills, float hillMin, float hillMax, bool island)
	15	{
	16	NumHills = numHills;
	17	HillMin = hillMin;
	18	HillMax = hillMax;
	19	Island = island;
	20
	21	heightmap = new float[256 * 256];
	22
	23	for (int i = 0; i < numHills; i++)
	24	{
	25	AddHill();
	26	}
	27
	28	Normalize();
	29
	30	return heightmap;
	31	}
	32
	33	private void AddHill()
	34	{
	35	float x, y;
	36	float radius = RandomRange(HillMin, HillMax);
	37
	38	if (Island)
	39	{
	40	// Which direction from the center of the map the hill is placed
	41	float theta = RandomRange(0, 6.28f);
	42
	43	// How far from the center of the map to place the hill. The radius
	44	// is subtracted from the range to prevent any part of the hill from
	45	// reaching the edge of the map
	46	float distance = RandomRange(radius / 2.0f, 128.0f - radius);
	47
	48	x = 128.0f + (float)Math.Cos(theta) * distance;
	49	y = 128.0f + (float)Math.Sin(theta) * distance;
	50	}
	51	else
	52	{
	53	x = RandomRange(-radius, 256.0f + radius);
	54	y = RandomRange(-radius, 256.0f + radius);
	55	}
	56
	57	float radiusSq = radius * radius;
	58	float distSq;
	59	float height;
	60
	61	int xMin = (int)(x - radius) - 1;
	62	int xMax = (int)(x + radius) + 1;
	63	if (xMin < 0) xMin = 0;
	64	if (xMax > 255) xMax = 255;
	65
	66	int yMin = (int)(y - radius) - 1;
	67	int yMax = (int)(y + radius) + 1;
	68	if (yMin < 0) yMin = 0;
	69	if (yMax > 255) yMax = 255;
	70
	71	// Loop through each affected cell and determine the height at that point
	72	for (int v = yMin; v <= yMax; ++v)
	73	{
	74	float fv = (float)v;
	75
	76	for (int h = xMin; h <= xMax; ++h)
	77	{
	78	float fh = (float)h;
	79
	80	// Determine how far from the center of this hill this point is
	81	distSq = (x - fh) * (x - fh) + (y - fv) * (y - fv);
	82	height = radiusSq - distSq;
	83
	84	// Don't add negative hill values
	85	if (height > 0.0f) heightmap[h + v * 256] += height;
	86	}
	87	}
	88	}
	89
	90	private void Normalize()
	91	{
	92	float min = heightmap[0];
	93	float max = heightmap[0];
	94
	95	for (int x = 0; x < 256; x++)
	96	{
	97	for (int y = 0; y < 256; y++)
	98	{
	99	if (heightmap[x + y * 256] < min) min = heightmap[x + y * 256];
	100	if (heightmap[x + y * 256] > max) max = heightmap[x + y * 256];
	101	}
	102	}
	103
	104	// Avoid a rare divide by zero
	105	if (min != max)
	106	{
	107	for (int x = 0; x < 256; x++)
	108	{
	109	for (int y = 0; y < 256; y++)
	110	{
	111	heightmap[x + y * 256] = ((heightmap[x + y * 256] - min) / (max - min)) * (HillMax - HillMin);
	112	}
	113	}
	114	}
	115	}
	116
	117	private float RandomRange(float min, float max)
	118	{
	119	return (float)Rand.NextDouble() * (max - min) + min;
	120	}
	121	}
	122	}