From 93da2086a916ef92a680ae211f6ca13ccc7ca1b1 Mon Sep 17 00:00:00 2001 From: gareth Date: Wed, 28 Feb 2007 14:33:10 +0000 Subject: Imported MW's terrain encoder/decoder --- src/world/TerrainDecoder.cs | 683 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 683 insertions(+) create mode 100644 src/world/TerrainDecoder.cs (limited to 'src') diff --git a/src/world/TerrainDecoder.cs b/src/world/TerrainDecoder.cs new file mode 100644 index 0000000..0f1b733 --- /dev/null +++ b/src/world/TerrainDecoder.cs @@ -0,0 +1,683 @@ +/* +* Copyright (c) OpenSim project, http://sim.opensecondlife.org/ +* +* 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 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 ``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 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 System.Collections.Generic; +//using libsecondlife; +using libsecondlife.Packets; + +namespace OpenSim +{ + /// + /// Description of TerrainDecoder. + /// + public class TerrainDecode + { + + public enum LayerType : byte + { + Land = 0x4C, + Water = 0x57, + Wind = 0x37, + Cloud = 0x38 + } + + public struct GroupHeader + { + public int Stride; + public int PatchSize; + public LayerType Type; + } + + public struct PatchHeader + { + public float DCOffset; + public int Range; + public int QuantWBits; + public int PatchIDs; + public uint WordBits; + } + + public class Patch + { + public float[] Heightmap; + } + + + /// + /// + /// + /// + /// + /// + /// + /// + // public delegate void LandPatchCallback(Simulator simulator, int x, int y, int width, float[] data); + + + /// + /// + /// + //public event LandPatchCallback OnLandPatch; + + private Random RandomClass = new Random(); + + private const byte END_OF_PATCHES = 97; + private const int PATCHES_PER_EDGE = 16; + private const float OO_SQRT2 = 0.7071067811865475244008443621049f; + + //private SecondLife Client; + private Dictionary SimPatches = new Dictionary(); + private float[] DequantizeTable16 = new float[16 * 16]; + private float[] DequantizeTable32 = new float[32 * 32]; + private float[] ICosineTable16 = new float[16 * 16]; + private float[] ICosineTable32 = new float[32 * 32]; + private int[] DeCopyMatrix16 = new int[16 * 16]; + private int[] DeCopyMatrix32 = new int[32 * 32]; + + + /// + /// + /// + /// + public TerrainDecode() + { + + // Initialize the decompression tables + BuildDequantizeTable16(); + BuildDequantizeTable32(); + SetupICosines16(); + SetupICosines32(); + BuildDecopyMatrix16(); + BuildDecopyMatrix32(); + + } + + + private void BuildDequantizeTable16() + { + for (int j = 0; j < 16; j++) + { + for (int i = 0; i < 16; i++) + { + DequantizeTable16[j * 16 + i] = 1.0f + 2.0f * (float)(i + j); + } + } + } + + private void BuildDequantizeTable32() + { + for (int j = 0; j < 32; j++) + { + for (int i = 0; i < 32; i++) + { + DequantizeTable32[j * 32 + i] = 1.0f + 2.0f * (float)(i + j); + } + } + } + + private void SetupICosines16() + { + const float hposz = (float)Math.PI * 0.5f / 16.0f; + + for (int u = 0; u < 16; u++) + { + for (int n = 0; n < 16; n++) + { + ICosineTable16[u * 16 + n] = (float)Math.Cos((2.0f * (float)n + 1.0f) * (float)u * hposz); + } + } + } + + private void SetupICosines32() + { + const float hposz = (float)Math.PI * 0.5f / 32.0f; + + for (int u = 0; u < 32; u++) + { + for (int n = 0; n < 32; n++) + { + ICosineTable32[u * 32 + n] = (float)Math.Cos((2.0f * (float)n + 1.0f) * (float)u * hposz); + } + } + } + + private void BuildDecopyMatrix16() + { + bool diag = false; + bool right = true; + int i = 0; + int j = 0; + int count = 0; + + while (i < 16 && j < 16) + { + DeCopyMatrix16[j * 16 + i] = count++; + + if (!diag) + { + if (right) + { + if (i < 16 - 1) i++; + else j++; + + right = false; + diag = true; + } + else + { + if (j < 16 - 1) j++; + else i++; + + right = true; + diag = true; + } + } + else + { + if (right) + { + i++; + j--; + if (i == 16 - 1 || j == 0) diag = false; + } + else + { + i--; + j++; + if (j == 16 - 1 || i == 0) diag = false; + } + } + } + } + + private void BuildDecopyMatrix32() + { + bool diag = false; + bool right = true; + int i = 0; + int j = 0; + int count = 0; + + while (i < 32 && j < 32) + { + DeCopyMatrix32[j * 32 + i] = count++; + + if (!diag) + { + if (right) + { + if (i < 32 - 1) i++; + else j++; + + right = false; + diag = true; + } + else + { + if (j < 32 - 1) j++; + else i++; + + right = true; + diag = true; + } + } + else + { + if (right) + { + i++; + j--; + if (i == 32 - 1 || j == 0) diag = false; + } + else + { + i--; + j++; + if (j == 32 - 1 || i == 0) diag = false; + } + } + } + } + + private void EncodePatchHeader(BitPacker bitpack, PatchHeader header) + { + bitpack.PackBits(header.QuantWBits,8); + + if (header.QuantWBits == END_OF_PATCHES) + return; + + bitpack.PackFloat(header.DCOffset); + bitpack.PackBits(header.Range,16); + bitpack.PackBits(header.PatchIDs,10); + + } + + public void DCTLine16(float[] In, float[] Out, int line) + { + int N =16; + int lineSize = line * 16; + + for(int k = 0; k < N;k++) + { + float sum = 0.0f; + for(int n = 0; n < N; n++) + { + float num = (float)(Math.PI*k*(2.0f*n+1)/(2*N)); + float cosine = (float)Math.Cos(num); + float product = In[lineSize +n] * cosine; + sum += product; + } + + float alpha; + if(k == 0) + { + alpha = (float)(1.0f/Math.Sqrt(2)); + } + else + { + alpha = 1; + } + Out[lineSize + k] =(float)( sum * alpha ); + + } + } + public void DCTColumn16(float[] In, float[] Out, int Column) + { + int N =16; + int uSize; + + for(int k = 0; k < N; k++){ + float sum = 0.0f; + for(int n = 0; n < N; n++) + { + uSize = n * 16; + float num = (float)(Math.PI*k*(2.0f*n+1)/(2*N)); + float cosine = (float)Math.Cos(num); + float product = In[uSize + Column] * cosine; + sum += product; + } + + float alpha; + if(k == 0) + { + alpha = (float)(1.0f/Math.Sqrt(2)); + } + else + { + alpha = 1; + } + Out[16 * k + Column] = (float)( sum * alpha * (2.0f /N)); + + } + } + + private void EncodePatch(int[] patches, BitPacker bitpack, int size) + { + int lastnum =0; + for(int n = 0; n < size * size; n++) + { + if(patches[n]!=0) + lastnum=n; + } + for (int n = 0; n < lastnum+1; n++) + { + if(patches[n] != 0) + { + bitpack.PackBits(1,1); //value or EOB + bitpack.PackBits(1,1); //value + if(patches[n] > 0) + { + + bitpack.PackBits(0,1); // positive + bitpack.PackBits(patches[n],13); + + } + else + { + bitpack.PackBits(1,1); // negative + + int temp = patches[n] * -1; + bitpack.PackBits(temp,13); + + } + } + else + { + bitpack.PackBits(0,1); // no value + } + } + + bitpack.PackBits(1,1); //value or EOB + bitpack.PackBits(0,1); // EOB + } + + public int[] CompressPatch(float[] patches) + { + int size = 16; + float[] block = new float[size * size]; + int[] output = new int[size * size]; + int prequant = (139 >> 4) + 2; + int quantize = 1 << prequant; + float ooq = 1.0f / (float)quantize; + float mult = ooq * (float)1; + float addval = mult * (float)(1 << (prequant - 1)) + 20.4989f; + + if (size == 16) + { + for (int n = 0; n < 16 * 16; n++) + { + block[n] = (float)((patches[n] - addval)/ mult); + } + + float[] ftemp = new float[32 * 32]; + + for (int o = 0; o < 16; o++) + this.DCTColumn16(block, ftemp, o); + for (int o = 0; o < 16; o++) + this.DCTLine16(ftemp, block, o); + } + + for (int j = 0; j < block.Length; j++) + { + output[DeCopyMatrix16[j]] = (int)(block[j] / DequantizeTable16[j]); + } + + return output; + } + + public Packet CreateLayerPacket(float[] heightmap, int minX, int maxX, int minY, int maxY) + { + //int minX = 0, maxX = 2, minY = 0, maxY = 1; //these should be passed to this function + LayerDataPacket layer = new LayerDataPacket(); + byte[] Encoded = new byte[2048]; + layer.LayerID.Type = 76; + GroupHeader header = new GroupHeader(); + header.Stride = 264; + header.PatchSize = 16; + header.Type = LayerType.Land; + BitPacker newpack = new BitPacker(Encoded,0); + newpack.PackBits(header.Stride,16); + newpack.PackBits(header.PatchSize,8); + newpack.PackBits((int)header.Type,8); + + + float[] height; + for(int y = minY; y< maxY; y++) + { + for(int x = minX ; x < maxX ; x++) + { + height = new float[256]; + Array.Copy(heightmap, (4096 *y) +(x *256), height, 0, 256); + + this.CreatePatch(height, newpack, x, y); + } + } + + PatchHeader headers = new PatchHeader(); + headers.QuantWBits = END_OF_PATCHES; + this.EncodePatchHeader(newpack, headers); + + int lastused=0; + for(int i = 0; i < 1024 ; i++) + { + if(Encoded[i] !=0) + lastused = i; + } + + byte[] data = new byte[lastused+1]; + Array.Copy(Encoded, data, lastused+1); + layer.LayerData.Data =data; + + return(layer); + } + public void CreatePatch(float[] heightmap, BitPacker newpack, int x, int y) + { + PatchHeader header = new PatchHeader(); + header.DCOffset = 20.4989f; + header.QuantWBits = 139; + header.Range = 1; + header.PatchIDs = (y & 0x1F); + header.PatchIDs += x <<5 ; + + this.EncodePatchHeader(newpack, header); + + int[] newpatch = this.CompressPatch(heightmap); + this.EncodePatch(newpatch, newpack, 16); + + } + } + + //*************************************************** + public class BitPacker + { + private const int MAX_BITS = 8; + + private byte[] Data; + public int bytePos; + public int bitPos; + + /// + /// Default constructor, initialize the bit packer / bit unpacker + /// with a byte array and starting position + /// + /// Byte array to pack bits in to or unpack from + /// Starting position in the byte array + public BitPacker(byte[] data, int pos) + { + Data = data; + bytePos = pos; + } + + /// + /// Pack a floating point value in to the data + /// + /// Floating point value to pack + public void PackFloat(float data) + { + byte[] input = BitConverter.GetBytes(data); + PackBitArray(input, 32); + } + + /// + /// Pack part or all of an integer in to the data + /// + /// Integer containing the data to pack + /// Number of bits of the integer to pack + public void PackBits(int data, int totalCount) + { + byte[] input = BitConverter.GetBytes(data); + PackBitArray(input, totalCount); + } + + /// + /// Unpacking a floating point value from the data + /// + /// Unpacked floating point value + public float UnpackFloat() + { + byte[] output = UnpackBitsArray(32); + + if (!BitConverter.IsLittleEndian) Array.Reverse(output); + return BitConverter.ToSingle(output, 0); + } + + /// + /// Unpack a variable number of bits from the data in to integer format + /// + /// Number of bits to unpack + /// An integer containing the unpacked bits + /// This function is only useful up to 32 bits + public int UnpackBits(int totalCount) + { + byte[] output = UnpackBitsArray(totalCount); + + if (!BitConverter.IsLittleEndian) Array.Reverse(output); + return BitConverter.ToInt32(output, 0); + } + + private void PackBitArray(byte[] data, int totalCount) + { + int count = 0; + int curBytePos = 0; + int curBitPos = 0; + + while (totalCount > 0) + { + if (totalCount > (MAX_BITS )) + { + count = MAX_BITS ; + totalCount -= MAX_BITS ; + } + else + { + count = totalCount; + totalCount = 0; + } + + while (count > 0) + { + switch(count) + { + case 1: + if ((data[curBytePos] & (0x01)) != 0) + { + Data[bytePos] |= (byte)(0x80 >> bitPos); + } + break; + case 2: + if ((data[curBytePos] & (0x02)) != 0) + { + Data[bytePos] |= (byte)(0x80 >> bitPos); + } + break; + case 3: + if ((data[curBytePos] & (0x04)) != 0) + { + Data[bytePos] |= (byte)(0x80 >> bitPos); + } + break; + case 4: + if ((data[curBytePos] & (0x08)) != 0) + { + Data[bytePos] |= (byte)(0x80 >> bitPos); + } + break; + case 5: + if ((data[curBytePos] & (0x10)) != 0) + { + Data[bytePos] |= (byte)(0x80 >> bitPos); + } + break; + case 6: + if ((data[curBytePos] & (0x20)) != 0) + { + Data[bytePos] |= (byte)(0x80 >> bitPos); + } + break; + case 7: + if ((data[curBytePos] & (0x40)) != 0) + { + Data[bytePos] |= (byte)(0x80 >> bitPos); + } + break; + case 8: + if ((data[curBytePos] & (0x80)) != 0) + { + Data[bytePos] |= (byte)(0x80 >> bitPos); + } + break; + } + + bitPos++; + --count; + ++curBitPos; + + if (bitPos >= MAX_BITS) + { + bitPos = 0; + ++bytePos; + } + if (curBitPos >= MAX_BITS) + { + curBitPos = 0; + ++curBytePos; + } + } + } + } + + + private byte[] UnpackBitsArray(int totalCount) + { + int count = 0; + byte[] output = new byte[4]; + int curBytePos = 0; + int curBitPos = 0; + + while (totalCount > 0) + { + if (totalCount > MAX_BITS) + { + count = MAX_BITS; + totalCount -= MAX_BITS; + } + else + { + count = totalCount; + totalCount = 0; + } + + while (count > 0) + { + // Shift the previous bits + output[curBytePos] <<= 1; + + // Grab one bit + if ((Data[bytePos] & (0x80 >> bitPos++)) != 0) + ++output[curBytePos]; + + --count; + ++curBitPos; + + if (bitPos >= MAX_BITS) + { + bitPos = 0; + ++bytePos; + } + if (curBitPos >= MAX_BITS) + { + curBitPos = 0; + ++curBytePos; + } + } + } + + return output; + } + } +} -- cgit v1.1