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14 KiB

//#define VERBOSE
using System;
using System.IO;
using Unity.Collections;
using UnityEngine;
namespace Unity.DemoTeam.DigitalHuman
{
public static class NativeMeshObjLoader
{
[Flags]
public enum VertexAttribs
{
Position = 1 << 0,
TexCoord = 1 << 1,
Normal = 1 << 2,
}
public enum VertexOrder
{
ByDefinition = 0,
ByReference = 1,
}
struct InputVertex
{
public uint idxPosition;
public uint idxTexCoord;
public uint idxNormal;
}
struct InputFace
{
public InputVertex v0;
public InputVertex v1;
public InputVertex v2;
}
public unsafe static NativeMeshSOA Parse(string path, Allocator outputAllocator = Allocator.Persistent, VertexAttribs vertexAttribs = VertexAttribs.Position, VertexOrder vertexOrder = VertexOrder.ByDefinition)
{
#if VERBOSE
Debug.LogFormat("trying {0}", path);
#endif
var text = File.ReadAllText(path);//TODO replace with native variant
var textSize = text.Length;
// measure the data
int numPositions = 0;
int numTexCoords = 0;
int numNormals = 0;
int numFaces = 0;
for (int i = 0; i < text.Length; i++)
{
if (ReadChar(text, ref i, 'v'))
{
if (ReadBlank(text, ref i))
{
numPositions++;
}
else if (ReadChar(text, ref i, 't') && ReadBlank(text, ref i))
{
numTexCoords++;
}
else if (ReadChar(text, ref i, 'n') && ReadBlank(text, ref i))
{
numNormals++;
}
}
else if (ReadChar(text, ref i, 'f') && ReadBlankGreedy(text, ref i))
{
int readVerts = 0;
while (ReadDigit(text, ref i))
{
ReadUntilNewlineOrBlank(text, ref i);
ReadBlankGreedy(text, ref i);
readVerts++;
}
if (readVerts > 2)
{
numFaces += readVerts - 2;
}
}
ReadUntilNewline(text, ref i);
}
#if VERBOSE
Debug.LogFormat("-- numPositions = {0}", numPositions);
Debug.LogFormat("-- numTexCoords = {0}", numTexCoords);
Debug.LogFormat("-- numNormals = {0}", numNormals);
Debug.LogFormat("-- numFaces = {0}", numFaces);
#endif
// allocate buffers
var inputPositions = new NativeArray<Vector3>(numPositions, Allocator.Temp, NativeArrayOptions.UninitializedMemory);
var inputTexCoords = new NativeArray<Vector2>(numTexCoords, Allocator.Temp, NativeArrayOptions.UninitializedMemory);
var inputNormals = new NativeArray<Vector3>(numNormals, Allocator.Temp, NativeArrayOptions.UninitializedMemory);
var inputFaces = new NativeArray<InputFace>(numFaces, Allocator.Temp, NativeArrayOptions.UninitializedMemory);
var outputIndicesMax = numFaces * 3;
var outputIndicesLUT = new NativeHashMap<Hash128, int>(outputIndicesMax, Allocator.Temp);
var outputPositions = new NativeArray<Vector3>(outputIndicesMax, Allocator.Temp, NativeArrayOptions.UninitializedMemory);
var outputTexCoords = new NativeArray<Vector2>(outputIndicesMax, Allocator.Temp, NativeArrayOptions.UninitializedMemory);
var outputNormals = new NativeArray<Vector3>(outputIndicesMax, Allocator.Temp, NativeArrayOptions.UninitializedMemory);
var outputIndices = new NativeArray<int>(outputIndicesMax, Allocator.Temp, NativeArrayOptions.UninitializedMemory);
// read the data
numPositions = 0;
numTexCoords = 0;
numNormals = 0;
numFaces = 0;
for (int i = 0; i < text.Length; i++)
{
if (ReadChar(text, ref i, 'v'))
{
if (ReadBlank(text, ref i))
{
Vector3 position;
ReadFloat(text, ref i, out position.x);
position.x *= -1.0f;//TODO remove this hack
ReadBlankGreedy(text, ref i);
ReadFloat(text, ref i, out position.y);
ReadBlankGreedy(text, ref i);
ReadFloat(text, ref i, out position.z);
inputPositions[numPositions++] = position;
}
else if (ReadChar(text, ref i, 't') && ReadBlank(text, ref i))
{
Vector2 texCoord;
ReadFloat(text, ref i, out texCoord.x);
ReadBlankGreedy(text, ref i);
ReadFloat(text, ref i, out texCoord.y);
inputTexCoords[numTexCoords++] = texCoord;
}
else if (ReadChar(text, ref i, 'n') && ReadBlank(text, ref i))
{
Vector3 normal;
ReadFloat(text, ref i, out normal.x);
normal.x *= -1.0f;//TODO remove this hack
ReadBlankGreedy(text, ref i);
ReadFloat(text, ref i, out normal.y);
ReadBlankGreedy(text, ref i);
ReadFloat(text, ref i, out normal.z);
inputNormals[numNormals++] = normal;
}
}
else if (ReadChar(text, ref i, 'f') && ReadBlankGreedy(text, ref i))
{
InputFace face = new InputFace();
if (ReadUInt(text, ref i, out face.v0.idxPosition))
{
ReadChar(text, ref i, '/');
ReadUInt(text, ref i, out face.v0.idxTexCoord);
ReadChar(text, ref i, '/');
ReadUInt(text, ref i, out face.v0.idxNormal);
int readVerts = 1;
while (ReadBlankGreedy(text, ref i))
{
face.v1 = face.v2;
if (ReadUInt(text, ref i, out face.v2.idxPosition))
{
ReadChar(text, ref i, '/');
ReadUInt(text, ref i, out face.v2.idxTexCoord);
ReadChar(text, ref i, '/');
ReadUInt(text, ref i, out face.v2.idxNormal);
if (++readVerts > 2)
{
inputFaces[numFaces++] = face;
}
}
}
}
}
ReadUntilNewline(text, ref i);
}
// process the data
int numOutputVertices = 0;
int numOutputIndices = 0;
if (vertexOrder == VertexOrder.ByReference)
{
for (int i = 0; i != numFaces; i++)
{
InputFace face = inputFaces[i];
var key0 = Hash(in face.v0);
var key1 = Hash(in face.v1);
var key2 = Hash(in face.v2);
int idx0, idx1, idx2;
if (outputIndicesLUT.TryGetValue(key0, out idx0) == false)
outputIndicesLUT[key0] = idx0 = numOutputVertices++;
if (outputIndicesLUT.TryGetValue(key1, out idx1) == false)
outputIndicesLUT[key1] = idx1 = numOutputVertices++;
if (outputIndicesLUT.TryGetValue(key2, out idx2) == false)
outputIndicesLUT[key2] = idx2 = numOutputVertices++;
outputPositions[idx0] = inputPositions[(int)face.v0.idxPosition - 1];
outputPositions[idx1] = inputPositions[(int)face.v1.idxPosition - 1];
outputPositions[idx2] = inputPositions[(int)face.v2.idxPosition - 1];
outputTexCoords[idx0] = inputTexCoords[(int)face.v0.idxTexCoord - 1];
outputTexCoords[idx1] = inputTexCoords[(int)face.v1.idxTexCoord - 1];
outputTexCoords[idx2] = inputTexCoords[(int)face.v2.idxTexCoord - 1];
outputNormals[idx0] = inputNormals[(int)face.v0.idxNormal - 1];
outputNormals[idx1] = inputNormals[(int)face.v1.idxNormal - 1];
outputNormals[idx2] = inputNormals[(int)face.v2.idxNormal - 1];
outputIndices[numOutputIndices++] = idx0;
outputIndices[numOutputIndices++] = idx1;
outputIndices[numOutputIndices++] = idx2;
}
}
else if (vertexOrder == VertexOrder.ByDefinition)
{
numOutputVertices = numPositions;
var indexVisited = new NativeArray<bool>(numPositions, Allocator.Temp, NativeArrayOptions.ClearMemory);
for (int i = 0; i != numFaces; i++)
{
InputFace face = inputFaces[i];
var key0 = Hash(in face.v0);
var key1 = Hash(in face.v1);
var key2 = Hash(in face.v2);
int idx0, idx1, idx2;
if (outputIndicesLUT.TryGetValue(key0, out idx0) == false)
{
if (indexVisited[idx0 = (int)face.v0.idxPosition - 1])
outputIndicesLUT[key0] = idx0 = numOutputVertices++;
else
outputIndicesLUT[key0] = idx0;
}
if (outputIndicesLUT.TryGetValue(key1, out idx1) == false)
{
if (indexVisited[idx1 = (int)face.v1.idxPosition - 1])
outputIndicesLUT[key1] = idx1 = numOutputVertices++;
else
outputIndicesLUT[key1] = idx1;
}
if (outputIndicesLUT.TryGetValue(key2, out idx2) == false)
{
if (indexVisited[idx2 = (int)face.v2.idxPosition - 1])
outputIndicesLUT[key2] = idx2 = numOutputVertices++;
else
outputIndicesLUT[key2] = idx2;
}
indexVisited[(int)face.v0.idxPosition - 1] = true;
indexVisited[(int)face.v1.idxPosition - 1] = true;
indexVisited[(int)face.v2.idxPosition - 1] = true;
outputPositions[idx0] = inputPositions[(int)face.v0.idxPosition - 1];
outputPositions[idx1] = inputPositions[(int)face.v1.idxPosition - 1];
outputPositions[idx2] = inputPositions[(int)face.v2.idxPosition - 1];
outputTexCoords[idx0] = inputTexCoords[(int)face.v0.idxTexCoord - 1];
outputTexCoords[idx1] = inputTexCoords[(int)face.v1.idxTexCoord - 1];
outputTexCoords[idx2] = inputTexCoords[(int)face.v2.idxTexCoord - 1];
outputNormals[idx0] = inputNormals[(int)face.v0.idxNormal - 1];
outputNormals[idx1] = inputNormals[(int)face.v1.idxNormal - 1];
outputNormals[idx2] = inputNormals[(int)face.v2.idxNormal - 1];
outputIndices[numOutputIndices++] = idx0;
outputIndices[numOutputIndices++] = idx1;
outputIndices[numOutputIndices++] = idx2;
}
indexVisited.Dispose();
}
#if VERBOSE
Debug.LogFormat("output vertex count = {0}", numOutputVertices);
Debug.LogFormat("output index count = {0}", numOutputIndices);
#endif
// copy to container
NativeMeshSOA mesh = new NativeMeshSOA()
{
vertexPositions = new NativeArray<Vector3>(numOutputVertices, outputAllocator, NativeArrayOptions.UninitializedMemory),
vertexTexCoords = new NativeArray<Vector2>(numOutputVertices, outputAllocator, NativeArrayOptions.UninitializedMemory),
vertexNormals = new NativeArray<Vector3>(numOutputVertices, outputAllocator, NativeArrayOptions.UninitializedMemory),
vertexCount = numOutputVertices,
faceIndices = new NativeArray<int>(numOutputIndices, outputAllocator, NativeArrayOptions.UninitializedMemory),
faceIndicesCount = numOutputIndices,
};
NativeArray<Vector3>.Copy(outputPositions, mesh.vertexPositions, numOutputVertices);
NativeArray<Vector2>.Copy(outputTexCoords, mesh.vertexTexCoords, numOutputVertices);
NativeArray<Vector3>.Copy(outputNormals, mesh.vertexNormals, numOutputVertices);
NativeArray<int>.Copy(outputIndices, mesh.faceIndices, numOutputIndices);
// free buffers
inputPositions.Dispose();
inputTexCoords.Dispose();
inputNormals.Dispose();
inputFaces.Dispose();
outputIndicesLUT.Dispose();
outputPositions.Dispose();
outputTexCoords.Dispose();
outputNormals.Dispose();
outputIndices.Dispose();
// done
return mesh;
}
static Hash128 Hash(in InputVertex v)
{
return new Hash128(v.idxPosition, v.idxTexCoord, v.idxNormal, 0);
}
static bool ReadChar(string text, ref int index, char value)
{
if (text[index] == value)
{
index++;
return true;
}
else
{
return false;
}
}
static bool ReadDigit(string text, ref int index)
{
if (text[index] >= '0' && text[index] <= '9')
{
index++;
return true;
}
else
{
return false;
}
}
static bool ReadUInt(string text, ref int index, out uint value)
{
unsafe
{
const uint READ_BASE = '0';
const uint READ_FAIL = uint.MaxValue;
const int READ_MAX = 32;
char* readBuf = stackalloc char[READ_MAX];
uint readPos = 0;
if (text[index] >= '0' && text[index] <= '9')
{
readBuf[readPos++] = text[index++];
while (text[index] >= '0' && text[index] <= '9')
{
if (readPos == READ_MAX)
{
value = READ_FAIL;
return false;
}
readBuf[readPos++] = text[index++];
}
value = readBuf[0] - READ_BASE;
for (uint i = 1; i != readPos; i++)
{
value = (value * 10) + (readBuf[i] - READ_BASE);
}
return true;
}
else
{
value = READ_FAIL;
return false;
}
}
}
//static int readfloat = 0;
static bool ReadFloat(string text, ref int index, out float value)
{
uint valueInt = 0u;
uint valueFrac = 0u;
bool readSign = ReadChar(text, ref index, '-');
bool readInt = ReadUInt(text, ref index, out valueInt);
int indexFrac = index;
bool readFrac = ReadChar(text, ref index, '.') && ReadUInt(text, ref index, out valueFrac);
int countFrac = index - indexFrac;
if (readInt || readFrac)
{
if (readFrac && valueFrac > 0)
{
value = (float)valueFrac;
value *= Mathf.Pow(10.0f, -(countFrac - 1));
}
else
{
value = 0.0f;
}
if (readInt && valueInt > 0)
{
value = ((float)valueInt + value);
}
if (readSign)
{
value = -value;
}
//readfloat++;
//if (readfloat == 1)
//{
// Debug.Log("read float (" + readfloat + ")");
// Debug.Log("-- readSign " + readSign);
// Debug.Log("-- readInt " + readInt);
// Debug.Log("-- readFrac " + readFrac);
// Debug.Log("-- valueInt " + valueInt);
// Debug.Log("-- valueFrac " + valueFrac);
// Debug.Log("read float VALUE " + value);
//}
return true;
}
else
{
value = float.NaN;
return false;
}
}
static bool ReadBlank(string text, ref int index)
{
if (text[index] == ' ' || text[index] == '\t')
{
index++;
return true;
}
else
{
return false;
}
}
static bool ReadBlankGreedy(string text, ref int index)
{
if (text[index] == ' ' || text[index] == '\t')
{
index++;
while (text[index] == ' ' || text[index] == '\t')
{
index++;
}
return true;
}
else
{
return false;
}
}
static bool ReadUntilNewline(string text, ref int index)
{
if (text[index] != '\n')
{
index++;
while (text[index] != '\n')
{
index++;
}
return true;
}
else
{
return false;
}
}
static bool ReadUntilNewlineOrBlank(string text, ref int index)
{
if (text[index] != '\n' && text[index] != ' ' && text[index] != '\t')
{
index++;
while (text[index] != '\n' && text[index] != ' ' && text[index] != '\t')
{
index++;
}
return true;
}
else
{
return false;
}
}
}
}