Add some code for USDA parser.

models/hair.usda

@@ -0,0 +1,67 @@
+#usda 1.0
+(
+    doc = "Blender v2.83.7"
+    metersPerUnit = 1
+    upAxis = "Z"
+)
+
+def Xform "Light"
+{
+    matrix4d xformOp:transform = ( (-0.29086464643478394, 0.9551711678504944, -0.05518905818462372, 0), (-0.7711008191108704, -0.1998833566904068, 0.6045247316360474, 0), (0.5663931965827942, 0.21839119493961334, 0.7946722507476807, 0), (4.076245307922363, 1.0054539442062378, 5.903861999511719, 1) )
+    uniform token[] xformOpOrder = ["xformOp:transform"]
+
+    def SphereLight "Light"
+    {
+        color3f color = (1, 1, 1)
+        float intensity = 10
+        float radius = 0.1
+        float specular = 1
+    }
+}
+
+def Xform "Camera"
+{
+    matrix4d xformOp:transform = ( (0.6859206557273865, 0.7276763319969177, 0, 0), (-0.32401347160339355, 0.305420845746994, 0.8953956365585327, 0), (0.6515582203865051, -0.6141703724861145, 0.44527140259742737, 0), (7.358891487121582, -6.925790786743164, 4.958309173583984, 1) )
+    uniform token[] xformOpOrder = ["xformOp:transform"]
+
+    def Camera "Camera"
+    {
+        float2 clippingRange = (0.1, 100)
+        float focalLength = 50
+        float horizontalAperture = 36
+        float horizontalApertureOffset = 0
+        token projection = "perspective"
+        float verticalAperture = 20.25
+        float verticalApertureOffset = 0
+    }
+}
+
+def Xform "Plane"
+{
+    matrix4d xformOp:transform = ( (1, 0, 0, 0), (0, 1, 0, 0), (0, 0, 1, 0), (0, 0, 0, 1) )
+    uniform token[] xformOpOrder = ["xformOp:transform"]
+
+    def BasisCurves "ParticleSettings"
+    {
+        uniform token basis = "bspline"
+        int[] curveVertexCounts = [9, 9, 9, 9, 9, 9, 9, 9, 9, 9]
+        point3f[] points = [(0.0825153, -0.7126689, 0), (0.0825153, -0.7126689, 0.41532692), (0.0825153, -0.7126689, 0.99539745), (0.0825153, -0.7126689, 1.4209023), (0.0825153, -0.7126689, 1.9300001), (0.0825153, -0.7126689, 2.439098), (0.0825153, -0.7126689, 2.8646023), (0.0825153, -0.7126689, 3.4446728), (0.0825153, -0.7126689, 3.8599997), (-0.74895674, -0.42046744, 0), (-0.74895674, -0.42046744, 0.41532692), (-0.74895674, -0.42046744, 0.99539745), (-0.74895674, -0.42046744, 1.4209023), (-0.74895674, -0.42046744, 1.9300001), (-0.74895674, -0.42046744, 2.439098), (-0.74895674, -0.42046744, 2.8646023), (-0.74895674, -0.42046744, 3.4446728), (-0.74895674, -0.42046744, 3.8599997), (-0.84020585, -0.8705612, 0), (-0.84020585, -0.8705612, 0.41532692), (-0.84020585, -0.8705612, 0.99539745), (-0.84020585, -0.8705612, 1.4209023), (-0.84020585, -0.8705612, 1.9300001), (-0.84020585, -0.8705612, 2.439098), (-0.84020585, -0.8705612, 2.8646023), (-0.84020585, -0.8705612, 3.4446728), (-0.84020585, -0.8705612, 3.8599997), (0.76589143, -0.48999798, 0), (0.76589143, -0.48999798, 0.41532692), (0.76589143, -0.48999798, 0.99539745), (0.76589143, -0.48999798, 1.4209023), (0.76589143, -0.48999798, 1.9300001), (0.76589143, -0.48999798, 2.439098), (0.76589143, -0.48999798, 2.8646023), (0.76589143, -0.48999798, 3.4446728), (0.76589143, -0.48999798, 3.8599997), (0.6797011, 0.63009846, 0), (0.6797011, 0.63009846, 0.41532692), (0.6797011, 0.63009846, 0.99539745), (0.6797011, 0.63009846, 1.4209023), (0.6797011, 0.63009846, 1.9300001), (0.6797011, 0.63009846, 2.439098), (0.6797011, 0.63009846, 2.8646023), (0.6797011, 0.63009846, 3.4446728), (0.6797011, 0.63009846, 3.8599997), (0.96835244, 0.24794665, 0), (0.96835244, 0.24794665, 0.41532692), (0.96835244, 0.24794665, 0.99539745), (0.96835244, 0.24794665, 1.4209023), (0.96835244, 0.24794665, 1.9300001), (0.96835244, 0.24794665, 2.439098), (0.96835244, 0.24794665, 2.8646023), (0.96835244, 0.24794665, 3.4446728), (0.96835244, 0.24794665, 3.8599997), (0.52848554, -0.86063015, 0), (0.52848554, -0.86063015, 0.41532692), (0.52848554, -0.86063015, 0.99539745), (0.52848554, -0.86063015, 1.4209023), (0.52848554, -0.86063015, 1.9300001), (0.52848554, -0.86063015, 2.439098), (0.52848554, -0.86063015, 2.8646023), (0.52848554, -0.86063015, 3.4446728), (0.52848554, -0.86063015, 3.8599997), (-0.20061585, 0.57317805, 0), (-0.20061585, 0.57317805, 0.41532692), (-0.20061585, 0.57317805, 0.99539745), (-0.20061585, 0.57317805, 1.4209023), (-0.20061585, 0.57317805, 1.9300001), (-0.20061585, 0.57317805, 2.439098), (-0.20061585, 0.57317805, 2.8646023), (-0.20061585, 0.57317805, 3.4446728), (-0.20061585, 0.57317805, 3.8599997), (-0.3693127, -0.7677623, 0), (-0.3693127, -0.7677623, 0.41532692), (-0.3693127, -0.7677623, 0.99539745), (-0.3693127, -0.7677623, 1.4209023), (-0.3693127, -0.7677623, 1.9300001), (-0.3693127, -0.7677623, 2.439098), (-0.3693127, -0.7677623, 2.8646023), (-0.3693127, -0.7677623, 3.4446728), (-0.3693127, -0.7677623, 3.8599997), (0.24664283, 0.7816913, 0), (0.24664283, 0.7816913, 0.41532692), (0.24664283, 0.7816913, 0.99539745), (0.24664283, 0.7816913, 1.4209023), (0.24664283, 0.7816913, 1.9300001), (0.24664283, 0.7816913, 2.439098), (0.24664283, 0.7816913, 2.8646023), (0.24664283, 0.7816913, 3.4446728), (0.24664283, 0.7816913, 3.8599997)]
+        color3f[] primvars:displayColor = [(0.5, 0.5, 0.5)]
+        uniform token type = "cubic"
+    }
+
+    def Mesh "Plane"
+    {
+        int[] faceVertexCounts = [4]
+        int[] faceVertexIndices = [0, 1, 3, 2]
+        normal3f[] normals = [(0, 0, 1), (0, 0, 1), (0, 0, 1), (0, 0, 1)] (
+            interpolation = "faceVarying"
+        )
+        point3f[] points = [(-1, -1, 0), (1, -1, 0), (-1, 1, 0), (1, 1, 0)]
+        texCoord2f[] primvars:UVMap = [(0, 0), (1, 0), (1, 1), (0, 1)] (
+            interpolation = "faceVarying"
+        )
+        uniform token subdivisionScheme = "none"
+    }
+}
+

sandbox/usda/Makefile

@@ -0,0 +1,28 @@
+CC=clang
+CXX=clang++
+INCFLAGS=-I../../src/external/ryu -I../../src
+
+# only applied to usda-parser.cc
+EXTRA_COMPILER_FLAGS=-Weverything -Werror -Wno-padded -Wno-c++98-compat
+CXXFLAGS=-std=c++11 -fsanitize=address 
+LDFLAGS=-fsanitize=address
+
+.PHONY: clean all
+
+all: usda-parser
+
+usda-parser: usda-parser.o d2s.o f2s.o
+	$(CXX) $(LDFLAGS) -o $@ $^
+	
+usda-parser.o: usda-parser.cc
+	$(CXX) $(INCFLAGS) $(CXXFLAGS) $(EXTRA_COMPILER_FLAGS) -c -o $@ $<
+
+d2s.o: ../../src/external/ryu/ryu/d2s.c
+	$(CC) $(INCFLAGS) $(CXXFLAGS) -c -o $@ $<
+
+f2s.o: ../../src/external/ryu/ryu/f2s.c
+	$(CC) $(INCFLAGS) $(CXXFLAGS) -c -o $@ $<
+
+clean:
+	@rm -rf usda-parser usda-parser.o d2s.o f2s.o
+

sandbox/usda/usda-parser.cc

@@ -0,0 +1,273 @@
+#include <iostream>
+#include <cstdlib>
+#include <fstream>
+#include <vector>
+#include <cassert>
+#include <stack>
+#include <sstream>
+
+#ifdef __clang__
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Weverything"
+#endif
+
+#include <ryu/ryu.h>
+#include <ryu/ryu_parse.h>
+
+#ifdef __clang__
+#pragma clang diagnostic pop
+#endif
+
+#include <stream-reader.hh>
+
+namespace tinyusdz {
+
+struct ErrorDiagnositc
+{
+  std::string err;
+  int line_row = -1;
+  int line_col = -1;
+};
+
+class USDAParser
+{
+ public:
+  struct ParseState {
+    int64_t loc{-1}; // byte location in StreamReder
+  };
+
+  USDAParser(tinyusdz::StreamReader *sr) : _sr(sr) {
+  }
+
+  bool SkipUntilNewline() {
+    while (!_sr->eof()) {
+      char c;
+      if (!_sr->read1(&c)) {
+        // this should not happen.
+        return false;
+      }
+
+      if ((c == '\n') || (c == '\r')) {
+        // continue
+      } else {
+        break;
+      }
+    }
+
+    _line_row++;
+    return true;
+  }
+
+  bool SkipWhitespace() {
+
+    while (!_sr->eof()) {
+      char c;
+      if (!_sr->read1(&c)) {
+        // this should not happen.
+        return false;
+      }
+
+      if ((c == ' ') || (c == '\t') || (c == '\f')) {
+        // continue
+      } else {
+        break;
+      }
+    }
+
+    // unwind 1 char
+    if (!_sr->seek_from_current(-1)) {
+      return false;
+    }
+
+    return true;
+  }
+
+  // #usda FLOAT
+  // `#` style comment
+  bool ParseHeader() {
+    SkipWhitespace();
+    if (_sr->eof()) {
+      return false;
+    }
+
+    {
+      char magic[5];
+      if (!_sr->read(5, 5, reinterpret_cast<uint8_t*>(magic))) {
+        // eol
+        return false;
+      }
+
+      if ((magic[0] == '#') && (magic[1] == 'u') &&
+          (magic[2] == 's') && (magic[3] == 'd') &&
+          (magic[4] == 'a')) {
+        // ok
+      } else {
+        ErrorDiagnositc diag;
+        diag.line_row = _line_row;
+        diag.line_col = _line_col;
+        diag.err = "Magic header must be `#usda` but got `" + std::string(magic, 5) + "`\n";
+        err_stack.push(diag);
+
+        return false;
+      }
+    }
+
+    if (!SkipWhitespace()) {
+      // eof
+      return false;
+    }
+
+    // current we only accept "1.0"
+    {
+      char ver[3];
+      if (!_sr->read(3, 3, reinterpret_cast<uint8_t*>(ver))) {
+        return false;
+      }
+
+      if ((ver[0] == '1') && (ver[1] == '.') &&
+          (ver[2] == '0')) {
+        // ok
+        _version = 1.0f;
+      } else {
+        ErrorDiagnositc diag;
+        diag.line_row = _line_row;
+        diag.line_col = _line_col;
+        diag.err = "Version must be `1.0` but got `" + std::string(ver, 3) + "`\n";
+        err_stack.push(diag);
+
+        return false;
+      }
+    }
+
+    SkipUntilNewline();
+
+    return true;
+  }
+
+  // `#` style comment
+  bool ParseSharpComment() {
+    char c;
+    if (!_sr->read1(&c)) {
+      // eol
+      return false;
+    }
+
+    if (c != '#') {
+      return false;
+    }
+
+    return true;
+  }
+
+  bool Push() {
+
+    // Stack size must be less than the number of input bytes.
+    assert (parse_stack.size() < _sr->size());
+
+    uint64_t loc = _sr->tell();
+
+    ParseState state;
+    state.loc = int64_t(loc);
+    parse_stack.push(state);
+
+    return true;
+  }
+
+  bool Pop(ParseState *state) {
+    if (parse_stack.empty()) {
+      return false;
+    }
+
+    (*state) = parse_stack.top();
+
+    parse_stack.pop();
+
+    return true; 
+  }
+
+  bool Parse() {
+    bool ok{false};
+
+    ok = ParseHeader();
+
+    return ok;
+  }
+
+  std::string GetError() {
+    if (err_stack.empty()) {
+      return std::string();
+    }
+
+    ErrorDiagnositc diag = err_stack.top();
+
+    std::stringstream ss;
+    ss << "line " << diag.line_row << ", col " << diag.line_col << ": ";
+    ss << diag.err << "\n";
+    return ss.str();
+  }
+
+ private:
+  const tinyusdz::StreamReader *_sr = nullptr;
+
+  std::stack<ErrorDiagnositc> err_stack;
+  std::stack<ParseState> parse_stack;
+
+  int _line_row{0};
+  int _line_col{0};
+
+  float _version{1.0f};
+
+};
+
+}
+
+int main(int argc, char **argv)
+{
+  if (argc < 2) {
+    std::cout << "Need input.usda\n";
+    exit(-1);
+  }
+
+  std::string filename = argv[1];
+
+  std::vector<uint8_t> data;
+  {
+    // TODO(syoyo): Support UTF-8 filename
+    std::ifstream ifs(filename.c_str(), std::ifstream::binary);
+    if (!ifs) {
+      std::cerr << "Failed to open file: " << filename << "\n";
+      return -1;
+    }
+
+    // TODO(syoyo): Use mmap
+    ifs.seekg(0, ifs.end);
+    size_t sz = static_cast<size_t>(ifs.tellg());
+    if (int64_t(sz) < 0) {
+      // Looks reading directory, not a file.
+      std::cerr << "Looks like filename is a directory : \"" << filename << "\"\n";
+      return -1;
+    }
+
+    data.resize(sz);
+
+    ifs.seekg(0, ifs.beg);
+    ifs.read(reinterpret_cast<char *>(&data.at(0)),
+             static_cast<std::streamsize>(sz));
+  }
+
+  tinyusdz::StreamReader sr(data.data(), data.size(), /* swap endian */false);
+  tinyusdz::USDAParser parser(&sr);
+
+  {
+    bool ret = parser.Parse();
+
+    if (!ret) {
+      std::cerr << "Failed to parse .usda: \n";
+      std::cerr << parser.GetError() << "\n";
+    }
+
+    std::cout << "ok\n";
+  }  
+
+  return 0;
+}

src/stream-reader.hh

@@ -121,7 +121,7 @@ class StreamReader {
     return true;
   }
 
-  bool seek_from_currect(const int64_t offset) const {
+  bool seek_from_current(const int64_t offset) const {
     if ((int64_t(idx_) + offset) < 0) {
       return false;
     }
@@ -340,6 +340,7 @@ class StreamReader {
 #endif
 
   size_t tell() const { return size_t(idx_); }
+  bool eof() const { return idx_ >= length_; }
 
   const uint8_t *data() const { return binary_; }