Support paring leadingdecimal dot of floating point value. Fixes #201

syoyo · syoyo · commit 7b410a0259bc · 2019-05-06T20:31:35.000+09:00
diff --git a/models/leading-decimal-dot-issue-201.mtl b/models/leading-decimal-dot-issue-201.mtl
@@ -0,0 +1,5 @@
+newmtl default
+Ka 0 0 0
+Kd 0 0 0
+Ks 0 0 0
+Kt 0.1 0.2 0.3
diff --git a/models/leading-decimal-dot-issue-201.obj b/models/leading-decimal-dot-issue-201.obj
@@ -0,0 +1,7 @@
+mtllib leading-decimal-dot-issue-201.mtl
+o Test
+v .8e-1 -.7e+2 -5.532511
+v .575869 -.666304 5.896140
+v .940448 1.000000 -1.971128
+usemtl default
+f 1 2 3
diff --git a/tests/tester.cc b/tests/tester.cc
@@ -1080,6 +1080,35 @@ TEST_CASE("colorspace", "[Issue184]") {
   REQUIRE(0 == materials[0].bump_texopt.colorspace.compare("linear"));
 }
 
+TEST_CASE("leading-decimal-dots", "[Issue201]") {
+  tinyobj::attrib_t attrib;
+  std::vector<tinyobj::shape_t> shapes;
+  std::vector<tinyobj::material_t> materials;
+
+  std::string warn;
+  std::string err;
+  bool ret =
+      tinyobj::LoadObj(&attrib, &shapes, &materials, &warn, &err,
+                       "../models/leading-decimal-dot-issue-201.obj", gMtlBasePath);
+
+  if (!warn.empty()) {
+    std::cout << "WARN: " << warn << std::endl;
+  }
+
+  if (!err.empty()) {
+    std::cerr << "ERR: " << err << std::endl;
+  }
+
+  REQUIRE(true == ret);
+  REQUIRE(1 == shapes.size());
+  REQUIRE(1 == materials.size());
+  REQUIRE(0.8e-1 == Approx(attrib.vertices[0]));
+  REQUIRE(-.7e+2 == Approx(attrib.vertices[1]));
+  REQUIRE(.575869 == Approx(attrib.vertices[3]));
+  REQUIRE(-.666304 == Approx(attrib.vertices[4]));
+  REQUIRE(.940448 == Approx(attrib.vertices[6]));
+}
+
 // Fuzzer test.
 // Just check if it does not crash.
 // Disable by default since Windows filesystem can't create filename of afl
diff --git a/tiny_obj_loader.h b/tiny_obj_loader.h
@@ -741,6 +741,7 @@ static bool tryParseDouble(const char *s, const char *s_end, double *result) {
   int read = 0;
   // Tells whether a loop terminated due to reaching s_end.
   bool end_not_reached = false;
+  bool leading_decimal_dots = false;
 
   /*
           BEGIN PARSING.
@@ -750,23 +751,35 @@ static bool tryParseDouble(const char *s, const char *s_end, double *result) {
   if (*curr == '+' || *curr == '-') {
     sign = *curr;
     curr++;
+    if ((curr != s_end) && (*curr == '.')) {
+      // accept. Somethig like `.7e+2`, `-.5234`
+      leading_decimal_dots = true;
+    }
   } else if (IS_DIGIT(*curr)) { /* Pass through. */
+  } else if (*curr == '.') {
+    // accept. Somethig like `.7e+2`, `-.5234`
+    leading_decimal_dots = true;
   } else {
     goto fail;
   }
 
   // Read the integer part.
   end_not_reached = (curr != s_end);
-  while (end_not_reached && IS_DIGIT(*curr)) {
-    mantissa *= 10;
-    mantissa += static_cast<int>(*curr - 0x30);
-    curr++;
-    read++;
-    end_not_reached = (curr != s_end);
+  if (!leading_decimal_dots) {
+    while (end_not_reached && IS_DIGIT(*curr)) {
+      mantissa *= 10;
+      mantissa += static_cast<int>(*curr - 0x30);
+      curr++;
+      read++;
+      end_not_reached = (curr != s_end);
+    }
   }
 
   // We must make sure we actually got something.
-  if (read == 0) goto fail;
+  if (!leading_decimal_dots) {
+    if (read == 0) goto fail;
+  }
+
   // We allow numbers of form "#", "###" etc.
   if (!end_not_reached) goto assemble;
 
