From d192402800906ff4a5e70eb07d8e888483fa0043 Mon Sep 17 00:00:00 2001
From: Syoyo Fujita <syoyo@lighttransport.com>
Date: Fri, 19 Aug 2016 20:19:28 +0900
Subject: [PATCH] Support `Tf` in MTL.

---
 models/issue-95-2.mtl |  5 +++++
 models/issue-95-2.obj |  7 +++++++
 models/issue-95.mtl   |  2 +-
 models/issue-95.obj   |  2 +-
 tests/tester.cc       | 35 +++++++++++++++++++++++++++++++++++
 tiny_obj_loader.h     |  3 ++-
 6 files changed, 51 insertions(+), 3 deletions(-)
 create mode 100644 models/issue-95-2.mtl
 create mode 100644 models/issue-95-2.obj

diff --git a/models/issue-95-2.mtl b/models/issue-95-2.mtl
new file mode 100644
index 0000000..68d484c
--- /dev/null
+++ b/models/issue-95-2.mtl
@@ -0,0 +1,5 @@
+newmtl default
+Ka 0 0 0
+Kd 0 0 0
+Ks 0 0 0
+Tf 0.1 0.2 0.3
diff --git a/models/issue-95-2.obj b/models/issue-95-2.obj
new file mode 100644
index 0000000..456f854
--- /dev/null
+++ b/models/issue-95-2.obj
@@ -0,0 +1,7 @@
+mtllib issue-95-2.mtl
+o Test
+v 1.864151 -1.219172 -5.532511
+v 0.575869 -0.666304 5.896140
+v 0.940448 1.000000 -1.971128
+usemtl default
+f 1 2 3
diff --git a/models/issue-95.mtl b/models/issue-95.mtl
index 68d484c..1d29fee 100644
--- a/models/issue-95.mtl
+++ b/models/issue-95.mtl
@@ -2,4 +2,4 @@ newmtl default
 Ka 0 0 0
 Kd 0 0 0
 Ks 0 0 0
-Tf 0.1 0.2 0.3
+Kt 0.1 0.2 0.3
diff --git a/models/issue-95.obj b/models/issue-95.obj
index f7be3b6..8ee267e 100644
--- a/models/issue-95.obj
+++ b/models/issue-95.obj
@@ -1,4 +1,4 @@
-mtllib issue-92.mtl
+mtllib issue-95.mtl
 o Test
 v 1.864151 -1.219172 -5.532511
 v 0.575869 -0.666304 5.896140
diff --git a/tests/tester.cc b/tests/tester.cc
index 8667888..5573bb6 100644
--- a/tests/tester.cc
+++ b/tests/tester.cc
@@ -385,6 +385,41 @@ TEST_CASE("transmittance_filter", "[Issue95]") {
   REQUIRE(0.3 == Approx(materials[0].transmittance[2]));
 }
 
+TEST_CASE("transmittance_filter_Tf", "[Issue95-Tf]") {
+  tinyobj::attrib_t attrib;
+  std::vector<tinyobj::shape_t> shapes;
+  std::vector<tinyobj::material_t> materials;
+
+  std::string err;
+  bool ret = tinyobj::LoadObj(&attrib, &shapes, &materials, &err, "../models/issue-95-2.obj", gMtlBasePath);
+
+  if (!err.empty()) {
+    std::cerr << err << std::endl;
+  }
+  REQUIRE(true == ret);
+  REQUIRE(1 == materials.size());
+  REQUIRE(0.1 == Approx(materials[0].transmittance[0]));
+  REQUIRE(0.2 == Approx(materials[0].transmittance[1]));
+  REQUIRE(0.3 == Approx(materials[0].transmittance[2]));
+}
+TEST_CASE("transmittance_filter_Kt", "[Issue95-Kt]") {
+  tinyobj::attrib_t attrib;
+  std::vector<tinyobj::shape_t> shapes;
+  std::vector<tinyobj::material_t> materials;
+
+  std::string err;
+  bool ret = tinyobj::LoadObj(&attrib, &shapes, &materials, &err, "../models/issue-95.obj", gMtlBasePath);
+
+  if (!err.empty()) {
+    std::cerr << err << std::endl;
+  }
+  REQUIRE(true == ret);
+  REQUIRE(1 == materials.size());
+  REQUIRE(0.1 == Approx(materials[0].transmittance[0]));
+  REQUIRE(0.2 == Approx(materials[0].transmittance[1]));
+  REQUIRE(0.3 == Approx(materials[0].transmittance[2]));
+}
+
 #if 0
 int
 main(
diff --git a/tiny_obj_loader.h b/tiny_obj_loader.h
index 34375e9..c2b49b3 100644
--- a/tiny_obj_loader.h
+++ b/tiny_obj_loader.h
@@ -740,7 +740,8 @@ void LoadMtl(std::map<std::string, int> *material_map,
     }
 
     // transmittance
-    if (token[0] == 'K' && token[1] == 't' && IS_SPACE((token[2]))) {
+    if ((token[0] == 'K' && token[1] == 't' && IS_SPACE((token[2]))) ||
+        (token[0] == 'T' && token[1] == 'f' && IS_SPACE((token[2])))) {
       token += 2;
       float r, g, b;
       parseFloat3(&r, &g, &b, &token);