From f5e5aa83b19cc478a1691391a2112bf45055476f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jan=20M=C3=B6bius?= <moebius@cs.rwth-aachen.de>
Date: Fri, 24 Sep 2021 11:10:47 +0200
Subject: [PATCH] Fixed OBJ reader not reading materials which start with a
 leading space

---
 src/OpenMesh/Core/IO/reader/OBJReader.cc  | 11 +++---
 src/Unittests/TestFiles/CubeCol.mtl       |  9 +++++
 src/Unittests/TestFiles/CubeCol.obj       | 28 ++++++++++++++++
 src/Unittests/unittests_read_write_OBJ.cc | 41 +++++++++++++++++++++++
 4 files changed, 84 insertions(+), 5 deletions(-)
 create mode 100644 src/Unittests/TestFiles/CubeCol.mtl
 create mode 100644 src/Unittests/TestFiles/CubeCol.obj

diff --git a/src/OpenMesh/Core/IO/reader/OBJReader.cc b/src/OpenMesh/Core/IO/reader/OBJReader.cc
index bdefcd7d..6fe6141e 100644
--- a/src/OpenMesh/Core/IO/reader/OBJReader.cc
+++ b/src/OpenMesh/Core/IO/reader/OBJReader.cc
@@ -188,23 +188,24 @@ read_material(std::fstream& _in)
 
     stream >> keyWrd;
 
-    if( ( isspace(line[0]) && line[0] != '\t' ) || line[0] == '#' )
+    if (keyWrd == "newmtl") // begin new material definition
     {
+      // If we are in a material definition (Already reading a material)
+      // And a material name has been set
+      // And the current material definition is valid
+      // Then Store the current material in our lookup table 
       if (indef && !key.empty() && mat.is_valid())
       {
         materials_[key] = mat;
         mat.cleanup();
       }
-    }
 
-    else if (keyWrd == "newmtl") // begin new material definition
-    {
       stream >> key;
       indef = true;
     }
 
     else if (keyWrd == "Kd") // diffuse color
-    {
+    { 
       stream >> f1; stream >> f2; stream >> f3;
 
       if( !stream.fail() )
diff --git a/src/Unittests/TestFiles/CubeCol.mtl b/src/Unittests/TestFiles/CubeCol.mtl
new file mode 100644
index 00000000..bcbb1b20
--- /dev/null
+++ b/src/Unittests/TestFiles/CubeCol.mtl
@@ -0,0 +1,9 @@
+newmtl cube
+Ns 10.0000
+Ni 1.000
+d 1.0000
+illum 2
+#Ambient, Diffuse, Specular colors
+ Ka 1.0000 0.7000 0.1000
+ Kd 0.1250 0.2500 0.5000
+ Ks 1.0000 0.6000 0.4000
diff --git a/src/Unittests/TestFiles/CubeCol.obj b/src/Unittests/TestFiles/CubeCol.obj
new file mode 100644
index 00000000..b6087333
--- /dev/null
+++ b/src/Unittests/TestFiles/CubeCol.obj
@@ -0,0 +1,28 @@
+# cube.obj
+#
+o cube
+mtllib CubeCol.mtl
+
+v -0.500000 -0.500000 0.500000
+v 0.500000 -0.500000 0.500000
+v -0.500000 0.500000 0.500000
+v 0.500000 0.500000 0.500000
+v -0.500000 0.500000 -0.500000
+v 0.500000 0.500000 -0.500000
+v -0.500000 -0.500000 -0.500000
+v 0.500000 -0.500000 -0.500000
+
+g cube
+usemtl cube
+f 1 2 3
+f 3 2 4
+f 3 4 5
+f 5 4 6
+f 5 6 7
+f 7 6 8
+f 7 8 1
+f 1 8 2
+f 2 8 4
+f 4 8 6
+f 7 1 5
+f 5 1 3
\ No newline at end of file
diff --git a/src/Unittests/unittests_read_write_OBJ.cc b/src/Unittests/unittests_read_write_OBJ.cc
index c779daa0..51671e9f 100644
--- a/src/Unittests/unittests_read_write_OBJ.cc
+++ b/src/Unittests/unittests_read_write_OBJ.cc
@@ -623,7 +623,48 @@ TEST_F(OpenMeshReadWriteOBJ, FaceTexCoordTest) {
 }
 
 
+/*
+ * Load, save and load a simple obj
+ */
+TEST_F(OpenMeshReadWriteOBJ, ReadOBJMTL) {
 
+  mesh_.clear();
+  mesh_.request_face_colors();
+
+  OpenMesh::IO::Options options;
+  options += OpenMesh::IO::Options::FaceColor;
+  bool ok = OpenMesh::IO::read_mesh(mesh_, "CubeCol.obj", options);
+
+  EXPECT_TRUE(ok) << "Unable to load CubeCol.obj";
+
+  OpenMesh::FaceHandle fh0 = mesh_.face_handle(0);
+  OpenMesh::FaceHandle fh1 = mesh_.face_handle(1);
+  OpenMesh::FaceHandle fh2 = mesh_.face_handle(2);
+  OpenMesh::FaceHandle fh3 = mesh_.face_handle(3);
+
+
+  EXPECT_TRUE(fh0.is_valid()) << "fh0 should be valid";
+  EXPECT_TRUE(fh1.is_valid()) << "fh1 should be valid";
+  EXPECT_TRUE(fh2.is_valid()) << "fh2 should be valid";
+  EXPECT_TRUE(fh3.is_valid()) << "fh3 should be valid";
+
+  EXPECT_FLOAT_EQ(32,    mesh_.color(fh0)[0] ) << "Wrong vertex color at face 0 component 0";
+  EXPECT_FLOAT_EQ(64 ,   mesh_.color(fh0)[1] ) << "Wrong vertex color at face 0 component 1";
+  EXPECT_FLOAT_EQ(128,   mesh_.color(fh0)[2] ) << "Wrong vertex color at face 0 component 2";
+
+  EXPECT_FLOAT_EQ(32,    mesh_.color(fh1)[0] ) << "Wrong vertex color at face 1 component 0";
+  EXPECT_FLOAT_EQ(64,    mesh_.color(fh1)[1] ) << "Wrong vertex color at face 1 component 1";
+  EXPECT_FLOAT_EQ(128,   mesh_.color(fh1)[2] ) << "Wrong vertex color at face 1 component 2";
+
+  EXPECT_FLOAT_EQ(32,    mesh_.color(fh2)[0] ) << "Wrong vertex color at face 2 component 0";
+  EXPECT_FLOAT_EQ(64,    mesh_.color(fh2)[1] ) << "Wrong vertex color at face 2 component 1";
+  EXPECT_FLOAT_EQ(128,   mesh_.color(fh2)[2] ) << "Wrong vertex color at face 2 component 2";
+
+  EXPECT_FLOAT_EQ(32,    mesh_.color(fh3)[0] ) << "Wrong vertex color at face 3 component 0";
+  EXPECT_FLOAT_EQ(64,    mesh_.color(fh3)[1] ) << "Wrong vertex color at face 3 component 1";
+  EXPECT_FLOAT_EQ(128,   mesh_.color(fh3)[2] ) << "Wrong vertex color at face 3 component 2";
+
+}