I added test for checking shape offsets after triangulation.

Author: wendyn-projects

test/fixtures/shapes-triangulation.obj

@@ -0,0 +1,56 @@
+# OBJ File: 'house'
+# by WENDYN
+
+o house
+v -1.0000  0.0000 -1.0000
+v  1.0000  0.0000 -1.0000
+v  1.0000  0.0000  1.0000
+v -1.0000  0.0000  1.0000
+v -1.0000  1.0000 -1.0000
+v  1.0000  1.0000 -1.0000
+v  1.0000  1.0000  1.0000
+v -1.0000  1.0000  1.0000
+v  0.0000  2.0000 -1.0000
+v  0.0000  2.0000  1.0000
+
+vn  0.0000 -1.0000  0.0000
+vn  0.0000  0.0000 -1.0000
+vn -1.0000  0.0000  0.0000
+vn  0.0000  0.0000  1.0000
+vn  1.0000  0.0000  0.0000
+vn  0.0000  1.0000  0.0000
+vn -0.7071  0.7071  0.0000
+vn  0.7071  0.7071  0.0000
+
+s off
+g base
+f 1//1 2//1 3//1 4//1
+
+g facade
+f 1//2 2//2 6//2 5//2
+f 5//2 6//2 9//2
+
+g left_wall
+f 4//3 1//3 5//3 8//3
+
+g back_wall
+f 3//4 4//4 8//4 7//4
+
+g back_roof_wall
+f 7//4 8//4 10//4
+
+g right_wall
+f 2//5 3//5 7//5 6//5
+
+g floor
+f 5//6 6//6 7//6
+f 5//6 7//6 8//6
+
+g left_roof
+f 8//7 5//7 9//7 10//7
+
+g right_roof
+f 6//8 7//8 10//8 9//8
+
+# TODO: Remove extra content at the end of the file when
+# https://github.com/syoyo/tinyobjloader-c/issues/12 is fixed

test/tinyobj_regression_tests.c

@@ -83,3 +83,44 @@ void test_tinyobj_negative_exponent(void)
         TEST_CHECK(float_equals(attrib.vertices[2], 2.0e-0f));
     }
 }
+
+void test_tinyobj_shapes_triangulation(void)
+{
+    {
+        const char * filename = "fixtures/shapes-triangulation.obj";
+
+        tinyobj_shape_t * shape = NULL;
+        tinyobj_material_t * material = NULL;
+        tinyobj_attrib_t attrib;
+
+        unsigned long num_shapes;
+        unsigned long num_materials;
+
+        tinyobj_attrib_init(&attrib);
+
+        int result = tinyobj_parse_obj(&attrib, &shape, &num_shapes, &material, &num_materials, filename, loadFile, NULL, TINYOBJ_FLAG_TRIANGULATE);
+
+        TEST_CHECK(result == TINYOBJ_SUCCESS);
+
+        TEST_CHECK(num_shapes == 9);
+
+        TEST_CHECK(shape[0].face_offset == 0);
+        TEST_CHECK(shape[0].length == 2);
+        TEST_CHECK(shape[1].face_offset == 2);
+        TEST_CHECK(shape[1].length == 3);
+        TEST_CHECK(shape[2].face_offset == 5);
+        TEST_CHECK(shape[2].length == 2);
+        TEST_CHECK(shape[3].face_offset == 7);
+        TEST_CHECK(shape[3].length == 2);
+        TEST_CHECK(shape[4].face_offset == 9);
+        TEST_CHECK(shape[4].length == 1);
+        TEST_CHECK(shape[5].face_offset == 10);
+        TEST_CHECK(shape[5].length == 2);
+        TEST_CHECK(shape[6].face_offset == 12);
+        TEST_CHECK(shape[6].length == 2);
+        TEST_CHECK(shape[7].face_offset == 14);
+        TEST_CHECK(shape[7].length == 2);
+        TEST_CHECK(shape[8].face_offset == 16);
+        TEST_CHECK(shape[8].length == 2);
+    }
+}

test/tinyobj_regression_tests.h

@@ -3,5 +3,6 @@
 
 void test_tinyobj_crlf_string(void);
 void test_tinyobj_negative_exponent(void);
+void test_tinyobj_shapes_triangulation(void);
 
 #endif

test/tinyobj_tests.c

@@ -34,6 +34,7 @@ TEST_LIST = {
 
     { "crlf_string",  test_tinyobj_crlf_string },
     { "negative_exponent_issue26",  test_tinyobj_negative_exponent },
+    { "shapes_triangulation",  test_tinyobj_shapes_triangulation },
 
     { 0 } // required by acutest
 };