add some kind of test for texture1D creation

#470

tests/src/test_lookup_table.cpp

@@ -20,19 +20,24 @@
 // limitations under the License.
 //------------------------------------------------------------------------------
 
+#include "catch/catch.hpp"
+
 #include "phx/resources/types/lookup_table.hpp"
 #include "phx/resources/types/transfer_function.hpp"
 
-#include "catch/catch.hpp"
+#include "trompeloeil.hpp"
+
+#include "mocks/opengl_mock.hpp"
 
 SCENARIO("Creating and accesing a Lookup Table", "[phx][phx::LookupTable]") {
+  OPENGL_MOCK_ALLOW_ANY_CALL
   GIVEN("A test transfer function") {
     phx::TransferFunction transfer_function;
     glm::vec4 red_color{1.0f, 0.0f, 0.0f, 0.0f};
     glm::vec4 black_color{0.0f, 0.0f, 0.0f, 0.0f};
     transfer_function.SetEntries({{0.0f, red_color}, {1.0f, black_color}});
 
-    WHEN("We create Lookup Table from the given Transfer function") {
+    WHEN("We create Lookup Table with the given Transfer function") {
       phx::LookupTable lut(transfer_function, 11);
 
       THEN("The Lookup Table is generated correctly") {
@@ -48,6 +53,11 @@ SCENARIO("Creating and accesing a Lookup Table", "[phx][phx::LookupTable]") {
         REQUIRE(lut.GetIndex(1.0f) == 10);
         REQUIRE(lut.GetIndex(0.56f) == 6);
       }
+
+      THEN("We can ask for a lookup table as texture1D") {
+        REQUIRE_CALL(open_gl_mock, glCreateTextures(_, _, _));
+        auto lookup_texture = lut.GetTexture1D();
+      }
     }
 
     WHEN("We ask for a nearest neighbor interpolated Lookup Table") {