refactor: add minimal material gpu binding

tests/Resources/Material/test_material.cpp

@@ -225,6 +225,75 @@ TEST(Material, SetTextureReplacesExistingBinding) {
     EXPECT_EQ(material.GetTexture("uDiffuse").Get(), secondTexture);
 }
 
+TEST(Material, ChangeVersionIncrementsWhenMaterialMutates) {
+    Material material;
+    const XCEngine::Core::uint64 initialVersion = material.GetChangeVersion();
+
+    material.SetFloat("uTime", 1.0f);
+    const XCEngine::Core::uint64 afterFloatVersion = material.GetChangeVersion();
+    EXPECT_GT(afterFloatVersion, initialVersion);
+
+    material.SetTexture("uDiffuse", ResourceHandle<Texture>(new Texture()));
+    EXPECT_GT(material.GetChangeVersion(), afterFloatVersion);
+}
+
+TEST(Material, UpdateConstantBufferPacksNumericPropertiesIntoStableSlots) {
+    Material material;
+    material.SetFloat("alpha", 3.5f);
+    material.SetFloat4("beta", Vector4(1.0f, 2.0f, 3.0f, 4.0f));
+    material.SetInt("gamma", 7);
+
+    const auto& constantBufferData = material.GetConstantBufferData();
+    ASSERT_EQ(constantBufferData.Size(), 48u);
+
+    const float* alphaSlot = reinterpret_cast<const float*>(constantBufferData.Data());
+    EXPECT_FLOAT_EQ(alphaSlot[0], 3.5f);
+    EXPECT_FLOAT_EQ(alphaSlot[1], 0.0f);
+    EXPECT_FLOAT_EQ(alphaSlot[2], 0.0f);
+    EXPECT_FLOAT_EQ(alphaSlot[3], 0.0f);
+
+    const float* betaSlot = reinterpret_cast<const float*>(constantBufferData.Data() + 16);
+    EXPECT_FLOAT_EQ(betaSlot[0], 1.0f);
+    EXPECT_FLOAT_EQ(betaSlot[1], 2.0f);
+    EXPECT_FLOAT_EQ(betaSlot[2], 3.0f);
+    EXPECT_FLOAT_EQ(betaSlot[3], 4.0f);
+
+    const XCEngine::Core::int32* gammaSlot =
+        reinterpret_cast<const XCEngine::Core::int32*>(constantBufferData.Data() + 32);
+    EXPECT_EQ(gammaSlot[0], 7);
+    EXPECT_EQ(gammaSlot[1], 0);
+    EXPECT_EQ(gammaSlot[2], 0);
+    EXPECT_EQ(gammaSlot[3], 0);
+}
+
+TEST(Material, RemoveTexturePropertyAlsoRemovesTextureBinding) {
+    Material material;
+    Texture* texture = new Texture();
+
+    material.SetTexture("uDiffuse", ResourceHandle<Texture>(texture));
+    ASSERT_EQ(material.GetTextureBindingCount(), 1u);
+
+    material.RemoveProperty("uDiffuse");
+
+    EXPECT_FALSE(material.HasProperty("uDiffuse"));
+    EXPECT_EQ(material.GetTextureBindingCount(), 0u);
+    EXPECT_EQ(material.GetTexture("uDiffuse").Get(), nullptr);
+}
+
+TEST(Material, ReplacingTexturePropertyWithScalarRemovesTextureBinding) {
+    Material material;
+    Texture* texture = new Texture();
+
+    material.SetTexture("uMain", ResourceHandle<Texture>(texture));
+    ASSERT_EQ(material.GetTextureBindingCount(), 1u);
+
+    material.SetFloat("uMain", 2.0f);
+
+    EXPECT_EQ(material.GetTextureBindingCount(), 0u);
+    EXPECT_EQ(material.GetTexture("uMain").Get(), nullptr);
+    EXPECT_FLOAT_EQ(material.GetFloat("uMain"), 2.0f);
+}
+
 TEST(Material, HasProperty) {
     Material material;