Test for correct vertex indices

source/Irrlicht/CGLTFMeshFileLoader.cpp

@@ -18,12 +18,6 @@
 #include <memory>
 #include <string>
 
-namespace irr
-{
-
-namespace scene
-{
-
 class BufferOffset
 {
 public:
@@ -50,20 +44,77 @@ private:
 	std::size_t m_offset;
 };
 
-static float readFloat(const BufferOffset& readFrom) {
-	unsigned char d[4]{};
-	for (int i = 0; i < 4; ++i) {
+namespace irr
+{
+
+namespace scene
+{
+
+static bool tryParseGLTF(io::IReadFile* file, tinygltf::Model& model)
+{
+	tinygltf::TinyGLTF loader {};
+	std::string err {};
+	std::string warn {};
+
+	auto buf = std::make_unique<char[]>(file->getSize());
+	file->read(buf.get(), file->getSize());
+	return loader.LoadASCIIFromString(
+		&model, &err, &warn, buf.get(), file->getSize(), "", 1);
+}
+
+template <class T>
+static T readPrimative(const BufferOffset& readFrom) {
+	unsigned char d[sizeof(T)]{};
+	for (std::size_t i = 0; i < sizeof(T); ++i) {
 		d[i] = readFrom.at(i);
 	}
-	return *reinterpret_cast<float*>(d);
+	return *reinterpret_cast<T*>(d);
 }
 
 static core::vector3df readVector(const BufferOffset& readFrom) {
 	// glTF coordinates are right-handed, minetest ones are left-handed
+	// 1 glTF coordinate is equivalent to 10 Irrlicht coordinates
 	return core::vector3df(
-		-readFloat(readFrom),
-		readFloat(BufferOffset(readFrom, sizeof(float))),
-		readFloat(BufferOffset(readFrom, 2 * sizeof(float))));
+		-1.0 * readPrimative<float>(readFrom),
+		1.0 * readPrimative<float>(BufferOffset(readFrom, sizeof(float))),
+		1.0 * readPrimative<float>(BufferOffset(readFrom, 2 * sizeof(float))));
+}
+
+static u16* readIndices(const BufferOffset& readFrom, const std::size_t count)
+{
+	auto* indices = new u16[count]{};
+	for (std::size_t i = 0; i < count; ++i) {
+		indices[i] = readPrimative<u16>(BufferOffset(readFrom, i * sizeof(u16)));
+	}
+	return indices;
+}
+
+video::S3DVertex* getVertices(const tinygltf::Model& model, const std::size_t accessorId)
+{
+	const auto& view = model.bufferViews[
+		model.accessors[accessorId].bufferView];
+	const auto& buffer = model.buffers[view.buffer];
+	const auto v1 = readVector(BufferOffset(
+		buffer.data, view.byteOffset));
+	const auto v2 = readVector(BufferOffset(
+		buffer.data, view.byteOffset + (3 * sizeof(float))));
+	const auto v3 = readVector(BufferOffset(
+		buffer.data, view.byteOffset + (6 * sizeof(float))));
+
+	return (new video::S3DVertex[3] {
+		{v1, {0.0f, 0.0f, 1.0f}, {}, {0.0f, 0.0f}},
+		{v2, {0.0f, 0.0f, 1.0f}, {}, {1.0f, 0.0f}},
+		{v3, {0.0f, 0.0f, 1.0f}, {}, {0.0f, 1.0f}} } );
+}
+
+u16* getIndices(const tinygltf::Model& model, const std::size_t accessorId)
+{
+	const auto& indicesView = model.bufferViews[
+		model.accessors[accessorId].bufferView];
+	const auto& indicesBuffer = model.buffers[indicesView.buffer];
+	return readIndices(
+		BufferOffset(indicesBuffer.data, indicesView.byteOffset),
+		model.accessors[0].count);
 }
 
 CGLTFMeshFileLoader::CGLTFMeshFileLoader()
@@ -84,24 +135,13 @@ IAnimatedMesh* CGLTFMeshFileLoader::createMesh(io::IReadFile* file)
 		return nullptr;
 	}
 
-	const auto& view = model.bufferViews[model.accessors[1].bufferView];
-	const auto& buffer = model.buffers[view.buffer];
-	const auto v1 = readVector(BufferOffset(
-		buffer.data, view.byteOffset));
-	const auto v2 = readVector(BufferOffset(
-		buffer.data, view.byteOffset + (3 * sizeof(float))));
-	const auto v3 = readVector(BufferOffset(
-		buffer.data, view.byteOffset + (6 * sizeof(float))));
+	auto* indices = getIndices(model, 0);
+	auto* vertices = getVertices(model, 1);
 
-	// sorry Bjarne
 	SMeshBuffer* meshbuf { new SMeshBuffer {} };
 
-	const video::S3DVertex* vertices { new video::S3DVertex[3] {
-		{v1, {0.0f, 0.0f, 1.0f}, {}, {0.0f, 0.0f}},
-		{v2, {0.0f, 0.0f, 1.0f}, {}, {1.0f, 0.0f}},
-		{v3, {0.0f, 0.0f, 1.0f}, {}, {0.0f, 1.0f}} } };
-	const u16* indices { new u16[3] {0, 2, 1} };
-	meshbuf->append(vertices, 3, indices, 3);
+	meshbuf->append(vertices, model.accessors[1].count,
+		indices, model.accessors[0].count);
 
 	SMesh* mesh { new SMesh {} };
 	mesh->addMeshBuffer(meshbuf);
@@ -112,20 +152,7 @@ IAnimatedMesh* CGLTFMeshFileLoader::createMesh(io::IReadFile* file)
 	return animatedMesh;
 }
 
-bool CGLTFMeshFileLoader::tryParseGLTF(io::IReadFile* file,
-		tinygltf::Model& model) const
-{
-	tinygltf::TinyGLTF loader {};
-	std::string err {};
-	std::string warn {};
-
-	auto buf = std::make_unique<char[]>(file->getSize());
-	file->read(buf.get(), file->getSize());
-	return loader.LoadASCIIFromString(
-		&model, &err, &warn, buf.get(), file->getSize(), "", 1);
-}
+} // namespace scene
 
 } // namespace irr
 
-} // namespace scene
-

source/Irrlicht/tests/testCGLTFMeshFileLoader.cpp

@@ -45,19 +45,30 @@ TEST_CASE("load empty gltf file") {
 	CHECK(sm.getMesh() == nullptr);
 }
 
-TEST_CASE("minimal triangle has correct vertices") {
+TEST_CASE("minimal triangle") {
 	ScopedMesh sm { "source/Irrlicht/tests/assets/minimal_triangle.gltf" };
 
 	auto* mesh = sm.getMesh();
 	REQUIRE(mesh != nullptr);
 	REQUIRE(mesh->getMeshBufferCount() == 1);
 	auto* meshbuf = mesh->getMeshBuffer(0);
-	REQUIRE(meshbuf->getVertexCount() == 3);
-	auto* vertices = reinterpret_cast<irr::video::S3DVertex*>(
-		meshbuf->getVertices());
-	CHECK(vertices[0].Pos == irr::core::vector3df {0.0f, 0.0f, 0.0f});
-	CHECK(vertices[1].Pos == irr::core::vector3df {-1.0f, 0.0f, 0.0f});
-	CHECK(vertices[2].Pos == irr::core::vector3df {0.0f, 1.0f, 0.0f});
+
+	SECTION("vertex coordinates are correct") {
+		REQUIRE(meshbuf->getVertexCount() == 3);
+		auto* vertices = reinterpret_cast<irr::video::S3DVertex*>(
+			meshbuf->getVertices());
+		CHECK(vertices[0].Pos == irr::core::vector3df {0.0f, 0.0f, 0.0f});
+		CHECK(vertices[1].Pos == irr::core::vector3df {-1.0f, 0.0f, 0.0f});
+		CHECK(vertices[2].Pos == irr::core::vector3df {0.0f, 1.0f, 0.0f});
+	}
+
+	SECTION("vertex indices are correct") {
+		REQUIRE(meshbuf->getIndexCount() == 3);
+		auto* indices = reinterpret_cast<irr::u16*>(meshbuf->getIndices());
+		CHECK(indices[0] == 0);
+		CHECK(indices[1] == 1);
+		CHECK(indices[2] == 2);
+	}
 }
 
 TEST_CASE("mesh loader returns nullptr when given null file pointer") {