exporting gltf with lines

Author: malytomas

sources/libcore/mesh/exportGltf.cpp

@@ -17,8 +17,8 @@ namespace cage
 		Holder<PointerRange<char>> exportImpl(const String &filename, const MeshExportGltfConfig &config)
 		{
 			CAGE_ASSERT(config.mesh);
-			if (config.mesh->type() != MeshTypeEnum::Triangles)
-				CAGE_THROW_ERROR(Exception, "exporting gltf requires triangle mesh");
+			if (config.mesh->type() != MeshTypeEnum::Triangles && config.mesh->type() != MeshTypeEnum::Lines)
+				CAGE_THROW_ERROR(Exception, "exporting gltf requires triangle or line mesh");
 			if (config.mesh->verticesCount() > 0 && config.mesh->indicesCount() == 0)
 				CAGE_THROW_ERROR(Exception, "exporting gltf requires indexed mesh");
 
@@ -289,7 +289,8 @@ namespace cage
 				if (!textures.empty())
 					tiJson = std::string() + ", \"textures\":[" + texturesJson + "],\"images\":[" + imagesJson + "]";
 
-				json = std::string() + "{\"scene\":0,\"scenes\":[{\"nodes\":[0]}],\"nodes\":[{\"mesh\":0,\"name\":\"" + config.name.c_str() + "\"}],\"meshes\":[{\"primitives\":[{\"attributes\":{" + attributesJson + "},\"indices\":" + (Stringizer() + indicesIndex).value.c_str() + ",\"material\":0}],\"name\":\"" + config.name.c_str() + "\"}],\"materials\":[{" + materialJson + "}]" + tiJson + ",\"buffers\":[{\"byteLength\":" + (Stringizer() + buffer.size()).value.c_str() + "}],\"bufferViews\":[" + viewsJson + "],\"accessors\":[" + accessorsJson + "],\"asset\":{\"version\":\"2.0\"}}";
+				const uint32 primitiveMode = (config.mesh->type() == MeshTypeEnum::Lines) ? 1 : 4; // 1=LINES, 4=TRIANGLES
+				json = std::string() + "{\"scene\":0,\"scenes\":[{\"nodes\":[0]}],\"nodes\":[{\"mesh\":0,\"name\":\"" + config.name.c_str() + "\"}],\"meshes\":[{\"primitives\":[{\"attributes\":{" + attributesJson + "},\"indices\":" + (Stringizer() + indicesIndex).value.c_str() + ",\"material\":0,\"mode\":" + (Stringizer() + primitiveMode).value.c_str() + "}],\"name\":\"" + config.name.c_str() + "\"}],\"materials\":[{" + materialJson + "}]" + tiJson + ",\"buffers\":[{\"byteLength\":" + (Stringizer() + buffer.size()).value.c_str() + "}],\"bufferViews\":[" + viewsJson + "],\"accessors\":[" + accessorsJson + "],\"asset\":{\"version\":\"2.0\"}}";
 
 				while ((json.length() % 4) != 0)
 					json += ' ';

sources/test-core/mesh.cpp

@@ -951,6 +951,23 @@ namespace
 		approxEqual(msh->boundingBox(), Aabb(Vec3(-1, -1, -2), Vec3(1, 1, 2)));
 		meshApplyTransform(+msh, Mat4(Mat3(10, 0, 0, 0, 0, 10, 0, -10, 0)));
 		approxEqual(msh->boundingBox(), Aabb(Vec3(-10, -20, -10), Vec3(10, 20, 10)));
+
+		{
+			CAGE_TESTCASE("export gltf");
+			MeshExportGltfConfig cfg;
+			cfg.mesh = +msh;
+			meshExportFiles("meshes/exports/lines.glb", cfg);
+		}
+
+		{
+			CAGE_TESTCASE("import gltf");
+			const auto imp = meshImportFiles("meshes/exports/lines.glb");
+			CAGE_TEST(imp.parts.size() == 1);
+			CAGE_TEST(imp.parts[0].mesh->type() == MeshTypeEnum::Lines);
+			approxEqual(imp.parts[0].mesh->boundingBox(), Aabb(Vec3(-10, -20, -10), Vec3(10, 20, 10)));
+			CAGE_TEST(imp.parts[0].mesh->verticesCount() == msh->verticesCount());
+			CAGE_TEST(imp.parts[0].mesh->indicesCount() == msh->indicesCount());
+		}
 	}
 
 	void testMeshConsistentWinding()