fixing optimizer and concurrency::reduce

tests/libslic3r/CMakeLists.txt

@@ -17,6 +17,7 @@ add_executable(${_TEST_NAME}_tests
 	test_marchingsquares.cpp
 	test_timeutils.cpp
 	test_voronoi.cpp
+    test_optimizers.cpp
     test_png_io.cpp
     test_timeutils.cpp
 	)

tests/libslic3r/test_optimizers.cpp

@@ -0,0 +1,59 @@
+#include <catch2/catch.hpp>
+#include <test_utils.hpp>
+
+#include <libslic3r/Optimize/BruteforceOptimizer.hpp>
+
+#include <libslic3r/Optimize/NLoptOptimizer.hpp>
+
+void check_opt_result(double score, double ref, double abs_err, double rel_err)
+{
+    double abs_diff = std::abs(score - ref);
+    double rel_diff = std::abs(abs_diff / std::abs(ref));
+
+    bool abs_reached = abs_diff < abs_err;
+    bool rel_reached = rel_diff < rel_err;
+    bool precision_reached = abs_reached || rel_reached;
+    REQUIRE(precision_reached);
+}
+
+template<class Opt> void test_sin(Opt &&opt)
+{
+    using namespace Slic3r::opt;
+
+    auto optfunc = [](const auto &in) {
+        auto [phi] = in;
+
+        return std::sin(phi);
+    };
+
+    auto init = initvals({PI});
+    auto optbounds = bounds({ {0., 2 * PI}});
+
+    Result result_min = opt.to_min().optimize(optfunc, init, optbounds);
+    Result result_max = opt.to_max().optimize(optfunc, init, optbounds);
+
+    check_opt_result(result_min.score, -1., 1e-2, 1e-4);
+    check_opt_result(result_max.score,  1., 1e-2, 1e-4);
+}
+
+template<class Opt> void test_sphere_func(Opt &&opt)
+{
+    using namespace Slic3r::opt;
+
+    Result result = opt.to_min().optimize([](const auto &in) {
+        auto [x, y] = in;
+
+        return x * x + y * y + 1.;
+    }, initvals({.6, -0.2}), bounds({{-1., 1.}, {-1., 1.}}));
+
+    check_opt_result(result.score, 1., 1e-2, 1e-4);
+}
+
+TEST_CASE("Test brute force optimzer for basic 1D and 2D functions", "[Opt]") {
+    using namespace Slic3r::opt;
+
+    Optimizer<AlgBruteForce> opt;
+
+    test_sin(opt);
+    test_sphere_func(opt);
+}