add more constexpr math and tests

1 files changed, 105 insertions, 0 deletions

diff --git a/test/math.cpp b/test/math.cpp
new file mode 100644
index 00000000..d70a64fb
--- /dev/null
+++ b/test/math.cpp
@@ -0,0 +1,105 @@
+#include "app.hpp"
+#include "compat/math.hpp"
+
+namespace floormat {
+
+namespace {
+
+constexpr bool test_double_sqrt()
+{
+    using F = double;
+    constexpr auto eps = F(1e-11);
+
+    static_assert(math::abs(math::sqrt((F)3)    - (F)1.73205080757) < eps);
+    return true;
+}
+
+template<typename F>
+bool test_sqrt()
+{
+    constexpr auto eps = F(1e-11);
+    constexpr auto test = [](double x)
+    {
+        auto x_ = (F)x;
+        auto y1 = math::sqrt(x_);
+        auto y2 = std::sqrt(x_);
+        return math::abs(y1 - y2) < eps;
+    };
+
+    static_assert(math::abs(math::sqrt((F)0)    - (F)0) < eps);
+    static_assert(math::abs(math::sqrt((F)0.5)  - (F)0.70710678118) < eps);
+    static_assert(math::abs(math::sqrt((F)1e-8) - (F)0.0001)        < eps);
+    static_assert(math::abs(math::sqrt((F)2)    - (F)1.41421356237) < eps);
+    static_assert(math::abs(math::sqrt((F)3)    - (F)1.73205080757) < (F)1e-6);
+
+    static_assert(math::sqrt((F)0)  == (F)0);
+    static_assert(math::sqrt((F)1)  == (F)1);
+    static_assert(math::sqrt((F)4)  == (F)2);
+    static_assert(math::sqrt((F)9)  == (F)3);
+    static_assert(math::sqrt((F)36) == (F)6);
+
+    fm_assert(test(0));
+    fm_assert(test(0.5));
+    fm_assert(test(1.5));
+    fm_assert(test(2));
+    fm_assert(test(3));
+    fm_assert(test(0));
+    fm_assert(test(42));
+    fm_assert(test(41.5));
+    fm_assert(test(1e-8));
+    fm_assert(test(1e8));
+    fm_assert(test(1.23456789));
+    fm_assert(test(1e10 + 1.23456789));
+    fm_assert(test(531610));
+    fm_assert(test(1e10));
+    fm_assert(test(1 << 20));
+
+    return true;
+}
+
+template<typename F>
+constexpr bool test_floor()
+{
+    fm_assert(math::floor((F)-1.5) == -2);
+    fm_assert(math::floor((F)0) == 0);
+    fm_assert(math::floor((F)1) == 1);
+    fm_assert(math::floor((F)-1) == -1);
+    fm_assert(math::floor((F)-2) == -2);
+    fm_assert(math::floor((F)1.0000001) == 1);
+    fm_assert(math::floor((F)-1.000001) == -2);
+    fm_assert(math::floor((F)1e-8) == 0);
+    fm_assert(math::floor((F)-1e-8) == -1);
+
+    return true;
+}
+
+template<typename F>
+constexpr bool test_ceil()
+{
+    fm_assert(math::ceil((F)-1.5) == -1);
+    fm_assert(math::ceil((F)0) == 0);
+    fm_assert(math::ceil((F)1) == 1);
+    fm_assert(math::ceil((F)-1) == -1);
+    fm_assert(math::ceil((F)-2) == -2);
+    fm_assert(math::ceil((F)1.0000001) == 2);
+    fm_assert(math::ceil((F)-1.000001) == -1);
+    fm_assert(math::ceil((F)1e-8) == 1);
+    fm_assert(math::ceil((F)-1e-8) == 0);
+
+    return true;
+}
+
+} // namespace
+
+void test_app::test_math()
+{
+    static_assert(test_double_sqrt());
+    fm_assert(test_sqrt<float>());
+    fm_assert(test_sqrt<double>());
+    static_assert(test_floor<float>());
+    static_assert(test_floor<double>());
+    static_assert(test_ceil<float>());
+    static_assert(test_ceil<double>());
+}
+
+} // namespace floormat