added triangle to lua

tests/lua/triangle_tests.lua

@@ -0,0 +1,82 @@
+local function approx(a, b, eps) return math.abs(a - b) < (eps or 1e-5) end
+
+function Triangle_Constructor_default()
+    local t = omath.Triangle.new()
+    assert(t.vertex1.x == 0 and t.vertex1.y == 0 and t.vertex1.z == 0)
+    assert(t.vertex2.x == 0 and t.vertex2.y == 0 and t.vertex2.z == 0)
+    assert(t.vertex3.x == 0 and t.vertex3.y == 0 and t.vertex3.z == 0)
+end
+
+function Triangle_Constructor_vertices()
+    local v1 = omath.Vec3.new(1, 0, 0)
+    local v2 = omath.Vec3.new(0, 1, 0)
+    local v3 = omath.Vec3.new(0, 0, 1)
+    local t = omath.Triangle.new(v1, v2, v3)
+    assert(t.vertex1.x == 1 and t.vertex1.y == 0 and t.vertex1.z == 0)
+    assert(t.vertex2.x == 0 and t.vertex2.y == 1 and t.vertex2.z == 0)
+    assert(t.vertex3.x == 0 and t.vertex3.y == 0 and t.vertex3.z == 1)
+end
+
+function Triangle_Vertex_mutation()
+    local t = omath.Triangle.new()
+    t.vertex1 = omath.Vec3.new(5, 6, 7)
+    assert(t.vertex1.x == 5 and t.vertex1.y == 6 and t.vertex1.z == 7)
+end
+
+-- Right triangle: v1=(0,3,0), v2=(0,0,0), v3=(4,0,0) — sides 3, 4, hypot 5
+function Triangle_SideALength()
+    local t = omath.Triangle.new(omath.Vec3.new(0, 3, 0), omath.Vec3.new(0, 0, 0), omath.Vec3.new(4, 0, 0))
+    assert(approx(t:side_a_length(), 3.0))
+end
+
+function Triangle_SideBLength()
+    local t = omath.Triangle.new(omath.Vec3.new(0, 3, 0), omath.Vec3.new(0, 0, 0), omath.Vec3.new(4, 0, 0))
+    assert(approx(t:side_b_length(), 4.0))
+end
+
+function Triangle_Hypot()
+    local t = omath.Triangle.new(omath.Vec3.new(0, 3, 0), omath.Vec3.new(0, 0, 0), omath.Vec3.new(4, 0, 0))
+    assert(approx(t:hypot(), 5.0))
+end
+
+function Triangle_SideAVector()
+    local t = omath.Triangle.new(omath.Vec3.new(0, 3, 0), omath.Vec3.new(0, 0, 0), omath.Vec3.new(4, 0, 0))
+    local a = t:side_a_vector()
+    assert(approx(a.x, 0) and approx(a.y, 3) and approx(a.z, 0))
+end
+
+function Triangle_SideBVector()
+    local t = omath.Triangle.new(omath.Vec3.new(0, 3, 0), omath.Vec3.new(0, 0, 0), omath.Vec3.new(4, 0, 0))
+    local b = t:side_b_vector()
+    assert(approx(b.x, 4) and approx(b.y, 0) and approx(b.z, 0))
+end
+
+function Triangle_IsRectangular_true()
+    local t = omath.Triangle.new(omath.Vec3.new(0, 3, 0), omath.Vec3.new(0, 0, 0), omath.Vec3.new(4, 0, 0))
+    assert(t:is_rectangular() == true)
+end
+
+function Triangle_IsRectangular_false()
+    -- equilateral-ish triangle, not rectangular
+    local t = omath.Triangle.new(omath.Vec3.new(0, 1, 0), omath.Vec3.new(-1, 0, 0), omath.Vec3.new(1, 0, 0))
+    assert(t:is_rectangular() == false)
+end
+
+function Triangle_MidPoint()
+    local t = omath.Triangle.new(omath.Vec3.new(3, 0, 0), omath.Vec3.new(0, 3, 0), omath.Vec3.new(0, 0, 3))
+    local m = t:mid_point()
+    assert(approx(m.x, 1.0) and approx(m.y, 1.0) and approx(m.z, 1.0))
+end
+
+function Triangle_CalculateNormal()
+    -- flat triangle in XY plane — normal should be (0, 0, 1)
+    local t = omath.Triangle.new(omath.Vec3.new(0, 1, 0), omath.Vec3.new(0, 0, 0), omath.Vec3.new(1, 0, 0))
+    local n = t:calculate_normal()
+    assert(approx(n.x, 0) and approx(n.y, 0) and approx(n.z, 1))
+end
+
+function Triangle_ToString()
+    local t = omath.Triangle.new(omath.Vec3.new(1, 0, 0), omath.Vec3.new(0, 1, 0), omath.Vec3.new(0, 0, 1))
+    local s = tostring(t)
+    assert(s == "Triangle((1, 0, 0), (0, 1, 0), (0, 0, 1))")
+end

tests/lua/unit_test_lua_triangle.cpp

@@ -0,0 +1,47 @@
+//
+// Created by orange on 10.03.2026.
+//
+#include <gtest/gtest.h>
+#include <lua.hpp>
+#include <omath/lua/lua.hpp>
+
+class LuaTriangle : public ::testing::Test
+{
+protected:
+    lua_State* L = nullptr;
+
+    void SetUp() override
+    {
+        L = luaL_newstate();
+        luaL_openlibs(L);
+        omath::lua::LuaInterpreter::register_lib(L);
+        if (luaL_dofile(L, LUA_SCRIPTS_DIR "/triangle_tests.lua") != LUA_OK)
+            FAIL() << lua_tostring(L, -1);
+    }
+
+    void TearDown() override { lua_close(L); }
+
+    void check(const char* func_name)
+    {
+        lua_getglobal(L, func_name);
+        if (lua_pcall(L, 0, 0, 0) != LUA_OK)
+        {
+            FAIL() << lua_tostring(L, -1);
+            lua_pop(L, 1);
+        }
+    }
+};
+
+TEST_F(LuaTriangle, Constructor_default)    { check("Triangle_Constructor_default"); }
+TEST_F(LuaTriangle, Constructor_vertices)   { check("Triangle_Constructor_vertices"); }
+TEST_F(LuaTriangle, Vertex_mutation)        { check("Triangle_Vertex_mutation"); }
+TEST_F(LuaTriangle, SideALength)            { check("Triangle_SideALength"); }
+TEST_F(LuaTriangle, SideBLength)            { check("Triangle_SideBLength"); }
+TEST_F(LuaTriangle, Hypot)                  { check("Triangle_Hypot"); }
+TEST_F(LuaTriangle, SideAVector)            { check("Triangle_SideAVector"); }
+TEST_F(LuaTriangle, SideBVector)            { check("Triangle_SideBVector"); }
+TEST_F(LuaTriangle, IsRectangular_true)     { check("Triangle_IsRectangular_true"); }
+TEST_F(LuaTriangle, IsRectangular_false)    { check("Triangle_IsRectangular_false"); }
+TEST_F(LuaTriangle, MidPoint)               { check("Triangle_MidPoint"); }
+TEST_F(LuaTriangle, CalculateNormal)        { check("Triangle_CalculateNormal"); }
+TEST_F(LuaTriangle, ToString)               { check("Triangle_ToString"); }