diff --git a/tests/general/unit_test_gjk_comprehensive.cpp b/tests/general/unit_test_gjk_comprehensive.cpp
new file mode 100644
index 0000000..46f07b8
--- /dev/null
+++ b/tests/general/unit_test_gjk_comprehensive.cpp
@@ -0,0 +1,277 @@
+//
+// Comprehensive GJK tests.
+// Covers: all 6 axis directions, diagonal cases, boundary touching,
+// asymmetric sizes, nesting, symmetry, simplex info, far separation.
+//
+#include <gtest/gtest.h>
+#include <omath/collision/gjk_algorithm.hpp>
+#include <omath/engines/source_engine/collider.hpp>
+#include <omath/engines/source_engine/mesh.hpp>
+
+using Mesh     = omath::source_engine::Mesh;
+using Collider = omath::source_engine::MeshCollider;
+using Gjk      = omath::collision::GjkAlgorithm<Collider>;
+using Vec3     = omath::Vector3<float>;
+
+namespace
+{
+    // Unit cube [-1, 1]^3 in local space.
+    const std::vector<omath::primitives::Vertex<>> k_cube_vbo = {
+        { { -1.f, -1.f, -1.f }, {}, {} },
+        { { -1.f, -1.f,  1.f }, {}, {} },
+        { { -1.f,  1.f, -1.f }, {}, {} },
+        { { -1.f,  1.f,  1.f }, {}, {} },
+        { {  1.f,  1.f,  1.f }, {}, {} },
+        { {  1.f,  1.f, -1.f }, {}, {} },
+        { {  1.f, -1.f,  1.f }, {}, {} },
+        { {  1.f, -1.f, -1.f }, {}, {} },
+    };
+    const std::vector<omath::Vector3<std::uint32_t>> k_empty_ebo{};
+
+    Collider make_cube(const Vec3& origin = {}, const Vec3& scale = { 1, 1, 1 })
+    {
+        Mesh m{ k_cube_vbo, k_empty_ebo, scale };
+        m.set_origin(origin);
+        return Collider{ m };
+    }
+} // namespace
+
+// ---------------------------------------------------------------------------
+// Separation — expect false
+// ---------------------------------------------------------------------------
+
+TEST(GjkComprehensive, Separated_AlongPosX)
+{
+    // A extends to x=1, B starts at x=1.1 → clear gap
+    EXPECT_FALSE(Gjk::is_collide(make_cube({ 0, 0, 0 }), make_cube({ 2.1f, 0, 0 })));
+}
+
+TEST(GjkComprehensive, Separated_AlongNegX)
+{
+    // B to the left of A
+    EXPECT_FALSE(Gjk::is_collide(make_cube({ 0, 0, 0 }), make_cube({ -2.1f, 0, 0 })));
+}
+
+TEST(GjkComprehensive, Separated_AlongPosY)
+{
+    EXPECT_FALSE(Gjk::is_collide(make_cube({ 0, 0, 0 }), make_cube({ 0, 2.1f, 0 })));
+}
+
+TEST(GjkComprehensive, Separated_AlongNegY)
+{
+    EXPECT_FALSE(Gjk::is_collide(make_cube({ 0, 0, 0 }), make_cube({ 0, -2.1f, 0 })));
+}
+
+TEST(GjkComprehensive, Separated_AlongPosZ)
+{
+    EXPECT_FALSE(Gjk::is_collide(make_cube({ 0, 0, 0 }), make_cube({ 0, 0, 2.1f })));
+}
+
+TEST(GjkComprehensive, Separated_AlongNegZ)
+{
+    EXPECT_FALSE(Gjk::is_collide(make_cube({ 0, 0, 0 }), make_cube({ 0, 0, -2.1f })));
+}
+
+TEST(GjkComprehensive, Separated_AlongDiagonal)
+{
+    // All components exceed 2.0 — no overlap on any axis
+    EXPECT_FALSE(Gjk::is_collide(make_cube({ 0, 0, 0 }), make_cube({ 2.1f, 2.1f, 2.1f })));
+}
+
+TEST(GjkComprehensive, Separated_LargeDistance)
+{
+    EXPECT_FALSE(Gjk::is_collide(make_cube({ 0, 0, 0 }), make_cube({ 100.f, 0, 0 })));
+}
+
+TEST(GjkComprehensive, Separated_AsymmetricSizes)
+{
+    // Big (scale 2, half-ext 2), small (scale 0.5, half-ext 0.5) at 2.6 → gap of 0.1
+    EXPECT_FALSE(Gjk::is_collide(make_cube({ 0, 0, 0 }, { 2, 2, 2 }), make_cube({ 2.6f, 0, 0 }, { 0.5f, 0.5f, 0.5f })));
+}
+
+// ---------------------------------------------------------------------------
+// Overlap — expect true
+// ---------------------------------------------------------------------------
+
+TEST(GjkComprehensive, Overlapping_AlongPosX)
+{
+    // B offset 1.5 → overlap depth 0.5 in X
+    EXPECT_TRUE(Gjk::is_collide(make_cube({ 0, 0, 0 }), make_cube({ 1.5f, 0, 0 })));
+}
+
+TEST(GjkComprehensive, Overlapping_AlongNegX)
+{
+    EXPECT_TRUE(Gjk::is_collide(make_cube({ 0, 0, 0 }), make_cube({ -1.5f, 0, 0 })));
+}
+
+TEST(GjkComprehensive, Overlapping_AlongPosZ)
+{
+    EXPECT_TRUE(Gjk::is_collide(make_cube({ 0, 0, 0 }), make_cube({ 0, 0, 1.5f })));
+}
+
+TEST(GjkComprehensive, Overlapping_AlongNegZ)
+{
+    EXPECT_TRUE(Gjk::is_collide(make_cube({ 0, 0, 0 }), make_cube({ 0, 0, -1.5f })));
+}
+
+TEST(GjkComprehensive, Overlapping_AlongDiagonalXY)
+{
+    // Minkowski sum extends ±2 on each axis; offset (1,1,0) is inside
+    EXPECT_TRUE(Gjk::is_collide(make_cube({ 0, 0, 0 }), make_cube({ 1.f, 1.f, 0.f })));
+}
+
+TEST(GjkComprehensive, Overlapping_AlongDiagonalXYZ)
+{
+    // All three axes overlap: (1,1,1) is inside the Minkowski sum
+    EXPECT_TRUE(Gjk::is_collide(make_cube({ 0, 0, 0 }), make_cube({ 1.f, 1.f, 1.f })));
+}
+
+TEST(GjkComprehensive, FullyNested_SmallInsideBig)
+{
+    // Small cube (half-ext 0.5) fully inside big cube (half-ext 2)
+    EXPECT_TRUE(Gjk::is_collide(make_cube({ 0, 0, 0 }, { 2, 2, 2 }), make_cube({ 0, 0, 0 }, { 0.5f, 0.5f, 0.5f })));
+}
+
+TEST(GjkComprehensive, FullyNested_OffCenter)
+{
+    // Small at (0.5, 0, 0) still fully inside big (half-ext 2)
+    EXPECT_TRUE(Gjk::is_collide(make_cube({ 0, 0, 0 }, { 2, 2, 2 }), make_cube({ 0.5f, 0, 0 }, { 0.5f, 0.5f, 0.5f })));
+}
+
+TEST(GjkComprehensive, Overlapping_AsymmetricSizes)
+{
+    // Big (scale 2, half-ext 2) and small (scale 0.5, half-ext 0.5) at 2.0 → overlap 0.5 in X
+    EXPECT_TRUE(Gjk::is_collide(make_cube({ 0, 0, 0 }, { 2, 2, 2 }), make_cube({ 2.0f, 0, 0 }, { 0.5f, 0.5f, 0.5f })));
+}
+
+// ---------------------------------------------------------------------------
+// Boundary cases
+// ---------------------------------------------------------------------------
+
+TEST(GjkComprehensive, BoundaryCase_JustColliding)
+{
+    // B at 1.999 — 0.001 overlap in X
+    EXPECT_TRUE(Gjk::is_collide(make_cube({ 0, 0, 0 }), make_cube({ 1.999f, 0, 0 })));
+}
+
+TEST(GjkComprehensive, BoundaryCase_JustSeparated)
+{
+    // B at 2.001 — 0.001 gap in X
+    EXPECT_FALSE(Gjk::is_collide(make_cube({ 0, 0, 0 }), make_cube({ 2.001f, 0, 0 })));
+}
+
+// ---------------------------------------------------------------------------
+// Symmetry
+// ---------------------------------------------------------------------------
+
+TEST(GjkComprehensive, Symmetry_WhenColliding)
+{
+    const auto a = make_cube({ 0, 0, 0 });
+    const auto b = make_cube({ 1.5f, 0, 0 });
+    EXPECT_EQ(Gjk::is_collide(a, b), Gjk::is_collide(b, a));
+}
+
+TEST(GjkComprehensive, Symmetry_WhenSeparated)
+{
+    const auto a = make_cube({ 0, 0, 0 });
+    const auto b = make_cube({ 2.1f, 0.5f, 0 });
+    EXPECT_EQ(Gjk::is_collide(a, b), Gjk::is_collide(b, a));
+}
+
+TEST(GjkComprehensive, Symmetry_DiagonalSeparation)
+{
+    const auto a = make_cube({ 0, 0, 0 });
+    const auto b = make_cube({ 1.5f, 1.5f, 1.5f });
+    EXPECT_EQ(Gjk::is_collide(a, b), Gjk::is_collide(b, a));
+}
+
+// ---------------------------------------------------------------------------
+// Simplex info
+// ---------------------------------------------------------------------------
+
+TEST(GjkComprehensive, SimplexInfo_HitProducesSimplex4)
+{
+    // On collision the simplex must be a full tetrahedron (4 points)
+    const auto [hit, simplex] = Gjk::is_collide_with_simplex_info(make_cube({ 0, 0, 0 }), make_cube({ 0.5f, 0, 0 }));
+    EXPECT_TRUE(hit);
+    EXPECT_EQ(simplex.size(), 4u);
+}
+
+TEST(GjkComprehensive, SimplexInfo_MissProducesLessThan4)
+{
+    // On non-collision the simplex can never be a full tetrahedron
+    const auto [hit, simplex] = Gjk::is_collide_with_simplex_info(make_cube({ 0, 0, 0 }), make_cube({ 2.1f, 0, 0 }));
+    EXPECT_FALSE(hit);
+    EXPECT_LT(simplex.size(), 4u);
+}
+
+TEST(GjkComprehensive, SimplexInfo_HitAlongY)
+{
+    const auto [hit, simplex] = Gjk::is_collide_with_simplex_info(make_cube({ 0, 0, 0 }), make_cube({ 0, 1.5f, 0 }));
+    EXPECT_TRUE(hit);
+    EXPECT_EQ(simplex.size(), 4u);
+}
+
+TEST(GjkComprehensive, SimplexInfo_HitAlongZ)
+{
+    const auto [hit, simplex] = Gjk::is_collide_with_simplex_info(make_cube({ 0, 0, 0 }), make_cube({ 0, 0, 1.5f }));
+    EXPECT_TRUE(hit);
+    EXPECT_EQ(simplex.size(), 4u);
+}
+
+TEST(GjkComprehensive, SimplexInfo_MissAlongDiagonal)
+{
+    const auto [hit, simplex] = Gjk::is_collide_with_simplex_info(make_cube({ 0, 0, 0 }), make_cube({ 2.1f, 2.1f, 2.1f }));
+    EXPECT_FALSE(hit);
+    EXPECT_LT(simplex.size(), 4u);
+}
+
+// ---------------------------------------------------------------------------
+// Non-trivial geometry — tetrahedron shaped colliders
+// ---------------------------------------------------------------------------
+
+TEST(GjkComprehensive, TetrahedronShapes_Overlapping)
+{
+    // A rough tetrahedron mesh; two of them close enough to overlap
+    const std::vector<omath::primitives::Vertex<>> tet_vbo = {
+        { {  0.f,  1.f,  0.f }, {}, {} },
+        { { -1.f, -1.f,  1.f }, {}, {} },
+        { {  1.f, -1.f,  1.f }, {}, {} },
+        { {  0.f, -1.f, -1.f }, {}, {} },
+    };
+
+    Mesh m_a{ tet_vbo, k_empty_ebo };
+    Mesh m_b{ tet_vbo, k_empty_ebo };
+    m_b.set_origin({ 0.5f, 0.f, 0.f });
+
+    EXPECT_TRUE(Gjk::is_collide(Collider{ m_a }, Collider{ m_b }));
+}
+
+TEST(GjkComprehensive, TetrahedronShapes_Separated)
+{
+    const std::vector<omath::primitives::Vertex<>> tet_vbo = {
+        { {  0.f,  1.f,  0.f }, {}, {} },
+        { { -1.f, -1.f,  1.f }, {}, {} },
+        { {  1.f, -1.f,  1.f }, {}, {} },
+        { {  0.f, -1.f, -1.f }, {}, {} },
+    };
+
+    Mesh m_a{ tet_vbo, k_empty_ebo };
+    Mesh m_b{ tet_vbo, k_empty_ebo };
+    m_b.set_origin({ 3.f, 0.f, 0.f });
+
+    EXPECT_FALSE(Gjk::is_collide(Collider{ m_a }, Collider{ m_b }));
+}
+
+// ---------------------------------------------------------------------------
+// Determinism
+// ---------------------------------------------------------------------------
+
+TEST(GjkComprehensive, Deterministic_SameResultOnRepeatedCalls)
+{
+    const auto a = make_cube({ 0, 0, 0 });
+    const auto b = make_cube({ 1.2f, 0.3f, 0.1f });
+    const bool first = Gjk::is_collide(a, b);
+    for (int i = 0; i < 10; ++i)
+        EXPECT_EQ(Gjk::is_collide(a, b), first);
+}