Temp (#123)

* Coverage

* added fixes

* removed spacing

* removed junk

* removed print

* removed coverage

* removed useless stuff

* fix

---------

Co-authored-by: Saikari <lin@sz.cn.eu.org>

tests/general/unit_test_line_tracer_more.cpp

@@ -0,0 +1,105 @@
+#include "omath/collision/line_tracer.hpp"
+#include "omath/linear_algebra/triangle.hpp"
+#include "omath/linear_algebra/vector3.hpp"
+#include <gtest/gtest.h>
+
+using omath::Vector3;
+using omath::collision::Ray;
+using omath::collision::LineTracer;
+using Triangle3 = omath::Triangle<Vector3<float>>;
+
+TEST(LineTracerMore, ParallelRayReturnsEnd)
+{
+    // Ray parallel to triangle plane: construct triangle in XY plane and ray along X axis
+    Triangle3 tri(Vector3<float>{0.f,0.f,0.f}, Vector3<float>{1.f,0.f,0.f}, Vector3<float>{0.f,1.f,0.f});
+    Ray ray; ray.start = {0.f,0.f,1.f}; ray.end = {1.f,0.f,1.f};
+
+    auto hit = LineTracer::get_ray_hit_point(ray, tri);
+    EXPECT_EQ(hit, ray.end);
+}
+
+TEST(LineTracerMore, UOutOfRangeReturnsEnd)
+{
+    // Construct a ray that misses due to u < 0
+    Triangle3 tri(Vector3<float>{0.f,0.f,0.f}, Vector3<float>{1.f,0.f,0.f}, Vector3<float>{0.f,1.f,0.f});
+    Ray ray; ray.start = {-1.f,-1.f,-1.f}; ray.end = {-0.5f,-1.f,1.f};
+
+    auto hit = LineTracer::get_ray_hit_point(ray, tri);
+    EXPECT_EQ(hit, ray.end);
+}
+
+TEST(LineTracerMore, VOutOfRangeReturnsEnd)
+{
+    // Construct ray that has v < 0
+    Triangle3 tri(Vector3<float>{0.f,0.f,0.f}, Vector3<float>{1.f,0.f,0.f}, Vector3<float>{0.f,1.f,0.f});
+    Ray ray; ray.start = {2.f,2.f,-1.f}; ray.end = {2.f,2.f,1.f};
+
+    auto hit = LineTracer::get_ray_hit_point(ray, tri);
+    EXPECT_EQ(hit, ray.end);
+}
+
+TEST(LineTracerMore, THitTooSmallReturnsEnd)
+{
+    Triangle3 tri(Vector3<float>{0.f,0.f,0.f}, Vector3<float>{1.f,0.f,0.f}, Vector3<float>{0.f,1.f,0.f});
+    Ray ray; ray.start = {0.f,0.f,0.0000000001f}; ray.end = {0.f,0.f,1.f};
+
+    auto hit = LineTracer::get_ray_hit_point(ray, tri);
+    EXPECT_EQ(hit, ray.end);
+}
+
+TEST(LineTracerMore, THitGreaterThanOneReturnsEnd)
+{
+    Triangle3 tri(Vector3<float>{0.f,0.f,0.f}, Vector3<float>{1.f,0.f,0.f}, Vector3<float>{0.f,1.f,0.f});
+    // Choose a ray and compute t_hit locally to assert consistency
+    Ray ray; ray.start = {0.f,0.f,-1.f}; ray.end = {0.f,0.f,-0.5f};
+
+    auto hit = LineTracer::get_ray_hit_point(ray, tri);
+
+    const float k_epsilon = std::numeric_limits<float>::epsilon();
+    const auto side_a = tri.side_a_vector();
+    const auto side_b = tri.side_b_vector();
+    const auto ray_dir = ray.direction_vector();
+    const auto p = ray_dir.cross(side_b);
+    const auto det = side_a.dot(p);
+
+    if (std::abs(det) < k_epsilon)
+    {
+        EXPECT_EQ(hit, ray.end);
+        return;
+    }
+
+    const auto inv_det = 1.0f / det;
+    const auto tvec = ray.start - tri.m_vertex2;
+    const auto q = tvec.cross(side_a);
+    const auto t_hit = side_b.dot(q) * inv_det;
+
+    if (t_hit <= k_epsilon || t_hit > 1.0f)
+        EXPECT_EQ(hit, ray.end) << "t_hit=" << t_hit << " hit=" << hit.x << "," << hit.y << "," << hit.z;
+    else
+        EXPECT_NE(hit, ray.end) << "t_hit=" << t_hit << " hit=" << hit.x << "," << hit.y << "," << hit.z;
+}
+
+TEST(LineTracerMore, InfiniteLengthWithSmallTHitReturnsEnd)
+{
+    Triangle3 tri(Vector3<float>{0.f,0.f,0.f}, Vector3<float>{1.f,0.f,0.f}, Vector3<float>{0.f,1.f,0.f});
+    Triangle3 tri2(Vector3<float>{0.f,0.f,-1e-8f}, Vector3<float>{1.f,0.f,-1e-8f}, Vector3<float>{0.f,1.f,-1e-8f});
+    Ray ray; ray.start = {0.f,0.f,0.f}; ray.end = {0.f,0.f,1.f}; ray.infinite_length = true;
+    // Create triangle slightly behind so t_hit <= eps
+    tri = tri2;
+
+    auto hit = LineTracer::get_ray_hit_point(ray, tri);
+    EXPECT_EQ(hit, ray.end);
+}
+
+TEST(LineTracerMore, SuccessfulHitReturnsPoint)
+{
+    Triangle3 tri(Vector3<float>{0.f,0.f,0.f}, Vector3<float>{1.f,0.f,0.f}, Vector3<float>{0.f,1.f,0.f});
+    Ray ray; ray.start = {0.1f,0.1f,-1.f}; ray.end = {0.1f,0.1f,1.f};
+
+    auto hit = LineTracer::get_ray_hit_point(ray, tri);
+    EXPECT_NE(hit, ray.end);
+    // Hit should be on plane z=0 and near x=0.1,y=0.1
+    EXPECT_NEAR(hit.z, 0.f, 1e-6f);
+    EXPECT_NEAR(hit.x, 0.1f, 1e-3f);
+    EXPECT_NEAR(hit.y, 0.1f, 1e-3f);
+}