Merge pull request #139 from orange-cpp/feature/mesh_line_tracer

Feature/mesh line tracer

Author: orange-cpp

include/omath/3d_primitives/mesh.hpp

@@ -101,7 +101,6 @@ namespace omath::primitives
 
         [[nodiscard]]
         VectorType vertex_position_to_world_space(const Vector3<float>& vertex_position) const
-        requires HasPosition<VertexType>
         {
             auto abs_vec = get_to_world_matrix()
                            * mat_column_from_vector<typename Mat4X4::ContainedType, Mat4X4::get_store_ordering()>(
@@ -112,11 +111,16 @@ namespace omath::primitives
 
         [[nodiscard]]
         Triangle<VectorType> make_face_in_world_space(const Ebo::const_iterator vao_iterator) const
-        requires HasPosition<VertexType>
         {
-            return {vertex_position_to_world_space(m_vertex_buffer.at(vao_iterator->x).position),
-                    vertex_position_to_world_space(m_vertex_buffer.at(vao_iterator->y).position),
-                    vertex_position_to_world_space(m_vertex_buffer.at(vao_iterator->z).position)};
+            if constexpr (HasPosition<VertexType>)
+            {
+                return {vertex_position_to_world_space(m_vertex_buffer.at(vao_iterator->x).position),
+                        vertex_position_to_world_space(m_vertex_buffer.at(vao_iterator->y).position),
+                        vertex_position_to_world_space(m_vertex_buffer.at(vao_iterator->z).position)};
+            }
+            return {vertex_position_to_world_space(m_vertex_buffer.at(vao_iterator->x)),
+                    vertex_position_to_world_space(m_vertex_buffer.at(vao_iterator->y)),
+                    vertex_position_to_world_space(m_vertex_buffer.at(vao_iterator->z))};
         }
 
     private:

include/omath/collision/line_tracer.hpp

@@ -33,5 +33,25 @@ namespace omath::collision
         // https://en.wikipedia.org/wiki/M%C3%B6ller%E2%80%93Trumbore_intersection_algorithm
         [[nodiscard]]
         static Vector3<float> get_ray_hit_point(const Ray& ray, const Triangle<Vector3<float>>& triangle) noexcept;
+
+        template<class MeshType>
+        [[nodiscard]]
+        static Vector3<float> get_ray_hit_point(const Ray& ray, const MeshType& mesh) noexcept
+        {
+            Vector3<float> mesh_hit = ray.end;
+
+            auto begin = mesh.m_element_buffer_object.cbegin();
+            auto end = mesh.m_element_buffer_object.cend();
+            for (auto current = begin; current < end; current = std::next(current))
+            {
+                auto face = mesh.make_face_in_world_space(current);
+
+                auto ray_stop_point = get_ray_hit_point(ray, face);
+                if (ray_stop_point.distance_to(ray.start) < mesh_hit.distance_to(ray.start))
+                    mesh_hit = ray_stop_point;
+            }
+
+            return mesh_hit;
+        }
     };
 } // namespace omath::collision

tests/general/unit_test_primitive_box.cpp

@@ -2,11 +2,15 @@
 // Created by Vladislav on 11.01.2026.
 //
 #include "omath/3d_primitives/box.hpp"
+#include "omath/collision/line_tracer.hpp"
 #include "omath/engines/opengl_engine/primitives.hpp"
 #include <gtest/gtest.h>
 
 TEST(test, test)
 {
-    auto result = omath::primitives::create_box<omath::opengl_engine::BoxMesh>({0.f, 30.f, 0.f}, {}, omath::opengl_engine::k_abs_forward,
-                                                omath::opengl_engine::k_abs_right);
+    auto result = omath::primitives::create_box<omath::opengl_engine::BoxMesh>(
+            {0.f, 30.f, 0.f}, {}, omath::opengl_engine::k_abs_forward, omath::opengl_engine::k_abs_right);
+
+    omath::collision::Ray ray{.start = {0, 0, 0}, .end = {-100, 0, 0}};
+    std::ignore = omath::collision::LineTracer::get_ray_hit_point(ray, result);
 }

tests/main.cpp

@@ -1,6 +1,7 @@
 #include <gtest/gtest.h>
 
-int main(int argc, char** argv) {
+int main(int argc, char** argv)
+{
     testing::InitGoogleTest(&argc, argv);
 
     return RUN_ALL_TESTS();