introduce intersectable interface

openVulkanoCpp/Scene/SimpleDrawable.cpp

@@ -5,6 +5,9 @@
  */
 
 #include "SimpleDrawable.hpp"
+#include "Scene/Geometry.hpp"
+#include "Scene/Shader/Shader.hpp"
+#include "Base/Logger.hpp"
 #include <stdexcept>
 
 namespace OpenVulkano::Scene
@@ -26,4 +29,61 @@ namespace OpenVulkano::Scene
 		m_uniBuffer = drawable->m_uniBuffer;
 		SetShader(drawable->GetShader());
 	}
+
+	std::optional<RayHit> SimpleDrawable::Intersect(const Ray& ray) const
+	{
+		if (!m_mesh || !GetShader())
+		{
+			return {};
+		}
+		if (m_mesh->aabb.IsEmpty())
+		{
+			m_mesh->CalculateAABB();
+		}
+		if (ray.IntersectAABB(m_mesh->aabb))
+		{
+			if (GetShader()->topology == Topology::TRIANGLE_LIST)
+			{
+				if (m_mesh->indexCount != 0)
+				{
+					for (int i = 0; i < m_mesh->indexCount / 3; i++)
+					{
+						if (m_mesh->indexType == VertexIndexType::UINT16)
+						{
+							uint16_t* indices = m_mesh->GetIndices16();
+							if (auto hit = ray.IntersectTriangle(m_mesh->vertices[indices[i * 3]].position,
+								m_mesh->vertices[indices[i * 3 + 1]].position,
+								m_mesh->vertices[indices[i * 3 + 2]].position))
+							{
+								return hit;
+							}
+						}
+						else
+						{
+							uint32_t* indices = m_mesh->GetIndices32();
+							if (auto hit = ray.IntersectTriangle(m_mesh->vertices[indices[i * 3]].position,
+							                                     m_mesh->vertices[indices[i * 3 + 1]].position,
+							                                     m_mesh->vertices[indices[i * 3 + 2]].position))
+							{
+								return hit;
+							}
+						}
+					}
+				}
+				else
+				{
+					for (int i = 0; i < m_mesh->vertexCount / 3; i++)
+					{
+						if (auto hit = ray.IntersectTriangle(m_mesh->vertices[i * 3].position,
+						                                     m_mesh->vertices[i * 3 + 1].position,
+						                                     m_mesh->vertices[i * 3 + 2].position))
+						{
+							return hit;
+						}
+					}
+				}
+			}
+		}
+		return {};
+	}
 }