Obb calculation with debug draw

include/nbl/asset/utils/COBBGenerator.h

@@ -0,0 +1,25 @@
+
+// Copyright (C) 2018-2023 - DevSH Graphics Programming Sp. z O.O.
+// This file is part of the "Nabla Engine".
+// For conditions of distribution and use, see copyright notice in nabla.h
+
+#ifndef _NBL_ASSET_C_OBB_GENERATOR_H_INCLUDED_
+#define _NBL_ASSET_C_OBB_GENERATOR_H_INCLUDED_
+
+#include "nbl/asset/utils/CPolygonGeometryManipulator.h"
+#include "nbl/builtin/hlsl/shapes/obb.hlsl"
+
+namespace nbl::asset
+{
+  class COBBGenerator
+  {
+    public:
+
+      using VertexCollection = CPolygonGeometryManipulator::VertexCollection;
+
+      static hlsl::shapes::OBB<> compute(const VertexCollection& vertices);
+
+  };
+}
+
+#endif

include/nbl/asset/utils/CPolygonGeometryManipulator.h

@@ -10,6 +10,7 @@
 #include "nbl/asset/ICPUPolygonGeometry.h"
 #include "nbl/asset/utils/CGeometryManipulator.h"
 #include "nbl/asset/utils/CSmoothNormalGenerator.h"
+#include "nbl/builtin/hlsl/shapes/obb.hlsl"
 
 namespace nbl::asset
 {
@@ -231,6 +232,26 @@ class NBL_API2 CPolygonGeometryManipulator
 			EEM_COUNT
 		};
 
+		struct VertexCollection
+		{
+			using FetchFn = std::function<hlsl::float32_t3(size_t vertexIndex)>;
+			FetchFn fetch;
+			size_t size;
+
+			static auto fromSpan(std::span<const hlsl::float32_t3> vertices) -> VertexCollection
+			{
+				return VertexCollection{
+					.fetch = [data = vertices.data()](size_t vertexIndex)-> hlsl::float32_t3
+					{
+						return data[vertexIndex];
+					},
+					.size = vertices.size()
+				};
+			}
+
+			hlsl::float32_t3 operator[](size_t index) const { return fetch(index); }
+		};
+    static hlsl::shapes::OBB<3, hlsl::float32_t> calculateOBB(const VertexCollection& vertexCollection);
 		static core::smart_refctd_ptr<ICPUPolygonGeometry> createUnweldedList(const ICPUPolygonGeometry* inGeo);
 
 		using SSNGVertexData = CSmoothNormalGenerator::VertexData;

include/nbl/builtin/hlsl/shapes/aabb.hlsl

@@ -60,6 +60,7 @@ struct AABB
     point_t maxVx;
 };
 
+
 namespace util
 {
 namespace impl

include/nbl/builtin/hlsl/shapes/obb.hlsl

@@ -0,0 +1,42 @@
+// Copyright (C) 2018-2023 - DevSH Graphics Programming Sp. z O.O.
+// This file is part of the "Nabla Engine".
+// For conditions of distribution and use, see copyright notice in nabla.h
+#ifndef _NBL_BUILTIN_HLSL_SHAPES_OBB_INCLUDED_
+#define _NBL_BUILTIN_HLSL_SHAPES_OBB_INCLUDED_
+
+namespace nbl
+{
+namespace hlsl
+{
+namespace shapes
+{
+
+template<int16_t D=3, typename Scalar=float32_t>
+struct OBB
+{
+	using scalar_t = Scalar;
+	using point_t = vector<Scalar,D>;
+
+	static OBB createAxisAligned(point_t mid, point_t len)
+	{
+		OBB ret;
+		ret.mid = mid;
+		ret.ext = len * 0.5f;
+		for (auto dim_i = 0; dim_i < D; dim_i++)
+		{
+			ret.axes[dim_i] = point_t(0);
+			ret.axes[dim_i][dim_i] = 1;
+		}
+		return ret;
+	}
+
+	point_t mid;
+	std::array<point_t, D> axes;
+	point_t ext;
+};
+
+}
+}
+}
+
+#endif

include/nbl/ext/DebugDraw/CDrawAABB.h

@@ -208,6 +208,8 @@ namespace nbl::ext::debug_draw
             return transform;
         }
 
+        static hlsl::float32_t3x4 getTransformFromOBB(const hlsl::shapes::OBB<3, float>& aabb);
+
     protected:
         struct ConstructorParams
         {

src/nbl/CMakeLists.txt

@@ -186,6 +186,7 @@ set(NBL_ASSET_SOURCES
 # Meshes
 	asset/utils/CForsythVertexCacheOptimizer.cpp
 	asset/utils/CSmoothNormalGenerator.cpp
+	asset/utils/COBBGenerator.cpp
 	asset/utils/CGeometryCreator.cpp
 	asset/utils/CPolygonGeometryManipulator.cpp
 	asset/utils/COverdrawPolygonGeometryOptimizer.cpp