MathLib: added CheckBox2DBox2DOverlap function

2 files changed, 96 insertions, 0 deletions

diff --git a/Common/interface/AdvancedMath.hpp b/Common/interface/AdvancedMath.hpp
index 8d1119e5..11af8e34 100644
--- a/Common/interface/AdvancedMath.hpp
+++ b/Common/interface/AdvancedMath.hpp
@@ -935,6 +935,38 @@ void RasterizeTriangle(Vector2<T> V0,
     }
 }
 
+
+/// Checks if two 2D-boxes overlap.
+
+/// \tparam [in] AllowTouch - Whether to consider two boxes overlapping if
+///                           they only touch at their boundaries or corners.
+/// \tparam [in] T          - Component type.
+///
+/// \param [in]  Box0Min - Min corner of the first box.
+/// \param [in]  Box0Max - Max corner of the first box.
+/// \param [in]  Box1Min - Min corner of the second box.
+/// \param [in]  Box1Max - Max corner of the second box.
+///
+/// \return     true if the bounding boxes overlap, and false otherwise.
+template <bool AllowTouch, typename T>
+bool CheckBox2DBox2DOverlap(const Vector2<T>& Box0Min,
+                            const Vector2<T>& Box0Max,
+                            const Vector2<T>& Box1Min,
+                            const Vector2<T>& Box1Max)
+{
+    VERIFY_EXPR(Box0Max.x >= Box0Min.x && Box0Max.y >= Box0Min.y &&
+                Box1Max.x >= Box1Min.x && Box1Max.y >= Box1Min.y);
+    if (AllowTouch)
+    {
+        return !(Box0Min.x > Box1Max.x || Box1Min.x > Box0Max.x || Box0Min.y > Box1Max.y || Box1Min.y > Box0Max.y);
+    }
+    else
+    {
+        return !(Box0Min.x >= Box1Max.x || Box1Min.x >= Box0Max.x || Box0Min.y >= Box1Max.y || Box1Min.y >= Box0Max.y);
+    }
+}
+
+
 } // namespace Diligent
 
 namespace std
diff --git a/Tests/DiligentCoreTest/src/Common/MathLibTest.cpp b/Tests/DiligentCoreTest/src/Common/MathLibTest.cpp
index 9c3d620f..3723f52a 100644
--- a/Tests/DiligentCoreTest/src/Common/MathLibTest.cpp
+++ b/Tests/DiligentCoreTest/src/Common/MathLibTest.cpp
@@ -1962,4 +1962,68 @@ TEST(Common_AdvancedMath, TransformBoundBox)
     }
 }
 
+TEST(Common_AdvancedMath, CheckBox2DBox2DOverlap)
+{
+    // clang-format off
+    // Self-intersection
+    EXPECT_TRUE(CheckBox2DBox2DOverlap<true> (uint2(0, 0), uint2(1, 1), uint2(0, 0), uint2(1, 1)));
+    EXPECT_TRUE(CheckBox2DBox2DOverlap<false>(uint2(0, 0), uint2(1, 1), uint2(0, 0), uint2(1, 1)));
+
+    // One box fully inside another
+    EXPECT_TRUE(CheckBox2DBox2DOverlap<true> (uint2(0, 0), uint2(10, 10), uint2(1, 1), uint2( 2,  2)));
+    EXPECT_TRUE(CheckBox2DBox2DOverlap<true> (uint2(1, 1), uint2( 2,  2), uint2(0, 0), uint2(10, 10)));
+    EXPECT_TRUE(CheckBox2DBox2DOverlap<false>(uint2(0, 0), uint2(10, 10), uint2(1, 1), uint2( 2,  2)));
+    EXPECT_TRUE(CheckBox2DBox2DOverlap<false>(uint2(1, 1), uint2( 2, 2 ), uint2(0, 0), uint2(10, 10)));
+
+    // Touching corners
+    EXPECT_TRUE (CheckBox2DBox2DOverlap<true> (int2(0, 0), int2(10, 10), int2(-1, -1), int2( 0,  0)));
+    EXPECT_FALSE(CheckBox2DBox2DOverlap<false>(int2(0, 0), int2(10, 10), int2(-1, -1), int2( 0,  0)));
+    EXPECT_TRUE (CheckBox2DBox2DOverlap<true> (int2(0, 0), int2(10, 10), int2(-1, 10), int2( 0, 11)));
+    EXPECT_FALSE(CheckBox2DBox2DOverlap<false>(int2(0, 0), int2(10, 10), int2(-1, 10), int2( 0, 11)));
+    EXPECT_TRUE (CheckBox2DBox2DOverlap<true> (int2(0, 0), int2(10, 10), int2(10, 10), int2(11, 11)));
+    EXPECT_FALSE(CheckBox2DBox2DOverlap<false>(int2(0, 0), int2(10, 10), int2(10, 10), int2(11, 11)));
+    EXPECT_TRUE (CheckBox2DBox2DOverlap<true> (int2(0, 0), int2(10, 10), int2(10, -1), int2(11,  0)));
+    EXPECT_FALSE(CheckBox2DBox2DOverlap<false>(int2(0, 0), int2(10, 10), int2(10, -1), int2(11,  0)));
+
+    // Intersections
+    EXPECT_TRUE(CheckBox2DBox2DOverlap<true> (float2(0, 0), float2(10, 10), float2(-1, -1), float2( 1,  1)));
+    EXPECT_TRUE(CheckBox2DBox2DOverlap<false>(float2(0, 0), float2(10, 10), float2(-1, -1), float2( 1,  1)));
+    EXPECT_TRUE(CheckBox2DBox2DOverlap<true> (float2(0, 0), float2(10, 10), float2(-1,  9), float2( 1, 11)));
+    EXPECT_TRUE(CheckBox2DBox2DOverlap<false>(float2(0, 0), float2(10, 10), float2(-1,  9), float2( 1, 11)));
+    EXPECT_TRUE(CheckBox2DBox2DOverlap<true> (float2(0, 0), float2(10, 10), float2( 9,  9), float2(11, 11)));
+    EXPECT_TRUE(CheckBox2DBox2DOverlap<false>(float2(0, 0), float2(10, 10), float2( 9,  9), float2(11, 11)));
+    EXPECT_TRUE(CheckBox2DBox2DOverlap<true> (float2(0, 0), float2(10, 10), float2( 9, -1), float2(11,  1)));
+    EXPECT_TRUE(CheckBox2DBox2DOverlap<false>(float2(0, 0), float2(10, 10), float2( 9, -1), float2(11,  1)));
+
+    // No intersections
+    EXPECT_FALSE(CheckBox2DBox2DOverlap<true> (float2(0, 0), float2(10, 10), float2(-2, -2), float2(-1, -1)));
+    EXPECT_FALSE(CheckBox2DBox2DOverlap<false>(float2(0, 0), float2(10, 10), float2(-2, -2), float2(-1, -1)));
+    EXPECT_FALSE(CheckBox2DBox2DOverlap<true> (float2(0, 0), float2(10, 10), float2(-2,  5), float2(-1,  6)));
+    EXPECT_FALSE(CheckBox2DBox2DOverlap<false>(float2(0, 0), float2(10, 10), float2(-2,  5), float2(-1,  6)));
+    EXPECT_FALSE(CheckBox2DBox2DOverlap<true> (float2(0, 0), float2(10, 10), float2(-2, 11), float2(-1, 12)));
+    EXPECT_FALSE(CheckBox2DBox2DOverlap<false>(float2(0, 0), float2(10, 10), float2(-2, 11), float2(-1, 12)));
+    EXPECT_FALSE(CheckBox2DBox2DOverlap<true> (float2(0, 0), float2(10, 10), float2( 5, 11), float2( 6, 12)));
+    EXPECT_FALSE(CheckBox2DBox2DOverlap<false>(float2(0, 0), float2(10, 10), float2( 5, 11), float2( 6, 12)));
+    EXPECT_FALSE(CheckBox2DBox2DOverlap<true> (float2(0, 0), float2(10, 10), float2(11, 11), float2(12, 12)));
+    EXPECT_FALSE(CheckBox2DBox2DOverlap<false>(float2(0, 0), float2(10, 10), float2(11, 11), float2(12, 12)));
+    EXPECT_FALSE(CheckBox2DBox2DOverlap<true> (float2(0, 0), float2(10, 10), float2(11,  5), float2(12,  6)));
+    EXPECT_FALSE(CheckBox2DBox2DOverlap<false>(float2(0, 0), float2(10, 10), float2(11,  5), float2(12,  6)));
+    EXPECT_FALSE(CheckBox2DBox2DOverlap<true> (float2(0, 0), float2(10, 10), float2(11, -2), float2(12, -1)));
+    EXPECT_FALSE(CheckBox2DBox2DOverlap<false>(float2(0, 0), float2(10, 10), float2(11, -2), float2(12, -1)));
+    EXPECT_FALSE(CheckBox2DBox2DOverlap<true> (float2(0, 0), float2(10, 10), float2( 5, -2), float2( 6, -1)));
+    EXPECT_FALSE(CheckBox2DBox2DOverlap<false>(float2(0, 0), float2(10, 10), float2( 5, -2), float2( 6, -1)));
+
+    // Touching boundaries
+    EXPECT_TRUE (CheckBox2DBox2DOverlap<true> (double2(0, 0), double2(10, 10), double2(-2,  5), double2( 0,  6)));
+    EXPECT_FALSE(CheckBox2DBox2DOverlap<false>(double2(0, 0), double2(10, 10), double2(-2,  5), double2( 0,  6)));
+    EXPECT_TRUE (CheckBox2DBox2DOverlap<true> (double2(0, 0), double2(10, 10), double2( 5, 10), double2( 6, 12)));
+    EXPECT_FALSE(CheckBox2DBox2DOverlap<false>(double2(0, 0), double2(10, 10), double2( 5, 10), double2( 6, 12)));
+    EXPECT_TRUE (CheckBox2DBox2DOverlap<true> (double2(0, 0), double2(10, 10), double2(10,  5), double2(12,  6)));
+    EXPECT_FALSE(CheckBox2DBox2DOverlap<false>(double2(0, 0), double2(10, 10), double2(10,  5), double2(12,  6)));
+    EXPECT_TRUE (CheckBox2DBox2DOverlap<true> (double2(0, 0), double2(10, 10), double2( 5, -2), double2( 6,  0)));
+    EXPECT_FALSE(CheckBox2DBox2DOverlap<false>(double2(0, 0), double2(10, 10), double2( 5, -2), double2( 6,  0)));
+
+    // clang-format on
+}
+
 } // namespace