Add snapToInt() method to Rect

Resolves: #528

Author: adazem009

include/scratchcpp/rect.h

@@ -32,6 +32,8 @@ class LIBSCRATCHCPP_EXPORT Rect
         double width() const;
         double height() const;
 
+        void snapToInt();
+
         bool intersects(const Rect &rect) const;
 
     private:

src/rect.cpp

@@ -78,6 +78,16 @@ double Rect::height() const
     return std::abs(impl->top - impl->bottom);
 }
 
+/*! Push out the rectangle to integer bounds. */
+void Rect::snapToInt()
+{
+    // https://github.com/scratchfoundation/scratch-render/blob/c3ede9c3d54769730c7b023021511e2aba167b1f/src/Rectangle.js#L136-L141
+    impl->left = std::floor(impl->left);
+    impl->right = std::ceil(impl->right);
+    impl->bottom = std::floor(impl->bottom);
+    impl->top = std::ceil(impl->top);
+}
+
 /*! Returns true if the rectangle intersects the given rectangle. */
 bool Rect::intersects(const Rect &rect) const
 {

test/rect/rect_test.cpp

@@ -78,6 +78,27 @@ TEST(RectTest, Height)
     ASSERT_EQ(rect.height(), 35.272);
 }
 
+TEST(RectTest, SnapToInt)
+{
+    {
+        Rect rect(20.5, 12.5, 22.5, 8.5);
+        rect.snapToInt();
+        ASSERT_EQ(rect.left(), 20);
+        ASSERT_EQ(rect.top(), 13);
+        ASSERT_EQ(rect.right(), 23);
+        ASSERT_EQ(rect.bottom(), 8);
+    }
+
+    {
+        Rect rect(20.5, 12.2, 22.3, 8.5);
+        rect.snapToInt();
+        ASSERT_EQ(rect.left(), 20);
+        ASSERT_EQ(rect.top(), 13);
+        ASSERT_EQ(rect.right(), 23);
+        ASSERT_EQ(rect.bottom(), 8);
+    }
+}
+
 TEST(RectTest, Intersects)
 {
     Rect rect1(-50, 25, 150, -75);