2 files changed, 12 insertions, 2 deletions

diff --git a/minui/include/minui/minui.h b/minui/include/minui/minui.h
index d6881e9a0..0b499e621 100644
--- a/minui/include/minui/minui.h
+++ b/minui/include/minui/minui.h
@@ -40,6 +40,9 @@ class GRSurface {
   static std::unique_ptr<GRSurface> Create(int width, int height, int row_bytes, int pixel_bytes,
                                            size_t data_size);
 
+  // Clones the current GRSurface instance (i.e. an image).
+  std::unique_ptr<GRSurface> Clone() const;
+
   virtual uint8_t* data() {
     return data_;
   }
@@ -59,6 +62,7 @@ class GRSurface {
 
  private:
   uint8_t* data_{ nullptr };
+  size_t data_size_;
 
   DISALLOW_COPY_AND_ASSIGN(GRSurface);
 };
diff --git a/minui/resources.cpp b/minui/resources.cpp
index 9c9af0242..9027bc668 100644
--- a/minui/resources.cpp
+++ b/minui/resources.cpp
@@ -44,13 +44,19 @@ std::unique_ptr<GRSurface> GRSurface::Create(int width, int height, int row_byte
   static constexpr size_t kSurfaceDataAlignment = 8;
   // Cannot use std::make_unique to access non-public ctor.
   auto result = std::unique_ptr<GRSurface>(new GRSurface(width, height, row_bytes, pixel_bytes));
-  size_t aligned_size =
+  result->data_size_ =
       (data_size + kSurfaceDataAlignment - 1) / kSurfaceDataAlignment * kSurfaceDataAlignment;
-  result->data_ = static_cast<uint8_t*>(aligned_alloc(kSurfaceDataAlignment, aligned_size));
+  result->data_ = static_cast<uint8_t*>(aligned_alloc(kSurfaceDataAlignment, result->data_size_));
   if (result->data_ == nullptr) return nullptr;
   return result;
 }
 
+std::unique_ptr<GRSurface> GRSurface::Clone() const {
+  auto result = GRSurface::Create(width, height, row_bytes, pixel_bytes, data_size_);
+  memcpy(result->data_, data_, data_size_);
+  return result;
+}
+
 GRSurface::~GRSurface() {
   if (data_ != nullptr) {
     free(data_);