fix document naming and file dialogs preset, add touch scroll, flip thumbnail, scroll gesture and wheel for sidebar

engine/image.cpp

@@ -22,3 +22,18 @@ bool Image::load(std::string filename)
     m_data = std::unique_ptr<uint8_t[]>(buffer);
     return true;
 }
+
+void Image::flip()
+{
+    auto flipped = std::make_unique<uint8_t[]>(width*height*4);
+    int line_size = width * 4;
+    const uint8_t* src = m_data.get();
+    uint8_t* dst = flipped.get() + line_size * (height - 1);
+    for (int y = 0; y < height; y++)
+    {
+        std::copy(src, src+line_size, dst);
+        src += line_size;
+        dst -= line_size;
+    }
+    std::swap(m_data, flipped);
+}