implement export/import ppbr

src/brush.cpp

@@ -373,6 +373,30 @@ bool Brush::valid()
     return true;
 }
 
+void Brush::relocate_paths(std::string base)
+{
+    if (!Asset::is_asset(m_brush_path))
+        m_brush_path = replace_path(m_brush_path, base + "/brushes/");
+    if (!Asset::is_asset(m_dual_path))
+        m_dual_path = replace_path(m_dual_path, base + "/brushes/");
+    if (!Asset::is_asset(m_pattern_path))
+        m_pattern_path = replace_path(m_pattern_path, base + "/patterns/");
+}
+
+std::string Brush::replace_path(std::string path, std::string new_base)
+{
+    if (path.empty())
+        return path;
+    std::regex r(R"((.*)[\\/]([^\\/]+)\.(\w+)$)");
+    std::smatch m;
+    if (!std::regex_search(path, m, r))
+        return path;
+    std::string base = m[1].str();
+    std::string name = m[2].str();
+    std::string ext = m[3].str();
+    return new_base + "/" + name + "." + ext;
+}
+
 bool Brush::read(BinaryStreamReader& r)
 {
     Serializer::Descriptor d;