[core] move BackendScope to gfx namespace

1 files changed, 38 insertions, 0 deletions

diff --git a/include/mbgl/gfx/backend_scope.hpp b/include/mbgl/gfx/backend_scope.hpp
new file mode 100644
index 0000000000..b92334ae0f
--- /dev/null
+++ b/include/mbgl/gfx/backend_scope.hpp
@@ -0,0 +1,38 @@
+#pragma once
+
+namespace mbgl {
+
+class RendererBackend;
+
+namespace gfx {
+
+class BackendScope {
+public:
+    // There are two types of scopes: Creating an "Implicit" scope tells Mapbox GL that the
+    // supporting windowing system has already activated the GL Backend and that no further actions
+    // are required. Creating an "Explicit" scope actually enables the GL Backend, and disables it
+    // when the BackendScope is destroyed.
+    enum class ScopeType : bool {
+        Implicit,
+        Explicit,
+    };
+
+    BackendScope(RendererBackend&, ScopeType = ScopeType::Explicit);
+    ~BackendScope();
+
+    // Returns true when there is currently a BackendScope active in this thread.
+    static bool exists();
+
+private:
+    void activate();
+    void deactivate();
+
+    BackendScope* priorScope;
+    BackendScope* nextScope;
+    RendererBackend& backend;
+    const ScopeType scopeType;
+    bool activated = false;
+};
+
+} // namespace gfx
+} // namespace mbgl