[macos,ios] don't roundtrip through encodePNG when converting images

1 files changed, 12 insertions, 0 deletions

diff --git a/platform/darwin/mbgl/util/image+MGLAdditions.hpp b/platform/darwin/mbgl/util/image+MGLAdditions.hpp
new file mode 100644
index 0000000000..c738b4523d
--- /dev/null
+++ b/platform/darwin/mbgl/util/image+MGLAdditions.hpp
@@ -0,0 +1,12 @@
+#pragma once
+
+#include <mbgl/util/image.hpp>
+
+#include <CoreGraphics/CGImage.h>
+
+// Creates a CGImage from a PremultipliedImage, taking over the memory ownership.
+CGImageRef CGImageFromMGLPremultipliedImage(mbgl::PremultipliedImage&&);
+
+// Creates a PremultipliedImage by copying the pixels of the CGImage.
+// Does not alter the retain count of the supplied CGImage.
+mbgl::PremultipliedImage MGLPremultipliedImageFromCGImage(CGImageRef);