[core] C++ port of TinySDF

1 files changed, 20 insertions, 0 deletions

diff --git a/src/mbgl/util/tiny_sdf.hpp b/src/mbgl/util/tiny_sdf.hpp
new file mode 100644
index 0000000000..33c9280cbd
--- /dev/null
+++ b/src/mbgl/util/tiny_sdf.hpp
@@ -0,0 +1,20 @@
+#pragma once
+
+#include <mbgl/util/image.hpp>
+
+namespace mbgl {
+namespace util {
+
+/*
+    C++ port of https://github.com/mapbox/tiny-sdf, which is in turn based on the
+    Felzenszwalb/Huttenlocher distance transform paper (https://cs.brown.edu/~pff/papers/dt-final.pdf).
+    Note there exists an alternative C++ implementation from the paper’s authors at
+    https://cs.brown.edu/~pff/dt/, which this implementation is not based on.
+ 
+    Takes an alpha channel raster input and transforms it into an alpha channel
+    Signed Distance Field (SDF) output of the same dimensions.
+*/
+AlphaImage transformRasterToSDF(const AlphaImage& rasterInput, double radius, double cutoff);
+
+} // namespace util
+} // namespace mbgl