1 files changed, 77 insertions, 0 deletions
diff --git a/include/mbgl/geometry/geometry.hpp b/include/mbgl/geometry/geometry.hpp
new file mode 100644
index 0000000000..47981ce83b
--- /dev/null
+++ b/include/mbgl/geometry/geometry.hpp
@@ -0,0 +1,77 @@
+#ifndef MBGL_GEOMETRY_GEOMETRY
+#define MBGL_GEOMETRY_GEOMETRY
+
+#include <mbgl/util/pbf.hpp>
+#include <mbgl/util/noncopyable.hpp>
+
+#include <cstdlib>
+
+namespace mbgl {
+
+class Geometry : private util::noncopyable {
+
+public:
+    inline explicit Geometry(pbf& data);
+  
+    enum command : uint8_t {
+        end = 0,
+        move_to = 1,
+        line_to = 2,
+        close = 7
+    };
+
+    inline command next(int32_t &rx, int32_t &ry);
+
+private:
+    pbf& data;
+    uint8_t cmd;
+    uint32_t length;
+    int32_t x, y;
+    int32_t ox, oy;
+};
+
+Geometry::Geometry(pbf& data)
+    : data(data),
+      cmd(1),
+      length(0),
+      x(0), y(0),
+      ox(0), oy(0) {}
+
+Geometry::command Geometry::next(int32_t &rx, int32_t &ry) {
+    if (data.data < data.end) {
+        if (length == 0) {
+            uint32_t cmd_length = static_cast<uint32_t>(data.varint());
+            cmd = cmd_length & 0x7;
+            length = cmd_length >> 3;
+        }
+
+        --length;
+
+        if (cmd == move_to || cmd == line_to) {
+            rx = (x += data.svarint());
+            ry = (y += data.svarint());
+
+            if (cmd == move_to) {
+                ox = x;
+                oy = y;
+                return move_to;
+            } else {
+                return line_to;
+            }
+        } else if (cmd == close) {
+            rx = ox;
+            ry = oy;
+            return close;
+        } else {
+            fprintf(stderr, "unknown command: %d\n", cmd);
+            // TODO: gracefully handle geometry parse failures
+            return end;
+        }
+    } else {
+        return end;
+    }
+}
+
+}
+
+#endif