1 files changed, 68 insertions, 0 deletions
diff --git a/include/mbgl/style/position.hpp b/include/mbgl/style/position.hpp
new file mode 100644
index 0000000000..3be8d1c55e
--- /dev/null
+++ b/include/mbgl/style/position.hpp
@@ -0,0 +1,68 @@
+#pragma once
+
+#include <mbgl/util/constants.hpp>
+
+#include <array>
+
+namespace mbgl {
+namespace style {
+class Position {
+public:
+    Position() = default;
+    Position(std::array<float, 3>& position_)
+        : radial(position_[0]), azimuthal(position_[1]), polar(position_[2]) {
+        calculateCartesian();
+    };
+
+    friend bool operator==(const Position& lhs, const Position& rhs) {
+        return lhs.radial == rhs.radial && lhs.azimuthal == rhs.azimuthal && lhs.polar == rhs.polar;
+        // TODO this doesn't address wrapping, which would be better addressed by comparing cartesian coordinates but being calculated floats are ont to be trusted.
+    }
+
+    friend bool operator!=(const Position& lhs, const Position& rhs) {
+        return !(lhs == rhs);
+    }
+
+    const std::array<float, 3> getCartesian() const {
+        return { { x, y, z } };
+    };
+
+    const std::array<float, 3> getSpherical() const {
+        return { { radial, azimuthal, polar } };
+    };
+
+    void set(std::array<float, 3>& position_) {
+        radial = position_[0];
+        azimuthal = position_[1];
+        polar = position_[2];
+        calculateCartesian();
+    };
+
+    // Utility function to be used only during interpolation; this leaves spherical coordinates undefined.
+    void setCartesian(std::array<float, 3>& position_) {
+        x = position_[0];
+        y = position_[1];
+        z = position_[2];
+    }
+
+private:
+    float radial;
+    float azimuthal;
+    float polar;
+    float x;
+    float y;
+    float z;
+
+    void calculateCartesian() {
+        // We abstract "north"/"up" (compass-wise) to be 0° when really this is 90° (π/2): we
+        // correct for that here
+        const float _a = (azimuthal + 90) * util::DEG2RAD;
+        const float _p = polar * util::DEG2RAD;
+
+        x = radial * std::cos(_a) * std::sin(_p);
+        y = radial * std::sin(_a) * std::sin(_p);
+        z = radial * std::cos(_p);
+    };
+};
+} // namespace style
+} // namespace mbgl