Wrap Rgb in landmark for swig

Author: Fabien Servant

src/aliceVision/sfmData/Landmark.i

@@ -8,6 +8,41 @@
 %eigen_typemaps(Vec3)
 
 %include <aliceVision/sfmData/Observation.i>
+
+// We don't want to have a direct access to rgb
+// It's easier to wrap it around a Vec3
+// As it's already binded to numpy
+%ignore aliceVision::sfmData::Landmark::rgb;
+
+//Add new swig only C++ code
+%extend aliceVision::sfmData::Landmark {
+
+    // From RgbColor to Vec3
+    Vec3 getRgb() const {
+        Vec3 ret;
+
+        ret.x() = $self->rgb.r();
+        ret.y() = $self->rgb.g();
+        ret.z() = $self->rgb.b();
+
+        return ret;
+    }
+    
+    // From Vec3 to RgbColor
+    void setRgb(Vec3 value) {
+        $self->rgb.r() = value.x();
+        $self->rgb.g() = value.y();
+        $self->rgb.b() = value.z();
+    }
+    
+    // If the user asks for the rgb property
+    // It is not a direct access to the rgb
+    // variable but a getter/setter
+    %pythoncode %{
+        rgb = property(getRgb, setRgb)
+    %}
+}
+
 %include <aliceVision/sfmData/Landmark.hpp>
 
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