NEW: add calibration

Change-Id: I03e5489a67042e7f76f5a42260a289d540b5a63a
(cherry picked from commit cbac2c639db830eb779b1979c8d6b4eb3decb7e6)

src/libslic3r/Calib.hpp

@@ -0,0 +1,26 @@
+#pragma once
+
+#include <string>
+#include "Point.hpp"
+namespace Slic3r {
+
+class GCode;
+
+enum class CalibMode : int {
+    Calib_None = 0,
+    Calib_PA_Line,
+    Calib_PA_Tower,
+    Calib_Flow_Rate,
+    Calib_Temp_Tower,
+    Calib_Vol_speed_Tower,
+    Calib_VFA_Tower
+
+};
+struct Calib_Params
+{
+    Calib_Params() : mode(CalibMode::Calib_None){}
+    double start, end, step;
+    bool print_numbers;
+    CalibMode mode;
+};
+} // namespace Slic3r