ENH: add new way to set bed temperature

jira:NONE

Signed-off-by: xun.zhang <xun.zhang@bambulab.com>
Change-Id: I99a9f67e9b13b2137ad371b22cf0999ccf9c096d
(cherry picked from commit 69c2947daf66eb0a6732b1b980c9b87f597c8da7)

src/libslic3r/PrintConfig.hpp

@@ -95,6 +95,12 @@ enum class WallInfillOrder {
     Count,
 };
 
+enum class BedTempFormula {
+    btfFirstFilament,
+    btfHighestTemp,
+    count,
+};
+
 // BBS
 enum class WallSequence {
     InnerOuter,
@@ -1235,6 +1241,7 @@ PRINT_CONFIG_CLASS_DEFINE(
     ((ConfigOptionIntsGroups,          unprintable_filament_map))
     //((ConfigOptionInts,                filament_extruder_id))
     ((ConfigOptionStrings,             filament_extruder_variant))
+    ((ConfigOptionEnum<BedTempFormula>, bed_temperature_formula))
     ((ConfigOptionInts,                physical_extruder_map))
     // BBS
     ((ConfigOptionBool,                scan_first_layer))