Implemented volumetric flow rate hints,

removed some C++11 conditioned compilation. Slic3r now requires C++11.

xs/src/libslic3r/Flow.cpp

@@ -8,39 +8,6 @@ namespace Slic3r {
 // This static method returns a sane extrusion width default.
 static inline float auto_extrusion_width(FlowRole role, float nozzle_diameter, float height)
 {
-#if 0
-    // Here we calculate a sane default by matching the flow speed (at the nozzle) and the feed rate.
-    // shape: rectangle with semicircles at the ends
-    // This "sane" extrusion width gives the following results for a 0.4mm dmr nozzle:
-    // Layer   Calculated  Calculated width 
-    // heigh   extrusion   over nozzle
-    //         width       diameter
-    // 0.40    0.40        1.00
-    // 0.35    0.43        1.09
-    // 0.30    0.48        1.21
-    // 0.25    0.56        1.39
-    // 0.20    0.67        1.68
-    // 0.15    0.87        2.17
-    // 0.10    1.28        3.20
-    // 0.05    2.52        6.31
-    //
-    float width = float(0.25 * (nozzle_diameter * nozzle_diameter) * PI / height + height * (1.0 - 0.25 * PI));
-
-    switch (role) {
-    case frExternalPerimeter:
-    case frSupportMaterial:
-    case frSupportMaterialInterface:
-        return nozzle_diameter;
-    case frPerimeter:
-    case frSolidInfill:
-    case frTopSolidInfill:
-        // do not limit width for sparse infill so that we use full native flow for it
-        return std::min(std::max(width, nozzle_diameter * 1.05f), nozzle_diameter * 1.7f);
-    case frInfill:
-    default:
-        return std::max(width, nozzle_diameter * 1.05f);
-    }
-#else
     switch (role) {
     case frSupportMaterial:
     case frSupportMaterialInterface:
@@ -53,7 +20,6 @@ static inline float auto_extrusion_width(FlowRole role, float nozzle_diameter, f
     case frInfill:
         return 1.125f * nozzle_diameter;
     }
-#endif
 }
 
 // This constructor builds a Flow object from an extrusion width config setting