Gmt module: Rewrite modgmt_func in more template way.

modules/gmt/modgmt.cpp

@@ -28,14 +28,14 @@ int gmt_module_init(void* p)
  RegisterFunction("GET",Get<ObjectGMTPen>);
  RegisterFunction("GET",Get<ObjectGMTLayer>);
 
- RegisterFunction("Coord",GMT_Coord);
- RegisterFunction("Region",GMT_Region);
- RegisterFunction("Projection",GMT_Projection);
- RegisterFunction("Color",GMT_Color);
+ RegisterFunction("Coord",GMT_Type<struct gmt_coord>);
+ RegisterFunction("Region",GMT_Type<struct gmt_region>);
+ RegisterFunction("Projection",GMT_Type<struct gmt_projection>);
+ RegisterFunction("Color",GMT_Type<struct gmt_color>);
  RegisterFunction("ColorGray",GMT_ColorGray);
  RegisterFunction("ColorRGB",GMT_ColorRGB);
  RegisterFunction("ColorHSV",GMT_ColorHSV);
  RegisterFunction("ColorCMYK",GMT_ColorCMYK);
- RegisterFunction("Pen",GMT_Pen);
+ RegisterFunction("Pen",GMT_Type<struct gmt_pen>);
  return 0;
 }

modules/gmt/modgmt_objects.cpp

@@ -49,3 +49,5 @@ void gmt_projection::FillProjNames()
 }
 
 const double gmt_projection::default_width=10.0;
+const double gmt_pen::default_width=1.0;
+const double gmt_dash::default_width=gmt_pen::default_width;

modules/gmt/modgmt_objects.h

@@ -3,6 +3,7 @@
 #include <cmath>
 #include <map>
 #include <string.h>
+#include <type_traits>
 #include <vector>
 #include "common.h"
 #include "modgmt_structs.h"
@@ -19,6 +20,7 @@ inline static double cm2GMT(double cm)
 template<class GMTStruct>
 class ObjectGMTClass: public ObjectBase
 {
+ static_assert(std::is_base_of<gmt_struct,GMTStruct>::value,"Template parameter of ObjectGMTClass must be gmt_struct-derived type");
  const static std::string type;
  GMTStruct s;
  public:

modules/gmt/modgmt_structs.h

@@ -6,8 +6,39 @@
 #include "common.h"
 #include "modgmt_colornames.h"
 
-// Helper classes for conversion of doubles from strings with varios checks
+// Helper template for checking double numbers acquired from Source with some Policies.
+// Main definition, never instantiated
+template<class Source, class... Policies>
+class GetDouble;
+
+// Recursive definition
+template<class Source, class Policy, class... Policies>
+class GetDouble<Source, Policy, Policies...>: public GetDouble<Source, Policies...>
+{
+ Policy p;
+ public:
+ GetDouble(GetDouble&&) = delete;
+ GetDouble(GetDouble&) = delete;
+ template<class... Args>
+ GetDouble(Args... args):GetDouble<Source,Policies...>(args...) {};
+ double operator()(bool* suc) const {return p(GetDouble<Source,Policies...>::operator()(suc),suc);}
+};
+
+// Bottom of recursion
+template<class Source>
+class GetDouble<Source>: public Source
+{
+ public:
+ GetDouble(GetDouble&&) = delete;
+ GetDouble(GetDouble&) = delete;
+ GetDouble() = delete;
+ template<class... Args>
+ GetDouble(Args... args):Source(args...) {};
+ double operator()(bool* suc) const {return Source::operator()(suc);}
+};
+
 // We use rational representation of floating point number, because double type values not allowed as template parameter
+// Policy to check if value is greater or equal num/denum
 template<int32_t num, uint32_t denum=1>
 class PMin
 {
@@ -15,6 +46,7 @@ class PMin
  double operator()(double v, bool* suc) const {if(v<static_cast<double>(num)/denum) *suc=false; return v;}
 };
 
+// Policy to check if value is lesser or equal num/denum
 template<int32_t num, uint32_t denum=1>
 class PMax
 {
@@ -22,13 +54,14 @@ class PMax
  double operator()(double v, bool* suc) const {if(v>static_cast<double>(num)/denum) *suc=false; return v;}
 };
 
-class PFromValue
+// Get double value from string or number
+class SourceValue
 {
  double d;
  bool ok;
  public:
- PFromValue(const std::string& s) {ok=str2double(s,&d);}
- PFromValue(double s):d(s),ok(true) {}
+ SourceValue(const std::string& s) {ok=str2double(s,&d);}
+ SourceValue(double s):d(s),ok(true) {}
  double operator()(bool* suc) const
  {
   if(!ok) *suc=false;
@@ -36,39 +69,19 @@ class PFromValue
  }
 };
 
-// Main definition, never instantiated
-template<class... Policies>
-class GetDouble;
-
-// Recursive definition
-template<class Policy, class... Policies>
-class GetDouble<Policy, Policies...>: public GetDouble<Policies...>
-{
- Policy p;
- public:
- GetDouble(GetDouble&&) = delete;
- GetDouble(GetDouble&) = delete;
- template<class... Args>
- GetDouble(Args... args):GetDouble<Policies...>(args...) {};
- double operator()(bool* suc) const {return p(GetDouble<Policies...>::operator()(suc),suc);}
-};
+// Helper types for colors
+typedef GetDouble<SourceValue,PMin<0>,PMax<255> > Value2RGB;
+typedef GetDouble<SourceValue,PMin<0>,PMax<360> > Value2Hue;
+typedef GetDouble<SourceValue,PMin<0>,PMax<1> > Value2SV;
+typedef GetDouble<SourceValue,PMin<0>,PMax<100> > Value2CMYK;
+typedef GetDouble<SourceValue,PMin<0>,PMax<100> > Value2Transp;
+// Helper type for pens and dashes
+typedef GetDouble<SourceValue,PMin<0> > Value2Width;
 
-// Special case for PFromString policy. This policy mast be last in policies list.
-template<>
-class GetDouble<PFromValue>
-{
- PFromValue p;
- public:
- GetDouble(GetDouble&&) = delete;
- GetDouble(GetDouble&) = delete;
- GetDouble() = delete;
- GetDouble(const std::string& str):p(str) {};
- GetDouble(double d):p(d) {};
- double operator()(bool* suc) const {return p(suc);}
-};
+class gmt_struct {}; // Base type for all gmt structures
 
 // Coordinate
-struct gmt_coord
+struct gmt_coord: public gmt_struct
 {
  bool isdeg;
  union
@@ -138,7 +151,7 @@ struct gmt_coord
 
 
 // Region
-struct gmt_region
+struct gmt_region: public gmt_struct
 {
  enum Type {NORMAL,BBOX,GLOBAL360,GLOBAL180};
  Type type;
@@ -190,7 +203,7 @@ struct gmt_region
 
 
 // Projection
-struct gmt_projection
+struct gmt_projection: public gmt_struct
 {
  // OBLIQMERCATOR types
  enum class OType {NOTDEF,A,B,C};
@@ -280,17 +293,11 @@ struct gmt_projection
  static std::map<std::string,projection> projnames;
 };
 
-// Helper types for colors
-typedef GetDouble<PMin<0>,PMax<255>,PFromValue> Value2RGB;
-typedef GetDouble<PMin<0>,PMax<360>,PFromValue> Value2Hue;
-typedef GetDouble<PMin<0>,PMax<1>,PFromValue> Value2SV;
-typedef GetDouble<PMin<0>,PMax<100>,PFromValue> Value2CMYK;
-typedef GetDouble<PMin<0>,PMax<100>,PFromValue> Value2Transp;
-
 // Color
-struct gmt_color
+struct gmt_color: public gmt_struct
 {
  public:
+
  enum ColorModel {RGB,GRAY,HSV,CMYK};
  ColorModel model;
  union
@@ -601,39 +608,40 @@ struct gmt_color
 #include "modgmt_colortransform.h"
 };
 
-// Helper types for pens
-typedef GetDouble<PMin<0>,PFromValue> Value2Width;
-
 // Dash
-struct gmt_dash
+struct gmt_dash: public gmt_struct
 {
  std::vector<double> dash;
  double shift;
+ double width;
+ bool wisrel;
+ static const double default_width;
  std::string Value() const
  {
   std::string ret;
   if(dash.empty()) return ret;
-  for(auto i:dash) ret+=std::to_string(i/10.0)+"_";
+  for(auto i:dash) ret+=std::to_string((wisrel?width:1.0)*i/10.0)+"_";
   ret.back()=':';
   ret+=std::to_string(shift)+"c";
   return ret;
  }
  operator bool() const {return !dash.empty();}
- void Clear() {dash.clear(); shift=0.0;}
+ void Clear() {dash.clear(); shift=0.0; wisrel=false;}
 
- bool Convert(const std::string& in, const double& w)
+ bool Convert(const std::string& in, double w=0.0)
  {
   Clear();
   shift=0;
   if(0==in.size()) return true; // No dash
   if(std::string::npos==in.find_first_not_of(".-")) // dot-dash form
   {
-   double width=(0==w)?1:w;
+   width=(0==w)?default_width:w;
+   wisrel=true;
    for(const auto& i:in)
    {
-    if('.'==i) dash.push_back(width); // Dot
-    else dash.push_back(8*width); // Dash
-    dash.push_back(4*width); // Gap
+    if('.'==i) dash.push_back(1); // Dot
+    else dash.push_back(8); // Dash
+    dash.push_back(4); // Gap
    }
    return true;
   }
@@ -665,11 +673,12 @@ struct gmt_dash
 
 
 // Pen
-struct gmt_pen
+struct gmt_pen: public gmt_struct
 {
  double width;
  struct gmt_color color;
  struct gmt_dash dash;
+ static const double default_width;
  std::string Value() const {return std::to_string(width/10.0)+"c,"+color.Value()+(dash?(","+dash.Value()):"");}
 
  // Interpret one numeric argument as width value
@@ -692,7 +701,7 @@ struct gmt_pen
   WordList wl=Split(str,",",true);
 
   // Defaults
-  width=1;
+  width=default_width;
   color.Convert(0); // Black
   dash.Clear();