Add 'round' key to [set_variable]...

...(http://www.wesnoth.org/forum/viewtopic.php?f=10&t=22879)

changelog

@@ -27,6 +27,8 @@ Version 1.5.6+svn:
    * Added a border and blurring to story screens' text blocks.
    * Improved wrapping in the new widgets.
    * Improved easy close handling.
+ * WML engine:
+   * Added the 'round' key to [set_variable].
  * Miscellaneous and bug fixes:
    * Included extra headers for certain g++ versions (patch #1113).
 

data/scenario-test.cfg

@@ -470,6 +470,49 @@ Xu          , Xu          , Qxu         , Qxu         , Ql          , Ql
             y=2,2
             terrain=Re
         [/terrain]
+        [label]
+            x,y=2,2
+            text="Math test"
+        [/label]
+        [event]
+            name=moveto
+            first_time_only=no
+            [filter]
+                side=1
+                x,y=2,2
+            [/filter]
+            [message]
+                speaker=narrator
+                image=wesnoth-icon.png
+                message="Enter a number."
+                [text_input]
+                    variable=number
+                    text=0
+                [/text_input]
+            [/message]
+            [message]
+                speaker=narrator
+                image=wesnoth-icon.png
+                message="How should we round $number|?
+`(any integer)
+`ceil
+`floor"
+                [text_input]
+                    variable=round
+                [/text_input]
+            [/message]
+            {VARIABLE rounded $number}
+#            {SET_VARIABLE rounded round $round}
+            [set_variable]
+                name=rounded
+                round=$round
+            [/set_variable]
+            [message]
+                speaker=narrator
+                image=wesnoth-icon.png
+                message="Rounding $number| to $round| results in $rounded|."
+            [/message]
+        [/event]
     [/event]
 
     [item]

src/game_events.cpp

@@ -1097,6 +1097,27 @@ namespace {
 			}
 		}
 
+		const std::string round_val = cfg["round"];
+		if(round_val.empty() == false) {
+			double value = lexical_cast<double>(var.c_str());
+			if (round_val == "ceil") {
+				//TODO precision stuff
+				value = ceil(value);
+			} else if (round_val == "floor") {
+				//TODO same
+				value = floor(value);
+			} else {
+				// We assume the value is an integer.
+				// Any non-numerical values will be interpreted as 0
+				// Which is probably what was intended anyway
+				const int decimals = atoi(round_val.c_str());
+				value *= pow(10, decimals); //add $decimals zeroes
+				value = round(value);
+				value *= pow(10, -decimals); //and remove them
+			}
+			var = str_cast(value);
+		}
+
 		const t_string string_length_target = cfg["string_length"];
 		if(string_length_target.empty() == false) {
 			const int value = string_length_target.str().length();