Move common/2d/line.c -> common/2d/line.cpp

SConstruct

@@ -608,7 +608,7 @@ class DXXArchive(DXXCommon):
 '2d/circle.cpp',
 '2d/disc.cpp',
 '2d/gpixel.cpp',
-'2d/line.c',
+'2d/line.cpp',
 '2d/pixel.c',
 '2d/rect.c',
 '2d/rle.c',

common/include/maths.h

@@ -10,6 +10,10 @@
 
 #define D_RAND_MAX 32767
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 void d_srand (unsigned int seed);
 int d_rand ();			// Random number function which returns in the range 0-0x7FFF
 
@@ -114,4 +118,8 @@ extern const short sincos_table[321];
 extern const ushort asin_table[258];
 extern const ushort acos_table[258];
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif