Use constants instead of defines for spiro point types

spiroentrypoints.h

@@ -7,19 +7,40 @@
 extern "C" {
 #endif
 
-    /* Possible values of the "ty" field. */
-#define SPIRO_CORNER		'v'
-#define SPIRO_G4		'o'
-#define SPIRO_G2		'c'
-#define SPIRO_LEFT		'['
-#define SPIRO_RIGHT		']'
+/* _ * Constants * _ */
 
-    /* For a closed contour add an extra cp with a ty set to */
-#define SPIRO_END		'z'
-    /* For an open contour the first cp must have a ty set to*/
-#define SPIRO_OPEN_CONTOUR	'{'
-    /* For an open contour the last cp must have a ty set to */
-#define SPIRO_END_OPEN_CONTOUR	'}'
+/* Possible values of the "ty" field. */
+static const char SPIRO_CORNER = 'v';
+static const char SPIRO_G4 = 'o';
+static const char SPIRO_G2 = 'c';
+static const char SPIRO_LEFT = '[';
+static const char SPIRO_RIGHT = ']';
+
+/* For a closed contour add an extra cp with a ty set to */
+static const char SPIRO_END = 'z';
+/* For an open contour the first cp must have a ty set to*/
+static const char SPIRO_OPEN_CONTOUR = '{';
+/* For an open contour the last cp must have a ty set to */
+static const char SPIRO_END_OPEN_CONTOUR = '}';
+
+/* Curve crossing point with a 'fixed angle' of crossing */
+static const char SPIRO_ANCHOR = 'a';
+/* Curve crossing handle cp(hx,hy) relative to cp(ax,ay) */
+static const char SPIRO_HANDLE = 'h';
+
+/* int ncq flags and values */
+static const int SPIRO_INCLUDE_LAST_KNOT = 0x0100;
+static const int SPIRO_RETRO_VER1 = 0x0400;
+static const int SPIRO_REVERSE_SRC = 0x0800;
+static const int SPIRO_ARC_CUB_QUAD_CLR = 0x7FFF;
+static const int SPIRO_ARC_CUB_QUAD_MASK = 0x7000;
+static const int SPIRO_CUBIC_TO_BEZIER = 0x0000;
+static const int SPIRO_CUBIC_MIN_MAYBE = 0x1000;
+static const int SPIRO_ARC_MAYBE = 0x2000;
+static const int SPIRO_ARC_MIN_MAYBE = 0x3000;
+static const int SPIRO_QUAD0_TO_BEZIER = 0x4000;
+
+/* _ * Functions * _ */
 
 /* These 6 functions are kept for backwards compatibility for older */
 /* programs. Please use the functions listed afterwards that return */
@@ -53,23 +74,6 @@ extern int TaggedSpiroCPsToBezier2(spiro_cp *spiros,int ncq,bezctx *bc);
 /* ncq allows you to toggle different outputs independent of spiros */
 extern int SpiroCPsToBezier2(spiro_cp *spiros,int n,int ncq,int isclosed,bezctx *bc);
 
-    /* Curve crossing point with a 'fixed angle' of crossing */
-#define SPIRO_ANCHOR		'a'
-    /* Curve crossing handle cp(hx,hy) relative to cp(ax,ay) */
-#define SPIRO_HANDLE		'h'
-
-/* int ncq flags and values */
-#define SPIRO_INCLUDE_LAST_KNOT	0x0100
-#define SPIRO_RETRO_VER1	0x0400
-#define SPIRO_REVERSE_SRC	0x0800
-#define SPIRO_ARC_CUB_QUAD_CLR	0x7FFF
-#define SPIRO_ARC_CUB_QUAD_MASK	0x7000
-#define SPIRO_CUBIC_TO_BEZIER	0x0000
-#define SPIRO_CUBIC_MIN_MAYBE	0x1000
-#define SPIRO_ARC_MAYBE		0x2000
-#define SPIRO_ARC_MIN_MAYBE	0x3000
-#define SPIRO_QUAD0_TO_BEZIER	0x4000
-
 #ifdef __cplusplus
 }
 #endif