First steps toward simplified macros/internals

The brief version::

In an attempt to make proj.4 code slightly more secure and much easier
to read and maintain, I'm trying to eliminate a few unfortunate design
decisions from the early days of proj.4

The work will be *very* intrusive, especially in the PJ_xxx segment of
the code tree, but great care has been taken to design a process that
can be implemented stepwise and localized, one projection at a time,
then finalized with a relatively small and concentrated work package.

The (very) long version: See the comments in PJ_minimal.c

1 files changed, 42 insertions, 15 deletions

diff --git a/src/PJ_merc.c b/src/PJ_merc.c
index 4b991c1c..89913e50 100644
--- a/src/PJ_merc.c
+++ b/src/PJ_merc.c
@@ -1,31 +1,53 @@
 #define PJ_LIB__
 #include	<projects.h>
 PROJ_HEAD(merc, "Mercator") "\n\tCyl, Sph&Ell\n\tlat_ts=";
+
 #define EPS10 1.e-10
-FORWARD(e_forward); /* ellipsoid */
-	if (fabs(fabs(lp.phi) - HALFPI) <= EPS10) F_ERROR;
+
+
+static XY e_forward (LP lp, PJ *P) {          /* Ellipsoidal, forward */
+    XY xy = {0.0,0.0};
+	if (fabs(fabs(lp.phi) - HALFPI) <= EPS10)
+        F_ERROR;
 	xy.x = P->k0 * lp.lam;
 	xy.y = - P->k0 * log(pj_tsfn(lp.phi, sin(lp.phi), P->e));
-	return (xy);
+	return xy;
 }
-FORWARD(s_forward); /* spheroid */
-	if (fabs(fabs(lp.phi) - HALFPI) <= EPS10) F_ERROR;
+
+
+static XY s_forward (LP lp, PJ *P) {           /* Spheroidal, forward */
+    XY xy = {0.0,0.0};
+	if (fabs(fabs(lp.phi) - HALFPI) <= EPS10)
+        F_ERROR;
 	xy.x = P->k0 * lp.lam;
 	xy.y = P->k0 * log(tan(FORTPI + .5 * lp.phi));
-	return (xy);
+	return xy;
 }
-INVERSE(e_inverse); /* ellipsoid */
-	if ((lp.phi = pj_phi2(P->ctx, exp(- xy.y / P->k0), P->e)) == HUGE_VAL) I_ERROR;
+
+
+static LP e_inverse (XY xy, PJ *P) {          /* Ellipsoidal, inverse */
+    LP lp = {0.0,0.0};
+	if ((lp.phi = pj_phi2(P->ctx, exp(- xy.y / P->k0), P->e)) == HUGE_VAL)
+        I_ERROR;
 	lp.lam = xy.x / P->k0;
-	return (lp);
+	return lp;
 }
-INVERSE(s_inverse); /* spheroid */
+
+
+static LP s_inverse (XY xy, PJ *P) {           /* Spheroidal, inverse */
+    LP lp = {0.0,0.0};
 	lp.phi = HALFPI - 2. * atan(exp(-xy.y / P->k0));
 	lp.lam = xy.x / P->k0;
-	return (lp);
+	return lp;
 }
-FREEUP; if (P) pj_dalloc(P); }
-ENTRY0(merc)
+
+
+static void freeup(PJ *P) {                             /* Destructor */
+    pj_dealloc(P);
+}
+
+
+PJ *PROJECTION(merc) {
 	double phits=0.0;
 	int is_phits;
 
@@ -33,15 +55,20 @@ ENTRY0(merc)
 		phits = fabs(pj_param(P->ctx, P->params, "rlat_ts").f);
 		if (phits >= HALFPI) E_ERROR(-24);
 	}
+
 	if (P->es) { /* ellipsoid */
 		if (is_phits)
 			P->k0 = pj_msfn(sin(phits), cos(phits), P->es);
 		P->inv = e_inverse;
 		P->fwd = e_forward;
-	} else { /* sphere */
+	}
+
+    else { /* sphere */
 		if (is_phits)
 			P->k0 = cos(phits);
 		P->inv = s_inverse;
 		P->fwd = s_forward;
 	}
-ENDENTRY(P)
+
+    return P;
+}