obs_api revision and improvements: new namespace etc. (#530)

* obs_api revision and improvements: new namespace etc.

* Minor corrections: use unused functions, add missing prototype, added fwd/invcoord to PJ

* Minor correction: MSVC barfs on va_arg type specification. Trying once more with added parens

* Reverting paren correction, which appears to be a non-solution

* Significant improvements to the OBS_API, plus a number of corrections, mostly in test code, to reflect API changes

* Added two missing prototypes

* Adding the proj_transform function and some related checks

* Improvements to proj_transform etc. based on suggestions from Even Rouault

* Reducing the libc include footprint of proj.h - again based on suggestions from Even Rouault

* A few minor corrections

* Eliminate a MSVC warning about non-initialized usage. Not an actual issue, as another check has locked the path, but at least this should calm down MSVC

* Improved support for the errno reset/restore paradigm

* Introduced the internal header proj_internal.h; Moved most non-API stuff from pj_obs_api.c to pj_internal.c

* Adding proj_internal.h to HEADERS_LIBPROJ to solve build problems

* Correcting a few pj...proj blunders in PJ_pipeline.c

* Correcting a few additional blunders in PJ_pipeline.c

* Changed angle-brackets to quotation marks in includes of proj_internal.h

* Some minor build system repairs

* Some PJ_CONTEXT usage simplifications following suggestions by Kristian Evers @kbevers

* Added version numbering to proj.h - Fixes #529

* remove proj_errno_restore macro, provide function implementation

* Add proj_get_definition. Fixes #538

* Added library specific deallocator proj_buffer_free, eliminating a potential cross heap issues on Windows. Thx to Even Rouault for spotting this

* Got rid of a meaningless cast in proj_buffer_free

* Added some missing functions to proj.def (again spotted by @rouault); removed some not-yet-implemented material from proj.h

* Renamed proj_get_definition/proj_buffer_free to proj_definition_create/proj_definition_destroy, for symmetry and clarity

* Renaming the definition handlers to proj_definition_retrieve / proj_free

* Renaming proj_free to proj_release

1 files changed, 5 insertions, 4 deletions

diff --git a/src/pj_fwd.c b/src/pj_fwd.c
index 598c6dd2..02f18d1c 100644
--- a/src/pj_fwd.c
+++ b/src/pj_fwd.c
@@ -1,21 +1,21 @@
 /* general forward projection */
 #define PJ_LIB__
+#include <proj.h>
 #include <projects.h>
-#include <errno.h>
 # define EPS 1.0e-12
 	XY /* forward projection entry */
 pj_fwd(LP lp, PJ *P) {
 	XY xy;
     XY err;
     double t;
+    int last_errno;
 
     /* cannot const-initialize this due to MSVC's broken (non const) HUGE_VAL */
     err.x = err.y = HUGE_VAL;
 
     if (0==P->fwd)
         return err;
-
-    P->ctx->last_errno = pj_errno = errno = 0;
+    last_errno = proj_errno_reset (P);
 
     /* Check input coordinates if angular */
     if ((P->left==PJ_IO_UNITS_CLASSIC)||(P->left==PJ_IO_UNITS_RADIANS)) {
@@ -39,7 +39,7 @@ pj_fwd(LP lp, PJ *P) {
 
     /* Do the transformation */
     xy = (*P->fwd)(lp, P);
-    if ( P->ctx->last_errno )
+    if ( proj_errno (P) )
         return err;
 
     /* Classic proj.4 functions return plane coordinates in units of the semimajor axis */
@@ -53,5 +53,6 @@ pj_fwd(LP lp, PJ *P) {
     xy.y = P->fr_meter * (xy.y + P->y0);
     /* z is not scaled since this is handled by vto_meter outside */
 
+    proj_errno_restore (P, last_errno);
     return xy;
 }