Discern between 2D projected and 3D cartesian linear units (#732)

10 files changed, 35 insertions, 28 deletions

diff --git a/src/PJ_axisswap.c b/src/PJ_axisswap.c
index aee3c56e..62a9fba3 100644
--- a/src/PJ_axisswap.c
+++ b/src/PJ_axisswap.c
@@ -242,10 +242,9 @@ PJ *CONVERSION(axisswap,0) {
         P->left  = PJ_IO_UNITS_RADIANS;
         P->right = PJ_IO_UNITS_RADIANS;
     } else {
-        P->left  = PJ_IO_UNITS_METERS;
-        P->right = PJ_IO_UNITS_METERS;
+        P->left  = PJ_IO_UNITS_PROJECTED;
+        P->right = PJ_IO_UNITS_PROJECTED;
     }
 
     return P;
 }
-
diff --git a/src/PJ_cart.c b/src/PJ_cart.c
index 12b5876a..8e11c030 100644
--- a/src/PJ_cart.c
+++ b/src/PJ_cart.c
@@ -214,7 +214,6 @@ PJ *CONVERSION(cart,1) {
     P->fwd    =  cart_forward;
     P->inv    =  cart_reverse;
     P->left   =  PJ_IO_UNITS_RADIANS;
-    P->right  =  PJ_IO_UNITS_METERS;
+    P->right  =  PJ_IO_UNITS_CARTESIAN;
     return P;
 }
-
diff --git a/src/PJ_deformation.c b/src/PJ_deformation.c
index d227e49f..797af006 100644
--- a/src/PJ_deformation.c
+++ b/src/PJ_deformation.c
@@ -306,8 +306,8 @@ PJ *TRANSFORMATION(deformation,1) {
     P->fwd    = 0;
     P->inv    = 0;
 
-    P->left  = PJ_IO_UNITS_METERS;
-    P->right = PJ_IO_UNITS_METERS;
+    P->left  = PJ_IO_UNITS_CARTESIAN;
+    P->right = PJ_IO_UNITS_CARTESIAN;
     P->destructor = destructor;
 
     return P;
diff --git a/src/PJ_helmert.c b/src/PJ_helmert.c
index ca14a5cb..f726d946 100644
--- a/src/PJ_helmert.c
+++ b/src/PJ_helmert.c
@@ -477,8 +477,14 @@ PJ *TRANSFORMATION(helmert, 0) {
     P->fwd    = helmert_forward;
     P->inv    = helmert_reverse;
 
-    P->left  = PJ_IO_UNITS_METERS;
-    P->right = PJ_IO_UNITS_METERS;
+    /* In most cases, we work on 3D cartesian coordinates */
+    P->left  = PJ_IO_UNITS_CARTESIAN;
+    P->right = PJ_IO_UNITS_CARTESIAN;
+    /* But in the 2D case, the coordinates are projected */
+    if (pj_param_exists (P->params, "theta")) {
+        P->left  = PJ_IO_UNITS_PROJECTED;
+        P->right = PJ_IO_UNITS_PROJECTED;
+    }
 
     /* Translations */
     if (pj_param (P->ctx, P->params, "tx").i)
diff --git a/src/PJ_horner.c b/src/PJ_horner.c
index fe0452d6..d1146aa1 100644
--- a/src/PJ_horner.c
+++ b/src/PJ_horner.c
@@ -434,7 +434,7 @@ PJ *PROJECTION(horner) {
     P->inv3d  =  0;
     P->fwd    =  0;
     P->inv    =  0;
-    P->left   =  P->right  =  PJ_IO_UNITS_METERS;
+    P->left   =  P->right  =  PJ_IO_UNITS_PROJECTED;
     P->destructor = horner_freeup;
 
     /* Polynomial degree specified? */
diff --git a/src/PJ_ob_tran.c b/src/PJ_ob_tran.c
index 43211fe7..debb211c 100644
--- a/src/PJ_ob_tran.c
+++ b/src/PJ_ob_tran.c
@@ -233,7 +233,7 @@ PJ *PROJECTION(ob_tran) {
     /* Support some rather speculative test cases, where the rotated projection */
     /* is actually latlong. We do not want scaling in that case... */
     if (Q->link->right==PJ_IO_UNITS_RADIANS)
-        P->right = PJ_IO_UNITS_METERS;
+        P->right = PJ_IO_UNITS_PROJECTED;
 
 
     return P;
diff --git a/src/PJ_unitconvert.c b/src/PJ_unitconvert.c
index bf1fcd37..06224362 100644
--- a/src/PJ_unitconvert.c
+++ b/src/PJ_unitconvert.c
@@ -397,8 +397,8 @@ PJ *CONVERSION(unitconvert,0) {
     P->fwd    = forward_2d;
     P->inv    = reverse_2d;
 
-    P->left  = PJ_IO_UNITS_METERS;
-    P->right = PJ_IO_UNITS_METERS;
+    P->left  = PJ_IO_UNITS_WHATEVER;
+    P->right = PJ_IO_UNITS_WHATEVER;
 
     /* if no time input/output unit is specified we can skip them */
     Q->t_in_id = -1;
@@ -485,4 +485,3 @@ PJ *CONVERSION(unitconvert,0) {
 
     return P;
 }
-
diff --git a/src/pj_internal.c b/src/pj_internal.c
index 88fb2b62..deb0c054 100644
--- a/src/pj_internal.c
+++ b/src/pj_internal.c
@@ -40,16 +40,16 @@
 
 enum pj_io_units pj_left (PJ *P) {
     enum pj_io_units u = P->inverted? P->right: P->left;
-    if (u==PJ_IO_UNITS_RADIANS)
-        return PJ_IO_UNITS_RADIANS;
-    return PJ_IO_UNITS_METERS;
+    if (u==PJ_IO_UNITS_CLASSIC)
+        return PJ_IO_UNITS_PROJECTED;
+    return u;
 }
 
 enum pj_io_units pj_right (PJ *P) {
     enum pj_io_units u = P->inverted? P->left: P->right;
-    if (u==PJ_IO_UNITS_RADIANS)
-        return PJ_IO_UNITS_RADIANS;
-    return PJ_IO_UNITS_METERS;
+    if (u==PJ_IO_UNITS_CLASSIC)
+        return PJ_IO_UNITS_PROJECTED;
+    return u;
 }
 
 
diff --git a/src/proj_internal.h b/src/proj_internal.h
index 3dd04e62..41f95c07 100644
--- a/src/proj_internal.h
+++ b/src/proj_internal.h
@@ -61,12 +61,14 @@ extern "C" {
 #define PJ_EPS_LAT 1e-12
 
 
-/* This enum is also conditionally defined in projects.h - but we need it here */
-/* for the pj_left/right prototypes, and enums cannot be forward declared      */
+/* This enum is also conditionally defined in projects.h - but enums cannot */
+/* be forward declared and we need it here for the pj_left/right prototypes */
 enum pj_io_units {
-    PJ_IO_UNITS_CLASSIC = 0,   /* Scaled meters (right) */
-    PJ_IO_UNITS_METERS  = 1,   /* Meters  */
-    PJ_IO_UNITS_RADIANS = 2    /* Radians */
+    PJ_IO_UNITS_WHATEVER  = 0,  /* Doesn't matter (or depends on pipeline neighbours) */
+    PJ_IO_UNITS_CLASSIC   = 1,  /* Scaled meters (right), projected system */
+    PJ_IO_UNITS_PROJECTED = 2,  /* Meters, projected system */
+    PJ_IO_UNITS_CARTESIAN = 3,  /* Meters, 3D cartesian system */
+    PJ_IO_UNITS_RADIANS   = 4   /* Radians */
 };
 enum pj_io_units pj_left (PJ *P);
 enum pj_io_units pj_right (PJ *P);
diff --git a/src/projects.h b/src/projects.h
index 209d6f39..86ca2524 100644
--- a/src/projects.h
+++ b/src/projects.h
@@ -192,9 +192,11 @@ typedef struct PJ_REGION_S  PJ_Region;
 typedef struct ARG_list paralist;   /* parameter list */
 #ifndef PROJ_INTERNAL_H
 enum pj_io_units {
-    PJ_IO_UNITS_CLASSIC = 0,   /* Scaled meters (right) */
-    PJ_IO_UNITS_METERS  = 1,   /* Meters  */
-    PJ_IO_UNITS_RADIANS = 2    /* Radians */
+    PJ_IO_UNITS_WHATEVER  = 0,  /* Doesn't matter (or depends on pipeline neighbours) */
+    PJ_IO_UNITS_CLASSIC   = 1,  /* Scaled meters (right), projected system */
+    PJ_IO_UNITS_PROJECTED = 2,  /* Meters, projected system */
+    PJ_IO_UNITS_CARTESIAN = 3,  /* Meters, 3D cartesian system */
+    PJ_IO_UNITS_RADIANS   = 4   /* Radians */
 };
 #endif
 #ifndef PROJ_H