Merge pull request #1896 from rouault/add_set_operation

Add +proj=set operation to set component(s) of a coordinate to a fixed value

1 files changed, 75 insertions, 0 deletions

diff --git a/src/conversions/set.cpp b/src/conversions/set.cpp
new file mode 100644
index 00000000..7628bf4f
--- /dev/null
+++ b/src/conversions/set.cpp
@@ -0,0 +1,75 @@
+#define PJ_LIB__
+
+#include "proj_internal.h"
+#include <errno.h>
+
+PROJ_HEAD(set, "Set coordinate value");
+
+/* Projection specific elements for the PJ object */
+namespace { // anonymous namespace
+struct Set {
+    bool v1;
+    bool v2;
+    bool v3;
+    bool v4;
+    double v1_val;
+    double v2_val;
+    double v3_val;
+    double v4_val;
+};
+} // anonymous namespace
+
+static PJ_COORD set_fwd_inv(PJ_COORD point, PJ *P) {
+
+    struct Set *set = static_cast<struct Set*>(P->opaque);
+
+    if (set->v1)
+        point.v[0] = set->v1_val;
+    if (set->v2)
+        point.v[1] = set->v2_val;
+    if (set->v3)
+        point.v[2] = set->v3_val;
+    if (set->v4)
+        point.v[3] = set->v4_val;
+
+    return point;
+}
+
+PJ *OPERATION(set, 0) {
+    P->inv4d = set_fwd_inv;
+    P->fwd4d = set_fwd_inv;
+
+    auto set = static_cast<struct Set*>(pj_calloc (1, sizeof(struct Set)));
+    P->opaque = set;
+    if (nullptr==P->opaque)
+        return pj_default_destructor(P, ENOMEM);
+
+    if (pj_param_exists(P->params, "v_1"))
+    {
+        set->v1 = true;
+        set->v1_val = pj_param (P->ctx, P->params, "dv_1").f;
+    }
+
+    if (pj_param_exists(P->params, "v_2"))
+    {
+        set->v2 = true;
+        set->v2_val = pj_param (P->ctx, P->params, "dv_2").f;
+    }
+
+    if (pj_param_exists(P->params, "v_3"))
+    {
+        set->v3 = true;
+        set->v3_val = pj_param (P->ctx, P->params, "dv_3").f;
+    }
+
+    if (pj_param_exists(P->params, "v_4"))
+    {
+        set->v4 = true;
+        set->v4_val = pj_param (P->ctx, P->params, "dv_4").f;
+    }
+
+    P->left  = PJ_IO_UNITS_WHATEVER;
+    P->right = PJ_IO_UNITS_WHATEVER;
+
+    return P;
+}