solstice-solver

commit 15bce572ec4ab60e396d05bb465da1e60aef7b9b
parent 6d506f2cdd00f5148e01a447f0fdfbb3f23b525b
Author: Christophe Coustet <christophe.coustet@meso-star.com>
Date:   Fri, 19 Jun 2026 12:35:47 +0200

 Add a new ssol_location struct

 Use it as argument to ssol_sun_set_location_and_date instead of 2
 separate double.

Diffstat:
M
src/ssol.h
 | 
9
+++++++--
M
src/ssol_sun.c
 | 
20
+++++++++++---------
M
src/test_ssol_sun.c
 | 
46
+++++++++++++++++++++++++---------------------

3 files changed, 43 insertions(+), 32 deletions(-)
diff --git a/src/ssol.h b/src/ssol.h
@@ -139,6 +139,12 @@ enum ssol_sun_direction_algorithm {
  SSOL_SUN_DIRECTION_ALGORITHM_PSA
 };
 
+/* The longitude must be in [-180, 180] degrees relative to Greenwich.
+ * The angle is positive towards the east.
+ * The latitude must be in [-90, 90] degrees relative to the equator.
+ * It is positive towards the north. */
+struct ssol_location { double latitude; double longitude; };
+
 /* Describe a vertex data */
 struct ssol_vertex_data {
   enum ssol_attrib_usage usage; /* Semantic of the data */
@@ -1044,8 +1050,7 @@ ssol_sun_set_direction
 SSOL_API res_T
 ssol_sun_set_location_and_date
   (struct ssol_sun* sun,
-   const double latitude,
-   const double longitude,
+   const struct ssol_location* location,
    const struct tm* date);
 
 /* Set the algorithm used to produce sun direction from location and date.
diff --git a/src/ssol_sun.c b/src/ssol_sun.c
@@ -168,26 +168,28 @@ ssol_sun_set_direction(struct ssol_sun* sun, const double direction[3])
 res_T
 ssol_sun_set_location_and_date
   (struct ssol_sun* sun,
-   const double latitude,
-   const double longitude,
+   const struct ssol_location* loc,
    const struct tm* date)
 {
   res_T res = RES_OK;
   struct scem_sun_pos sun_pos;
-  struct scem_location loc;
+  struct scem_location scem_loc;
   enum scem_sun_algo algorithm;
 
-  if(!sun || !date) {
+  if(!sun || !loc|| !date) {
     res = RES_BAD_ARG;
     goto error;
   }
-  if(latitude < -90 || latitude > 90 || longitude < -180 || longitude > 180) {
+
+  if(loc->latitude < -90 || loc->latitude > 90
+      || loc->longitude < -180 || loc->longitude > 180)
+  {
     res = RES_BAD_ARG;
     goto error;
   }
 
-  loc.latitude = latitude;
-  loc.longitude = longitude;
+  scem_loc.latitude = loc->latitude;
+  scem_loc.longitude = loc->longitude;
 
   switch(sun->algorithm ) {
     case SSOL_SUN_DIRECTION_ALGORITHM_PSA :
@@ -196,9 +198,9 @@ ssol_sun_set_location_and_date
     case SSOL_SUN_DIRECTION_ALGORITHM_MEEUS :
       algorithm = SCEM_SUN_MEEUS ;
       break;
-    default: FATAL("Unknown enum value.");
+    default: FATAL("Unknown sun positioning algorithm.");
   }
-  res = scem_sun_position_from_earth(date, &loc, algorithm, &sun_pos);
+  res = scem_sun_position_from_earth(date, &scem_loc, algorithm, &sun_pos);
   if(res != RES_OK) goto error;
 
   scem_to_cartesian_sun_dir(&sun_pos, sun->direction);
diff --git a/src/test_ssol_sun.c b/src/test_ssol_sun.c
@@ -37,6 +37,7 @@ main(int argc, char** argv)
   double dni;
   struct tm date;
   enum ssol_sun_direction_algorithm algo;
+  struct ssol_location loc;
   (void) argc, (void) argv;
 
   mem_init_proxy_allocator(&allocator, &mem_default_allocator);
@@ -85,49 +86,52 @@ main(int argc, char** argv)
 
   CHK(ssol_sun_set_algorithm(sun, SSOL_SUN_DIRECTION_ALGORITHM_MEEUS) == RES_OK);
   strptime("2026-6-21T12:4:0", "%Y-%m-%dT%H:%M:%S", &date);
-  CHK(ssol_sun_set_location_and_date(NULL, 100, 200, NULL) == RES_BAD_ARG);
-  CHK(ssol_sun_set_location_and_date(NULL, 100, 200, &date) == RES_BAD_ARG);
-  CHK(ssol_sun_set_location_and_date(NULL, 100, 0, NULL) == RES_BAD_ARG);
-  CHK(ssol_sun_set_location_and_date(NULL, 100, 0, &date) == RES_BAD_ARG);
-  CHK(ssol_sun_set_location_and_date(NULL, 0, 200, NULL) == RES_BAD_ARG);
-  CHK(ssol_sun_set_location_and_date(NULL, 0, 200, &date) == RES_BAD_ARG);
-  CHK(ssol_sun_set_location_and_date(NULL, 0, 0, NULL) == RES_BAD_ARG);
-  CHK(ssol_sun_set_location_and_date(NULL, 0, 0, &date) == RES_BAD_ARG);
-  CHK(ssol_sun_set_location_and_date(sun, 100, 200, NULL) == RES_BAD_ARG);
-  CHK(ssol_sun_set_location_and_date(sun, 100, 200, &date) == RES_BAD_ARG);
-  CHK(ssol_sun_set_location_and_date(sun, 100, 0, NULL) == RES_BAD_ARG);
-  CHK(ssol_sun_set_location_and_date(sun, 100, 0, &date) == RES_BAD_ARG);
-  CHK(ssol_sun_set_location_and_date(sun, 0, 200, NULL) == RES_BAD_ARG);
-  CHK(ssol_sun_set_location_and_date(sun, 0, 200, &date) == RES_BAD_ARG);
-  CHK(ssol_sun_set_location_and_date(sun, 0, 0, NULL) == RES_BAD_ARG);
-  CHK(ssol_sun_set_location_and_date(sun, 23.436, 0, &date) == RES_OK);
+  loc.latitude = 0; loc.longitude = 0;
+  CHK(ssol_sun_set_location_and_date(NULL, NULL, NULL) == RES_BAD_ARG);
+  CHK(ssol_sun_set_location_and_date(NULL, NULL, &date) == RES_BAD_ARG);
+  CHK(ssol_sun_set_location_and_date(NULL, &loc, NULL) == RES_BAD_ARG);
+  CHK(ssol_sun_set_location_and_date(sun, NULL, NULL) == RES_BAD_ARG);
+  CHK(ssol_sun_set_location_and_date(NULL, &loc, &date) == RES_BAD_ARG);
+  CHK(ssol_sun_set_location_and_date(sun, &loc, NULL) == RES_BAD_ARG);
+  CHK(ssol_sun_set_location_and_date(sun, NULL, &date) == RES_BAD_ARG);
+  loc.latitude = 100; loc.longitude = 0;
+  CHK(ssol_sun_set_location_and_date(sun, &loc, &date) == RES_BAD_ARG);
+  loc.latitude = 0; loc.longitude = 200;
+  CHK(ssol_sun_set_location_and_date(sun, &loc, &date) == RES_BAD_ARG);
+  loc.latitude = 100; loc.longitude = 200;
+  CHK(ssol_sun_set_location_and_date(sun, &loc, &date) == RES_BAD_ARG);
+  loc.latitude = 23.436; loc.longitude = 0;
+  CHK(ssol_sun_set_location_and_date(sun, &loc, &date) == RES_OK);
 
   CHK(ssol_sun_get_direction(sun, tmp) == RES_OK);
   d3(res, 0,0,-1);
   CHK(d3_eq_eps(res, tmp, 1e-4) == 1);
 
   CHK(ssol_sun_set_algorithm(sun, SSOL_SUN_DIRECTION_ALGORITHM_PSA) == RES_OK);
+  loc.latitude = 23.436; loc.longitude = 0;
   strptime("2026-6-21T12:1:49", "%Y-%m-%dT%H:%M:%S", &date);
-  CHK(ssol_sun_set_location_and_date(sun, 23.436, 0, &date) == RES_OK);
+  CHK(ssol_sun_set_location_and_date(sun, &loc, &date) == RES_OK);
 
   CHK(ssol_sun_get_direction(sun, tmp) == RES_OK);
   d3(res, 0,0,-1);
   CHK(d3_eq_eps(res, tmp, 1e-4) == 1);
 
   CHK(ssol_sun_set_algorithm(sun, SSOL_SUN_DIRECTION_ALGORITHM_MEEUS) == RES_OK);
+  loc.latitude = 0; loc.longitude = 0;
   strptime("2026-6-21T10:0:0", "%Y-%m-%dT%H:%M:%S", &date);
-  CHK(ssol_sun_set_location_and_date(sun, 0, 0, &date) == RES_OK);
+  CHK(ssol_sun_set_location_and_date(sun, &loc, &date) == RES_OK);
 
   CHK(ssol_sun_get_direction(sun, tmp) == RES_OK);
-  d3(res, -0.397792,-0.47252,-0.78643);
+  d3(res, -0.47252,-0.397792,-0.78643);
   CHK(d3_eq_eps(res, tmp, 1e-4) == 1);
 
   CHK(ssol_sun_set_algorithm(sun, SSOL_SUN_DIRECTION_ALGORITHM_PSA) == RES_OK);
+  loc.latitude = 0; loc.longitude = 0;
   strptime("2026-6-21T10:0:0", "%Y-%m-%dT%H:%M:%S", &date);
-  CHK(ssol_sun_set_location_and_date(sun, 0, 0, &date) == RES_OK);
+  CHK(ssol_sun_set_location_and_date(sun, &loc, &date) == RES_OK);
 
   CHK(ssol_sun_get_direction(sun, tmp) == RES_OK);
-  d3(res, -0.397733,-0.465014,-0.79093);
+  d3(res, -0.465014,-0.397733,-0.79093);
   CHK(d3_eq_eps(res, tmp, 1e-4) == 1);
 
   CHK(ssol_sun_set_dni(NULL, 1000) == RES_BAD_ARG);