rnatm

commit 3e8b20486a297f30a9e4c017afe061c02ea94e82
parent 6665e77837092e655c3422e51b28e2d794f14cd3
Author: Vincent Forest <vincent.forest@meso-star.com>
Date:   Fri, 28 Oct 2022 10:30:52 +0200

Add functions rnatm_find_bands and rnatm_band_sample_quad_pt

Diffstat:
M
src/rnatm.c
 | 
54
++++++++++++++++++++++++++++++++++++++++++++++++++++++
M
src/rnatm.h
 | 
16
++++++++++++++++

2 files changed, 70 insertions(+), 0 deletions(-)
diff --git a/src/rnatm.c b/src/rnatm.c
@@ -381,6 +381,60 @@ rnatm_get_spectral_items_count(const struct rnatm* atm)
   return darray_accel_struct_size_get(&atm->accel_structs);
 }
 
+res_T
+rnatm_find_bands
+  (const struct rnatm* rnatm,
+   const double range[2], /* In nm. Limits are inclusive */
+   size_t ibands[2]) /* Range of overlaped bands. Limits are inclusive */
+{
+  double range_adjusted[2];
+
+  if(!rnatm
+  || !range
+  || range[0] > rnatm->spectral_range[1]
+  || range[1] < rnatm->spectral_range[0])
+    return RES_BAD_ARG;
+
+  /* Clamp the submitted range to the spectral domain of the atmosphere */
+  range_adjusted[0] = MMAX(range[0], rnatm->spectral_range[0]);
+  range_adjusted[1] = MMIN(range[1], rnatm->spectral_range[1]);
+
+  return sck_find_bands(rnatm->gas.ck, range_adjusted, ibands);
+}
+
+res_T
+rnatm_band_sample_quad_pt
+  (const struct rnatm* rnatm,
+   const double r, /* Canonical random number in [0, 1[ */
+   const size_t iband,
+   size_t* iquad)
+{
+  struct sck_band band;
+  res_T res = RES_OK;
+
+  if(!rnatm || !iquad) {
+    res = RES_BAD_ARG;
+    goto error;
+  }
+
+  res = sck_get_band(rnatm->gas.ck, iband, &band);
+  if(res != RES_OK) goto error;
+
+  /* Reject the band if it does not overlap the atmosphere spectral domain */
+  if(band.lower/*Inclusive*/  > rnatm->spectral_range[1]
+  || band.upper/*Exclusive*/ <= rnatm->spectral_range[0]) {
+    return RES_BAD_ARG;
+  }
+
+  res = sck_band_sample_quad_pt(&band, r, iquad);
+  if(res != RES_OK) goto error;
+
+exit:
+  return res;
+error:
+  goto exit;
+}
+
 /*******************************************************************************
  * Local functions
  ******************************************************************************/
diff --git a/src/rnatm.h b/src/rnatm.h
@@ -275,6 +275,22 @@ RNATM_API size_t
 rnatm_get_spectral_items_count
   (const struct rnatm* atm);
 
+/* Returns the range of band indices covered by a given spectral range. The
+ * returned index range is degenerated (i.e. ibands[0] > ibands[1]) if no band
+ * is found */
+RNATM_API res_T
+rnatm_find_bands
+  (const struct rnatm* rnatm,
+   const double range[2], /* In nm. Limits are inclusive */
+   size_t ibands[2]); /* Range of overlaped bands. Limits are inclusive */
+
+RNATM_API res_T
+rnatm_band_sample_quad_pt
+  (const struct rnatm* rnatm,
+   const double r, /* Canonical random number in [0, 1[ */
+   const size_t iband, /* Index of the band to sample */
+   size_t* iquad);
+
 /* Writes a set of octrees following the VTK file format */
 RNATM_API res_T
 rnatm_write_vtk_octrees