htgop

commit bd52e9b29762aaf79b1262e7ceb9fafad65db3a1
parent 4f403b04ecbac79a0fae222e0051812ed0b6ca3b
Author: Vincent Forest <vincent.forest@meso-star.com>
Date:   Fri, 27 Jul 2018 16:52:26 +0200

Add the sample_sw_spectral_interval_CIE<X|Y|Z> functions

Diffstat:
M
src/htgop.c
 | 
83
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
M
src/htgop.h
 | 
26
++++++++++++++++++++++----

2 files changed, 105 insertions(+), 4 deletions(-)
diff --git a/src/htgop.c b/src/htgop.c
@@ -17,6 +17,7 @@
 #include "htgop_c.h"
 #include "htgop_reader.h"
 
+#include <rsys/algorithm.h>
 #include <rsys/cstr.h>
 #include <rsys/logger.h>
 #include <rsys/mem_allocator.h>
@@ -49,6 +50,14 @@ log_msg
   }
 }
 
+static INLINE int
+cmp_dbl(const void* a, const void* b)
+{
+  const double d0 = *((const double*)a);
+  const double d1 = *((const double*)b);
+  return d0 < d1 ? -1 : (d0 > d1 ? 1 : 0);
+}
+
 static FINLINE double
 trapezoidal_integration
   (const double lambda_lo, /* Integral lower bound. In nanometer */
@@ -221,6 +230,41 @@ error:
   goto exit;
 }
 
+static INLINE res_T
+sample_sw_spectral_interval_CIE
+  (const struct htgop* htgop,
+   const char* caller,
+   const double* cdf,
+   const size_t cdf_length,
+   const double r, /* Canonical number in [0, 1[ */
+   size_t* id)
+{
+  double* find;
+  size_t i;
+  ASSERT(htgop && cdf && cdf_length);
+
+  if(!id) return RES_BAD_ARG;
+  if(r < 0 || r >= 1) {
+    log_err(htgop, "%s: invalid canonical random number `%g'.\n", caller, r);
+    return RES_BAD_ARG;
+  }
+
+  find = search_lower_bound(&r, &cdf, cdf_length, sizeof(double), cmp_dbl);
+  if(!find) {
+    log_err(htgop,
+      "%s: could not sample a spectral interval in the CIE XYZ interval.\n",
+      caller);
+    return RES_BAD_OP;
+  }
+
+  ASSERT(find);
+  i = (size_t)(find - cdf);
+  ASSERT(i < cdf_length && cdf[i] > r && (!i || cdf[i-1] < r));
+  *id = i;
+  return RES_OK;
+}
+
+
 static res_T
 parse_spectral_intervals
   (struct htgop* htgop,
@@ -780,6 +824,45 @@ htgop_get_sw_spectral_interval
   return RES_OK;
 }
 
+res_T
+htgop_sample_sw_spectral_interval_CIE_X
+  (const struct htgop* htgop,
+   const double r, /* Canonical number in [0, 1[ */
+   size_t* ispecint)
+{
+  if(!htgop) return RES_BAD_ARG;
+  return sample_sw_spectral_interval_CIE(htgop, FUNC_NAME,
+    darray_double_cdata_get(&htgop->sw_X_cdf),
+    darray_double_size_get(&htgop->sw_X_cdf),
+    r, ispecint);
+}
+
+res_T
+htgop_sample_sw_spectral_interval_CIE_Y
+  (const struct htgop* htgop,
+   const double r, /* Canonical number in [0, 1[ */
+   size_t* ispecint)
+{
+  if(!htgop) return RES_BAD_ARG;
+  return sample_sw_spectral_interval_CIE(htgop, FUNC_NAME,
+    darray_double_cdata_get(&htgop->sw_Y_cdf),
+    darray_double_size_get(&htgop->sw_Y_cdf),
+    r, ispecint);
+}
+
+res_T
+htgop_sample_sw_spectral_interval_CIE_Z
+  (const struct htgop* htgop,
+   const double r, /* Canonical number in [0, 1[ */
+   size_t* ispecint)
+{
+  if(!htgop) return RES_BAD_ARG;
+  return sample_sw_spectral_interval_CIE(htgop, FUNC_NAME,
+    darray_double_cdata_get(&htgop->sw_Y_cdf),
+    darray_double_size_get(&htgop->sw_Y_cdf),
+    r, ispecint);
+}
+
 /*******************************************************************************
  * Local functions
  ******************************************************************************/
diff --git a/src/htgop.h b/src/htgop.h
@@ -50,8 +50,8 @@ struct htgop_ground {
 };
 
 struct htgop_spectral_interval {
-  double wave_numbers[2]; /* Lower/Upper wave number of the interval */
-  const double* quadrature; /* Weights of the spectral interval quadrature */
+  double wave_numbers[2]; /* Lower/Upper wave number of the interval in cm^-1 */
+  const double* quadrature; /* Weights of the quadrature points */
   size_t quadrature_length; /* #quadrature points of the interval */
 };
 
@@ -83,14 +83,14 @@ struct htgop_layer_lw_spectral_interval_tab {
 
 struct htgop_layer_sw_spectral_interval {
   const double* ka_nominal; /* Per quadrature point absorption coef */
-  const double* ks_nominal; /* Per quadrature point scatteriing coef */
+  const double* ks_nominal; /* Per quadrature point scattering coef */
   size_t quadrature_length;
   const void* data__; /* Internal data */
 };
 
 struct htgop_layer_sw_spectral_interval_tab {
   const double* ka_tab; /* Tabulated absorption coef */
-  const double* ks_tab; /* Tabulated scatteriing coef */
+  const double* ks_tab; /* Tabulated scattering coef */
   size_t tab_length;
 };
 
@@ -162,6 +162,24 @@ htgop_get_sw_spectral_intervals_count
    size_t* nspecints);
 
 HTGOP_API res_T
+htgop_sample_sw_spectral_interval_CIE_X
+  (const struct htgop* htgop,
+   const double r, /* Canonical random number in [0, 1[ */
+   size_t* ispecint); /* Id of the sampled interval */
+
+HTGOP_API res_T
+htgop_sample_sw_spectral_interval_CIE_Y
+  (const struct htgop* htgop,
+   const double r, /* Canonical random number in [0, 1[ */
+   size_t* ispecint); /* Id of the sampled interval */
+
+HTGOP_API res_T
+htgop_sample_sw_spectral_interval_CIE_Z
+  (const struct htgop* htgop,
+   const double r, /* Canonical random number in [0, 1[ */
+   size_t* ispecint); /* Id of the sampled interval */
+
+HTGOP_API res_T
 htgop_get_lw_spectral_intervals_wave_numbers
   (const struct htgop* htgop,
    const double* wave_numbers[]);