htrdr

commit 7784a2feab50a1deaa101d628f0c04cb82ddc628
parent cbb0e0652c75724d72cccef31c14d35ff536dc9e
Author: Vincent Forest <vincent.forest@meso-star.com>
Date:   Thu, 12 Jul 2018 17:02:56 +0200

Add the htrdr_sun_get_XYZ_spectral_bands_range function

Diffstat:
M
src/htrdr_sky.c
 | 
8
++++----
M
src/htrdr_sun.c
 | 
42
++++++++++++++++++++++++++++++++++++++----
M
src/htrdr_sun.h
 | 
7
+++++++

3 files changed, 49 insertions(+), 8 deletions(-)
diff --git a/src/htrdr_sky.c b/src/htrdr_sky.c
@@ -487,7 +487,7 @@ htrdr_sky_fetch_raw_property
   || pos[0] > sky->cloud_desc.upper[0]
   || pos[1] > sky->cloud_desc.upper[1]
   || pos[2] > sky->cloud_desc.upper[2]) {
-    comp_mask &= ~HTRDR_PARTICLES; /* No particle */  
+    comp_mask &= ~HTRDR_PARTICLES; /* No particle */
   }
 
   /* Compute the index of the voxel to fetch */
@@ -497,9 +497,9 @@ htrdr_sky_fetch_raw_property
     /* The voxels along the Z dimension have the same size */
     ivox[2] = (size_t)((pos[2] - sky->cloud_desc.lower[2])/sky->htcp_desc.vxsz_z[0]);
   } else {
-    /* Irregular voxel size along the Z dimension. Compute the index Z position
-     * in the svx2htcp_z Look Up Table and use the LUT to define the voxel
-     * index into the HTCP descripptor */
+    /* Irregular voxel size along the Z dimension. Compute the index of the Z
+     * position in the svx2htcp_z Look Up Table and use the LUT to define the
+     * voxel index into the HTCP descripptor */
     const struct split* splits = darray_split_cdata_get(&sky->svx2htcp_z);
     const size_t n = darray_split_size_get(&sky->svx2htcp_z);
     const double sz = sky->cloud_desc.upper[2] - sky->cloud_desc.lower[2];
diff --git a/src/htrdr_sun.c b/src/htrdr_sun.c
@@ -94,8 +94,8 @@ htrdr_sun_create(struct htrdr* htrdr, struct htrdr_sun** out_sun)
   if(!sun) {
     htrdr_log_err(htrdr, "could not allocate the sun data structure.\n");
     res = RES_MEM_ERR;
-    goto error;
-  }
+  goto error;
+}
   ref_init(&sun->ref);
   sun->htrdr = htrdr;
   darray_double_init(htrdr->allocator, &sun->radiances_sw);
@@ -234,12 +234,46 @@ htrdr_sun_get_spectral_band_bounds
    const size_t ispectral_band,
    double bounds[2])
 {
+  size_t iband_wlen;
   const double* wnums;
   ASSERT(sun && ispectral_band < htrdr_sun_get_spectral_bands_count(sun));
   ASSERT(ispectral_band + 1 < darray_double_size_get(&sun->wavenumbers_sw));
+
+  /* The spectral bands are internally defined with wavenumbers, while the sun
+   * API uses wavelengths. But since wavelengths are inversely proportionnal to
+   * wavenumbers, one have to reversed the spectral band index */
+  iband_wlen = htrdr_sun_get_spectral_bands_count(sun) - 1 - ispectral_band;
   wnums = darray_double_cdata_get(&sun->wavenumbers_sw);
-  bounds[0] = wavenumber_to_wavelength(wnums[ispectral_band+0]);
-  bounds[1] = wavenumber_to_wavelength(wnums[ispectral_band+1]);
+  bounds[1] = wavenumber_to_wavelength(wnums[iband_wlen+0]);
+  bounds[0] = wavenumber_to_wavelength(wnums[iband_wlen+1]);
   ASSERT(bounds[0] <= bounds[1]);
 }
 
+void
+htrdr_sun_get_XYZ_spectral_bands_range
+  (const struct htrdr_sun* sun, size_t band_range[2])
+{
+  /* Bounds of the X, Y and Z functions as defined by the CIE */
+  const double nu_min = wavelength_to_wavenumber(780); /* In cm^-1 */
+  const double nu_max = wavelength_to_wavenumber(380); /* In cm^-1 */
+  const double* wnums = NULL;
+  size_t iband_low_nu = SIZE_MAX;
+  size_t iband_upp_nu = SIZE_MAX;
+  size_t i;
+  ASSERT(sun && band_range);
+
+  wnums = darray_double_cdata_get(&sun->wavenumbers_sw);
+
+  /* Perform a linear search since the number of spectral bands is small */
+  FOR_EACH(i, 0, htrdr_sun_get_spectral_bands_count(sun)) {
+    if(wnums[i] <= nu_min && nu_min < wnums[i+1]) iband_low_nu = i;
+    if(wnums[i] <= nu_max && nu_max < wnums[i+1]) iband_upp_nu = i;
+  }
+  ASSERT(iband_low_nu <= iband_upp_nu);
+
+  /* Transform the band index from "wavenumber space" to "wavelength space" */
+  band_range[0] = htrdr_sun_get_spectral_bands_count(sun) - 1 - iband_upp_nu;
+  band_range[1] = htrdr_sun_get_spectral_bands_count(sun) - 1 - iband_low_nu;
+  ASSERT(band_range[0] <= band_range[1]);
+}
+
diff --git a/src/htrdr_sun.h b/src/htrdr_sun.h
@@ -73,4 +73,11 @@ htrdr_sun_get_spectral_band_bounds
    const size_t ispectral_band,
    double bounds[2]); /* Lower and upper wavelength in nanometer */
 
+/* Return the ranges of the spectral bands where the XYZ color space is defined
+ * XYZ in [band_min, band_max] */
+extern LOCAL_SYM void
+htrdr_sun_get_XYZ_spectral_bands_range
+  (const struct htrdr_sun* sun,
+   size_t band_range[2]);
+
 #endif /* HTRDR_SUN_H */