solstice-solver

commit 92bbf9ae66bdc1c165263a2623946396528238b3
parent b388fd6822edd4712e9a14f4b678e65100d38c0d
Author: Vincent Forest <vincent.forest@meso-star.com>
Date:   Wed,  7 Feb 2018 20:51:02 +0100

Merge branch 'release_0.7.2'

Diffstat:
M
README.md
 | 
4
++++
M
cmake/CMakeLists.txt
 | 
2
+-
M
src/ssol_ranst_sun_dir.c
 | 
14
+++++++++-----

3 files changed, 14 insertions(+), 6 deletions(-)
diff --git a/README.md b/README.md
@@ -26,6 +26,10 @@ variable the install directories of its dependencies.
 
 ## Release notes
 
+### Version 0.7.2
+
+- Fix the gaussian sunshape.
+
 ### Version 0.7.1
 
 - Fix the creation of a glossy BSDF that uses a pillbox microfacet
diff --git a/cmake/CMakeLists.txt b/cmake/CMakeLists.txt
@@ -51,7 +51,7 @@ rcmake_append_runtime_dirs(_runtime_dirs RSys Star3D Star3DUT StarCPR StarSF Sta
 ################################################################################
 set(VERSION_MAJOR 0)
 set(VERSION_MINOR 7)
-set(VERSION_PATCH 1)
+set(VERSION_PATCH 2)
 set(VERSION ${VERSION_MAJOR}.${VERSION_MINOR}.${VERSION_PATCH})
 
 set(SSOL_FILES_SRC
diff --git a/src/ssol_ranst_sun_dir.c b/src/ssol_ranst_sun_dir.c
@@ -275,16 +275,20 @@ ran_gaussian_get
    double dir[3])
 {
   double pt[3];
-  double phi, theta, sin_theta;
+  double phi, cos_theta, sin_theta;
 
+  /* The following is not truly a gaussian sunshape,
+   * but an accurate enough approximation for small angles */
   ASSERT(ran && 0 <= ran->state.gaussian.std_dev);
-  theta = ssp_ran_gaussian(rng, 0, ran->state.gaussian.std_dev);
-  sin_theta = sin(theta);
+  sin_theta
+    = ran->state.gaussian.std_dev * sqrt(-2 * log(ssp_rng_canonical(rng)));
+  sin_theta = MMIN(1, sin_theta); /* macro: don't merge with previous line! */
+  cos_theta = sin2cos(sin_theta);
   phi = ssp_rng_uniform_double(rng, 0, 2 * PI);
   pt[0] = cos(phi) * sin_theta;
   pt[1] = sin(phi) * sin_theta;
-  pt[2] = cos(theta);
-  d33_muld3(dir, ran->state.pillbox.basis, pt);
+  pt[2] = cos_theta;
+  d33_muld3(dir, ran->state.gaussian.basis, pt);
   d3_normalize(dir, dir);
   return dir;
 }