star-sf

commit dd12aef4d278b36f1c0e3fb48103b9a09718d9fe
parent 5a40091b2ee0c091749c60e57d612939f1a32de0
Author: Vincent Forest <vincent.forest@meso-star.com>
Date:   Fri, 20 Jul 2018 14:49:42 +0200

Test the Rayleigh function

Diffstat:
M
cmake/CMakeLists.txt
 | 
1
+
M
src/test_ssf_phase_hg.c
 | 
2
+-
A
src/test_ssf_phase_rayleigh.c
 | 
82
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

3 files changed, 84 insertions(+), 1 deletion(-)
diff --git a/cmake/CMakeLists.txt b/cmake/CMakeLists.txt
@@ -118,6 +118,7 @@ if(NOT NO_TEST)
   new_test(test_ssf_microfacet_reflection)
   new_test(test_ssf_phase)
   new_test(test_ssf_phase_hg)
+  new_test(test_ssf_phase_rayleigh)
   new_test(test_ssf_specular_reflection)
   new_test(test_ssf_thin_specular_dielectric)
 
diff --git a/src/test_ssf_phase_hg.c b/src/test_ssf_phase_hg.c
@@ -75,7 +75,7 @@ main(int argc, char** argv)
       CHK(eq_eps(r, ref, 1.e-6));
       CHK(eq_eps(r, pdf, 1.e-6));
     }
-    /* On average cos(wo, wi) should be g */
+    /* On average cos(-wo,wi) should be g */
     E = sum_cos / NSAMPS;
     V = sum_cos_sqr / NSAMPS - E*E;
     SE = sqrt(V/NSAMPS);
diff --git a/src/test_ssf_phase_rayleigh.c b/src/test_ssf_phase_rayleigh.c
@@ -0,0 +1,82 @@
+/* Copyright (C) |Meso|Star> 2016-2018 (contact@meso-star.com)
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>. */
+
+#include "ssf.h"
+#include "test_ssf_utils.h"
+
+#define NSAMPS 10000
+
+int
+main(int argc, char** argv)
+{
+  struct mem_allocator allocator;
+  struct ssf_phase* phase;
+  struct ssp_rng* rng;
+  double wo[3];
+  double sum_cos = 0;
+  double sum_cos_sqr = 0;
+  double sum_cos_sqr2 = 0;
+  double E, V, SE;
+  size_t i;
+  (void)argc, (void)argv;
+
+  mem_init_proxy_allocator(&allocator, &mem_default_allocator);
+  CHK(ssp_rng_create(&allocator, &ssp_rng_mt19937_64, &rng) == RES_OK);
+
+  CHK(ssf_phase_create(&allocator, &ssf_phase_rayleigh, &phase) == RES_OK);
+
+  ssp_ran_sphere_uniform(rng, wo, NULL);
+  FOR_EACH(i, 0, NSAMPS) {
+    double wi[3];
+    double w[3];
+    double weight;
+    double pdf;
+    double ref;
+    double r;
+    ssf_phase_sample(phase, rng, wo, wi, &pdf);
+    CHK(d3_is_normalized(wi));
+    CHK(eq_eps(ssf_phase_pdf(phase, wo, wi), pdf, 1.e-6f));
+    d3_minus(w, wo);
+    weight = d3_dot(wo, wi);
+    sum_cos += weight;
+    sum_cos_sqr += weight*weight;
+    sum_cos_sqr2 += weight*weight*weight*weight;
+
+    r = ssf_phase_eval(phase, wo, wi);
+    ref = 3.0/(16.0*PI)*(1.0+weight*weight);
+    CHK(eq_eps(r, ref, 1.e-6));
+    CHK(eq_eps(r, pdf, 1.e-6));
+  }
+
+  /* On average cos(-wo,wi) should be 0 */
+  E = sum_cos / NSAMPS;
+  V = sum_cos_sqr / NSAMPS - E*E;
+  SE = sqrt(V/NSAMPS);
+  CHK(eq_eps(E, 0, SE));
+
+  /* On average cos(-wo,wi)^2 should be 2/5 */
+  E = sum_cos_sqr / NSAMPS;
+  V = sum_cos_sqr2 / NSAMPS - E*E;
+  SE = sqrt(V/NSAMPS);
+  CHK(eq_eps(E, 2.0/5.0, SE));
+
+  CHK(ssf_phase_ref_put(phase) == RES_OK);
+  CHK(ssp_rng_ref_put(rng) == RES_OK);
+
+  check_memory_allocator(&allocator);
+  mem_shutdown_proxy_allocator(&allocator);
+  CHK(mem_allocated_size() == 0);
+  return 0;
+}