star-sf

commit 46e0e9b89ecbd6afb1287ecc623dab288b5ddda4
parent 4fe8e6e919eafceb6473491e755e67e3d3c30975
Author: Vincent Forest <vincent.forest@meso-star.com>
Date:   Wed, 18 Jul 2018 16:49:10 +0200

Test the Henyey & Greenstein phase function

Diffstat:
M
cmake/CMakeLists.txt
 | 
1
+
A
src/test_ssf_phase_hg.c
 | 
83
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
M
src/test_ssf_utils.h
 | 
57
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++

3 files changed, 141 insertions(+), 0 deletions(-)
diff --git a/cmake/CMakeLists.txt b/cmake/CMakeLists.txt
@@ -116,6 +116,7 @@ if(NOT NO_TEST)
   new_test(test_ssf_microfacet_distribution)
   new_test(test_ssf_microfacet_reflection)
   new_test(test_ssf_phase)
+  new_test(test_ssf_phase_hg)
   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
@@ -0,0 +1,83 @@
+/* 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 NG 10
+#define NSAMPS 10000
+
+int
+main(int argc, char** argv)
+{
+  struct mem_allocator allocator;
+  struct ssf_phase* phase;
+  struct ssf_phase* dummy;
+  struct ssp_rng* rng;
+  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_hg, &phase) == RES_OK);
+  CHK(ssf_phase_create(&allocator, &phase_dummy, &dummy) == RES_OK);
+
+  CHK(ssf_phase_hg_setup(NULL, -2) == RES_BAD_ARG);
+  CHK(ssf_phase_hg_setup(phase, -2) == RES_BAD_ARG);
+  CHK(ssf_phase_hg_setup(NULL, -1) == RES_BAD_ARG);
+  CHK(ssf_phase_hg_setup(phase, -1) == RES_OK);
+  CHK(ssf_phase_hg_setup(phase, 0) == RES_OK);
+  CHK(ssf_phase_hg_setup(phase, 1) == RES_OK);
+  CHK(ssf_phase_hg_setup(dummy, 1) == RES_BAD_ARG);
+
+  FOR_EACH(i, 0, NG) {
+    const double g = ssp_rng_uniform_double(rng, -1, +1);
+    double wo[3];
+    double sum_cos = 0;
+    double sum_cos_sqr = 0;
+    double E, V, SE;
+    size_t isamp;
+
+    CHK(ssf_phase_hg_setup(phase, g) == RES_OK);
+
+    ssp_ran_sphere_uniform(rng, wo, NULL);
+    FOR_EACH(isamp, 0, NSAMPS) {
+      double wi[3];
+      double pdf;
+      double w;
+      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-6));
+      w = d3_dot(wo, wi);
+      sum_cos += w;
+      sum_cos_sqr += w*w;
+    }
+    /* On average cos(wo, wi) should be g */
+    E = sum_cos / NSAMPS;
+    V = sum_cos_sqr / NSAMPS - E*E;
+    SE = sqrt(V/NSAMPS);
+    CHK(eq_eps(sum_cos / NSAMPS, E, SE) == 1);
+  }
+
+  CHK(ssf_phase_ref_put(phase) == RES_OK);
+  CHK(ssf_phase_ref_put(dummy) == 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;
+}
diff --git a/src/test_ssf_utils.h b/src/test_ssf_utils.h
@@ -178,6 +178,63 @@ static const struct ssf_microfacet_distribution_type microfacet_dummy = {
 };
 
 /*******************************************************************************
+ * Dummy Phase function type
+ ******************************************************************************/
+static res_T
+phase_dummy_init(struct mem_allocator* allocator, void* phase)
+{
+  (void)allocator, (void)phase;
+  return RES_OK;
+}
+
+static void
+phase_dummy_release(void* phase)
+{
+  (void)phase;
+}
+
+static double
+phase_dummy_sample
+  (void* phase,
+   struct ssp_rng* rng,
+   const double w[3],
+   double dir[3],
+   double* pdf)
+{
+  (void)phase, (void)rng, (void)w, (void)dir, (void)pdf;
+  return 0.0;
+}
+
+static double
+phase_dummy_eval
+  (void* phase,
+   const double wo[3],
+   const double wi[3])
+{
+  (void)phase, (void)wo, (void)wi;
+  return 0.0;
+}
+
+static double
+phase_dummy_pdf
+  (void* phase,
+   const double wo[3],
+   const double wi[3])
+{
+  (void)phase, (void)wo, (void)wi;
+  return 0.0;
+}
+
+static const struct ssf_phase_type phase_dummy = {
+  phase_dummy_init,
+  phase_dummy_release,
+  phase_dummy_sample,
+  phase_dummy_eval,
+  phase_dummy_pdf,
+  0, 1
+};
+
+/*******************************************************************************
  * Miscellaneous functions
  ******************************************************************************/
 static INLINE void