X-Git-Url: http://git.treefish.org/~alex/seamulator.git/blobdiff_plain/5baf6f709bb7943c95318e709efa907a0f3f1986..f2e44f70d56b60e6eef78656ca4b558917474276:/sea.cpp?ds=sidebyside

diff --git a/sea.cpp b/sea.cpp
index b76a9dd..85191d4 100644
--- a/sea.cpp
+++ b/sea.cpp
@@ -6,7 +6,7 @@
 
 #include "watersurface.h"
 
-const double Sea::PHILLIPS_CONSTANT{0.0000003};
+const double Sea::PHILLIPS_CONSTANT{0.0000001};
 const double Sea::GRAVITATIONAL_CONSTANT{9.8};
 
 Sea::Sea(WaterSurfacePtr surface) :
@@ -16,12 +16,9 @@ Sea::Sea(WaterSurfacePtr surface) :
   m_randomGenerator{m_randomDevice()},
   m_normalDistribution{0.0, 1.0}
 {
-  m_fourierAmplitudes.resize(pow(m_surface->size(), 2));
+  m_fourierAmplitudes.resize(pow(m_surface->size() + 1, 2));
   generateFourierAmplitudes();
 
-  fftw_init_threads();
-  fftw_plan_with_nthreads(4);
-
   m_fftwIn = (fftw_complex*)
     fftw_malloc(sizeof(fftw_complex) * pow(m_surface->size(), 2));
   m_fftwOut = (fftw_complex*)
@@ -63,8 +60,8 @@ void Sea::update()
       const double omega = sqrt(GRAVITATIONAL_CONSTANT * k);
 
       std::complex<double> amplitude =
-	fourierAmplitudeAt(n, m).first * exp(1i * omega * runtime) +
-	fourierAmplitudeAt(n, m).second * exp(-1i * omega * runtime);
+       	fourierAmplitudeAt(n, m) * exp(1i * omega * runtime) +
+       	std::conj(fourierAmplitudeAt(-n, -m)) * exp(-1i * omega * runtime);
 
       const int positiveN = (n + m_surface->size()) % m_surface->size();
       int fftwIndex = positiveM + positiveN * m_surface->size();
@@ -96,16 +93,7 @@ double Sea::phillipsSpectrum(double k_x, double k_y) const
     cosineFactor;
 }
 
-ComplexPair Sea::generateFourierAmplitude(double k_x, double k_y)
-{
-  std::complex<double> cDist(m_normalDistribution(m_randomGenerator),
-			     m_normalDistribution(m_randomGenerator));
-
-  return {cDist * sqrt(phillipsSpectrum(k_x, k_y)) / sqrt(2),
-      std::conj(cDist) * sqrt(phillipsSpectrum(-k_x, -k_y)) / sqrt(2)};
-}
-
-ComplexPair& Sea::fourierAmplitudeAt(int n, int m)
+std::complex<double>& Sea::fourierAmplitudeAt(int n, int m)
 {
   return m_fourierAmplitudes.at
     (n + m_surface->size()/2 +
@@ -120,12 +108,28 @@ double Sea::spatialFrequencyForIndex(int n) const
 void Sea::generateFourierAmplitudes()
 {
   for (int m = -m_surface->size()/2; m < m_surface->size()/2; ++m) {
+    const double k_y = spatialFrequencyForIndex(m);
+
     for (int n = -m_surface->size()/2; n < m_surface->size()/2; ++n) {
+      const double k_x = spatialFrequencyForIndex(n);
+
+      std::complex<double> cDist(m_normalDistribution(m_randomGenerator),
+				 m_normalDistribution(m_randomGenerator));
+
       fourierAmplitudeAt(n, m) =
-	generateFourierAmplitude(spatialFrequencyForIndex(n),
-				 spatialFrequencyForIndex(m));
+	cDist * sqrt(phillipsSpectrum(k_x, k_y)) / sqrt(2);
     }
   }
 
+  for (int n = -m_surface->size()/2; n < m_surface->size()/2; ++n) {
+    fourierAmplitudeAt(n, m_surface->size()/2) =
+      fourierAmplitudeAt(n, -m_surface->size()/2);
+  }
+
+  for (int m = -m_surface->size()/2; m < m_surface->size()/2; ++m) {
+    fourierAmplitudeAt(m_surface->size()/2, m) =
+      fourierAmplitudeAt(-m_surface->size()/2, m);
+  }
+
   fourierAmplitudeAt(0, 0) = {0, 0};
 }