public void SimulateWaves(float t)
{
InitWaveSpectrum(t);
m_idx = m_fourier.PeformFFT(0, m_fourierBuffer0, m_fourierBuffer1, m_fourierBuffer2);
PackTextures();
}
void EvaluateWavesFFT(float t)
{
float kx, kz, len, lambda = -1.0f;
int index, index1;
for (int m_prime = 0; m_prime < N; m_prime++)
{
kz = Mathf.PI * (2.0f * m_prime - N) / m_length;
for (int n_prime = 0; n_prime < N; n_prime++)
{
kx = Mathf.PI * (2 * n_prime - N) / m_length;
len = Mathf.Sqrt(kx * kx + kz * kz);
index = m_prime * N + n_prime;
Vector2 c = InitSpectrum(t, n_prime, m_prime);
m_heightBuffer[1, index].x = c.x;
m_heightBuffer[1, index].y = c.y;
m_slopeBuffer[1, index].x = -c.y * kx;
m_slopeBuffer[1, index].y = c.x * kx;
m_slopeBuffer[1, index].z = -c.y * kz;
m_slopeBuffer[1, index].w = c.x * kz;
if (len < 0.000001f)
{
m_displacementBuffer[1, index].x = 0.0f;
m_displacementBuffer[1, index].y = 0.0f;
m_displacementBuffer[1, index].z = 0.0f;
m_displacementBuffer[1, index].w = 0.0f;
}
else
{
m_displacementBuffer[1, index].x = -c.y * -(kx / len);
m_displacementBuffer[1, index].y = c.x * -(kx / len);
m_displacementBuffer[1, index].z = -c.y * -(kz / len);
m_displacementBuffer[1, index].w = c.x * -(kz / len);
}
}
}
m_fourier.PeformFFT(0, m_heightBuffer);
m_fourier.PeformFFT(0, m_slopeBuffer);
m_fourier.PeformFFT(0, m_displacementBuffer);
Vector3[] vertices = m_mesh.vertices;
Vector3[] normals = m_mesh.normals;
int sign;
float[] signs = new float[] { 1.0f, -1.0f };
Vector3 n;
for (int m_prime = 0; m_prime < N; m_prime++)
{
for (int n_prime = 0; n_prime < N; n_prime++)
{
index = m_prime * N + n_prime; // index into buffers
index1 = m_prime * Nplus1 + n_prime; // index into vertices
sign = (int)signs[(n_prime + m_prime) & 1];
// height
vertices[index1].y = m_heightBuffer[1, index].x * sign;
// displacement
vertices[index1].x = m_position[index1].x + m_displacementBuffer[1, index].x * lambda * sign;
vertices[index1].z = m_position[index1].z + m_displacementBuffer[1, index].z * lambda * sign;
// normal
n = new Vector3(-m_slopeBuffer[1, index].x * sign, 1.0f, -m_slopeBuffer[1, index].z * sign);
n.Normalize();
normals[index1].x = n.x;
normals[index1].y = n.y;
normals[index1].z = n.z;
// for tiling
if (n_prime == 0 && m_prime == 0)
{
vertices[index1 + N + Nplus1 * N].y = m_heightBuffer[1, index].x * sign;
vertices[index1 + N + Nplus1 * N].x = m_position[index1 + N + Nplus1 * N].x + m_displacementBuffer[1, index].x * lambda * sign;
vertices[index1 + N + Nplus1 * N].z = m_position[index1 + N + Nplus1 * N].z + m_displacementBuffer[1, index].z * lambda * sign;
normals[index1 + N + Nplus1 * N].x = n.x;
normals[index1 + N + Nplus1 * N].y = n.y;
normals[index1 + N + Nplus1 * N].z = n.z;
}
if (n_prime == 0)
{
vertices[index1 + N].y = m_heightBuffer[1, index].x * sign;
vertices[index1 + N].x = m_position[index1 + N].x + m_displacementBuffer[1, index].x * lambda * sign;
vertices[index1 + N].z = m_position[index1 + N].z + m_displacementBuffer[1, index].z * lambda * sign;
normals[index1 + N].x = n.x;
normals[index1 + N].y = n.y;
normals[index1 + N].z = n.z;
}
if (m_prime == 0)
{
vertices[index1 + Nplus1 * N].y = m_heightBuffer[1, index].x * sign;
vertices[index1 + Nplus1 * N].x = m_position[index1 + Nplus1 * N].x + m_displacementBuffer[1, index].x * lambda * sign;
vertices[index1 + Nplus1 * N].z = m_position[index1 + Nplus1 * N].z + m_displacementBuffer[1, index].z * lambda * sign;
normals[index1 + Nplus1 * N].x = n.x;
normals[index1 + Nplus1 * N].y = n.y;
normals[index1 + Nplus1 * N].z = n.z;
}
}
}
m_mesh.vertices = vertices;
m_mesh.normals = normals;
m_mesh.RecalculateBounds();
}
