fluidsGL_kernels.h

/*
 * Kinect Fluids - Based on NVIDIA CUDA SDK example
 * Copyright (C) 2011-2012 Cyrille Favreau <cyrille_favreau@hotmail.com>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library 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
 * Library 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/>.
 */

/*
 * Author: Cyrille Favreau <cyrille_favreau@hotmail.com>
 *
 */

#ifndef __STABLEFLUIDS_KERNELS_CUH_
#define __STABLEFLUIDS_KERNELS_CUH_

// Vector data type used to velocity and force fields
typedef float3 cData;

void setupTexture(int x, int y);
void bindTexture(void);
void unbindTexture(void);
void updateTexture(cData *data, size_t w, size_t h, size_t pitch);
void deleteTexture(void);

// This method adds constant force vectors to the velocity field 
// stored in 'v' according to v(x,t+1) = v(x,t) + dt * f.
__global__ void 
addForces_k(cData *v, int dx, int dy, int spx, int spy, float fx, float fy, int r, size_t pitch);

// This method performs the velocity advection step, where we
// trace velocity vectors back in time to update each grid cell.
// That is, v(x,t+1) = v(p(x,-dt),t). Here we perform bilinear
// interpolation in the velocity space.
__global__ void 
advectVelocity_k(cData *v, float *vx, float *vy,
                 int dx, int pdx, int dy, float dt, int lb);

// This method performs velocity diffusion and forces mass conservation 
// in the frequency domain. The inputs 'vx' and 'vy' are complex-valued 
// arrays holding the Fourier coefficients of the velocity field in
// X and Y. Diffusion in this space takes a simple form described as:
// v(k,t) = v(k,t) / (1 + visc * dt * k^2), where visc is the viscosity,
// and k is the wavenumber. The projection step forces the Fourier
// velocity vectors to be orthogonal to the wave wave vectors for each
// wavenumber: v(k,t) = v(k,t) - ((k dot v(k,t) * k) / k^2.
__global__ void 
diffuseProject_k(cData *vx, cData *vy, int dx, int dy, float dt, 
                 float visc, int lb);
    
// This method updates the velocity field 'v' using the two complex 
// arrays from the previous step: 'vx' and 'vy'. Here we scale the 
// real components by 1/(dx*dy) to account for an unnormalized FFT. 
__global__ void 
updateVelocity_k(cData *v, float *vx, float *vy, 
                 int dx, int pdx, int dy, int lb, size_t pitch);

// This method updates the particles by moving particle positions
// according to the velocity field and time step. That is, for each
// particle: p(t+1) = p(t) + dt * v(p(t)).  
__global__ void 
advectParticles_k(cData *part, cData *v, int dx, int dy, 
                  float dt, int lb, size_t pitch);

#endif