Added time_step_multiplicator for integrate_particles() function in PARTICLES extension, fixed bug in write_file() template functions

Author: ProjectPhysX

src/kernel.cpp

@@ -1922,7 +1922,7 @@ string opencl_c_container() { return R( // ########################## begin of O
 )+"#endif"+R( // FORCE_FIELD
 
 )+"#ifdef PARTICLES"+R(
-)+R(kernel void integrate_particles)+"("+R(global float* particles, const global float* u // ) {
+)+R(kernel void integrate_particles)+"("+R(global float* particles, const global float* u, const float time_step_multiplicator // ) {
 )+"#ifdef FORCE_FIELD"+R(
 	, volatile global float* F, const float fx, const float fy, const float fz
 )+"#endif"+R( // FORCE_FIELD
@@ -1937,7 +1937,7 @@ string opencl_c_container() { return R( // ########################## begin of O
 		spread_force(F, p0, Fn); // do force spreading
 	}
 )+"#endif"+R( // FORCE_FIELD
-	const float3 un = interpolate_u(mirror_position(p0), u); // trilinear interpolation of velocity at point p
+	const float3 un = interpolate_u(mirror_position(p0), u)*time_step_multiplicator; // trilinear interpolation of velocity at point p
 	const float3 p = mirror_position(p0+un); // advect particles
 	particles[                           n] = p.x;
 	particles[    def_particles_N+(ulong)n] = p.y;

src/lbm.cpp

@@ -102,7 +102,7 @@ void LBM_Domain::allocate(Device& device) {
 
 #ifdef PARTICLES
 	particles = Memory<float>(device, (ulong)particles_N, 3u);
-	kernel_integrate_particles = Kernel(device, (ulong)particles_N, "integrate_particles", particles, u);
+	kernel_integrate_particles = Kernel(device, (ulong)particles_N, "integrate_particles", particles, u, 1.0f);
 #ifdef FORCE_FIELD
 	kernel_integrate_particles.add_parameters(F, fx, fy, fz);
 #endif // FORCE_FIELD
@@ -150,17 +150,17 @@ void LBM_Domain::enqueue_update_moving_boundaries() { // mark/unmark nodes next
 }
 #endif // MOVING_BOUNDARIES
 #ifdef PARTICLES
-void LBM_Domain::enqueue_integrate_particles() { // intgegrate particles forward in time and couple particles to fluid
+void LBM_Domain::enqueue_integrate_particles(const uint time_step_multiplicator) { // intgegrate particles forward in time and couple particles to fluid
 #ifdef FORCE_FIELD
 	if(particles_rho!=1.0f) kernel_reset_force_field.enqueue_run(); // only reset force field if particles have buoyancy and apply forces on fluid
-	kernel_integrate_particles.set_parameters(3u, fx, fy, fz);
+	kernel_integrate_particles.set_parameters(4u, fx, fy, fz);
 #endif // FORCE_FIELD
-	kernel_integrate_particles.enqueue_run();
+	kernel_integrate_particles.set_parameters(2u, (float)time_step_multiplicator).enqueue_run();
 }
 #endif // PARTICLES
 
-void LBM_Domain::increment_time_step() {
-	t++; // increment time step
+void LBM_Domain::increment_time_step(const uint steps) {
+	t += (ulong)steps; // increment time step
 #ifdef UPDATE_FIELDS
 	t_last_update_fields = t;
 #endif // UPDATE_FIELDS
@@ -830,18 +830,18 @@ void LBM::update_moving_boundaries() { // mark/unmark nodes next to TYPE_S nodes
 #endif // MOVING_BOUNDARIES
 
 #if defined(PARTICLES)&&!defined(FORCE_FIELD)
-void LBM::integrate_particles(const ulong steps) { // intgegrate passive tracer particles forward in time in stationary flow field
+void LBM::integrate_particles(const ulong steps, const uint time_step_multiplicator) { // intgegrate passive tracer particles forward in time in stationary flow field
 	info.append(steps, get_t());
 	Clock clock;
-	for(ulong i=1ull; i<=steps; i++) {
+	for(ulong i=1ull; i<=steps; i+=(ulong)time_step_multiplicator) {
 #if defined(INTERACTIVE_GRAPHICS)||defined(INTERACTIVE_GRAPHICS_ASCII)
 		while(!key_P&&running) sleep(0.016);
 		if(!running) break;
 #endif // INTERACTIVE_GRAPHICS_ASCII || INTERACTIVE_GRAPHICS
 		clock.start();
-		for(uint d=0u; d<get_D(); d++) lbm[d]->enqueue_integrate_particles();
+		for(uint d=0u; d<get_D(); d++) lbm[d]->enqueue_integrate_particles(time_step_multiplicator);
 		for(uint d=0u; d<get_D(); d++) lbm[d]->finish_queue();
-		for(uint d=0u; d<get_D(); d++) lbm[d]->increment_time_step();
+		for(uint d=0u; d<get_D(); d++) lbm[d]->increment_time_step(time_step_multiplicator);
 		info.update(clock.stop());
 	}
 }

src/lbm.hpp

@@ -99,10 +99,10 @@ class LBM_Domain {
 	void enqueue_update_moving_boundaries(); // mark/unmark nodes next to TYPE_S nodes with velocity!=0 with TYPE_MS
 #endif // MOVING_BOUNDARIES
 #ifdef PARTICLES
-	void enqueue_integrate_particles(); // intgegrates particles forward in time and couples particles to fluid
+	void enqueue_integrate_particles(const uint time_step_multiplicator=1u); // intgegrates particles forward in time and couples particles to fluid
 #endif // PARTICLES
 
-	void increment_time_step(); // increment time step
+	void increment_time_step(const uint steps=1u); // increment time step
 	void reset_time_step(); // reset time step
 	void finish_queue();
 
@@ -387,7 +387,7 @@ class LBM {
 	void update_moving_boundaries(); // mark/unmark nodes next to TYPE_S nodes with velocity!=0 with TYPE_MS
 #endif // MOVING_BOUNDARIES
 #if defined(PARTICLES)&&!defined(FORCE_FIELD)
-	void integrate_particles(const ulong steps=max_ulong); // intgegrate passive tracer particles forward in time in stationary flow field
+	void integrate_particles(const ulong steps=max_ulong, const uint time_step_multiplicator=1u); // intgegrate passive tracer particles forward in time in stationary flow field
 #endif // PARTICLES&&!FORCE_FIELD
 
 	uint get_Nx() const { return Nx; } // get (global) lattice dimensions in x-direction

src/utilities.hpp

@@ -3927,13 +3927,13 @@ inline void write_line(const string& filename, const string& content="") {
 	file.write(s.c_str(), s.length());
 	file.close();
 }
-template<typename T> inline void write_file(const string& filename, const uint n, const T* y, const string& header="") {
+template<typename T> inline void write_file(const string& filename, const string& header, const uint n, const T* y) {
 	string s = header;
 	if(length(s)>0u && !ends_with(s, "\n")) s += "\n";
 	for(uint i=0u; i<n; i++) s += to_string(i)+"\t"+to_string(y[i])+"\n";
 	write_file(filename, s);
 }
-template<typename T, typename U> inline void write_file(const string& filename, const uint n, const T* x, const U* y, const string& header="") {
+template<typename T, typename U> inline void write_file(const string& filename, const string& header, const uint n, const T* x, const U* y) {
 	string s = header;
 	if(length(s)>0u && !ends_with(s, "\n")) s += "\n";
 	for(uint i=0u; i<n; i++) s += to_string(x[i])+"\t"+to_string(y[i])+"\n";