YouTube-simulations/mangrove.c
2022-11-20 23:17:39 +01:00

1320 lines
55 KiB
C

/*********************************************************************************/
/* */
/* Animation of wave equation in a planar domain */
/* */
/* N. Berglund, december 2012, may 2021 */
/* */
/* UPDATE 24/04: distinction between damping and "elasticity" parameters */
/* UPDATE 27/04: new billiard shapes, bug in color scheme fixed */
/* UPDATE 28/04: code made more efficient, with help of Marco Mancini */
/* */
/* Feel free to reuse, but if doing so it would be nice to drop a */
/* line to nils.berglund@univ-orleans.fr - Thanks! */
/* */
/* compile with */
/* gcc -o wave_billiard wave_billiard.c */
/* -L/usr/X11R6/lib -ltiff -lm -lGL -lGLU -lX11 -lXmu -lglut -O3 -fopenmp */
/* */
/* OMP acceleration may be more effective after executing */
/* export OMP_NUM_THREADS=2 in the shell before running the program */
/* */
/* To make a video, set MOVIE to 1 and create subfolder tif_wave */
/* It may be possible to increase parameter PAUSE */
/* */
/* create movie using */
/* ffmpeg -i wave.%05d.tif -vcodec libx264 wave.mp4 */
/* */
/*********************************************************************************/
/*********************************************************************************/
/* */
/* NB: The algorithm used to simulate the wave equation is highly paralellizable */
/* One could make it much faster by using a GPU */
/* */
/*********************************************************************************/
#include <math.h>
#include <string.h>
#include <GL/glut.h>
#include <GL/glu.h>
#include <unistd.h>
#include <sys/types.h>
#include <tiffio.h> /* Sam Leffler's libtiff library. */
#include <omp.h>
#define MOVIE 0 /* set to 1 to generate movie */
#define SAVE_MEMORY 0 /* set to 1 to save memory when writing tiff images */
/* General geometrical parameters */
#define WINWIDTH 1280 /* window width */
#define WINHEIGHT 720 /* window height */
#define NX 640 /* number of grid points on x axis */
#define NY 360 /* number of grid points on y axis */
// #define NX 1280 /* number of grid points on x axis */
// #define NY 720 /* number of grid points on y axis */
#define XMIN -2.0
#define XMAX 2.0 /* x interval */
#define YMIN -1.125
#define YMAX 1.125 /* y interval for 9/16 aspect ratio */
#define JULIA_SCALE 1.0 /* scaling for Julia sets */
/* Choice of the billiard table */
#define B_DOMAIN 20 /* choice of domain shape, see list in global_pdes.c */
// #define CIRCLE_PATTERN 1 /* pattern of circles, see list in global_pdes.c */
#define CIRCLE_PATTERN 8 /* pattern of circles, see list in global_pdes.c */
#define P_PERCOL 0.25 /* probability of having a circle in C_RAND_PERCOL arrangement */
#define NPOISSON 340 /* number of points for Poisson C_RAND_POISSON arrangement */
#define RANDOM_POLY_ANGLE 0 /* set to 1 to randomize angle of polygons */
#define LAMBDA 0.85 /* parameter controlling the dimensions of domain */
#define MU 0.03 /* parameter controlling the dimensions of domain */
#define NPOLY 3 /* number of sides of polygon */
#define APOLY 1.0 /* angle by which to turn polygon, in units of Pi/2 */
#define MDEPTH 4 /* depth of computation of Menger gasket */
#define MRATIO 3 /* ratio defining Menger gasket */
#define MANDELLEVEL 1000 /* iteration level for Mandelbrot set */
#define MANDELLIMIT 10.0 /* limit value for approximation of Mandelbrot set */
#define FOCI 1 /* set to 1 to draw focal points of ellipse */
#define NGRIDX 15 /* number of grid point for grid of disks */
#define NGRIDY 20 /* number of grid point for grid of disks */
#define X_SHOOTER -0.2
#define Y_SHOOTER -0.6
#define X_TARGET 0.4
#define Y_TARGET 0.7 /* shooter and target positions in laser fight */
#define ISO_XSHIFT_LEFT -1.65
#define ISO_XSHIFT_RIGHT 0.4
#define ISO_YSHIFT_LEFT -0.05
#define ISO_YSHIFT_RIGHT -0.05
#define ISO_SCALE 0.85 /* coordinates for isospectral billiards */
/* You can add more billiard tables by adapting the functions */
/* xy_in_billiard and draw_billiard below */
/* Physical parameters of wave equation */
#define TWOSPEEDS 1 /* set to 1 to replace hardcore boundary by medium with different speed */
#define OSCILLATE_LEFT 1 /* set to 1 to add oscilating boundary condition on the left */
#define OSCILLATE_TOPBOT 0 /* set to 1 to enforce a planar wave on top and bottom boundary */
#define X_SHIFT -0.9 /* x range on which to apply OSCILLATE_TOPBOT */
#define OMEGA 0.00133333333 /* frequency of periodic excitation */
#define K_BC 3.0 /* spatial period of periodic excitation in y direction */
#define KX_BC 10.0 /* spatial period of periodic excitation in x direction */
#define KY_BC 3.3333 /* spatial period of periodic excitation in y direction */
// #define KX_BC 20.0 /* spatial period of periodic excitation in x direction */
// #define KY_BC 6.66666 /* spatial period of periodic excitation in y direction */
// #define OMEGA 0.002 /* frequency of periodic excitation */
// #define K_BC 3.0 /* spatial period of periodic excitation in y direction */
// #define KX_BC 30.0 /* spatial period of periodic excitation in x direction */
// #define KY_BC 10.0 /* spatial period of periodic excitation in y direction */
#define AMPLITUDE 1.0 /* amplitude of periodic excitation */
#define COURANT 0.02 /* Courant number */
#define COURANTB 0.015 /* Courant number in medium B */
// #define COURANTB 0.00666 /* Courant number in medium B */
#define GAMMA 3.0e-6 /* damping factor in wave equation */
#define GAMMAB 5.0e-4 /* damping factor in wave equation */
// #define GAMMA 2.0e-6 /* damping factor in wave equation */
// #define GAMMAB 2.5e-4 /* damping factor in wave equation */
#define GAMMA_SIDES 1.0e-4 /* damping factor on boundary */
#define GAMMA_TOPBOT 1.0e-6 /* damping factor on boundary */
#define KAPPA 0.0 /* "elasticity" term enforcing oscillations */
#define KAPPAB 1.0e-6 /* "elasticity" term enforcing oscillations */
#define KAPPA_SIDES 5.0e-4 /* "elasticity" term on absorbing boundary */
#define KAPPA_TOPBOT 0.0 /* "elasticity" term on absorbing boundary */
/* The Courant number is given by c*DT/DX, where DT is the time step and DX the lattice spacing */
/* The physical damping coefficient is given by GAMMA/(DT)^2 */
/* Increasing COURANT speeds up the simulation, but decreases accuracy */
/* For similar wave forms, COURANT^2*GAMMA should be kept constant */
/* Boundary conditions, see list in global_pdes.c */
#define B_COND 3
/* Parameters for length and speed of simulation */
#define NSTEPS 2000 /* number of frames of movie */
// #define NSTEPS 5500 /* number of frames of movie */
#define NVID 60 /* number of iterations between images displayed on screen */
#define NSEG 100 /* number of segments of boundary */
#define INITIAL_TIME 100 /* time after which to start saving frames */
#define BOUNDARY_WIDTH 2 /* width of billiard boundary */
#define PAUSE 1000 /* number of frames after which to pause */
#define PSLEEP 1 /* sleep time during pause */
#define SLEEP1 1 /* initial sleeping time */
#define SLEEP2 1 /* final sleeping time */
#define END_FRAMES 100 /* number of still frames at end of movie */
/* Parameters of initial condition */
#define INITIAL_AMP 0.2 /* amplitude of initial condition */
#define INITIAL_VARIANCE 0.002 /* variance of initial condition */
#define INITIAL_WAVELENGTH 0.1 /* wavelength of initial condition */
/* Plot type, see list in global_pdes.c */
#define PLOT 0
/* Color schemes */
#define COLOR_PALETTE 0 /* Color palette, see list in global_pdes.c */
#define BLACK 1 /* background */
#define COLOR_SCHEME 1 /* choice of color scheme, see list in global_pdes.c */
#define SCALE 0 /* set to 1 to adjust color scheme to variance of field */
#define SLOPE 1.0 /* sensitivity of color on wave amplitude */
#define PHASE_FACTOR 1.0 /* factor in computation of phase in color scheme P_3D_PHASE */
#define PHASE_SHIFT 0.0 /* shift of phase in color scheme P_3D_PHASE */
#define ATTENUATION 0.0 /* exponential attenuation coefficient of contrast with time */
#define E_SCALE 2500.0 /* scaling factor for energy representation */
#define LOG_SCALE 1.0 /* scaling factor for energy log representation */
#define LOG_SHIFT 0.0 /* shift of colors on log scale */
#define FLUX_SCALE 1.0e4 /* scaling factor for enegy flux represtnation */
#define RESCALE_COLOR_IN_CENTER 0 /* set to 1 to decrease color intentiy in the center (for wave escaping ring) */
#define COLORHUE 260 /* initial hue of water color for scheme C_LUM */
#define COLORDRIFT 0.0 /* how much the color hue drifts during the whole simulation */
#define LUMMEAN 0.5 /* amplitude of luminosity variation for scheme C_LUM */
#define LUMAMP 0.3 /* amplitude of luminosity variation for scheme C_LUM */
#define HUEMEAN 220.0 /* mean value of hue for color scheme C_HUE */
#define HUEAMP -50.0 /* amplitude of variation of hue for color scheme C_HUE */
/* mangrove properties */
#define MANGROVE_HUE_MIN 180.0 /* color of original mangrove */
#define MANGROVE_HUE_MAX -50.0 /* color of saturated mangrove */
// #define MANGROVE_EMAX 5.0e-3 /* max energy for mangrove to survive */
#define MANGROVE_EMAX 1.5e-3 /* max energy for mangrove to survive */
#define RANDOM_RADIUS 1 /* set to 1 for random circle radius */
#define ERODE_MANGROVES 1 /* set to 1 for mangroves to be eroded */
#define RECOVER_MANGROVES 1 /* set to 1 to allow mangroves to recover */
#define MOVE_MANGROVES 1 /* set to 1 for mobile mangroves */
#define DETACH_MANGROVES 1 /* set to 1 for mangroves to be able to detach */
#define INERTIA 1 /* set to 1 for taking inertia into account */
#define REPELL_MANGROVES 1 /* set to 1 for mangroves to repell each other */
#define DT_MANGROVE 0.1 /* time step for mangrove displacement */
#define KSPRING 0.05 /* spring constant of mangroves */
#define KWAVE 4.0 /* constant in force due to wave gradient */
#define KREPEL 5.0 /* constant in repelling force between mangroves */
#define REPEL_RADIUS 1.1 /* radius in which repelling force acts (in units of mangrove radius) */
#define DXMAX 0.02 /* max displacement of mangrove in one time step */
#define L_DETACH 0.25 /* spring length beyond which mangroves detach */
#define DAMP_MANGROVE 0.1 /* damping coefficient of mangroves */
#define MANGROVE_MASS 1.5 /* mass of mangrove of radius MU */
#define HASHX 25 /* size of hashgrid in x direction */
#define HASHY 15 /* size of hashgrid in y direction */
#define HASHMAX 10 /* maximal number of mangroves per hashgrid cell */
#define HASHGRID_PADDING 0.1 /* padding of hashgrid outside simulation window */
#define DRAW_COLOR_SCHEME 0 /* set to 1 to plot the color scheme */
#define COLORBAR_RANGE 8.0 /* scale of color scheme bar */
#define COLORBAR_RANGE_B 12.0 /* scale of color scheme bar for 2nd part */
#define ROTATE_COLOR_SCHEME 0 /* set to 1 to draw color scheme horizontally */
/* For debugging purposes only */
#define FLOOR 1 /* set to 1 to limit wave amplitude to VMAX */
#define VMAX 10.0 /* max value of wave amplitude */
/* the following constants are only used by wave_billiard and wave_3d so far */
#define COMPARISON 0 /* set to 1 to compare two different patterns */
#define B_DOMAIN_B 20 /* second domain shape, for comparisons */
#define CIRCLE_PATTERN_B 0 /* second pattern of circles or polygons */
#define OSCILLATION_SCHEDULE 3 /* oscillation schedule, see list in global_pdes.c */
#define ACHIRP 0.2 /* acceleration coefficient in chirp */
#define DAMPING 0.0 /* damping of periodic excitation */
/* end of constants only used by wave_billiard and wave_3d */
/* for compatibility with sub_wave and sub_maze */
#define NXMAZE 7 /* width of maze */
#define NYMAZE 7 /* height of maze */
#define MAZE_MAX_NGBH 4 /* max number of neighbours of maze cell */
#define RAND_SHIFT 24 /* seed of random number generator */
#define MAZE_XSHIFT 0.0 /* horizontal shift of maze */
#define ADD_POTENTIAL 0
#define POT_MAZE 7
#define POTENTIAL 0
/* end of constants only used by sub_wave and sub_maze */
#include "global_pdes.c"
#include "sub_maze.c" /* support for generating mazes */
#include "sub_wave.c"
#include "wave_common.c"
double courant2, courantb2; /* Courant parameters squared */
typedef struct
{
double xc, yc, radius; /* center and radius of circle */
short int active; /* circle is active */
double energy; /* dissipated energy */
double yc_wrapped; /* position of circle centers wrapped vertically */
double anchorx; /* points moving circles are attached to */
double anchory; /* points moving circles are attached to */
double vx; /* x velocity of circles */
double vy; /* y velocity of circles */
double radius_initial; /* initial circle radii */
double mass_inv; /* inverse of mangrove mass */
short int attached; /* has value 1 if the circle is attached to its anchor */
int hashx; /* hash grid positions of mangroves */
int hashy; /* hash grid positions of mangroves */
} t_mangrove;
typedef struct
{
int number; /* total number of mangroves in cell */
int mangroves[HASHMAX]; /* numbers of mangroves in cell */
} t_hashgrid;
/*********************/
/* animation part */
/*********************/
void init_bc_phase(double left_bc[NY], double top_bc[NX], double bot_bc[NX])
/* initialize boundary condition phase KX*x + KY*y */
{
int i, j;
double xy[2];
for (j=0; j<NY; j++)
{
ij_to_xy(0, j, xy);
left_bc[j] = KX_BC*XMIN + KY_BC*xy[1];
}
for (i=0; i<NX; i++)
{
ij_to_xy(i, 0, xy);
bot_bc[i] = KX_BC*xy[0] + KY_BC*YMIN;
top_bc[i] = KX_BC*xy[0] + KY_BC*YMAX;
}
}
// void evolve_wave_half_old(double *phi_in[NX], double *psi_in[NX], double *phi_out[NX], double *psi_out[NX],
// short int *xy_in[NX])
// // void evolve_wave_half(phi_in, psi_in, phi_out, psi_out, xy_in)
// /* time step of field evolution */
// /* phi is value of field at time t, psi at time t-1 */
// {
// int i, j, iplus, iminus, jplus, jminus, tb_shift;
// double delta, x, y, c, cc, gamma, kappa, phase, phasemin;
// static long time = 0;
// static int init_bc = 1;
// static double left_bc[NY], top_bc[NX], bot_bc[NX];
//
// time++;
//
// /* initialize boundary condition phase KX*x + KY*y */
// if ((OSCILLATE_LEFT)&&(init_bc))
// {
// init_bc_phase(left_bc, top_bc, bot_bc);
// tb_shift = (int)((X_SHIFT - XMIN)*(double)NX/(XMAX - XMIN));
// printf("tb_shift %i\n", tb_shift);
// init_bc = 0;
// }
//
// #pragma omp parallel for private(i,j,iplus,iminus,jplus,jminus,delta,x,y,c,cc,gamma,kappa)
// for (i=0; i<NX; i++){
// for (j=0; j<NY; j++){
// if (xy_in[i][j])
// {
// c = COURANT;
// cc = courant2;
// gamma = GAMMA;
// kappa = KAPPA;
// }
// else if (TWOSPEEDS)
// {
// c = COURANTB;
// cc = courantb2;
// gamma = GAMMAB;
// kappa = KAPPAB;
// }
//
// if ((TWOSPEEDS)||(xy_in[i][j])){
// /* discretized Laplacian for various boundary conditions */
// if ((B_COND == BC_DIRICHLET)||(B_COND == BC_ABSORBING))
// {
// iplus = (i+1); if (iplus == NX) iplus = NX-1;
// iminus = (i-1); if (iminus == -1) iminus = 0;
// jplus = (j+1); if (jplus == NY) jplus = NY-1;
// jminus = (j-1); if (jminus == -1) jminus = 0;
// }
// else if (B_COND == BC_PERIODIC)
// {
// iplus = (i+1) % NX;
// iminus = (i-1) % NX;
// if (iminus < 0) iminus += NX;
// jplus = (j+1) % NY;
// jminus = (j-1) % NY;
// if (jminus < 0) jminus += NY;
// }
// else if (B_COND == BC_VPER_HABS)
// {
// iplus = (i+1); if (iplus == NX) iplus = NX-1;
// iminus = (i-1); if (iminus == -1) iminus = 0;
// jplus = (j+1) % NY;
// jminus = (j-1) % NY;
// if (jminus < 0) jminus += NY;
// }
//
// /* imposing linear wave on top and bottom by making Laplacian 1d */
// if ((OSCILLATE_TOPBOT)&&(i < tb_shift))
// {
// if (j == NY-1)
// {
// jminus = NY-1;
// jplus = NY-1;
// }
// else if (j == 0)
// {
// jminus = 0;
// jplus = 0;
// }
// }
//
// delta = phi_in[iplus][j] + phi_in[iminus][j] + phi_in[i][jplus] + phi_in[i][jminus] - 4.0*phi_in[i][j];
//
// x = phi_in[i][j];
// y = psi_in[i][j];
//
// /* evolve phi */
// if ((B_COND == BC_PERIODIC)||(B_COND == BC_DIRICHLET))
// phi_out[i][j] = -y + 2*x + cc*delta - kappa*x - gamma*(x-y);
// else if (B_COND == BC_ABSORBING)
// {
// if ((i>0)&&(i<NX-1)&&(j>0)&&(j<NY-1))
// phi_out[i][j] = -y + 2*x + cc*delta - kappa*x - gamma*(x-y);
//
// /* upper border */
// else if (j==NY-1)
// phi_out[i][j] = x - c*(x - phi_in[i][NY-2]) - KAPPA_TOPBOT*x - GAMMA_TOPBOT*(x-y);
//
// /* lower border */
// else if (j==0)
// phi_out[i][j] = x - c*(x - phi_in[i][1]) - KAPPA_TOPBOT*x - GAMMA_TOPBOT*(x-y);
//
// /* right border */
// if (i==NX-1)
// phi_out[i][j] = x - c*(x - phi_in[NX-2][j]) - KAPPA_SIDES*x - GAMMA_SIDES*(x-y);
//
// /* left border */
// else if (i==0)
// phi_out[i][j] = x - c*(x - phi_in[1][j]) - KAPPA_SIDES*x - GAMMA_SIDES*(x-y);
// }
// else if (B_COND == BC_VPER_HABS)
// {
// if ((i>0)&&(i<NX-1))
// phi_out[i][j] = -y + 2*x + cc*delta - kappa*x - gamma*(x-y);
//
// /* right border */
// else if (i==NX-1)
// phi_out[i][j] = x - c*(x - phi_in[NX-2][j]) - KAPPA_SIDES*x - GAMMA_SIDES*(x-y);
//
// /* left border */
// else if (i==0)
// phi_out[i][j] = x - c*(x - phi_in[1][j]) - KAPPA_SIDES*x - GAMMA_SIDES*(x-y);
// }
// psi_out[i][j] = x;
//
// /* add oscillating boundary condition on the left */
// // if ((i == 0)&&(OSCILLATE_LEFT))
// // {
// // phase = (double)time*OMEGA - DPI*K_BC*(double)j/(double)NY;
// // if (phase < 0.0) phase = 0.0;
// // phi_out[i][j] = AMPLITUDE*sin(phase);
// // }
//
// /* add oscillating boundary condition on the left */
// if (OSCILLATE_LEFT)
// {
// phasemin = left_bc[0];
// if (i == 0)
// {
// phase = (double)time*OMEGA - left_bc[j] + phasemin;
// if (phase < 0.0) phase = 0.0;
// phi_out[i][j] = AMPLITUDE*sin(phase);
// }
// if ((j == 0)&&(i < tb_shift))
// {
// phase = (double)time*OMEGA - bot_bc[i] + phasemin;
// if (phase < 0.0) phase = 0.0;
// phi_out[i][j] = AMPLITUDE*sin(phase);
// }
// else if ((j == NY-1)&&(i < tb_shift))
// {
// phase = (double)time*OMEGA - top_bc[i] + phasemin;
// if (phase < 0.0) phase = 0.0;
// phi_out[i][j] = AMPLITUDE*sin(phase);
// }
// }
//
// if (FLOOR)
// {
// if (phi_out[i][j] > VMAX) phi_out[i][j] = VMAX;
// if (phi_out[i][j] < -VMAX) phi_out[i][j] = -VMAX;
// if (psi_out[i][j] > VMAX) psi_out[i][j] = VMAX;
// if (psi_out[i][j] < -VMAX) psi_out[i][j] = -VMAX;
// }
// }
// }
// }
// // printf("phi(0,0) = %.3lg, psi(0,0) = %.3lg\n", phi[NX/2][NY/2], psi[NX/2][NY/2]);
// }
void evolve_wave_half(double *phi_in[NX], double *psi_in[NX], double *phi_out[NX],
short int *xy_in[NX])
/* time step of field evolution */
/* phi is value of field at time t, psi at time t-1 */
/* this version of the function has been rewritten in order to minimize the number of if-branches */
{
int i, j, iplus, iminus, jplus, jminus, tb_shift;
double delta, x, y, c, cc, gamma, kappa, phase, phasemin;
static long time = 0;
static double tc[NX][NY], tcc[NX][NY], tgamma[NX][NY], left_bc[NY], top_bc[NX], bot_bc[NX];
static short int first = 1, init_bc = 1;
time++;
/* initialize boundary condition phase KX*x + KY*y */
if ((OSCILLATE_LEFT)&&(init_bc))
{
init_bc_phase(left_bc, top_bc, bot_bc);
tb_shift = (int)((X_SHIFT - XMIN)*(double)NX/(XMAX - XMIN));
printf("tb_shift %i\n", tb_shift);
init_bc = 0;
}
/* initialize tables with wave speeds and dissipation */
// if (first)
{
for (i=0; i<NX; i++){
for (j=0; j<NY; j++){
if (xy_in[i][j] != 0)
{
tc[i][j] = COURANT;
tcc[i][j] = courant2;
if (xy_in[i][j] == 1) tgamma[i][j] = GAMMA;
else tgamma[i][j] = GAMMAB;
}
else if (TWOSPEEDS)
{
tc[i][j] = COURANTB;
tcc[i][j] = courantb2;
tgamma[i][j] = GAMMAB;
}
}
}
// first = 0;
}
#pragma omp parallel for private(i,j,iplus,iminus,jplus,jminus,delta,x,y)
/* evolution in the bulk */
for (i=1; i<NX-1; i++){
for (j=1; j<NY-1; j++){
if ((TWOSPEEDS)||(xy_in[i][j] != 0)){
x = phi_in[i][j];
y = psi_in[i][j];
/* discretized Laplacian */
delta = phi_in[i+1][j] + phi_in[i-1][j] + phi_in[i][j+1] + phi_in[i][j-1] - 4.0*x;
/* evolve phi */
phi_out[i][j] = -y + 2*x + tcc[i][j]*delta - KAPPA*x - tgamma[i][j]*(x-y);
}
}
}
/* left boundary */
// if (OSCILLATE_LEFT) for (j=1; j<NY-1; j++) phi_out[0][j] = AMPLITUDE*cos((double)time*OMEGA);
if (OSCILLATE_LEFT) for (j=1; j<NY-1; j++)
{
phasemin = left_bc[0];
phase = (double)time*OMEGA - left_bc[j] + phasemin;
if (phase < 0.0) phase = 0.0;
phi_out[0][j] = AMPLITUDE*sin(phase);
}
else for (j=1; j<NY-1; j++){
if ((TWOSPEEDS)||(xy_in[0][j] != 0)){
x = phi_in[0][j];
y = psi_in[0][j];
switch (B_COND) {
case (BC_DIRICHLET):
{
delta = phi_in[1][j] + phi_in[0][j+1] + phi_in[0][j-1] - 3.0*x;
phi_out[0][j] = -y + 2*x + tcc[0][j]*delta - KAPPA*x - tgamma[0][j]*(x-y);
break;
}
case (BC_PERIODIC):
{
delta = phi_in[1][j] + phi_in[NX-1][j] + phi_in[0][j+1] + phi_in[0][j-1] - 4.0*x;
phi_out[0][j] = -y + 2*x + tcc[0][j]*delta - KAPPA*x - tgamma[0][j]*(x-y);
break;
}
case (BC_ABSORBING):
{
delta = phi_in[1][j] + phi_in[0][j+1] + phi_in[0][j-1] - 3.0*x;
phi_out[0][j] = x - tc[0][j]*(x - phi_in[1][j]) - KAPPA_SIDES*x - GAMMA_SIDES*(x-y);
break;
}
case (BC_VPER_HABS):
{
delta = phi_in[1][j] + phi_in[0][j+1] + phi_in[0][j-1] - 3.0*x;
phi_out[0][j] = x - tc[0][j]*(x - phi_in[1][j]) - KAPPA_SIDES*x - GAMMA_SIDES*(x-y);
break;
}
}
}
}
/* right boundary */
for (j=1; j<NY-1; j++){
if ((TWOSPEEDS)||(xy_in[NX-1][j] != 0)){
x = phi_in[NX-1][j];
y = psi_in[NX-1][j];
switch (B_COND) {
case (BC_DIRICHLET):
{
delta = phi_in[NX-2][j] + phi_in[NX-1][j+1] + phi_in[NX-1][j-1] - 3.0*x;
phi_out[NX-1][j] = -y + 2*x + tcc[NX-1][j]*delta - KAPPA*x - tgamma[NX-1][j]*(x-y);
break;
}
case (BC_PERIODIC):
{
delta = phi_in[NX-2][j] + phi_in[0][j] + phi_in[NX-1][j+1] + phi_in[NX-1][j-1] - 4.0*x;
phi_out[NX-1][j] = -y + 2*x + tcc[NX-1][j]*delta - KAPPA*x - tgamma[NX-1][j]*(x-y);
break;
}
case (BC_ABSORBING):
{
delta = phi_in[NX-2][j] + phi_in[NX-1][j+1] + phi_in[NX-1][j-1] - 3.0*x;
phi_out[NX-1][j] = x - tc[NX-1][j]*(x - phi_in[NX-2][j]) - KAPPA_SIDES*x - GAMMA_SIDES*(x-y);
break;
}
case (BC_VPER_HABS):
{
delta = phi_in[NX-2][j] + phi_in[NX-1][j+1] + phi_in[NX-1][j-1] - 3.0*x;
phi_out[NX-1][j] = x - tc[NX-1][j]*(x - phi_in[NX-2][j]) - KAPPA_SIDES*x - GAMMA_SIDES*(x-y);
break;
}
}
}
}
/* top boundary */
for (i=0; i<NX; i++){
if ((TWOSPEEDS)||(xy_in[i][NY-1] != 0)){
x = phi_in[i][NY-1];
y = psi_in[i][NY-1];
if ((OSCILLATE_TOPBOT)&&(i < tb_shift))
{
iplus = i+1;
iminus = i-1; if (iminus < 0) iminus = 0;
delta = phi_in[iplus][NY-1] + phi_in[iminus][NY-1] + - 2.0*x;
phi_out[i][NY-1] = -y + 2*x + tcc[i][NY-1]*delta - KAPPA*x - tgamma[i][NY-1]*(x-y);
}
else if ((OSCILLATE_LEFT)&&(i < tb_shift))
{
phasemin = left_bc[0];
phase = (double)time*OMEGA - top_bc[i] + phasemin;
if (phase < 0.0) phase = 0.0;
phi_out[i][NY-1] = AMPLITUDE*sin(phase);
}
else switch (B_COND) {
case (BC_DIRICHLET):
{
iplus = (i+1); if (iplus == NX) iplus = NX-1;
iminus = (i-1); if (iminus == -1) iminus = 0;
delta = phi_in[iplus][NY-1] + phi_in[iminus][NY-1] + phi_in[i][NY-2] - 3.0*x;
phi_out[i][NY-1] = -y + 2*x + tcc[i][NY-1]*delta - KAPPA*x - tgamma[i][NY-1]*(x-y);
break;
}
case (BC_PERIODIC):
{
iplus = (i+1) % NX;
iminus = (i-1) % NX;
if (iminus < 0) iminus += NX;
delta = phi_in[iplus][NY-1] + phi_in[iminus][NY-1] + phi_in[i][NY-2] + phi_in[i][0] - 4.0*x;
phi_out[i][NY-1] = -y + 2*x + tcc[i][NY-1]*delta - KAPPA*x - tgamma[i][NY-1]*(x-y);
break;
}
case (BC_ABSORBING):
{
iplus = (i+1); if (iplus == NX) iplus = NX-1;
iminus = (i-1); if (iminus == -1) iminus = 0;
delta = phi_in[iplus][NY-1] + phi_in[iminus][NY-1] + phi_in[i][NY-2] - 3.0*x;
phi_out[i][NY-1] = x - tc[i][NY-1]*(x - phi_in[i][NY-2]) - KAPPA_TOPBOT*x - GAMMA_TOPBOT*(x-y);
break;
}
case (BC_VPER_HABS):
{
iplus = (i+1); if (iplus == NX) iplus = NX-1;
iminus = (i-1); if (iminus == -1) iminus = 0;
delta = phi_in[iplus][NY-1] + phi_in[iminus][NY-1] + phi_in[i][NY-2] + phi_in[i][0] - 4.0*x;
phi_out[i][NY-1] = -y + 2*x + tcc[i][NY-1]*delta - KAPPA*x - tgamma[i][NY-1]*(x-y);
break;
}
}
}
}
/* bottom boundary */
for (i=0; i<NX; i++){
if ((TWOSPEEDS)||(xy_in[i][0] != 0)){
x = phi_in[i][0];
y = psi_in[i][0];
if ((OSCILLATE_TOPBOT)&&(i < tb_shift))
{
iplus = i+1;
iminus = i-1; if (iminus < 0) iminus = 0;
delta = phi_in[iplus][0] + phi_in[iminus][0] + - 2.0*x;
phi_out[i][0] = -y + 2*x + tcc[i][0]*delta - KAPPA*x - tgamma[i][0]*(x-y);
}
else if ((OSCILLATE_LEFT)&&(i < tb_shift))
{
phasemin = left_bc[0];
phase = (double)time*OMEGA - bot_bc[i] + phasemin;
if (phase < 0.0) phase = 0.0;
phi_out[i][0] = AMPLITUDE*sin(phase);
}
else switch (B_COND) {
case (BC_DIRICHLET):
{
iplus = (i+1); if (iplus == NX) iplus = NX-1;
iminus = (i-1); if (iminus == -1) iminus = 0;
delta = phi_in[iplus][0] + phi_in[iminus][0] + phi_in[i][1] - 3.0*x;
phi_out[i][0] = -y + 2*x + tcc[i][0]*delta - KAPPA*x - tgamma[i][0]*(x-y);
break;
}
case (BC_PERIODIC):
{
iplus = (i+1) % NX;
iminus = (i-1) % NX;
if (iminus < 0) iminus += NX;
delta = phi_in[iplus][0] + phi_in[iminus][0] + phi_in[i][1] + phi_in[i][NY-1] - 4.0*x;
phi_out[i][0] = -y + 2*x + tcc[i][0]*delta - KAPPA*x - tgamma[i][0]*(x-y);
break;
}
case (BC_ABSORBING):
{
iplus = (i+1); if (iplus == NX) iplus = NX-1;
iminus = (i-1); if (iminus == -1) iminus = 0;
delta = phi_in[iplus][0] + phi_in[iminus][0] + phi_in[i][1] - 3.0*x;
phi_out[i][0] = x - tc[i][0]*(x - phi_in[i][1]) - KAPPA_TOPBOT*x - GAMMA_TOPBOT*(x-y);
break;
}
case (BC_VPER_HABS):
{
iplus = (i+1); if (iplus == NX) iplus = NX-1;
iminus = (i-1); if (iminus == -1) iminus = 0;
delta = phi_in[iplus][0] + phi_in[iminus][0] + phi_in[i][1] + phi_in[i][NY-1] - 4.0*x;
phi_out[i][0] = -y + 2*x + tcc[i][0]*delta - KAPPA*x - tgamma[i][0]*(x-y);
break;
}
}
}
}
/* add oscillating boundary condition on the left corners - NEEDED ? */
if ((i == 0)&&(OSCILLATE_LEFT))
{
phi_out[i][0] = AMPLITUDE*cos((double)time*OMEGA);
phi_out[i][NY-1] = AMPLITUDE*cos((double)time*OMEGA);
}
/* for debugging purposes/if there is a risk of blow-up */
if (FLOOR) for (i=0; i<NX; i++){
for (j=0; j<NY; j++){
if (xy_in[i][j] != 0)
{
if (phi_out[i][j] > VMAX) phi_out[i][j] = VMAX;
if (phi_out[i][j] < -VMAX) phi_out[i][j] = -VMAX;
}
}
}
}
void evolve_wave(double *phi[NX], double *psi[NX], double *tmp[NX], short int *xy_in[NX])
/* time step of field evolution */
/* phi is value of field at time t, psi at time t-1 */
{
evolve_wave_half(phi, psi, tmp, xy_in);
evolve_wave_half(tmp, phi, psi, xy_in);
evolve_wave_half(psi, tmp, phi, xy_in);
}
void hash_xy_to_ij(double x, double y, int ij[2])
{
static int first = 1;
static double lx, ly;
int i, j;
if (first)
{
lx = XMAX - XMIN + 2.0*HASHGRID_PADDING;
ly = YMAX - YMIN + 2.0*HASHGRID_PADDING;
first = 0;
}
i = (int)((double)HASHX*(x - XMIN + HASHGRID_PADDING)/lx);
j = (int)((double)HASHY*(y - YMIN + HASHGRID_PADDING)/ly);
if (i<0) i = 0;
if (i>=HASHX) i = HASHX-1;
if (j<0) j = 0;
if (j>=HASHY) j = HASHY-1;
ij[0] = i;
ij[1] = j;
// printf("Mapped (%.3f,%.3f) to (%i, %i)\n", x, y, ij[0], ij[1]);
}
void compute_repelling_force(int i, int j, double force[2], t_mangrove* mangrove)
/* compute repelling force of mangrove j on mangrove i */
{
double x1, y1, x2, y2, distance, r, f;
x1 = mangrove[i].xc;
y1 = mangrove[i].yc;
x2 = mangrove[j].xc;
y2 = mangrove[j].yc;
distance = module2(x2 - x1, y2 - y1);
r = mangrove[i].radius + mangrove[j].radius;
if (r <= 0.0) r = 0.001*MU;
f = KREPEL/(0.001 + distance*distance);
if ((distance > 0.0)&&(distance < REPEL_RADIUS*r))
{
force[0] = f*(x1 - x2)/distance;
force[1] = f*(y1 - y2)/distance;
}
else
{
force[0] = 0.0;
force[1] = 0.0;
}
}
void update_hashgrid(t_mangrove* mangrove, int* hashgrid_number, int* hashgrid_mangroves)
{
int i, j, k, n, m, ij[2], max = 0;
printf("Updating hashgrid_number\n");
for (i=0; i<HASHX*HASHY; i++) hashgrid_number[i] = 0;
printf("Updated hashgrid_number\n");
/* place each mangrove in hash grid */
for (k=1; k<ncircles; k++)
// if (circleactive[k])
{
// printf("placing circle %i\t", k);
hash_xy_to_ij(mangrove[k].xc, mangrove[k].yc, ij);
i = ij[0]; j = ij[1];
// printf("ij = (%i, %i)\t", i, j);
n = hashgrid_number[i*HASHY + j];
m = i*HASHY*HASHMAX + j*HASHMAX + n;
// printf("n = %i, m = %i\n", n, m);
if (m < HASHX*HASHY*HASHMAX) hashgrid_mangroves[m] = k;
else printf("Too many mangroves in hash cell, try increasing HASHMAX\n");
hashgrid_number[i*HASHY + j]++;
mangrove[k].hashx = i;
mangrove[k].hashy = j;
if (n > max) max = n;
// printf("Placed mangrove %i at (%i,%i) in hashgrid\n", k, ij[0], ij[1]);
// printf("%i mangroves at (%i,%i)\n", hashgrid_number[ij[0]][ij[1]], ij[0], ij[1]);
}
printf("Maximal number of mangroves per hash cell: %i\n", max);
}
void animation()
{
double time, scale, diss, rgb[3], hue, y, dissip, ej, gradient[2], dx, dy, dt, xleft, xright,
length, fx, fy, force[2];
double *phi[NX], *psi[NX], *tmp[NX];
short int *xy_in[NX], redraw = 0;
int i, j, k, n, s, ij[2], i0, iplus, iminus, j0, jplus, jminus, p, q;
static int imin, imax;
static short int first = 1;
t_mangrove *mangrove;
int *hashgrid_number, *hashgrid_mangroves;
t_hashgrid *hashgrid;
/* Since NX and NY are big, it seemed wiser to use some memory allocation here */
for (i=0; i<NX; i++)
{
phi[i] = (double *)malloc(NY*sizeof(double));
psi[i] = (double *)malloc(NY*sizeof(double));
tmp[i] = (double *)malloc(NY*sizeof(double));
xy_in[i] = (short int *)malloc(NY*sizeof(short int));
}
mangrove = (t_mangrove *)malloc(NMAXCIRCLES*sizeof(t_mangrove)); /* mangroves */
hashgrid = (t_hashgrid *)malloc(HASHX*HASHY*sizeof(t_hashgrid)); /* hashgrid */
hashgrid_number = (int *)malloc(HASHX*HASHY*sizeof(int)); /* total number of mangroves in each hash grid cell */
hashgrid_mangroves = (int *)malloc(HASHX*HASHY*HASHMAX*sizeof(int)); /* numbers of mangroves in each hash grid cell */
/* initialise positions and radii of circles */
if ((B_DOMAIN == D_CIRCLES)||(B_DOMAIN == D_CIRCLES_IN_RECT)) ncircles = init_circle_config(circles);
else if (B_DOMAIN == D_POLYGONS) ncircles = init_polygon_config(polygons);
courant2 = COURANT*COURANT;
courantb2 = COURANTB*COURANTB;
// dt = 0.01;
/* initialize wave with a drop at one point, zero elsewhere */
init_wave_flat(phi, psi, xy_in);
/* initialise mangroves */
for (i=0; i < ncircles; i++)
{
/* to avoid having to recode init_circle_config, would be more elegant in C++ */
mangrove[i].xc = circles[i].xc;
mangrove[i].yc = circles[i].yc;
mangrove[i].radius = circles[i].radius;
mangrove[i].active = circles[i].active;
mangrove[i].energy = 0.0;
y = mangrove[i].yc;
if (y >= YMAX) y -= mangrove[i].radius;
if (y <= YMIN) y += mangrove[i].radius;
// if (y >= YMAX) y -= (YMAX - YMIN);
// if (y <= YMIN) y += (YMAX - YMIN);
mangrove[i].yc_wrapped = y;
// mangrove[i].active = 1;
if (RANDOM_RADIUS) mangrove[i].radius = mangrove[i].radius*(0.75 + 0.5*((double)rand()/RAND_MAX));
mangrove[i].radius_initial = mangrove[i].radius;
mangrove[i].attached = 1;
mangrove[i].mass_inv = MU*MU/(MANGROVE_MASS*mangrove[i].radius*mangrove[i].radius);
if (MOVE_MANGROVES)
{
mangrove[i].anchorx = mangrove[i].xc;
mangrove[i].anchory = mangrove[i].yc_wrapped;
// mangrove[i].anchory = mangrove[i].yc;
}
if (INERTIA)
{
mangrove[i].vx = 0.0;
mangrove[i].vy = 0.0;
}
}
/* initialise hash table for interacting mangroves */
if (REPELL_MANGROVES) update_hashgrid(mangrove, hashgrid_number, hashgrid_mangroves);
if (first) /* compute box limits where circles are reset */
{
/* find leftmost and rightmost circle */
for (i=0; i<ncircles; i++)
if ((mangrove[i].active)&&(mangrove[i].xc - mangrove[i].radius < xleft)) xleft = mangrove[i].xc - mangrove[i].radius;
for (i=0; i<ncircles; i++)
if ((mangrove[i].active)&&(mangrove[i].xc + mangrove[i].radius > xright)) xright = mangrove[i].xc + mangrove[i].radius;
xy_to_ij(xleft, 0.0, ij);
imin = ij[0] - 10;
if (imin < 0) imin = 0;
xy_to_ij(xright, 0.0, ij);
imax = ij[0];
if (imax >= NX) imax = NX-1;
first = 0;
printf("xleft = %.3lg, xright = %.3lg, imin = %i, imax = %i\n", xleft, xright, imin, imax);
}
blank();
glColor3f(0.0, 0.0, 0.0);
draw_wave(phi, psi, xy_in, 1.0, 0, PLOT);
draw_billiard(0, 1.0);
glutSwapBuffers();
sleep(SLEEP1);
for (i=0; i<=INITIAL_TIME + NSTEPS; i++)
{
printf("Computing frame %d\n",i);
/* compute the variance of the field to adjust color scheme */
/* the color depends on the field divided by sqrt(1 + variance) */
if (SCALE)
{
scale = sqrt(1.0 + compute_variance(phi,psi, xy_in));
// printf("Scaling factor: %5lg\n", scale);
}
else scale = 1.0;
printf("Drawing wave\n");
draw_wave(phi, psi, xy_in, scale, i, PLOT);
printf("Evolving wave\n");
for (j=0; j<NVID; j++)
{
// printf("%i ", j);
evolve_wave(phi, psi, tmp, xy_in);
// if (i % 10 == 9) oscillate_linear_wave(0.2*scale, 0.15*(double)(i*NVID + j), -1.5, YMIN, -1.5, YMAX, phi, psi);
}
/* move mangroves */
if (MOVE_MANGROVES) for (j=0; j<ncircles; j++) if (mangrove[j].active)
{
compute_gradient(phi, psi, mangrove[j].xc, mangrove[j].yc_wrapped, gradient);
// printf("gradient = (%.3lg, %.3lg)\t", gradient[0], gradient[1]);
// if (j%NGRIDY == 0) printf("gradient (%.3lg, %.3lg)\n", gradient[0], gradient[1]);
// if (j%NGRIDY == 0) printf("circle %i (%.3lg, %.3lg) -> ", j, mangrove[j].xc, mangrove[j].yc);
/* compute force of wave */
dx = DT_MANGROVE*KWAVE*gradient[0];
dy = DT_MANGROVE*KWAVE*gradient[1];
/* compute force of spring */
if (mangrove[j].attached)
{
dx += DT_MANGROVE*(-KSPRING*(mangrove[j].xc - mangrove[j].anchorx));
dy += DT_MANGROVE*(-KSPRING*(mangrove[j].yc_wrapped - mangrove[j].anchory));
}
/* compute repelling force from other mangroves */
if (REPELL_MANGROVES)
{
/* determine neighboring grid points */
i0 = mangrove[j].hashx;
iminus = i0 - 1; if (iminus < 0) iminus = 0;
iplus = i0 + 1; if (iplus >= HASHX) iplus = HASHX-1;
j0 = mangrove[j].hashy;
jminus = j0 - 1; if (jminus < 0) jminus = 0;
jplus = j0 + 1; if (jplus >= HASHY) jplus = HASHY-1;
fx = 0.0;
fy = 0.0;
for (p=iminus; p<= iplus; p++)
for (q=jminus; q<= jplus; q++)
for (k=0; k<hashgrid_number[p*HASHY+q]; k++)
if (mangrove[hashgrid_mangroves[p*HASHY*HASHMAX + q*HASHMAX + k]].active)
{
compute_repelling_force(j, hashgrid_mangroves[p*HASHY*HASHMAX + q*HASHMAX + k], force, mangrove);
fx += force[0];
fy += force[1];
}
// if (fx*fx + fy*fy > 0.001) printf("Force on mangrove %i: (%.3f, %.3f)\n", j, fx, fy);
dx += DT_MANGROVE*fx;
dy += DT_MANGROVE*fy;
}
/* detach mangrove if spring is too long */
if (DETACH_MANGROVES)
{
length = module2(mangrove[j].xc - mangrove[j].anchorx, mangrove[j].yc_wrapped - mangrove[j].anchory);
// if (j%NGRIDY == 0) printf("spring length %.i: %.3lg\n", j, length);
// if (length > L_DETACH) mangrove[j].attached = 0;
if (length*mangrove[j].mass_inv > L_DETACH) mangrove[j].attached = 0;
}
if (dx > DXMAX) dx = DXMAX;
if (dx < -DXMAX) dx = -DXMAX;
if (dy > DXMAX) dy = DXMAX;
if (dy < -DXMAX) dy = -DXMAX;
if (INERTIA)
{
mangrove[j].vx += (dx - DAMP_MANGROVE*mangrove[j].vx)*mangrove[j].mass_inv;
mangrove[j].vy += (dy - DAMP_MANGROVE*mangrove[j].vy)*mangrove[j].mass_inv;
mangrove[j].xc += mangrove[j].vx*DT_MANGROVE;
mangrove[j].yc += mangrove[j].vy*DT_MANGROVE;
mangrove[j].yc_wrapped += mangrove[j].vy*DT_MANGROVE;
// if (j%NGRIDY == 0)
// printf("circle %.i: (dx,dy) = (%.3lg,%.3lg), (vx,vy) = (%.3lg,%.3lg)\n",
// j, mangrove[j].xc-mangrove[j].anchorx, mangrove[j].yc-mangrove[j].anchory, mangrove[j].vx, mangrove[j].vy);
}
else
{
mangrove[j].xc += dx*mangrove[j].mass_inv*DT_MANGROVE;
mangrove[j].yc += dy*mangrove[j].mass_inv*DT_MANGROVE;
mangrove[j].yc_wrapped += dy*mangrove[j].mass_inv*DT_MANGROVE;
}
if (mangrove[j].xc <= XMIN) mangrove[j].xc = XMIN;
if (mangrove[j].xc >= XMAX) mangrove[j].xc = XMAX;
if (mangrove[j].yc_wrapped <= YMIN) mangrove[j].yc_wrapped = YMIN;
if (mangrove[j].yc_wrapped >= YMAX) mangrove[j].yc_wrapped = YMAX;
// if (j%NGRIDY == 0) printf("(%.3lg, %.3lg)\n", mangrove[j].xc, mangrove[j].yc);
redraw = 1;
}
/* test for debugging */
if (1) for (j=0; j<ncircles; j++)
{
dissip = compute_dissipation(phi, psi, xy_in, mangrove[j].xc, mangrove[j].yc_wrapped);
/* make sure the dissipation does not grow too fast because of round-off/blow-up */
if (dissip > 0.1*MANGROVE_EMAX)
{
dissip = 0.1*MANGROVE_EMAX;
printf("Flooring dissipation!\n");
}
if (mangrove[j].active)
{
mangrove[j].energy += dissip;
ej = mangrove[j].energy;
// printf("ej = %.3f\n", ej);
if (ej <= MANGROVE_EMAX)
{
if (ej > 0.0)
{
hue = MANGROVE_HUE_MIN + (MANGROVE_HUE_MAX - MANGROVE_HUE_MIN)*ej/MANGROVE_EMAX;
if (hue < 0.0) hue += 360.0;
}
else hue = MANGROVE_HUE_MIN;
hsl_to_rgb(hue, 0.9, 0.5, rgb);
// if (j%NGRIDY == 0) printf("Circle %i, energy %.5lg, hue %.5lg\n", j, ej, hue);
draw_colored_circle(mangrove[j].xc, mangrove[j].yc, mangrove[j].radius, NSEG, rgb);
/* shrink mangrove */
if ((ERODE_MANGROVES)&&(ej > 0.0))
{
mangrove[j].radius = mangrove[j].radius_initial*(1.0 - ej*ej/(MANGROVE_EMAX*MANGROVE_EMAX));
redraw = 1;
}
else mangrove[j].radius = mangrove[j].radius_initial;
}
else /* remove mangrove */
{
mangrove[j].active = 0;
/* reinitialize table xy_in */
redraw = 1;
}
}
else if (RECOVER_MANGROVES) /* allow disabled mangroves to recover */
{
mangrove[j].energy -= 0.15*dissip;
printf("Circle %i energy %.3lg\n", j, mangrove[j].energy);
if (mangrove[j].energy < 0.0)
{
printf("Reactivating circle %i?\n", j);
/* THE PROBLEM occurs when circleactive[0] is set to 1 again */
if (j>0) mangrove[j].active = 1;
mangrove[j].radius = mangrove[j].radius_initial;
mangrove[j].energy = -MANGROVE_EMAX;
/* reinitialize table xy_in */
redraw = 1;
}
}
}
/* for compatibility with draw_billiard, may be improvable */
for (j=0; j<ncircles; j++)
{
circles[j].xc = mangrove[j].xc;
circles[j].yc = mangrove[j].yc;
circles[j].radius = mangrove[j].radius;
}
/* compute energy dissipated in obstacles */
/* if (ERODE_MANGROVES) for (j=0; j<ncircles; j++)
{
// printf("j = %i\t", j);
dissip = compute_dissipation(phi, psi, xy_in, mangrove[j].xc, mangrove[j].yc_wrapped);
printf("dissip = %.3f\t", dissip);
/* make sure the dissipation does not grow too fast because of round-off/blow-up */
// if (dissip > 0.1*MANGROVE_EMAX)
// {
// dissip = 0.1*MANGROVE_EMAX;
// printf("Flooring dissipation!\n");
// }
//
// if (mangrove[j].active)
// {
// mangrove[j].energy += dissip;
// ej = mangrove[j].energy;
// printf("ej = %.3f\n", ej);
// if (ej <= MANGROVE_EMAX)
// {
// if (ej > 0.0)
// {
// hue = MANGROVE_HUE_MIN + (MANGROVE_HUE_MAX - MANGROVE_HUE_MIN)*ej/MANGROVE_EMAX;
// if (hue < 0.0) hue += 360.0;
// }
// else hue = MANGROVE_HUE_MIN;
// hsl_to_rgb(hue, 0.9, 0.5, rgb);
// if (j%NGRIDY == 0) printf("Circle %i, energy %.5lg, hue %.5lg\n", j, ej, hue);
// draw_colored_circle(mangrove[j].xc, mangrove[j].yc, mangrove[j].radius, NSEG, rgb);
//
// /* shrink mangrove */
// if (ej > 0.0)
// {
// mangrove[j].radius -= MU*ej*ej/(MANGROVE_EMAX*MANGROVE_EMAX);
// if (mangrove[j].radius < 0.0) mangrove[j].radius = 0.0;
// mangrove[j].radius = mangrove[j].radius_initial*(1.0 - ej*ej/(MANGROVE_EMAX*MANGROVE_EMAX));
// redraw = 1;
// }
// else mangrove[j].radius = mangrove[j].radius_initial;
// }
// else /* remove mangrove */
// {
// mangrove[j].active = 0;
/* reinitialize table xy_in */
// redraw = 1;
// }
// }
// else /* allow disabled mangroves to recover */
// {
// mangrove[j].energy -= 0.15*dissip;
// printf("ej = %.3f\n", mangrove[j].energy);
// mangrove[j].radius += 0.005*MU;
// if (mangrove[j].radius > MU) mangrove[j].radius = MU;
// if ((mangrove[j].energy < 0.0)&&(mangrove[j].radius > 0.0))
// if (mangrove[j].energy < 0.0)
// {
// mangrove[j].active = 1;
// mangrove[j].radius = mangrove[j].radius*(0.75 + 0.5*((double)rand()/RAND_MAX));
// mangrove[j].radius = mangrove[j].radius_initial;
// mangrove[j].energy = -MANGROVE_EMAX;
/* reinitialize table xy_in */
// redraw = 1;
// }
// }
// printf("Circle %i, energy %.5lg\n", j, mangrove[j].energy);
// }
printf("Updating hashgrid\n");
if (REPELL_MANGROVES) update_hashgrid(mangrove, hashgrid_number, hashgrid_mangroves);
printf("Drawing billiard\n");
draw_billiard(0, 1.0);
glutSwapBuffers();
if (redraw)
{
printf("Reinitializing xy_in\n");
init_xyin_xrange(xy_in, imin, NX);
// init_xyin_xrange(xy_in, imin, imax);
}
redraw = 0;
if (MOVIE)
{
if (i >= INITIAL_TIME) save_frame();
else printf("Initial phase time %i of %i\n", i, INITIAL_TIME);
/* it seems that saving too many files too fast can cause trouble with the file system */
/* so this is to make a pause from time to time - parameter PAUSE may need adjusting */
if (i % PAUSE == PAUSE - 1)
{
printf("Making a short pause\n");
sleep(PSLEEP);
s = system("mv wave*.tif tif_wave/");
}
}
}
if (MOVIE)
{
for (i=0; i<END_FRAMES; i++) save_frame();
s = system("mv wave*.tif tif_wave/");
}
for (i=0; i<NX; i++)
{
free(phi[i]);
free(psi[i]);
free(tmp[i]);
free(xy_in[i]);
}
free(mangrove);
free(hashgrid_number);
free(hashgrid_mangroves);
}
void display(void)
{
glPushMatrix();
blank();
glutSwapBuffers();
blank();
glutSwapBuffers();
animation();
sleep(SLEEP2);
glPopMatrix();
glutDestroyWindow(glutGetWindow());
}
int main(int argc, char** argv)
{
glutInit(&argc, argv);
glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH);
glutInitWindowSize(WINWIDTH,WINHEIGHT);
glutCreateWindow("Wave equation in a planar domain");
init();
glutDisplayFunc(display);
glutMainLoop();
return 0;
}