//The main fluid simulation step
void FluidSim::advance(float dt) {
float t = 0;
while(t < dt) {
float substep = cfl();
if(t + substep > dt)
substep = dt - t;
//Passively advect particles
advect_particles(substep);
//Estimate the liquid signed distance
compute_phi();
//Advance the velocity
advect(substep);
add_force(substep);
apply_viscosity(substep);
apply_projection(substep);
//Pressure projection only produces valid velocities in faces with non-zero associated face area.
//Because the advection step may interpolate from these invalid faces,
//we must extrapolate velocities from the fluid domain into these zero-area faces.
extrapolate(u, u_valid);
extrapolate(v, v_valid);
//For extrapolated velocities, replace the normal component with
//that of the object.
constrain_velocity();
t+=substep;
}
}
void FluidSim::project(float dt) {
//Estimate the liquid signed distance
compute_phi();
//Compute finite-volume type face area weight for each velocity sample.
compute_weights();
//Set up and solve the variational pressure solve.
solve_pressure(dt);
}
int main()
{
char pattern[30];
char text[200];
int i;
int ch;
pattern[0] = '0';
printf("Pattern = ");
scanf("%s\n", &pattern[1]);
arr = (int *)malloc(sizeof(char) * (strlen(pattern) + 1) );
compute_phi(pattern);
text[0] = '0';
scanf("%s", &text[1]);
for( i = 1; i<=strlen(&text[1]); i++)
printf("%2d ",i);
printf("\n");
for( i = 1; i<=strlen(&text[1]); i++)
printf("%2c ", text[i]);
printf("\n");
for( i = 1; i<=strlen(&pattern[1]); i++)
printf("%2c ", pattern[i]);
printf("\n");
while(1) {
match(text, pattern);
printf("\n\n\n ");
int retval;
int i=1;
int ch;
ch = getc(stdin);
if( ch == EOF)
break;
while(ch!='\n' && ch != EOF ){
text[i++] = ch;
ch = getc(stdin);
}
text[i]='\0';
printf("%s\n", &text[1]);
if( retval < 0 ){
printf("finished\n");
break;
}
}
}
static gboolean
process (GeglOperation *operation,
GeglBuffer *input,
GeglBuffer *output,
const GeglRectangle *roi,
gint level)
{
GeglOperationAreaFilter *op_area = GEGL_OPERATION_AREA_FILTER (operation);
GeglProperties *o = GEGL_PROPERTIES (operation);
gfloat *in_buf, *out_buf, *out_pixel;
gint x, y;
GeglRectangle src_rect;
GeglRectangle *whole_region;
gdouble angle;
gdouble center_x, center_y;
whole_region = gegl_operation_source_get_bounding_box (operation, "input");
center_x = gegl_coordinate_relative_to_pixel (
o->center_x, whole_region->width);
center_y = gegl_coordinate_relative_to_pixel (
o->center_y, whole_region->height);
src_rect = *roi;
src_rect.x -= op_area->left;
src_rect.y -= op_area->top;
src_rect.width += op_area->left + op_area->right;
src_rect.height += op_area->top + op_area->bottom;
in_buf = g_new (gfloat, src_rect.width * src_rect.height * 4);
out_buf = g_new0 (gfloat, roi->width * roi->height * 4);
out_pixel = out_buf;
gegl_buffer_get (input, &src_rect, 1.0, babl_format ("RaGaBaA float"),
in_buf, GEGL_AUTO_ROWSTRIDE, GEGL_ABYSS_NONE);
angle = o->angle * G_PI / 180.0;
while (angle < 0.0)
angle += 2 * G_PI;
for (y = roi->y; y < roi->height + roi->y; ++y)
{
for (x = roi->x; x < roi->width + roi->x; ++x)
{
gint c, i;
gdouble phi_base, phi_start, phi_step;
gfloat sum[] = {0, 0, 0, 0};
gint count = 0;
gdouble xr = x - center_x;
gdouble yr = y - center_y;
gdouble radius = sqrt (SQR (xr) + SQR (yr));
/* This is not the "real" length, a bit shorter */
gdouble arc_length = radius * angle * SQRT_2;
/* ensure quality with small angles */
gint n = MAX (ceil (arc_length), 3);
/* performance concern */
if (n > NOMINAL_NUM_IT)
n = NOMINAL_NUM_IT + (gint) sqrt (n - NOMINAL_NUM_IT);
phi_base = compute_phi (xr, yr);
phi_start = phi_base + angle / 2.0;
phi_step = angle / (gdouble) n;
/* Iterate other the arc */
for (i = 0; i < n; i++)
{
gfloat s_val = sin (phi_start - i * phi_step);
gfloat c_val = cos (phi_start - i * phi_step);
gfloat ix = center_x + radius * c_val;
gfloat iy = center_y + radius * s_val;
if (ix >= whole_region->x && ix < whole_region->x + whole_region->width &&
iy >= whole_region->y && iy < whole_region->y + whole_region->height)
{
/* do bilinear interpolation to get a nice smooth result */
gfloat dx = ix - floor (ix);
gfloat dy = iy - floor (iy);
gfloat *pix0, *pix1, *pix2, *pix3;
gfloat mixy0[4];
gfloat mixy1[4];
pix0 = get_pixel_color (in_buf, &src_rect, ix, iy);
pix1 = get_pixel_color (in_buf, &src_rect, ix+1, iy);
pix2 = get_pixel_color (in_buf, &src_rect, ix, iy+1);
pix3 = get_pixel_color (in_buf, &src_rect, ix+1, iy+1);
for (c = 0; c < 4; ++c)
{
mixy0[c] = dy * (pix2[c] - pix0[c]) + pix0[c];
mixy1[c] = dy * (pix3[c] - pix1[c]) + pix1[c];
sum[c] += dx * (mixy1[c] - mixy0[c]) + mixy0[c];
}
count++;
}
}
if (count == 0)
{
gfloat *pix = get_pixel_color (in_buf, &src_rect, x, y);
for (c = 0; c < 4; ++c)
*out_pixel++ = pix[c];
}
else
{
for (c = 0; c < 4; ++c)
*out_pixel++ = sum[c] / (gfloat) count;
}
}
}
gegl_buffer_set (output, roi, 0, babl_format ("RaGaBaA float"),
out_buf, GEGL_AUTO_ROWSTRIDE);
g_free (in_buf);
g_free (out_buf);
return TRUE;
}
