static void add_bump(union vec3 p, float r, float h)
{
struct bump *b;
const union vec3 right_at_ya = { { 0.0f, 0.0f, 1.0f } };
const union vec3 up = { { 0.0f, 1.0f, 0.0f } };
if (totalbumps >= MAXBUMPS)
return;
b = &bumplist[totalbumps];
b->p = p;
b->r = r;
b->h = h;
b->tx = (int) ((float) samplew / RADII + 0.5 * snis_random_float() *
(RADII - 2.0f) / RADII * (float) samplew);
b->ty = (int) ((float) sampleh / RADII + 0.5 * snis_random_float() *
(RADII - 2.0f) / RADII * (float) sampleh);
if (samplew < sampleh)
b->ts = samplew / RADII;
else
b->ts = sampleh / RADII;
b->sampledata = sampledata;
b->samplew = samplew;
b->sampleh = sampleh;
b->sample_bytes_per_row = sample_bytes_per_row;
b->is_crater = 0;
quat_from_u2v(&b->texelq, &p, &right_at_ya, &up);
totalbumps++;
}
static void add_crater(int i, union vec3 p, float r, float h)
{
struct bump *b;
const union vec3 right_at_ya = { { 0.0f, 0.0f, 1.0f } };
const union vec3 up = { { 0.0f, 1.0f, 0.0f } };
float crater_r;
b = &craterlist[i];
b->is_crater = 1;
b->p = p;
b->r = r;
b->h = h;
b->tx = 512;
b->ty = 512;
b->ts = 512;
b->sampledata = malloc(3 * 1024 * 1024);
memset(b->sampledata, crater_base_level, 3 * 1024 * 1024);
b->samplew = 1024;
b->sampleh = 1024;
b->sample_bytes_per_row = 3 * b->samplew;
crater_r = (0.5 * (snis_random_float() + 1.0) * 5.5) *
(0.5 * (snis_random_float() + 1.0) * 5.5) + 2.5;
create_crater_heightmap((unsigned char *) b->sampledata, 1024, 1024, 512, 512, (int) crater_r, 3);
quat_from_u2v(&b->texelq, &p, &right_at_ya, &up);
}
static void __attribute__((unused)) uniform_random_point_in_spehere(float r, float *x, float *y)
{
float a = M_PI * snis_random_float();
r = r * sqrt(fabs(snis_random_float()));
*x = r * cos(a);
*y = r * sin(a);
}
/* return a random point in an annulus on a plane in 3d, r1=inner radius, r2=outer radius, c=center, n=normal */
void random_point_in_3d_annulus(float r1, float r2, const union vec3 *center, const union vec3 *u, const union vec3 *v, union vec3 *point)
{
float angle = snis_random_float() * M_PI;
float r = fabs(snis_random_float()) * (r2 - r1) + r1;
point->v.x = center->v.x + r * cos(angle) * u->v.x + r * sin(angle) * v->v.x;
point->v.y = center->v.y + r * cos(angle) * u->v.y + r * sin(angle) * v->v.y;
point->v.z = center->v.z + r * cos(angle) * u->v.z + r * sin(angle) * v->v.z;
}
struct mesh *init_burst_rod_mesh(int streaks, double h, double r1, double r2)
{
struct mesh *my_mesh = malloc(sizeof(*my_mesh));
if (!my_mesh)
return my_mesh;
memset(my_mesh, 0, sizeof(*my_mesh));
my_mesh->geometry_mode = MESH_GEOMETRY_PARTICLE_ANIMATION;
my_mesh->nlines = streaks;
my_mesh->nvertices = my_mesh->nlines * 2;
my_mesh->ntriangles = 0;
my_mesh->t = 0;
my_mesh->v = malloc(sizeof(*my_mesh->v) * my_mesh->nvertices);
my_mesh->l = malloc(sizeof(*my_mesh->l) * my_mesh->nlines);
my_mesh->tex = 0;
my_mesh->radius = fmax(sqrt(h * h / 4.0 + r1 * r1), sqrt(h * h / 4.0 + r2 * r2));
my_mesh->graph_ptr = 0;
int line_index;
for (line_index = 0; line_index < streaks; line_index++) {
float p = fabs(snis_random_float());
float pr = p * (r2 - r1) + r1;
float ph = p * h - h / 2.0;
float pa = fabs(snis_random_float()) * 2.0 * M_PI;
int v_index = line_index * 2;
my_mesh->v[v_index + 0].x = ph;
my_mesh->v[v_index + 0].y = 0;
my_mesh->v[v_index + 0].z = 0;
my_mesh->v[v_index + 1].x = ph;
my_mesh->v[v_index + 1].y = sin(pa) * pr;
my_mesh->v[v_index + 1].z = cos(pa) * pr;
my_mesh->l[line_index].start = &my_mesh->v[v_index + 0];
my_mesh->l[line_index].end = &my_mesh->v[v_index + 1];
my_mesh->l[line_index].flag = 0;
my_mesh->l[line_index].additivity = 1.0;
my_mesh->l[line_index].opacity = 1.0;
my_mesh->l[line_index].tint_color.red = 1.0;
my_mesh->l[line_index].tint_color.green = 1.0;
my_mesh->l[line_index].tint_color.blue = 1.0;
my_mesh->l[line_index].time_offset = fabs(snis_random_float());
}
mesh_graph_dev_init(my_mesh);
return my_mesh;
}
static void create_particle(float h, float r1, struct particle *particles, int i)
{
particles[i].offset = fabs(snis_random_float());
particles[i].lifetime = fabs(snis_random_float());
particles[i].decay = 0.1;
particles[i].xpos = 0.0;
particles[i].ypos = 0.0;
particles[i].zpos = 0.0;
/* uniform_random_point_in_spehere(r1 * 0.1, &particles[i].yspeed, &particles[i].zspeed); */
particles[i].xspeed = -fabs(snis_random_float()) * h * 0.1;
particles[i].yspeed = 0;
particles[i].zspeed = 0;
particles[i].active = 1;
}
void create_crater_heightmap(unsigned char *image, int imagew, int imageh, int x, int y, int r, int h)
{
int i, npoints = (int) (1.7 * (M_PI * 2.0 * r));
float angle;
crater_dimple(image, imagew, imageh, x, y, r * 0.95, base_level);
for (i = 0; i < npoints; i++) {
int tx, ty;
angle = (2.0 * M_PI * i) / (float) npoints + snis_random_float() * 10.0 * M_PI / 180.0;
tx = x + cos(angle) * r + snis_random_float() * snis_random_float() * r * 3.9;
ty = y - sin(angle) * r + snis_random_float() * snis_random_float() * r * 3.9;
add_cone(image, imagew, imageh, tx, ty, (0.2 + 0.50 * zerotoone()) * r, h);
}
add_rays(image, imagew, imageh, x, y, r, h * 2.75, 50 + snis_randn(350));
}
static void recursive_add_bump(union vec3 pos, float r, float h,
float shrink, float rlimit)
{
float hoffset;
add_bump(pos, r, h);
if (r * shrink < rlimit)
return;
for (int i = 0; i < nbumps; i++) {
union vec3 d;
d.v.x = snis_random_float() * r * scatterfactor;
d.v.y = snis_random_float() * r * scatterfactor;
d.v.z = snis_random_float() * r * scatterfactor;
vec3_add_self(&d, &pos);
vec3_normalize_self(&d);
hoffset = snis_random_float() * h * shrink * 0.5;
recursive_add_bump(d, r * shrink, h * (shrink + 0.5 * (1.0 - shrink)) + hoffset, shrink, rlimit);
}
}
static void add_ray(unsigned char *image, int imagew, int imageh, int x, int y, int r, int h)
{
int i;
int npoints = snis_randn(100);
float angle = snis_random_float() * 2.0 * M_PI;
float radius = r;
float con_rad = radius * 0.1;
float tx, ty;
float height = h;
for (i = 0; i < npoints; i++) {
tx = x + cos(angle) * radius;
ty = y - sin(angle) * radius;
add_cone(image, imagew, imageh, tx, ty, (int) con_rad, height);
con_rad = con_rad * 0.98;
height = height * (0.9 + 0.08 * zerotoone());
radius = radius + zerotoone() * r * 0.3;
}
}
static void add_bumps(const int initial_bumps)
{
int i;
float h;
if (nbumps == 1) /* If we're not doing any recursive bumps, then make the bumps taller */
h = 0.3;
else
h = 0.1;
printf("adding bumps:");
for (i = 0; i < initial_bumps; i++) {
union vec3 p;
float r = 0.5 * (snis_random_float() + 1.0f) * initial_bump_size;
random_point_on_sphere(1.0, &p.v.x, &p.v.y, &p.v.z);
recursive_add_bump(p, r, h, shrink_factor, rlimit);
printf(".");
fflush(stdout);
}
printf("\n");
}
static float zerotoone()
{
return 0.5 * (1.0 + snis_random_float());
}