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#include <stdlib.h>
#include "draw.h"
#include "particle.h"
#include "particles.h"
/* a "simple" particle type */
#define SIMPLE_MAX_DECAY_RATE 20
#define SIMPLE_MIN_DECAY_RATE 2
#define SIMPLE_MAX_LIFETIME 110
#define SIMPLE_MIN_LIFETIME 30
#define SIMPLE_MAX_SPAWN 15
#define SIMPLE_MIN_SPAWN 2
extern particle_ops_t rocket_ops;
typedef struct _simple_ctxt_t {
int decay_rate;
int longevity;
int lifetime;
} simple_ctxt_t;
static int simple_init(particles_t *particles, particle_t *p)
{
simple_ctxt_t *ctxt = p->ctxt;
ctxt->decay_rate = rand_within_range(SIMPLE_MIN_DECAY_RATE, SIMPLE_MAX_DECAY_RATE);
ctxt->lifetime = ctxt->longevity = rand_within_range(SIMPLE_MIN_LIFETIME, SIMPLE_MAX_LIFETIME);
if (!p->props->of_use) {
/* everything starts from the bottom center */
p->props->position.x = 0;
p->props->position.y = 0;
p->props->position.z = 0;
/* TODO: direction random-ish within the range of a narrow upward facing cone */
p->props->direction.x = (float)(rand_within_range(0, 6) - 3) * .1f;
p->props->direction.y = 1.0f + (float)(rand_within_range(0, 6) - 3) * .1f;
p->props->direction.z = (float)(rand_within_range(0, 6) - 3) * .1f;
p->props->direction = v3f_normalize(&p->props->direction);
p->props->velocity = (float)rand_within_range(300, 800) / 100000.0;
p->props->drag = 0.03;
p->props->mass = 0.3;
p->props->of_use = 1;
} /* else { we've been given properties, manipulate them or run with them? } */
return 1;
}
static particle_status_t simple_sim(particles_t *particles, particle_t *p)
{
simple_ctxt_t *ctxt = p->ctxt;
/* a particle is free to manipulate its children list when aging, but not itself or its siblings */
/* return PARTICLE_DEAD to remove kill yourself, do not age children here, the age pass will recurse
* into children and age them independently _after_ their parents have been aged
*/
if (!ctxt->longevity || (ctxt->longevity -= ctxt->decay_rate) <= 0) {
ctxt->longevity = 0;
return PARTICLE_DEAD;
}
/* create particles inheriting our type based on some silly conditions, with some tweaks to their direction */
if (ctxt->longevity == 42 || (ctxt->longevity > 500 && !(ctxt->longevity % 50))) {
int i, num = rand_within_range(SIMPLE_MIN_SPAWN, SIMPLE_MAX_SPAWN);
for (i = 0; i < num; i++) {
particle_props_t props = *p->props;
particle_ops_t *ops = INHERIT_OPS;
if (i == (SIMPLE_MAX_SPAWN - 2)) {
ops = &rocket_ops;
props.velocity = (float)rand_within_range(60, 100) / 1000000.0;
} else {
props.velocity = (float)rand_within_range(30, 100) / 10000.0;
}
props.direction.x += (float)(rand_within_range(0, 315 * 2) - 315) / 100.0;
props.direction.y += (float)(rand_within_range(0, 315 * 2) - 315) / 100.0;
props.direction.z += (float)(rand_within_range(0, 315 * 2) - 315) / 100.0;
props.direction = v3f_normalize(&props.direction);
particles_spawn_particle(particles, p, &props, ops); // XXX
}
}
return PARTICLE_ALIVE;
}
static void simple_draw(particles_t *particles, particle_t *p, int x, int y, fb_fragment_t *f)
{
simple_ctxt_t *ctxt = p->ctxt;
if (!draw_pixel(f, x, y, makergb(0xff, 0xff, 0xff, ((float)ctxt->longevity / ctxt->lifetime)))) {
/* immediately kill off stars that wander off screen */
ctxt->longevity = 0;
}
}
particle_ops_t simple_ops = {
.context_size = sizeof(simple_ctxt_t),
.sim = simple_sim,
.init = simple_init,
.draw = simple_draw,
.cleanup = NULL,
};
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