HATPC/engine/particle_sys.c

289 lines
8.9 KiB
C

#include "particle_sys.h"
#include "assets.h"
#include "raymath.h"
#include <string.h>
#include <stdlib.h>
void init_particle_system(ParticleSystem_t* system)
{
memset(system, 0, sizeof(ParticleSystem_t));
sc_queue_init(&system->free_list);
for ( uint32_t i = 1; i <= MAX_ACTIVE_PARTICLE_EMITTER; ++i)
{
sc_queue_add_last(&system->free_list, i);
}
system->tail_idx = 0;
}
uint16_t get_number_of_free_emitter(ParticleSystem_t* system)
{
return sc_queue_size(&system->free_list);
}
static inline float generate_randrange(float lo, float hi)
{
float val = hi - lo;
val *= (float)rand() / (float)RAND_MAX;
val += lo;
return val;
}
static inline void spawn_particle(ParticleEmitter_t* emitter, uint32_t idx)
{
float lifetime = (emitter->config->particle_lifetime[1] - emitter->config->particle_lifetime[0]);
emitter->particles[idx].timer = emitter->config->particle_lifetime[0];
emitter->particles[idx].timer += lifetime * rand()/ (float)RAND_MAX;
emitter->particles[idx].alive = true;
float angle = generate_randrange(emitter->config->launch_range[0], emitter->config->launch_range[1]);
if(angle > 360) angle -= 360;
if(angle < -360) angle += 360;
float speed = generate_randrange(emitter->config->speed_range[0], emitter->config->speed_range[1]);
emitter->particles[idx].velocity.x = speed * cos(angle * PI / 180);
emitter->particles[idx].velocity.y = speed * sin(angle * PI / 180);
emitter->particles[idx].position = emitter->position;
emitter->particles[idx].rotation = generate_randrange(
emitter->config->angle_range[0], emitter->config->angle_range[1]
);
emitter->particles[idx].angular_vel = generate_randrange(
emitter->config->rotation_range[0], emitter->config->rotation_range[1]
);
emitter->particles[idx].size = 10 + 20 * (float)rand() / (float)RAND_MAX;
emitter->particles[idx].spawned = true;
;
}
uint16_t load_in_particle_emitter(ParticleSystem_t* system, const ParticleEmitter_t* in_emitter)
{
if (in_emitter == NULL) return 0;
if (in_emitter->config == NULL) return 0 ;
if (in_emitter->config->type == EMITTER_UNKNOWN) return 0;
if (sc_queue_empty(&system->free_list)) return 0;
uint16_t idx = sc_queue_del_first(&system->free_list);
system->emitters[idx] = *in_emitter;
system->emitters[idx].active = true;
if (system->emitters[idx].n_particles > MAX_PARTICLES)
{
system->emitters[idx].n_particles = MAX_PARTICLES;
}
system->emitter_list[idx].playing = false;
return idx;
}
void play_emitter_handle(ParticleSystem_t* system, uint16_t handle)
{
if (handle == 0) return;
if (!system->emitter_list[handle].playing)
{
ParticleEmitter_t* emitter = system->emitters + handle;
if (emitter->config->type == EMITTER_BURST)
{
for (uint32_t i = 0; i < emitter->n_particles; ++i)
{
spawn_particle(emitter, i);
}
}
else if (emitter->config->type == EMITTER_STREAM)
{
// TODO: deal with stream type
//spawn_particle(emitter, 0);
float incr = 0;
for (uint32_t i = 0; i < emitter->n_particles; ++i)
{
emitter->particles[i].timer = incr;
emitter->particles[i].alive = false;
emitter->particles[i].spawned = false;
incr += emitter->config->initial_spawn_delay;
}
}
system->emitter_list[system->tail_idx].next = handle;
system->tail_idx = handle;
system->emitter_list[handle].next = 0;
system->emitter_list[handle].playing = true;
}
system->emitters[handle].active = true;
}
// An emitter cannot be unloaded or paused mid-way when particles to still
// emitting, so defer into update function to do so
void stop_emitter_handle(ParticleSystem_t* system, EmitterHandle handle)
{
if (handle == 0) return;
//if (!system->emitter_list[handle].playing) return;
system->emitters[handle].active = false;
}
void update_emitter_handle_position(ParticleSystem_t* system, EmitterHandle handle, Vector2 pos)
{
if (handle == 0) return;
system->emitters[handle].position = pos;
}
void unload_emitter_handle(ParticleSystem_t* system, EmitterHandle handle)
{
if (handle == 0) return;
system->emitters[handle].active = false;
system->emitters[handle].finished = true;
}
bool is_emitter_handle_alive(ParticleSystem_t* system, EmitterHandle handle)
{
if (handle == 0) return false;
return !system->emitters[handle].finished;
}
EmitterHandle play_particle_emitter(ParticleSystem_t* system, const ParticleEmitter_t* in_emitter)
{
EmitterHandle idx = load_in_particle_emitter(system, in_emitter);
if (idx == 0) return 0;
play_emitter_handle(system, idx);
return idx;
}
void update_particle_system(ParticleSystem_t* system, float delta_time)
{
uint32_t emitter_idx = system->emitter_list[0].next;
uint32_t prev_idx = 0;
while (emitter_idx != 0)
{
ParticleEmitter_t* emitter = system->emitters + emitter_idx;
uint32_t inactive_count = 0;
if (emitter->emitter_update_func != NULL && emitter->active)
{
emitter->active = emitter->emitter_update_func(emitter, delta_time);
}
for (uint32_t i = 0; i < emitter->n_particles; ++i)
{
// TODO: If a particle is not spawned, run its timer. Spawn on zero
// Otherwise do the usual check
if (emitter->particles[i].alive)
{
if (emitter->update_func != NULL)
{
emitter->update_func(emitter->particles + i, emitter->user_data, delta_time);
}
}
emitter->particles[i].timer -= delta_time;
if (emitter->particles[i].timer <= 0.0f)
{
if (emitter->particles[i].spawned)
{
emitter->particles[i].alive = false;
}
else
{
emitter->particles[i].spawned = true;
spawn_particle(emitter, i);
}
}
if (emitter->particles[i].spawned)
{
if (!emitter->particles[i].alive)
{
if (!emitter->active)
{
inactive_count++;
}
else if (emitter->config->one_shot)
{
inactive_count++;
}
else
{
// If not one shot, immediately revive the particle
spawn_particle(emitter, i);
}
}
}
}
if (inactive_count == emitter->n_particles)
{
// Stop playing only if all particles is inactive
if (!emitter->finished)
{
emitter->finished = true;
}
}
if (emitter->finished)
{
system->emitter_list[prev_idx].next = system->emitter_list[emitter_idx].next;
system->emitter_list[emitter_idx].next = 0;
system->emitter_list[emitter_idx].playing = false;
if (system->tail_idx == emitter_idx)
{
system->tail_idx = prev_idx;
}
if (emitter->finished)
{
sc_queue_add_last(&system->free_list, emitter_idx);
emitter_idx = prev_idx;
}
}
prev_idx = emitter_idx;
emitter_idx = system->emitter_list[emitter_idx].next;
}
}
void draw_particle_system(ParticleSystem_t* system)
{
uint32_t emitter_idx = system->emitter_list[0].next;
while (emitter_idx != 0)
{
ParticleEmitter_t* emitter = system->emitters + emitter_idx;
Particle_t* part = emitter->particles;
for (uint32_t i = 0; i < emitter->n_particles; ++i, ++part)
{
if (part->alive)
{
if (emitter->spr == NULL)
{
Rectangle rect = {
.x = part->position.x,
.y = part->position.y,
.width = part->size,
.height = part->size
};
Vector2 origin = (Vector2){
part->size / 2,
part->size / 2
};
DrawRectanglePro(rect, origin, part->rotation, BLACK);
}
else
{
draw_sprite(emitter->spr, 0, part->position, part->rotation, false);
}
}
}
emitter_idx = system->emitter_list[emitter_idx].next;
}
}
void deinit_particle_system(ParticleSystem_t* system)
{
sc_queue_term(&system->free_list);
}