Rework stream handling function

Changelog:
- Add callback function to stop the emitter
    - This is use to automatically stop the emitter when the condition
      is met
- Update particle test program

engine/particle_sys.c

@@ -103,7 +103,7 @@ void play_emitter_handle(ParticleSystem_t* system, uint16_t handle)
 
 // An emitter cannot be unloaded or paused mid-way when particles to still
 // emitting, so defer into update function to do so
-void pause_emitter_handle(ParticleSystem_t* system, uint16_t handle)
+void stop_emitter_handle(ParticleSystem_t* system, EmitterHandle handle)
 {
     if (handle == 0) return;
     //if (!system->emitter_list[handle].playing) return;
@@ -118,7 +118,7 @@ void update_emitter_handle_position(ParticleSystem_t* system, EmitterHandle hand
     system->emitters[handle].position = pos;
 }
 
-void unload_emitter_handle(ParticleSystem_t* system, uint16_t handle)
+void unload_emitter_handle(ParticleSystem_t* system, EmitterHandle handle)
 {
     if (handle == 0) return;
 
@@ -126,12 +126,13 @@ void unload_emitter_handle(ParticleSystem_t* system, uint16_t handle)
     system->emitters[handle].finished = true;
 }
 
-void play_particle_emitter(ParticleSystem_t* system, const ParticleEmitter_t* in_emitter)
+EmitterHandle play_particle_emitter(ParticleSystem_t* system, const ParticleEmitter_t* in_emitter)
 {
-    uint16_t idx = load_in_particle_emitter(system, in_emitter);
+    EmitterHandle idx = load_in_particle_emitter(system, in_emitter);
-    if (idx == 0) return;
+    if (idx == 0) return 0 ;
 
     play_emitter_handle(system, idx);
+    return idx;
 }
 
 void update_particle_system(ParticleSystem_t* system)
@@ -143,6 +144,12 @@ void update_particle_system(ParticleSystem_t* system)
     {
         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);
+        }
+
         for (uint32_t i = 0; i < emitter->n_particles; ++i)
         {
             // TODO: If a particle is not spawned, run its timer. Spawn on zero
@@ -187,10 +194,11 @@ void update_particle_system(ParticleSystem_t* system)
                 }
             }
         }
+
         if (inactive_count == emitter->n_particles)
         {
             // Stop playing only if all particles is inactive
-            if (!emitter->finished && emitter->config->one_shot)
+            if (!emitter->finished)
             {
                 emitter->finished = true;
             }
@@ -213,6 +221,7 @@ void update_particle_system(ParticleSystem_t* system)
         emitter_idx = system->emitter_list[emitter_idx].next;
     }
 }
+
 void draw_particle_system(ParticleSystem_t* system)
 {
     uint32_t emitter_idx = system->emitter_list[0].next;

engine/particle_sys.h

@@ -29,7 +29,10 @@ typedef struct Particle
     bool spawned;
 }Particle_t;
 
+typedef struct ParticleEmitter ParticleEmitter_t;
+
 typedef void (*particle_update_func_t)(Particle_t* part, void* user_data);
+typedef bool (*emitter_check_func_t)(const ParticleEmitter_t* emitter);
 
 typedef struct EmitterConfig
 {
@@ -41,7 +44,7 @@ typedef struct EmitterConfig
     bool one_shot;
 }EmitterConfig_t;
 
-typedef struct ParticleEmitter
+struct ParticleEmitter
 {
     const EmitterConfig_t* config;
     Sprite_t* spr;
@@ -53,7 +56,8 @@ typedef struct ParticleEmitter
     bool active;
     void* user_data;
     particle_update_func_t update_func;
-}ParticleEmitter_t;
+    emitter_check_func_t emitter_update_func;
+};
 
 typedef struct IndexList
 {
@@ -75,11 +79,11 @@ void init_particle_system(ParticleSystem_t* system);
 uint16_t get_number_of_free_emitter(ParticleSystem_t* system);
 
 // For one-shots
-void play_particle_emitter(ParticleSystem_t* system, const ParticleEmitter_t* in_emitter);
+EmitterHandle play_particle_emitter(ParticleSystem_t* system, const ParticleEmitter_t* in_emitter);
 
 EmitterHandle load_in_particle_emitter(ParticleSystem_t* system, const ParticleEmitter_t* in_emitter);
 void play_emitter_handle(ParticleSystem_t* system, EmitterHandle handle);
-void pause_emitter_handle(ParticleSystem_t* system, EmitterHandle handle);
+void stop_emitter_handle(ParticleSystem_t* system, EmitterHandle handle);
 void update_emitter_handle_position(ParticleSystem_t* system, EmitterHandle handle, Vector2 pos);
 void unload_emitter_handle(ParticleSystem_t* system, EmitterHandle handle);
 

particle_test.c

@@ -45,6 +45,12 @@ void simple_particle_system_update(Particle_t* part, void* user_data)
         }
     }
 }
+
+static bool check_mouse_click(const ParticleEmitter_t* emitter)
+{
+    return IsMouseButtonDown(MOUSE_RIGHT_BUTTON);
+}
+
 int main(void)
 {
     InitWindow(1280, 640, "raylib");
@@ -76,6 +82,7 @@ int main(void)
         .config = &conf,
         .n_particles = MAX_PARTICLES,
         .update_func = &simple_particle_system_update,
+        .emitter_update_func = NULL,
         .spr = (tex.width == 0) ? NULL : &spr,
     };
 
@@ -92,15 +99,14 @@ int main(void)
         .config = &conf2,
         .n_particles = MAX_PARTICLES,
         .update_func = &simple_particle_system_update,
+        .emitter_update_func = &check_mouse_click,
         .spr = (tex.width == 0) ? NULL : &spr,
     };
 
-    EmitterHandle han = load_in_particle_emitter(&part_sys, &emitter2);
-    assert(han != 0);
-
     bool key_press = false;
     uint8_t key2_press = 0;
     char text_buffer[32];
+    EmitterHandle han = 0;
     while(!WindowShouldClose())
     {
         Vector2 mouse_pos = GetMousePosition();
@@ -121,8 +127,9 @@ int main(void)
 
         if (key2_press == 0b01)
         {
+            han = play_particle_emitter(&part_sys, &emitter2);
             update_emitter_handle_position(&part_sys, han, mouse_pos);
-            play_emitter_handle(&part_sys, han);
+            //play_emitter_handle(&part_sys, han);
         }
         else if(key2_press == 0b11)
         {
@@ -130,7 +137,8 @@ int main(void)
         }
         else if (key2_press == 0b10)
         {
-            pause_emitter_handle(&part_sys, han);
+            stop_emitter_handle(&part_sys, han);
+            han = 0;
         }
 
         update_particle_system(&part_sys);