speck bounce and speck reusage

3 files changed, 74 insertions, 10 deletions

diff --git a/src/objs/player.lua b/src/objs/player.lua
index 4f05c3b..3f1e2aa 100644
--- a/src/objs/player.lua
+++ b/src/objs/player.lua
@@ -96,6 +96,13 @@ function new_player(x, y)
 
   add_comp(ent, "Player")
   add_comp(ent, "Speck_System")
+  ent.speck_sys.interval = 0.05
+
+  ent.speck_sys.lifetime_max = 0.6
+  ent.speck_sys.lifetime_min = 0.3
+
+  ent.speck_sys.forcey = 1000
+  ent.speck_sys.bounce = true
 
   add_comp(ent, "Body", x, y, 8, 14, {
     offsetx = -4,
diff --git a/src/objs/specks.lua b/src/objs/specks.lua
index fdfeb26..d9ed5ea 100644
--- a/src/objs/specks.lua
+++ b/src/objs/specks.lua
@@ -9,6 +9,7 @@ function Speck_Sys.new()
     pos = {},
     vel = {},
 
+    alive = {},
     lifetime = {},
     lifetime_max = {},
 
@@ -16,13 +17,19 @@ function Speck_Sys.new()
     scale_end = {}
   }
 
+  self.free_ids = {}
+  self.free_ids_size = 0
+
   self.scale_curve = lerp
-  self.scale_start_min = 1
-  self.scale_start_max = 1
+  self.scale_start_min = 0.8
+  self.scale_start_max = 1.25
 
   self.scale_end_min = 0
   self.scale_end_max = 0
 
+  self.forcex = 0
+  self.forcey = 0
+
   self.lifetime_min = 1
   self.lifetime_max = 5
 
@@ -36,34 +43,80 @@ function Speck_Sys.new()
   return self
 end
 
+function Speck_Sys:check_bounce(i)
+  if not self.bounce then
+    return false
+  end
+
+  local scn = get_current_scene()
+  assert(scn, "No scene set.")
+
+  return has_tile(
+    scn.tilemap,
+    to_tile_coords(self.data.pos[i].x, self.data.pos[i].y))
+end
+
 function Speck_Sys:update(dt)
   local data = self.data
 
+  -- particle spawning
   self.spawn_timer = self.spawn_timer - dt
   if self.spawn_timer <= 0 then
     self.spawn_timer = self.interval
 
-    data.size = data.size + 1
-    data.pos[data.size] = { x = self.x, y = self.y }
-    data.vel[data.size] = { x = 0, y = 0 }
+    local id
+    if self.free_ids_size > 0 then
+      id = self.free_ids[self.free_ids_size]
+      self.free_ids_size = self.free_ids_size - 1
+    else
+      self.data.size = self.data.size + 1
+      id = self.data.size
+    end
+
+    data.alive[id] = true
+
+    data.pos[id] = { x = self.x, y = self.y }
+    data.vel[id] = { x = 0, y = 0 }
 
-    data.lifetime[data.size] = lmath.random(
+    data.lifetime[id] = randf_range(
       self.lifetime_min, self.lifetime_max)
-    data.lifetime_max[data.size] = data.lifetime[data.size]
+    data.lifetime_max[id] = data.lifetime[id]
 
-    data.scale_start[data.size] = lmath.random(
+    data.scale_start[id] = randf_range(
       self.scale_start_min, self.scale_start_max)
-    data.scale_end[data.size] = lmath.random(
+    data.scale_end[id] = randf_range(
       self.scale_end_min, self.scale_end_max)
   end
 
+  -- particles processing
   for i = 1, data.size do
+    if not data.alive[i] then
+      goto next_speck_update
+    end
+
     if data.lifetime[i] <= 0 then
+      data.alive[i] = false
+
+      self.free_ids_size = self.free_ids_size + 1
+      self.free_ids[self.free_ids_size] = i
       goto next_speck_update
     end
 
+    data.vel[i].x = data.vel[i].x + self.forcex * dt
+    data.vel[i].y = data.vel[i].y + self.forcey * dt
+
+    -- move and bounce
     data.pos[i].x = data.pos[i].x + data.vel[i].x * dt
+    if self:check_bounce(i) then
+      data.vel[i].x = -data.vel[i].x
+      data.pos[i].x = data.pos[i].x + data.vel[i].x * dt
+    end
+
     data.pos[i].y = data.pos[i].y + data.vel[i].y * dt
+    if self:check_bounce(i) then
+      data.vel[i].y = -data.vel[i].y
+      data.pos[i].y = data.pos[i].y + data.vel[i].y * dt
+    end
 
     data.lifetime[i] = data.lifetime[i] - dt
 
@@ -76,7 +129,7 @@ function Speck_Sys:draw()
   local data = self.data
 
   for i = 1, data.size do
-    if data.lifetime[i] <= 0 then
+    if not data.alive[i] then
       goto next_speck_draw
     end
 
diff --git a/src/utils.lua b/src/utils.lua
index 02ca522..56479b8 100644
--- a/src/utils.lua
+++ b/src/utils.lua
@@ -1,4 +1,8 @@
 
+function randf_range(max, min)
+  return math.random() * (max - min) + min
+end
+
 function lerp(a, b, c)
   return a + (b - a) * c
 end