First demo commit.

lib/multisource.lua

@@ -0,0 +1,91 @@
+--[[
+-- multisource lib
+-- A multisource is a wrapper on top of a LÖVE source. It allows
+-- creating multiple sounds easily. It uses an internal pool of
+-- resources.
+-- * multisource:play() finds a stopped resource from the pool,
+--   or creates a new one, and plays and returns it.
+-- * multisouce:cleanup() liberates the memory of old unplayed sources.
+]]
+
+local multisource = {}
+
+local MultiSource   = {}
+local MultiSourceMt = {__index = MultiSource}
+
+function MultiSource:cleanup(older_than)
+  older_than = older_than or 5
+
+  local now = love.timer.getTime()
+
+  for instance, lastPlayed in pairs(self.instances) do
+    local age = now - lastPlayed
+    if age > older_than and instance:isStopped() then
+      self.instances[instance] = nil
+    end
+  end
+end
+
+function MultiSource:getStoppedOrNewInstance()
+  for instance in pairs(self.instances) do
+    if instance:isStopped() then return instance end
+  end
+  return self.source:clone()
+end
+
+function MultiSource:play()
+  local instance = self:getStoppedOrNewInstance()
+  self.instances[instance] = love.timer.getTime()
+
+  instance:play()
+
+  return instance
+end
+
+function MultiSource:stop()
+  for instance in pairs(self.instances) do
+    instance:stop()
+  end
+end
+
+function MultiSource:pause()
+  for instance in pairs(self.instances) do
+    instance:pause()
+  end
+end
+
+function MultiSource:setLooping(looping)
+  self.source:setLooping(looping)
+end
+
+function MultiSource:resume()
+  for instance in pairs(self.instances) do
+    instance:resume()
+  end
+end
+
+function MultiSource:countPlayingInstances()
+  local count = 0
+  for instance in pairs(self.instances) do
+    if instance:isPlaying() then
+      count = count + 1
+    end
+  end
+  return count
+end
+
+function MultiSource:countInstances()
+  local count = 0
+  for instance in pairs(self.instances) do
+    count = count + 1
+  end
+  return count
+end
+
+----
+
+multisource.new = function(source)
+  return setmetatable({source = source, instances = {}}, MultiSourceMt)
+end
+
+return multisource