pattern time overdub (#1127)

* typed but not tested

* forgotten line

* pattern time overdub (#1126)

* debugging

- include `overdub` in the constructor
- `overdub_event`: insert both `.time` and `.event`
- `overdub_event`: calculates previous step's time adjustment so total time after overdub remains the same

* force step increase after overdub event

this keeps the overdub entry from overriding total loop time

Co-authored-by: dan derks <[email protected]>

lua/lib/pattern_time.lua

@@ -10,6 +10,7 @@ function pattern.new()
   setmetatable(i, pattern)
   i.rec = 0
   i.play = 0
+  i.overdub = 0
   i.prev_time = 0
   i.event = {}
   i.time = {}
@@ -29,6 +30,7 @@ function pattern:clear()
   self.metro:stop()
   self.rec = 0
   self.play = 0
+  self.overdub = 0
   self.prev_time = 0
   self.event = {}
   self.time = {}
@@ -54,22 +56,24 @@ function pattern:rec_stop()
   if self.rec == 1 then
     self.rec = 0
     if self.count ~= 0 then
-      print("count "..self.count)
+      --print("count "..self.count)
       local t = self.prev_time
       self.prev_time = util.time()
       self.time[self.count] = self.prev_time - t
       --tab.print(self.time)
     else
-      print("no events recorded")
+      print("pattern_time: no events recorded")
     end 
-  else print("not recording")
+  else print("pattern_time: not recording")
   end
 end
 
 --- watch
 function pattern:watch(e)
   if self.rec == 1 then
     self:rec_event(e)
+  elseif self.overdub == 1 then
+    self:overdub_event(e)
   end
 end
 
@@ -78,21 +82,33 @@ function pattern:rec_event(e)
   local c = self.count + 1
   if c == 1 then
     self.prev_time = util.time()
-    --print("first event")
   else
     local t = self.prev_time
     self.prev_time = util.time()
     self.time[c-1] = self.prev_time - t
-    --print(self.time[c-1])
   end
   self.count = c
   self.event[c] = e
 end
 
+--- add overdub event
+function pattern:overdub_event(e)
+  local c = self.step + 1
+  local t = self.prev_time
+  self.prev_time = util.time()
+  local a = self.time[c-1]
+  self.time[c-1] = self.prev_time - t
+  table.insert(self.time, c, a - self.time[c-1])
+  table.insert(self.event, c, e)
+  self.step = self.step + 1
+  self.count = self.count + 1
+end
+
 --- start this pattern
 function pattern:start()
   if self.count > 0 then
-    print("start pattern ")
+    --print("start pattern ")
+    self.prev_time = util.time()
     self.process(self.event[1])
     self.play = 1
     self.step = 1
@@ -103,6 +119,7 @@ end
 
 --- process next event
 function pattern:next_event()
+  self.prev_time = util.time()
   if self.step == self.count then self.step = 1
   else self.step = self.step + 1 end
   --print("next step "..self.step)
@@ -116,10 +133,19 @@ end
 --- stop this pattern
 function pattern:stop()
   if self.play == 1 then
-    print("stop pattern ")
     self.play = 0
+    self.overdub = 0
     self.metro:stop()
-  else print("not playing") end
+  else print("pattern_time: not playing") end
+end
+
+--- set overdub
+function pattern:set_overdub(s)
+  if s==1 and self.play == 1 and self.rec == 0 then
+    self.overdub = 1
+  else
+    self.overdub = 0
+  end
 end
 
 return pattern