add a rudimentary 7-bag system

2 files changed, 49 insertions, 3 deletions

diff --git a/game/bag.lua b/game/bag.lua
new file mode 100644
index 0000000..76e6308
--- /dev/null
+++ b/game/bag.lua
@@ -0,0 +1,46 @@
+local tetrominoes = require "game.tetrominoes"
+
+local M = {}
+M.__index = M
+
+M.new = function()
+    local new = setmetatable({}, M)
+    new.queue = {}
+    new.pool = {}
+    return new
+end
+
+function M:lookahead(amount)
+    local res = {}
+    for i=1, amount do
+        if self.queue[i] then
+            table.insert(res, self.queue[i])
+        else
+            if #self.pool == 0 then
+                self.pool = {
+                    tetrominoes.i,
+                    tetrominoes.j,
+                    tetrominoes.l,
+                    tetrominoes.o,
+                    tetrominoes.s,
+                    tetrominoes.t,
+                    tetrominoes.z,
+                }
+            end
+            local choice = math.random(1, #self.pool)
+            local choice_tetr = self.pool[choice]
+            table.remove(self.pool, choice)
+            table.insert(self.queue, choice_tetr)
+            table.insert(res, choice_tetr)
+        end
+    end
+    return res
+end
+
+function M:next_piece()
+    local res = self:lookahead(1)[1]
+    table.remove(self.queue, 1)
+    return res
+end
+
+return M
\ No newline at end of file
diff --git a/game/init.lua b/game/init.lua
index 0056ccb..48f9a15 100644
--- a/game/init.lua
+++ b/game/init.lua
@@ -2,6 +2,7 @@ local evloop = require "evloop"
 local playfield = require "game.playfield"
 local tetrominoes = require "game.tetrominoes"
 local gfx = require "game.gfx"
+local bag = require "game.bag"
 
 local M = {}
 M.__index = M
@@ -14,6 +15,7 @@ function M.new(params)
 	new.can_hold = true
 	new.gfx = gfx.new(new)
 	new.gravity_delay = 0.5
+	new.bag = bag.new() -- TODO: bag should be seeded
 	return new
 end
 
@@ -70,10 +72,8 @@ local pieces = {
 }
 
 function M:next_piece()
-	-- TODO: interface with configurable random system (it should implement
-	-- seeds, bags)
 	self.can_hold = true
-	self.piece = pieces[love.math.random(#pieces)]:drop(self.field)
+	self.piece = self.bag:next_piece():drop(self.field)
 	return self.piece and true or false
 end