allow setting of world-level, plus random option

config.lua

@@ -43,6 +43,9 @@ local common_cfg = {
     timer_loser = 1/2,
     decrement_reward = false, -- bad idea, encourages mario to run into goombas.
     score_multiplier = 1, -- how much the ingame score influences our rewards.
+
+    starting_world = 1, -- set to 0 for random!
+    starting_level = 1, -- set to 0 for random!
 }
 
 local cfg = {

main.lua

@@ -26,6 +26,7 @@ local force_start = false
 local force_start_old = false
 
 local startsave = savestate.create(1)
+local any_random = cfg.starting_world == 0 or cfg.starting_level == 0
 
 local poketime = false
 local max_time
@@ -41,7 +42,7 @@ local status_old
 local coins_old
 local score_old
 
-local once = false
+local state_saved = false
 local reset = true
 
 local state_old = ''
@@ -457,6 +458,25 @@ local function joypad_mash(button)
     joypad.write(1, jp_mash)
 end
 
+local function loadlevel(world, level)
+    if world == 0 then world = random(1, 8) end
+    if level == 0 then level = random(1, 4) end
+    emu.poweron()
+    while emu.framecount() < 60 do
+        if emu.framecount() == 32 then
+            local area = game.area_lut[world * 10 + level]
+            game.W(0x75F, world - 1)
+            game.W(0x75C, level - 1)
+            game.W(0x760, area)
+        end
+        if emu.framecount() == 42 then
+            game.W(0x7A0, 0) -- world screen timer (reduces startup time)
+        end
+        joypad_mash('start')
+        emu.frameadvance()
+    end
+end
+
 local function do_reset()
     local state = game.get_state()
     -- be a little more descriptive.
@@ -495,6 +515,10 @@ local function do_reset()
         if epoch_i > 0 then learn_from_epoch() end
         if not cfg.playback_mode then epoch_i = epoch_i + 1 end
         prepare_epoch()
+        if any_random then
+            loadlevel(cfg.starting_world, cfg.starting_level)
+            state_saved = false
+        end
     end
 
     if game.get_state() == 'loading' then game.advance() end -- kind of a hack.
@@ -516,12 +540,12 @@ local function do_reset()
     max_time = min(6 * sqrt(480 / cfg.epoch_trials * (epoch_i - 1)) + 60, cfg.cap_time)
     max_time = ceil(max_time)
 
-    if once then
+    if state_saved then
         savestate.load(startsave)
     else
         savestate.save(startsave)
     end
-    once = true
+    state_saved = true
 
     jp = nil
     screen_scroll_delta = 0
@@ -549,11 +573,9 @@ local function init()
     emu.unpause()
     if not cfg.playable_mode then emu.speedmode("turbo") end
 
-    while emu.framecount() < 195 do  -- FIXME: don't hardcode this.
+    if not any_random then
-        joypad_mash('start')
+        loadlevel(cfg.starting_world, cfg.starting_level)
-        emu.frameadvance()
     end
-    --print(emu.framecount())
 
     local res, err = pcall(network.load, network, cfg.params_fn)
     if res == false then print(err) end

smb.lua

@@ -27,6 +27,20 @@ for i, v in ipairs(valid_tiles) do
     tile_lut[v] = i - 1
 end
 
+local area_lut = {
+    -- first digit: world number.
+    -- second digit: level number.
+    -- note: excludes pipe intros.
+    [11] = 0, [12] = 2, [13] = 3, [14] = 4,
+    [21] = 0, [22] = 2, [23] = 3, [24] = 4,
+    [31] = 0, [32] = 1, [33] = 2, [34] = 3,
+    [41] = 0, [42] = 2, [43] = 3, [44] = 4,
+    [51] = 0, [52] = 1, [53] = 2, [54] = 3,
+    [61] = 0, [62] = 1, [63] = 2, [64] = 3,
+    [71] = 0, [72] = 2, [73] = 3, [74] = 4,
+    [81] = 0, [82] = 1, [83] = 2, [84] = 3,
+}
+
 local rotation_offsets = { -- FIXME: not all of these are pixel-perfect.
     0, -40, -- 0x00
     6, -38,
@@ -295,6 +309,7 @@ S=S,
 overlay=overlay,
 
 valid_tiles=valid_tiles,
+area_lut=area_lut,
 
 sprite_input=sprite_input,
 tile_input=tile_input,