drops can fall left or right

picogora.p8

@@ -26,7 +26,15 @@ end
 -->8
 -- game code
 
-bg = 12
+bg = blue
+
+function _init()
+  -- button-press initial delay
+  poke(0x5f5c, 2)
+  -- button-press repeat
+  poke(0x5f5d, 2)
+  init_world()
+end
 
 function init_world()
   player = {}
@@ -38,20 +46,8 @@ function init_world()
   ramps = {}
   add_ramp(50,20,15,10)
   add_ramp(60,50,15,-15)
-  add_ramp(50,60,20,0)
-end
-
-function _init()
-  -- button-press initial delay
-  poke(0x5f5c, 1)
-  -- button-press repeat
-  poke(0x5f5d, 2)
-  init_world()
-end
-
-function _update()
-  update_player()
-  update_drops()
+  add_ramp(48,60,20,0)
+  add_ramp(45,75,10,30)
 end
 
 function add_ramp(x,y,dx,dy)
@@ -63,6 +59,11 @@ function add_ramp(x,y,dx,dy)
   add(ramps, r)
 end
 
+function _update()
+  update_player()
+  update_drops()
+end
+
 function update_player()
   if btn(0) then
     player.x -= 1
@@ -89,14 +90,39 @@ function update_player()
   end
 end
 
+function update_drop(d)
+  if d.y == 127 or pget(d.x,d.y+1) == bg then
+    d.y += 1
+    return
+  end
+
+  left = pget(d.x-1,d.y) == bg and pget(d.x-1,d.y+1) == bg
+  right = pget(d.x+1,d.y) == bg and pget(d.x+1,d.y+1) == bg
+
+  if left and right then
+    d.y += 1
+    if rnd() < 0.5 then
+      d.x -= 1
+    else
+      d.x += 1
+    end
+  elseif left then
+    d.y += 1
+    d.x -= 1
+  elseif right then
+    d.y += 1
+    d.x += 1
+  end
+end
+
 function update_drops()
   draw_world()
   new_drops = {}
   for i=1,#drops do
-    drop = drops[i]
-    drop.y += 1
-    if drop.y < 128 then
-      add(new_drops, drop)
+    d = drops[i]
+    update_drop(d)
+    if d.y < 128 then
+      add(new_drops, d)
     end
   end
   drops = new_drops
@@ -122,7 +148,6 @@ function draw_drop(drop)
   pset(drop.x, drop.y, white)
 end
 
-
 __gfx__
 000000000a0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000
 00000000aaa000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000