add momentum to sideways movement

drip.p8

@@ -15,7 +15,7 @@ function _init()
   -- button-press initial delay
   poke(0x5f5c, 1)
   -- button-press repeat
-  poke(0x5f5d, 1)
+  poke(0x5f5d, 2)
   init_world()
 end
 
@@ -66,21 +66,34 @@ function update_drops()
   for i=1,#drops do
     drop = drops[i]
     try_left = rnd() < 0.5
+    if drop.momentum == 0 then
+      if try_left then
+        drop.momentum = -1
+      else
+        drop.momentum = 1
+      end
+    end
     if pget(drop.x, drop.y+1) == black then
       drop.y += 1
-    elseif try_left and drop.x > 0 then
-      if pget(drop.x-1, drop.y+1) == black then
+    elseif try_left and drop.x > 0 and
+        pget(drop.x-1, drop.y+1) == black then
+      drop.x -= 1
+      drop.y += 1
+	   elseif drop.x < 127 and
+        pget(drop.x+1, drop.y+1) == black then
+      drop.x += 1
+      drop.y += 1
+    elseif drop.momentum == -1 then
+      if drop.x > 0 and pget(drop.x-1, drop.y) == black then
         drop.x -= 1
-        drop.y += 1
-      elseif pget(drop.x-1, drop.y) == black then
-	       drop.x -= 1
-	     end
-	   elseif drop.x < 127 then
-	     if pget(drop.x+1, drop.y+1) == black then
-	       drop.x += 1
-	       drop.y += 1
-      elseif pget(drop.x+1, drop.y) == black then
+      else
+        drop.momentum = 0
+      end
+    elseif drop.momentum == 1 then
+      if drop.x < 127 and pget(drop.x+1, drop.y) == black then
         drop.x += 1
+      else
+        drop.momentum = 0
       end
 	   end
     if drop.y > 127 then drop.y = 127 end