_calc_push golf redux

Removed unnecessary variable declarations and conditional cases by using an "assume, alternate, verify assumption" pattern and reusing ax0/ay0 when they would never be referenced again.

chameleonic.p8

@@ -1645,21 +1645,16 @@ function rope:_calc_push(
    smy=-smy
   end
   
-  local mx,dmx
+  local dmx=1 -- maybe push right?
   if anch.adx==-1 and a0.x>an.x+7 then
    -- push left
-   mx=ax0-1
-   dmx=-1
-  elseif anch.adx==1 and a0.x<an.x-7 then
-   -- push right
-   mx=ax0
-   dmx=1
-  else
+   ax0, dmx=ax0-1,-1
+  elseif anch.adx!=1 or a0.x>=an.x-7 then
    return {}
   end
   
   for my=my0,my1,smy do
-   add(ops,{mx,my,dmx,0})
+   add(ops,{ax0,my,dmx,0})
   end
  end
  
@@ -1671,22 +1666,16 @@ function rope:_calc_push(
    smx=-smx
   end
   
-  local my,dmy
+  local dmy=1 -- maybe push down?
   if anch.ady==-1 and a0.y>an.y+6 then
    -- push up
-   my=ay0-1
-   dmy=-1
-   
-  elseif anch.ady==1 and a0.y<an.y-6 then
-   -- push down
-   my=ay0
-   dmy=1
-  else
+   ay0,dmy=ay0-1,dmy=-1
+  elseif anch.ady!=1 or a0.y>=an.y-6 then
    return {}
   end
   
   for mx=mx0,mx1,smx do
-   add(ops,{mx,my,0,dmy})
+   add(ops,{mx,ay0,0,dmy})
   end
  end