From 71b150cb33658cfcb8e57bad0001fa6e220f065d Mon Sep 17 00:00:00 2001
From: Nyeogmi <economicsbat@gmail.com>
Date: Sat, 31 Dec 2022 16:18:24 -0800
Subject: [PATCH] Golf the sweep code

---
 chameleonic.p8 | 73 +++++++++++++++++++-------------------------------
 1 file changed, 28 insertions(+), 45 deletions(-)

diff --git a/chameleonic.p8 b/chameleonic.p8
index ae900a5..ee6e2ac 100644
--- a/chameleonic.p8
+++ b/chameleonic.p8
@@ -1053,8 +1053,6 @@ function rope:relax()
   local n1=n0.next
   if (not n1) break
   local n2=n1.next
-
-
   if n0.ax==n1.ax and n0.ay==n1.ay then 
    n0.next=n2 
    if (n2) n2.prev=n0
@@ -1160,8 +1158,6 @@ function would_stick(anchor,x0,y0,x1,y1,x2,y2)
  x1,y1=x1 or anchor.ax,y1 or anchor.ay
 
  local dx,dy=x2-x0,y2-y0
- if (x1==x0 and y1==y0) return 
- if (x1==x2 and y1==y2) return 
 
  local function switch_ends() 
   dx,dy,x0,y0,x2,y2=-dx,-dy,x2,y2,x0,y0
@@ -1259,57 +1255,44 @@ function rope:_be_pushed_by1(ax_old,ay_old,ax_new,ay_new,anch)
 end
 
 function rope:_drag(n1,ax1_new,ay1_new,ax_removing,ay_removing)
- local function _sweep_radar(ax_lhs,ay_lhs,ax_rhs,ay_rhs,ax_pivot,ay_pivot,ax_far0,ay_far0,ax_far1,ay_far1)
+ local function _sweep_radar(ax_lhs,ay_lhs,ax_rhs,ay_rhs,ax_pivot,ay_pivot,ax_src,ay_src,ax_dst,ay_dst)
+  if (ax_src==ax_dst and ay_src==ay_dst) return 
+
   local function _uncreatable(anchor)
-   return (anchor.ax==ax_lhs and anchor.ay==ay_lhs) or
-    (anchor.ax==ax_rhs and anchor.ay==ay_rhs) or
-    (anchor.ax==ax_removing and anchor.ay==ay_removing)
+   return anchor.ax==ax_lhs and anchor.ay==ay_lhs or
+    anchor.ax==ax_rhs and anchor.ay==ay_rhs or
+    anchor.ax==ax_removing and anchor.ay==ay_removing
   end
 
-  if (ax_far0==ax_far1 and ay_far0==ay_far1) return 
-
-  if ax_far0==ax_far1 then
-   local ax_far=ax_far0
-   local ax0,ax1=_mnmx(ax_pivot,ax_far)
-
-   ay_far_old=ay_far0
-   for ay_far_new in _stepfrom(ay_far0,ay_far1) do
+  local function _sweep(extent_old,extent_new,cb_in_bounds,cb_would_stick,cb_side)
+   for extent_new in _stepfrom(extent_old, extent_new) do
     for anchor in level:anchor_points() do
-     if 
-      not _uncreatable(anchor) and
-      (ax0<=anchor.ax and anchor.ax<=ax1) and 
-      would_stick(anchor,ax_pivot,ay_pivot,nil,nil,ax_far,ay_far_new) and
-      (
-        _which_side(anchor.ax,anchor.ay,ax_pivot,ay_pivot,ax_far,ay_far_old) !=
-        _which_side(anchor.ax,anchor.ay,ax_pivot,ay_pivot,ax_far,ay_far_new)
-      )
+     if not _uncreatable(anchor) and cb_in_bounds(anchor) and 
+      cb_would_stick(anchor,extent_new) and
+      cb_side(anchor,extent_old)!=cb_side(anchor,extent_new)
      then
       return anchor
      end
     end
-    ay_far_old=ay_far_new
+    extent_old=extent_new
    end
-  elseif ay_far0==ay_far1 then
-   local ay_far=ay_far0
-   local ay0,ay1=_mnmx(ay_pivot,ay_far)
+  end
 
-   ax_far_old=ax_far0
-   for ax_far_new in _stepfrom(ax_far0,ax_far1) do
-    for anchor in level:anchor_points() do
-     if 
-      not _uncreatable(anchor) and
-      (ay0<=anchor.ay and anchor.ay<=ay1) and 
-      would_stick(anchor,ax_pivot,ay_pivot,nil,nil,ax_far_new,ay_far) and
-      (
-        _which_side(anchor.ax,anchor.ay,ax_pivot,ay_pivot,ax_far_old,ay_far) !=
-        _which_side(anchor.ax,anchor.ay,ax_pivot,ay_pivot,ax_far_new,ay_far)
-      )
-     then
-      return anchor
-     end
-    end
-    ax_far_old=ax_far_new
-   end
+  if ax_src==ax_dst then
+   return _sweep(
+    ay_src,ay_dst,
+    function(anchor) return mid(ax_pivot,anchor.ax,ax_dst)==anchor.ax end,
+    function(anchor,ay) return would_stick(anchor,ax_pivot,ay_pivot,nil,nil,ax_dst,ay) end,
+    function(anchor,ay) return _which_side(anchor.ax,anchor.ay,ax_pivot,ay_pivot,ax_dst,ay) end
+   )
+  else
+   assert(ay_src==ay_dst)
+   return _sweep(
+    ax_src,ax_dst,
+    function(anchor) return mid(ay_pivot,anchor.ay,ay_dst)==anchor.ay end,
+    function(anchor,ax) return would_stick(anchor,ax_pivot,ay_pivot,nil,nil,ax,ay_dst) end,
+    function(anchor,ax) return _which_side(anchor.ax,anchor.ay,ax_pivot,ay_pivot,ax,ay_dst) end
+   )
   end
  end