From f3df6c674a6210672b72038e92a2aa4f1e87b4bb Mon Sep 17 00:00:00 2001
From: Nyeogmi <economicsbat@gmail.com>
Date: Mon, 19 Dec 2022 23:15:55 -0800
Subject: [PATCH] Rope rewrite, part one

---
 chameleonic.p8 | 498 ++++++++++++-------------------------------------
 1 file changed, 124 insertions(+), 374 deletions(-)

diff --git a/chameleonic.p8 b/chameleonic.p8
index fb75cbe..aede61f 100644
--- a/chameleonic.p8
+++ b/chameleonic.p8
@@ -415,35 +415,27 @@ function add_adjacent_anchors(tbl,mx,my)
  end
 end
 
-function level:reanchor(remove)
- if remove or not self._anch then
-  self._anch={}
- end
-
- for ax0=0,31 do
-  local ax1 = ax0-1+2*(ax0%2)
-  local mx0,mx1 = ax0\2,ax1\2
-  for ay0=0,31 do
-   local ay1=ay0-1+2*(ay0%2)
-   local my0,my1=ay0\2,ay1\2
-
-   if (
-    not self:mcoll(mx0,my0) and
-    not self:mcoll(mx0,my1) and
-    not self:mcoll(mx1,my0) and
-    self:mcoll(mx1,my1)
-   ) then
-    local px0,py0=level:a2p(ax0,ay0)
-    self._anch[_amix(ax0,ay0)]={ax=ax0,ay=ay0,x=px0,y=py0}
+function level:reanchor()
+ self._anch={}
+ for dxy in all{{-1,-1},{1,-1},{-1,1},{1,1}} do
+  local dx,dy=unpack(dxy)
+  assert(dx!=0 and dy!=0)
+  for mx0=0,15 do
+   for my0=0,15 do
+    local mx1,my1=mx0+dx,my0+dy
+    if (
+     self:mcoll(mx0,my0) and
+     not self:mcoll(mx0,my1) and
+     not self:mcoll(mx1,my0) and
+     not self:mcoll(mx1,my1)
+    ) then
+     add(self._anch, {
+      ax=max(mx0,mx1),ay=max(my0,my1),adx=-dx,ady=-dy
+     })
+    end
    end
   end
  end
-
- for _,cr in pairs(self._crates) do
-  add_adjacent_anchors(self._anch,cr.mx,cr.my)
- end
-
- if (player.rope!=nil) player.rope:make_dirty()
 end
 
 function level:win_at(mx,my)
@@ -453,20 +445,6 @@ function level:anchor_points()
  return pairs(self._anch)
 end
 
-function level:anchors_in(px0,py0,px1,py1)
- local anch,ax,xlim,sy,ylim=self._anch,px0\4,(px1+3)\4,py0\4,(py1+3)\4
- local ay=sy-1
- return function()
-  while true do
-   ay+=1
-   if(ay>ylim)ay,ax=sy,ax+1
-   if(ax>xlim)return nil
-   local anc=anch[_amix(ax,ay)]
-   if (anc) return anc
-  end
- end
-end
-
 function level:get_open_pit(mx,my)
  local pit=self._pits[_mix(mx,my)]
  if (pit and pit.contents==nil) return pit
@@ -574,8 +552,8 @@ function level:get_latch(dx,dy,px,py)
    return {
     el="crate",
     dx=dx1,dy=dy1,
-    px_offset=px-crate.px+dx1,
-    py_offset=py-crate.py+dy1,
+    ax_offset=dx1*0.5,
+    ay_offset=dy1*0.5,
     rec=crate
    }
   end
@@ -758,7 +736,6 @@ end
 function player:any_busy()
  if (#self.todo>0) return true
  if (level:busy()) return true
- if (self.rope!=nil and self.rope:busy()) return true
  return false
 end
 
@@ -826,10 +803,17 @@ function player:update()
      self.todo=f4({{orienty=1,py=2},{py=7},{y=self.y+1}})
     else wrongbleep:bleep() end
    elseif self.rope==nil and kbd:btnr(4) then
-    local rx,ry,rx2,ry2=self:_rope_pos()
-    local dx,dy=12*self.orientx,12*self.orienty
+    local dx,dy=self.orientx,self.orienty
     if (dy!=0) dx=0
-    self.rope=rope:new(rx,ry,rx2,ry2,dx,dy)
+
+    local x,y=self.x,self.y
+    while not level:mcoll(x,y) do x+=dx y+=dy end
+
+    self.rope=rope:new(
+     x+0.5-dx*0.5,y+0.5-dy*0.5,
+     self.x+0.5,self.y+0.5,
+     level:get_latch(dx,dy,x*8,y*8)
+    )
     
     self.todo={{
      update=function()
@@ -848,8 +832,7 @@ function player:update()
 
  if self.rope then
   self.rope:update()
-  local rx,ry=self:_rope_pos()
-  self.rope:drag_dst(rx,ry)
+  self.rope:drag_dst(self.x+0.5,self.y+0.5)
 
   local tdx,tdy=self.rope:tug_orientxy()
   if (tdx!=0) self.orientx=tdx
@@ -881,14 +864,6 @@ function player:_fall()
  if (self.fall_frame<10) self.fall_frame+=1
 end
 
-function player:_rope_pos()
- local px=self.x*8+self.px+4
- local px2=px
- local py=self.y*8+self.py+3
- local py2=py
- return px,py,px2,py2
-end
-
 function player:draw()
  local px=self.x*8+self.px
  local py=self.y*8+self.py
@@ -956,18 +931,21 @@ rope={}
 rope.__index=rope
 
 function rope:new(
- x,y,src_x,src_y,dx,dy
+ src_ax,src_ay,dst_ax,dst_ay,latch
 )
  local r={
   id=0,
-  src={x=src_x,y=src_y,todo={}},
-  ancs={},
-  dst={x=x,y=y,todo={}},
-  state={name="cast",dx=dx,dy=dy},
-  dirty=true,
-  latch=nil,
-  latch_frame=0,
+  anchors={
+   {ax=src_ax,ay=src_ay,prev=nil,next=nil},
+   {ax=dst_ax,ay=dst_ay,prev=nil,next=nil}
+  },
+  state={name="cast",frame=0},
+  latch=latch,
  }
+ r.src=r.anchors[1]
+ r.dst=r.anchors[2]
+ r.src.next=r.dst
+ r.dst.prev=r.src
  setmetatable(r,rope)
  return r
 end
@@ -980,30 +958,12 @@ function rope:done()
  return self.state.name=="done"
 end
 
-function rope:busy()
- for i=0,#self.ancs+1 do
-  if (#(self:_anc(i).todo)>0) return true
- end
- return false
-end
-
 function rope:update()
- local was_busy=self:busy()
- for i=0,#self.ancs+1 do
-  local anc=self:_anc(i)
-  _apply(anc,anc.todo,i)
- end
- local is_busy=self:busy()
- if (was_busy and not is_busy) self.dirty=true
-
  if self.state.name=="cast" then
-  self:continue_cast()
- elseif self.state.name=="latched" then
-  self.latch_frame+=1
-  if self.latch_frame>=10 then
-   self.latch_frame=10
-  end
+  self.state.frame+=1
+  if (self.state.frame>=3) self.state={name="latched"}
 
+ elseif self.state.name=="latched" then
   if (self.latch==nil) wrongbleep:bleep(3) self:destroy() return
 
   if 
@@ -1011,8 +971,8 @@ function rope:update()
    self.latch.rec!=nil 
   then
    self:drag_src(
-    self.latch.rec.px+self.latch.px_offset,
-    self.latch.rec.py+self.latch.py_offset
+    self.latch.rec.mx+0.5+self.latch.ax_offset,
+    self.latch.rec.my+0.5+self.latch.ay_offset
    )
 
    if #self.latch.rec.todo==0 then
@@ -1022,7 +982,6 @@ function rope:update()
    end
   end
 
-  if (not is_busy) self:_tidy_up_gen()
  elseif self.state.name=="destroy" then -- destroy
   self.state.frame+=1
   if (self.state.frame>=5) self.state={name="done"}
@@ -1036,41 +995,11 @@ function rope:destroy()
  self.state={name="destroy",frame=0}
 end
 
-function rope:continue_cast()
- local dx,dy=self.state.dx,self.state.dy
- local x0=self.src.x
- local y0=self.src.y
- local x1=x0+dx
- local y1=y0+dy
- 
- for x,y in _rast(
-  x0,y0,x1,y1
- ) do
-  local latch=
-   level:get_latch(dx,dy,x,y)
-
-  if latch!=nil or level:pcoll(x,y) then
-   self.latch=latch
-   self.state={name="latched"}
-   break
-  end
-  self.src={x=x,y=y,todo={},dirty=true}
- end
-end
-
-function rope:_reindex()
- self.src.ix=0
- self.dst.ix=#self.ancs
- for i,anc in ipairs(self.ancs) do
-  anc.ix=i
- end
-end
-
 function rope:draw(artificial_dx,artificial_dy)
  local points,highlight=self:_tug(true)
- if (self:busy()) highlight=nil
  if (self.state.name=="done") return
  local perc_to_show=1.0
+ if (self.state.name=="cast") perc_to_show=self.state.frame/2
  if (self.state.name=="destroy") perc_to_show=(1.0-self.state.frame/5)^2
 
  points[#points]={x=points[#points].x+artificial_dx,y=points[#points].y+artificial_dy}
@@ -1123,7 +1052,13 @@ function rope:draw(artificial_dx,artificial_dy)
    rectfill(x,y-1,x-1,y-3,color)
   end
  end
+ for _,p in pairs(level._anch) do
+	 pset(p.ax*8,p.ay*8,11)
+	 pset(p.ax*8+p.adx,p.ay*8,11)
+	 pset(p.ax*8,p.ay*8+p.ady,11)
+	end
 
+ --[[
  for i=0,#self.ancs+1 do
   p=self:_anc(i)
   local c=12
@@ -1131,10 +1066,6 @@ function rope:draw(artificial_dx,artificial_dy)
   rectfill(p.x-1,p.y-1,p.x+1,p.y+1,c)
   print(tostr(p.id)..":"..p.x..","..p.y..","..#p.todo,0,i*8,12)
  end
- --[[
- for _,p in pairs(level._anch) do
-	 pset(p.x,p.y,11)
-	end
  print("dirty:"..tostr(self.dirty),32,0,9)
  print("busy:"..tostr(self:busy()),32,7,9)
  print("state:"..tostr(self.state.name),32,14,9)
@@ -1147,247 +1078,72 @@ function rope:draw(artificial_dx,artificial_dy)
  ]]--
 end
 
-function rope:_anc(i)
- if (i==0) return self.src
- if (i==#self.ancs+1) return self.dst
- return self.ancs[i]
-end
-
 function rope:drag_dst(x,y)
- self:drag(function() return #self.ancs+1 end,x,y)
+ self:drag(self.dst,x,y)
 end
 
 function rope:drag_src(x,y)
- self:drag(function() return 0 end,x,y)
+ self:drag(self.src,x,y)
 end
 
 function rope:drag(
- i,x,y
+ n1,ax_new,ay_new
 )
- local anc=self:_anc(i())
- local busy=self:busy()
-
- for x,y in _rast(
-  anc.x,anc.y,x,y
- ) do
-  local a=self:_anc(i())
-  if not (_point_eq(a,{x=x,y=y})) then
-   a.x=x
-   a.y=y
-   a.dirty=true
-   self.dirty=true
-   if (not busy) self:_tidy_up_gen()
-  end
- end
+ -- TODO: stepwise?
+ rope:_drag1(n1,ax_new,ay_new)
 end
 
-function rope:make_dirty(only_if_invalid)
- local invalid=false
- for a=0,#self.ancs do
-  local a0=self:_anc(a)
-  local a1=self:_anc(a+1)
-  if not level:can_stretch(a0,a1) then
-   a0.dirty=true
-   a1.dirty=true
-   invalid=true
-  end
- end
- if (invalid or not only_if_invalid) self.dirty=true
-end
+-- TODO: Upon adding a point, start from there to see if we need another
+-- rather than adding at most one
+function rope:_drag1(n1,ax1_new,ay1_new)
+ local ax1_old,ay1_old=n1.ax,n1.ay
+ local n0=n1.prev
 
-function rope:_tidy_up_gen()
- self:make_dirty(true) 
-
- local busy=self:busy()
- if (not self:latched()) return
- if (not self.dirty) return
-
- local settled=true
- local loop=function(f)
-  local a=0
-  while a<=#self.ancs+1 do
-   local anc=self:_anc(a)
-   if anc.dirty then
-    anc.seen=true
-    if self[f](self,a,busy) then
-     settled=false anc.changed=true 
-     a=0
-    end
-   end
-   a+=1
-  end
- end
-
- local mark_unseen=function()
-  touched={}
-  for a=0,#self.ancs+1,1 do
-   local anc=self:_anc(a)
-   anc.seen=false
-   anc.changed=false
-  end
- end
-
- local propagate_dirty=function(f)
-  for a=0,#self.ancs+1,1 do
-   local a1=self:_anc(a)
-   if a1.dirty then
-    local a0=self:_anc(a-1)
-    if (a0!=nil) a0.dirty=true
-
-    local a2=self:_anc(a+1)
-    if (a2!=nil) a2.dirty=true
+ if n0!=nil then
+  local ax0,ay0=n0.ax,n0.ay
+  for _,anchor in level:anchor_points() do
+   if 
+    (_in_box(anchor.ax,anchor.ay,ax0,ay0,ax1_old,ay1_old) or
+    _in_box(anchor.ax,anchor.ay,ax0,ay0,ax1_new,ay1_new)) and
+    _which_side(anchor.ax,anchor.ay,ax0,ay0,ax1_old,ay1_old) !=
+    _which_side(anchor.ax,anchor.ay,ax0,ay0,ax1_new,ay1_new)
+   then
+    local n05={ax=anchor.ax,ay=anchor.ay,prev=n0,next=n1}
+    n0.next = n05
+    n1.prev = n05
    end
   end
  end
 
- while true do
-  settled=true
-
-  mark_unseen()
-  propagate_dirty()
-
-  loop("_find_needed_anchors")
-  loop("_find_touched_anchors")
-  loop("_elide_point")
-
-  for a=0,#self.ancs+1,1 do
-   local anc=self:_anc(a)
-   if (anc.seen) anc.dirty=anc.changed
-   if (anc.dirty) settled=false
-  end
-
-  if (settled) break
- end
-
- if (self:busy()) return
-
- for i=0,#self.ancs do
-  local a0=self:_anc(i)
-  local a1=self:_anc(i+1)
-  if not level:can_stretch(a0,a1) then
-   self:destroy()
+ local n2=n1.next
+ if n2!=nil then
+  local ax2,ay2=n2.ax,n2.ay
+  for _,anchor in level:anchor_points() do
+   if 
+    (_in_box(anchor.ax,anchor.ay,ax1_old,ay1_old,ax2,ay2) or
+    _in_box(anchor.ax,anchor.ay,ax1_new,ay1_new,ax2,ay2)) and
+    _which_side(anchor.ax,anchor.ay,ax1_old,ay1_old,ax2,ay2) !=
+    _which_side(anchor.ax,anchor.ay,ax1_new,ay1_new,ax2,ay2)
+   then
+    local n15={ax=anchor.ax,ay=anchor.ay,prev=n1,next=n2}
+    n1.next = n15
+    n2.prev = n15
+   end
   end
  end
 
- self.dirty=false
+ n1.ax=ax1_new
+ n1.ay=ay1_new
 end
 
-function rope:_find_needed_anchors(i,busy)
- if (i<=0) return false
- if (#self.ancs+1<i) return false
-
- local a0=self:_anc(i-1)
- local a2=self:_anc(i)
-
- if (level:pcoll(a2.x,a2.y)) return false
- if (level:pcoll(a0.x,a0.y)) return false 
- if (level:can_stretch(a0,a2)) return false
-
- local anchors_bydist={}
- local x0,x2=_mnmx(a0.x,a2.x)
- local y0,y2=_mnmx(a0.y,a2.y)
- for a1 in level:anchors_in(x0-1,y0-1,x2+1,y2+1) do
-  add(anchors_bydist,{el=a1,key=_linedist(a0,a1,a2)})
- end
- shellsort(anchors_bydist)
-
- for a1 in all(anchors_bydist) do
-  a1=a1.el
-  if level:can_stretch(a0,a1) and
-   level:can_stretch(a1,a2)
-  then
-   local id=self.id
-   add(self.ancs,{id=id,x=a1.x,y=a1.y,dirty=true,todo={}},i)
-   self.id+=1
-
-   return true
-  end
- end
+function _in_box(x,y,x0,y0,x1,y1)
+ x0,x1=_mnmx(x0,x1)
+ y0,y1=_mnmx(y0,y1)
+ return x0<=x and y0<=y and x<=x1 and y<=y1
 end
 
-local ELIDE_POINT=0.01
-function rope:_find_touched_anchors(i)
- if (i<=0) return false
- if (#self.ancs<i) return false
-
- local a0=self:_anc(i-1)
- local a2=self:_anc(i)
-
- if (level:pcoll(a0.x,a0.y)) return false
- if (level:pcoll(a2.x,a2.y)) return false
-
- for bx,by in _rast(a0.x,a0.y,a2.x,a2.y) do
-  local a1=level:point_anchor(bx,by)
-  if 
-   a1!=nil and not _point_eq(a0,a1) and not _point_eq(a1,a2)
-   and _linedist(a0,a1,a2)<ELIDE_POINT
-  then
-   local id=self.id
-   add(self.ancs,{id=id,x=a1.x,y=a1.y,dirty=true,todo={}},i)
-   self.id+=1
-
-   return true
-  end
- end
- return false
-end
-
-function rope:_elide_point(i,busy)
- if (i<=0) return false
- if (#self.ancs<i) return false
-
- local a0=self:_anc(i-1)
- local a1=self:_anc(i)
- local a2=self:_anc(i+1)
-
- local level_anc=level:point_anchor(a1.x,a1.y)
- if _point_eq(a0,a1) or _point_eq(a1,a2) or (not busy and level_anc==nil) then
-  -- do it unconditionally
- else
-  if _linedist(a0,a1,a2) < ELIDE_POINT then
-   return false
-  end
-
-  if not level:can_stretch(a0,a2) then
-   return false
-  end
-  
-  local midpoint={
-   x=(a0.x+a2.x)\2,
-   y=(a0.y+a2.y)\2
-  }
-
-  if not self:_can_move_midpoint(a0,a1,midpoint,a2) then
-   return false
-  end
- end
- 
- deli(self.ancs,i)
- a0.dirty=true a0.changed=true
- a2.dirty=true a2.changed=true
- return true
-end
-
-function rope:_can_move_midpoint(a0,a1_0,a1_1,a2)
- if not level:can_stretch(a1_0, a1_1) then
-  return false
- end
- if not level:can_stretch(a0,a1_1) then
-  return false
- end
- if not level:can_stretch(a1_1,a2) then
-  return false
- end
- for x,y in _rastn(a1_0.x,a1_0.y,a1_1.x,a1_1.y,8,8) do
-  local tm={x=x,y=y}
-  if not level:can_stretch(a0,tm) then
-   return false
-  end
-  if not level:can_stretch(tm,a2) then
-   return false
-  end
- end
- return true
+function _which_side(x,y,x0,y0,x1,y1)
+ return sgn0((x1-x0)*(y-y0) - (y1-y0)*(x-x0))
 end
 
 function _linedist(x0,v,x1)
@@ -1409,16 +1165,18 @@ function distance(p1,p2)
 end
 
 function rope:collide_rect(x1,y1,x2,y2,exclude_src,exclude_dst)
- local last=#self.ancs-exclude_dst
- for i=exclude_src,last,1 do
-  local a0=self:_anc(i)
-  local a1=self:_anc(i+1)
+ local a0=self.src
+ while true do
+  local a1=a0.next
+  if (a1==nil) return false
+  --[[
   if (_line_line(a0.x,a0.y,a1.x,a1.y,x1,y1,x2,y1)) return true
   if (_line_line(a0.x,a0.y,a1.x,a1.y,x1,y1,x1,y2)) return true
   if (_line_line(a0.x,a0.y,a1.x,a1.y,x1,y2,x2,y2)) return true
   if (_line_line(a0.x,a0.y,a1.x,a1.y,x2,y1,x2,y2)) return true
+  ]]--
+  a0=a0.next
  end
- return false
 end
 
 function _line_line(x1,y1,x2,y2,x3,y3,x4,y4)
@@ -1451,28 +1209,25 @@ end
 -- moved here because it's complicated
 
 function rope:tug_orientxy()
- local a1=self:_anc(#self.ancs+1)
- local a0=self:_anc(#self.ancs)
- local dx=a0.x-a1.x
+ local a1=self.dst
+ local a0=self.dst.prev
+ local dx=a0.ax-a1.ax
  local tdx=0
- if (dx>3) tdx=1
- if (dx<-3) tdx=-1
+ if (dx>3/8) tdx=1
+ if (dx<-3/8) tdx=-1
 
- local dy=a0.y-a1.y
+ local dy=a0.ay-a1.ay
  local tdy=0
  if abs(dy)>abs(dx)/2 then 
-  if (dy>3) tdy=1
-  if (dy<-3) tdy=-1
+  if (dy>3/8) tdy=1
+  if (dy<-3/8) tdy=-1
  end
  return tdx,tdy
 end
 
 function rope:tug()
- self:_tidy_up_gen()
  if (not self:latched()) return
- local rc=self:_tug()
- self:_tidy_up_gen()
- return rc
+ return self:_tug()
 end
 
 function rope:_tug(hypothetically)
@@ -1568,12 +1323,7 @@ function rope:_tug(hypothetically)
   then
    if (hypothetically) return ancs,0
 
-   level:tug_crate(
-    mx0,my0,
-    dmx,dmy
-   ) 
-   -- be busy for 4 ticks while the crate moves
-   self:_anc(0).todo={{},{},{},{},{}}
+   level:tug_crate(mx0,my0,dmx,dmy) 
    return true
   end
  end
@@ -1666,26 +1416,26 @@ end
 
 function rope:_anchors_simplified()
  -- todo: cache this
- self:_reindex()
-
  local points={}
  local _slope = function(p0,p1)
   return atan2(p1.y-p0.y,p1.x-p0.x)
  end
- for i=0,#self.ancs+1,1 do
-  local anc=self:_anc(i)
+ a=self.src
+ while a!=nil do
+  local point={x=a.ax*8,y=a.ay*8,ax=a.ax,ay=a.ay}
   if #points<=1 then 
-   add(points,anc)
+   add(points,point)
   elseif abs(
    _slope(points[#points-1],points[#points])-
-   _slope(points[#points],anc)
+   _slope(points[#points],point)
   )==0 then  -- epsilon?
-   points[#points]=anc
+   points[#points]=point
   else
-   add(points,anc)
+   add(points,point)
   end
+  a=a.next
+  assert(#points<100)
  end
- 
  return points
 end