From 37db329b08f021498d1cfdb28efe3c0e828e2adf Mon Sep 17 00:00:00 2001
From: Nyeogmi <economicsbat@gmail.com>
Date: Sun, 18 Dec 2022 17:20:59 -0800
Subject: [PATCH] Fix rope bug in pull code

---
 chameleonic.p8 | 32 ++++++++++++++++++++++++++------
 1 file changed, 26 insertions(+), 6 deletions(-)

diff --git a/chameleonic.p8 b/chameleonic.p8
index f61c39b..7442438 100644
--- a/chameleonic.p8
+++ b/chameleonic.p8
@@ -1199,8 +1199,11 @@ end
 function _vec_ang_diff(x0,y0,x1,y1)
  local ang0=atan2(x0,y0)
  local ang1=atan2(x1,y1)
+ return _ang_diff(ang0,ang1)
+end
 
- return (ang1-ang0+0.5)%1-0.5
+function _ang_diff(ang0,ang1)
+ return abs((ang1-ang0+0.5)%1-0.5)
 end
 
 function sum_distance(x,y,z)
@@ -1387,8 +1390,8 @@ function rope:_tug(hypothetically)
  local touched={}
 
  for i=#ancs-1,2,-1 do
-  local ops_before_trash=self:_calc_push(ancs[i+1],ancs[i],ancs[i-1])
-  local ops_after_trash=self:_calc_push(ancs[i-2],ancs[i-1],ancs[i])
+  local ops_before_trash=self:_calc_push(ancs[i+1],ancs[i],ancs[i-1],ancs[i-2])
+  local ops_after_trash=self:_calc_push(ancs[i-2],ancs[i-1],ancs[i],ancs[i+1])
   local ops_to_do={}
   if #ops_before_trash>0 then 
    ops_to_do=ops_before_trash 
@@ -1474,7 +1477,7 @@ function rope:_tug(hypothetically)
    (dmx!=0 and sgn0(pull_dx)!=dmx) or
    (dmy!=0 and sgn0(pull_dy)!=dmy) or
 
-   abs(_vec_ang_diff(pull_anc.x\8-mx0,pull_anc.y\8-my0,dmx,dmy)) > 0.125 or
+   _vec_ang_diff(pull_anc.x\8-mx0,pull_anc.y\8-my0,dmx,dmy) > 0.125 or
 
    sgn0(mx0-mxa)!=
    sgn0(mx0+dmx-mxa) or
@@ -1503,12 +1506,17 @@ function rope:_tug(hypothetically)
 end
 
 function rope:_calc_push(
- an,a0,a1
+ an,a0,a1,af
 )
  local ops={}
  if (an==nil) return ops
- 
+ local pull_ang=atan2(
+  a0.x\8 - an.x\8,
+  a0.y\8-an.y\8
+ )
+
  if a0.x==a1.x then
+  -- no far side applying pressure?
   local y0,y1=_mnmx(a0.y,a1.y)
   local my0,my1,smy=(y0+1)\8,(y1-1)\8,1
   if a0.y>a1.y then
@@ -1518,10 +1526,16 @@ function rope:_calc_push(
   
   local mx,dmx
   if a0.x%8==0 and a0.x>an.x+7 then
+   local needs_good_pull=af==nil or af.x>=a1.x
+   if (needs_good_pull and _ang_diff(pull_ang,0.5)>=0.125) return {}
+
    -- push left
    mx=(a0.x-1)\8
    dmx=-1
   elseif a0.x%8==7 and a0.x<an.x-7 then
+   local needs_good_pull=af==nil or af.x<=a1.x
+   if (needs_good_pull and _ang_diff(pull_ang,0.0)>=0.125) return {}
+
    -- push right
    mx=(a0.x+1)\8
    dmx=1
@@ -1544,11 +1558,17 @@ function rope:_calc_push(
   
   local my,dmy
   if a0.y%8==0 and a0.y>an.y+6 then
+   local needs_good_pull=af==nil or af.x>=a1.x
+   if (needs_good_pull and _ang_diff(pull_ang,0.75)>=0.125) return {}
+
    -- push up
    my=(a0.y-1)\8
    dmy=-1
    
   elseif a0.y%8==7 and a0.y<an.y-6 then
+   local needs_good_pull=af==nil or af.x>=a1.x
+   if (needs_good_pull and _ang_diff(pull_ang,0.25)>=0.125) return {}
+
    -- push down
    my=(a0.y+1)\8
    dmy=1