chameleonic.p8

@@ -53,21 +53,19 @@ function linefill(ax,ay,bx,by,r,c)
  local dx,dy=bx-ax,by-ay
  -- avoid overflow
  -- credits: https://www.lexaloffle.com/bbs/?tid=28999
- local d=max(abs(dx),abs(dy))
+ local n,d=_mnmx(abs(dx),abs(dy)) 
- local n=min(abs(dx),abs(dy))/d
+ n/=d
  d*=sqrt(n*n+1)
  if(d<0.001) return
  local ca,sa=dx/d,-dy/d
    
  -- polygon points
- local s={
+ local s={{0,-r},{d,-r},{d,r},{0,r}}
-  {0,-r},{d,-r},{d,r},{0,r}
+ local spans={}
- }
+ local function calcxy(u,v) return ax+u*ca+v*sa,ay-u*sa+v*ca end
- local u,v,spans=s[4][1],s[4][2],{}
+ local x0,y0=calcxy(0,r)
- local x0,y0=ax+u*ca+v*sa,ay-u*sa+v*ca
  for i=1,4 do
-  local u,v=s[i][1],s[i][2]
+  local x1,y1=calcxy(unpack(s[i]))
-  local x1,y1=ax+u*ca+v*sa,ay-u*sa+v*ca
   local _x1,_y1=x1,y1
   if(y0>y1) x0,y0,x1,y1=x1,y1,x0,y0
   local dx=(x1-x0)/(y1-y0)
@@ -78,11 +76,8 @@ function linefill(ax,ay,bx,by,r,c)
   for y=y0\1+1,min(y1\1,127) do
    -- open span?
    local span=spans[y]
-   if span then
+   if (span) rectfill(x0,y,span,y)
-    rectfill(x0,y,span,y)
+   spans[y]=x0
-   else
-    spans[y]=x0
-   end
    x0+=dx
   end
   x0,y0=_x1,_y1