Changed drawing order and updated line connecting

grid.lua

@@ -22,20 +22,26 @@ end
 
 -- Draw lines and the whole grid
 function Grid:draw()
-    -- Draw lines
+    -- Draw grid
+    for x = 1, self.size.x do-- Draw lines
     for _, line in ipairs( self.lines ) do
         line:draw()
     end
-    -- Draw grid
-    for x = 1, self.size.x do
+
         for y = 1, self.size.y do
             local px, py = x * Config.cellSize, y * Config.cellSize
             love.graphics.circle( "fill", px - Config.cellSize / 2, py - Config.cellSize / 2, Config.pointRadius)
         end
     end
+    -- Draw lines
+    for _, line in ipairs( self.lines ) do
+        line:draw()
+    end
+
 end
 
 -- Check all lines and return one, which contains point (if any)
+-- TODO: rewrite this function to extract clear/reverse behavior
 function Grid:matchesLine( point, ignoreEnd )
     local line = self.lines[tableFind( self.lines, point,
         function( value, innervalue )
@@ -71,6 +77,13 @@ function Grid:matchesLine( point, ignoreEnd )
     return line
 end
 
+function Grid:isOtherEndpoint( line, point )
+    return tableHas( self.lines, { line=line, point=point }, function( value, innervalue )
+        return innervalue ~= value.line and innervalue.endpoint:equals( value.point )
+    end
+    )
+end
+
 function Grid:inBounds( point )
     return point.x <= self.size.x and point.y <= self.size.y
 end

main.lua

@@ -56,8 +56,14 @@ function love.update( dt )
         if vectorLength( mouse.point, lastLinePoint ) == 1 
             and gameGrid:inBounds( mouse.point )
             and gameGrid:matchesLine( mouse.point, true ) == nil 
-            and not lastLinePoint:equals( mouse.lastLine.endpoint ) then
+            and not lastLinePoint:equals( mouse.lastLine.endpoint )
+            and not gameGrid:isOtherEndpoint( mouse.lastLine, mouse.point ) then
             mouse.lastLine:push( mouse.point )
+        elseif mouse.lastLine:has( mouse.point ) 
+            and not mouse.point:equals( lastLinePoint ) then
+            while not mouse.lastLine.points[#mouse.lastLine.points]:equals( mouse.point ) do
+                mouse.lastLine:pop()
+            end
         end
     end