allow C to be visible

Author: SimonEnsemble

src/draw/draw2d.jl

@@ -28,6 +28,7 @@ Default setting parameters of the molecule drawing canvas.
                    `:alongside` for others (default)
 - `:atomcolor`(Dict{Symbol,Color}) atom symbol and bond colors for organic atoms
 - `:defaul_atom_color`(Dict{Symbol,Color}) colors for other atoms
+- `:C_visible`(Bool) if C atoms should be visible
 """
 const DRAW_SETTING = Dict(
     :display_terminal_carbon => false,
@@ -48,7 +49,8 @@ const DRAW_SETTING = Dict(
         :Br => Color(0, 192, 0),
         :I => Color(0, 128, 0)
     ),
-    :default_atom_color => Color(0, 192, 192)
+    :default_atom_color => Color(0, 192, 192),
+    :C_visible => false
 )
 
 # For 3d rendering, we use white for hydrogen
@@ -87,7 +89,7 @@ Return whether the atom is visible in the 2D drawing.
     mul_ = multiplicity(mol)
     mas_ = getproperty.(nodeattrs(mol), :mass)
     for i in 1:nodecount(mol)
-        sym_[i] === :C || continue
+        (sym_[i] === :C && ! setting[:C_visible]) || continue
         chg_[i] == 0 || continue
         mul_[i] == 1 || continue
         mas_[i] === nothing || continue