Added environment variable to enable the new drawing routine

TermTk/TTkCore/canvas.py

@@ -760,7 +760,7 @@ class TTkCanvas:
         self._bufferedData, self._bufferedColors = data, colors
         self._data,         self._colors         = oldData, oldColors
 
-    def pushToTerminalBufferedOld(self, x, y, w, h):
+    def pushToTerminalBufferedNew(self, x, y, w, h):
         # TTkLog.debug("pushToTerminal")
         data, colors = self._data, self._colors
         oldData, oldColors = self._bufferedData, self._bufferedColors

TermTk/TTkCore/cfg.py

@@ -33,6 +33,7 @@ class TTkCfg:
     toolTipTime = 1
     maxFps = 65
     doubleBuffer = True
+    doubleBufferNew = False
 
     scrollDelta = 5
     theme = None

TermTk/TTkCore/helper.py

@@ -329,6 +329,8 @@ class TTkHelper:
                 TTkTerm.Cursor.hide()
             if TTkCfg.doubleBuffer:
                 TTkHelper._rootCanvas.pushToTerminalBuffered(0, 0, TTkGlbl.term_w, TTkGlbl.term_h)
+            elif TTkCfg.doubleBufferNew:
+                TTkHelper._rootCanvas.pushToTerminalBufferedNew(0, 0, TTkGlbl.term_w, TTkGlbl.term_h)
             else:
                 TTkHelper._rootCanvas.pushToTerminal(0, 0, TTkGlbl.term_w, TTkGlbl.term_h)
             if TTkHelper._cursor:

TermTk/TTkCore/ttk.py

@@ -113,6 +113,10 @@ class TTk(TTkContainer):
         w,h = TTkTerm.getTerminalSize()
         self.setGeometry(0,0,w,h)
 
+        if 'TERMTK_NEWRENDERER' in os.environ:
+            TTkCfg.doubleBuffer = False
+            TTkCfg.doubleBufferNew = True
+
         TTkHelper.registerRootWidget(self)
 
     frame = 0