From 8e937d5a8d920dba42d6ef7df65ff4d0d707a723 Mon Sep 17 00:00:00 2001
From: Eugenio Parodi <ceccopierangiolieugenio@googlemail.com>
Date: Mon, 15 Mar 2021 10:29:01 +0000
Subject: [PATCH] Improved DoubleBuffer

---
 TermTk/TTkCore/canvas.py | 23 ++++++++++++++++++++---
 TermTk/TTkCore/cfg.py    |  1 +
 TermTk/TTkCore/helper.py | 27 +++++----------------------
 3 files changed, 26 insertions(+), 25 deletions(-)

diff --git a/TermTk/TTkCore/canvas.py b/TermTk/TTkCore/canvas.py
index 3fd16eaa..1b41a1d3 100644
--- a/TermTk/TTkCore/canvas.py
+++ b/TermTk/TTkCore/canvas.py
@@ -49,10 +49,17 @@ class TTkCanvas:
       in  w = the width of the new canvas
       in  h = the height of the new canvas
     '''
-    __slots__ = ('_widget', '_width', '_height', '_newWidth', '_newHeight','_theme', '_data', '_colors', '_visible')
+    __slots__ = (
+        '_widget',
+        '_width', '_height', '_newWidth', '_newHeight',
+        '_theme',
+        '_data', '_colors',
+        '_bufferedData', '_bufferedColors',
+        '_visible', '_doubleBuffer')
     def __init__(self, *args, **kwargs):
         self._widget = kwargs.get('widget', None)
         self._visible = True
+        self._doubleBuffer = False
         self._width = 0
         self._height = 0
         self._data = [[0]]
@@ -65,6 +72,10 @@ class TTkCanvas:
 
     def getWidget(self): return self._widget
 
+    def enableDoubleBuffer(self):
+        self._doubleBuffer = True
+        self._bufferedData, self._bufferedColors = self.copy()
+
     def updateSize(self):
         if not self._visible: return
         w,h = self._newWidth, self._newHeight
@@ -77,6 +88,8 @@ class TTkCanvas:
             self._colors[i] = [TTkColor.RST]*w
         self._width  = w
         self._height = h
+        if self._doubleBuffer:
+            self._bufferedData, self._bufferedColors = self.copy()
 
     def resize(self, w, h):
         self._newWidth = w
@@ -90,7 +103,7 @@ class TTkCanvas:
             for ix in range(x,x+w):
                 self._data[iy][ix] = ' '
                 self._colors[iy][ix] = TTkColor.RST
-    
+
     def copy(self):
         w,h = self._width, self._height
         retData = [[]]*h
@@ -520,8 +533,9 @@ class TTkCanvas:
                 ansi+=ch
             lbt.Term.push(ansi)
 
-    def pushToTerminalBuffered(self, x, y, w, h, oldData, oldColors):
+    def pushToTerminalBuffered(self, x, y, w, h):
         # TTkLog.debug("pushToTerminal")
+        oldData, oldColors = self._bufferedData, self._bufferedColors
         lastcolor = TTkColor.RST
         empty = True
         for y in range(0, self._height):
@@ -545,3 +559,6 @@ class TTkCanvas:
             if not empty:
                 lbt.Term.push(ansi)
                 empty=True
+        # Switch the buffer
+        self._bufferedData, self._bufferedColors = self._data, self._colors
+        self._data, self._colors = oldData, oldColors
diff --git a/TermTk/TTkCore/cfg.py b/TermTk/TTkCore/cfg.py
index ca0184b2..dfe0db75 100644
--- a/TermTk/TTkCore/cfg.py
+++ b/TermTk/TTkCore/cfg.py
@@ -30,6 +30,7 @@ class TTkCfg:
     color_depth: int = TTkK.DEP_24
 
     maxFps = 35
+    doubleBuffer = True
 
     scrollDelta = 5
     theme = None
diff --git a/TermTk/TTkCore/helper.py b/TermTk/TTkCore/helper.py
index b917a6ca..f8d20c9b 100644
--- a/TermTk/TTkCore/helper.py
+++ b/TermTk/TTkCore/helper.py
@@ -86,6 +86,7 @@ class TTkHelper:
     @staticmethod
     def registerRootCanvas(canvas):
         TTkHelper._rootCanvas = canvas
+        TTkHelper._rootCanvas.enableDoubleBuffer()
         TTkHelper._updateBuffer = []
         TTkHelper._updateWidget = []
 
@@ -126,7 +127,6 @@ class TTkHelper:
         if TTkHelper._rootCanvas is None:
             return
         TTkHelper._rootCanvas.updateSize()
-        bufferData, bufferColors = TTkHelper._rootCanvas.copy()
 
         # Build a list of buffers to be repainted
         updateBuffers = TTkHelper._updateBuffer.copy()
@@ -182,32 +182,15 @@ class TTkHelper:
         if pushToTerminal:
             if TTkHelper._cursor:
                 lbt.Term.hideCursor()
-            # TTkHelper._rootCanvas.pushToTerminal(0, 0, TTkGlbl.term_w, TTkGlbl.term_h)
-            TTkHelper._rootCanvas.pushToTerminalBuffered(0, 0, TTkGlbl.term_w, TTkGlbl.term_h, bufferData, bufferColors)
-            # TTkHelper.pushToTerminal(TTkHelper._rootCanvas, bufferData, bufferColors )
+            if TTkCfg.doubleBuffer:
+                TTkHelper._rootCanvas.pushToTerminalBuffered(0, 0, TTkGlbl.term_w, TTkGlbl.term_h)
+            else:
+                TTkHelper._rootCanvas.pushToTerminal(0, 0, TTkGlbl.term_w, TTkGlbl.term_h)
             if TTkHelper._cursor:
                 x,y = TTkHelper._cursorPos
                 lbt.Term.push(lbt.Mv.to(y+1,x+1))
                 lbt.Term.showCursor(TTkHelper._cursorType)
 
-    @staticmethod
-    def pushToTerminal(canvas, bufferData, bufferColors):
-        from TermTk.TTkCore.color import TTkColor
-        # TTkLog.debug("pushToTerminal")
-        data = canvas._data
-        colors = canvas._colors
-        lastcolor = TTkColor.RST
-        for y in range(0, self._height):
-            ansi = TTkColor.RST+lbt.Mv.t(y+1,1)
-            for x in range(0, self._width):
-                ch = data[y][x]
-                color = colors[y][x]
-                if color != lastcolor:
-                    ansi += color-lastcolor
-                    lastcolor = color
-                ansi+=ch
-            lbt.Term.push(ansi)
-
     @staticmethod
     def widgetDepth(widget) -> int:
         if widget is None: