From 821d2d98207c4f01e9f5482f0f308192ee16b3f9 Mon Sep 17 00:00:00 2001
From: Bob van Loosen <bob.loosen@gmail.com>
Date: Mon, 18 Feb 2013 18:38:41 +0100
Subject: [PATCH] added: disable dither by default, and enable it when the -s
 argument is passed

---
 src/bitx11/bitx11.cpp | 22 +++++++++++++++-------
 src/bitx11/bitx11.h   |  1 +
 2 files changed, 16 insertions(+), 7 deletions(-)

diff --git a/src/bitx11/bitx11.cpp b/src/bitx11/bitx11.cpp
index 801f714..b47d602 100644
--- a/src/bitx11/bitx11.cpp
+++ b/src/bitx11/bitx11.cpp
@@ -32,12 +32,13 @@ CBitX11::CBitX11(int argc, char *argv[])
   m_port = 1337;
   m_address = NULL;
   m_fps = 30.0f;
+  m_dither = false;
   m_destwidth = 120;
   m_destheight = 48;
   m_debug = false;
   m_debugscale = 2;
 
-  const char* flags = "p:a:f:d:";
+  const char* flags = "p:a:f:d:s";
   int c;
   while ((c = getopt(argc, argv, flags)) != -1)
   {
@@ -80,6 +81,10 @@ CBitX11::CBitX11(int argc, char *argv[])
 
       m_debugscale = scale;
     }
+    else if (c == 's') //dither
+    {
+      m_dither = true;
+    }
   }
 
   //if no address is specified, turn on the debug window instead
@@ -205,7 +210,7 @@ void CBitX11::Process()
     }
     avg /= m_destwidth * m_destheight * 2;
 
-    //quantize the planes, apply Floy-Steinberg dithering, and write into the buffer for the socket
+    //quantize the planes, optionally apply Floy-Steinberg dithering, and write into the buffer for the socket
     CTcpData data;
     data.SetData(":00");
     for (int y = 0; y < m_destheight; y++)
@@ -244,14 +249,17 @@ void CBitX11::Process()
             ledpos++;
           }
 
-          //apply Floyd-Steinberg dither
           quanterror = *line - quantval;
           *line = quantval;
 
-          line[1] += quanterror * 7 / 16;
-          line[m_destwidth - 1] += quanterror * 3 / 16;
-          line[m_destwidth] += quanterror * 5 / 16;
-          line[m_destwidth + 1] += quanterror / 16;
+          //apply Floyd-Steinberg dither
+          if (m_dither)
+          {
+            line[1] += quanterror * 7 / 16;
+            line[m_destwidth - 1] += quanterror * 3 / 16;
+            line[m_destwidth] += quanterror * 5 / 16;
+            line[m_destwidth + 1] += quanterror / 16;
+          }
 
           line++;
         }
diff --git a/src/bitx11/bitx11.h b/src/bitx11/bitx11.h
index 8bf9d50..658382a 100644
--- a/src/bitx11/bitx11.h
+++ b/src/bitx11/bitx11.h
@@ -42,6 +42,7 @@ class CBitX11
     int                m_port;
     const char*        m_address;
     float              m_fps;
+    bool               m_dither;
 
     CTcpClientSocket   m_socket;