From 2a4076b3f75980c3ef54bad576bb1db002deee54 Mon Sep 17 00:00:00 2001
From: george82 <george82@3789f03b-4d11-0410-bbf8-ca57d06f2519>
Date: Thu, 26 Oct 2006 15:34:10 +0000
Subject: [PATCH] Added definitions of the 1-D filters and routines using for
 the image scaling.

git-svn-id: svn://svn.code.sf.net/p/tigervnc/code/trunk@2108 3789f03b-4d11-0410-bbf8-ca57d06f2519
---
 common/rfb/ScaleFilters.h | 79 +++++++++++++++++++++++++++++++++++++++
 common/rfb/rfb.dsp        |  4 ++
 2 files changed, 83 insertions(+)
 create mode 100644 common/rfb/ScaleFilters.h

diff --git a/common/rfb/ScaleFilters.h b/common/rfb/ScaleFilters.h
new file mode 100644
index 00000000..950838a2
--- /dev/null
+++ b/common/rfb/ScaleFilters.h
@@ -0,0 +1,79 @@
+/* Copyright (C) 2006 TightVNC Team.  All Rights Reserved.
+ *    
+ * This is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ * 
+ * This software is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ * 
+ * You should have received a copy of the GNU General Public License
+ * along with this software; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307,
+ * USA.
+ */
+
+// -=- ScaleFilters.h
+//
+// Definitions of the 1-D filters and routines using for the image scaling.
+//  
+// 
+
+#include <math.h>
+
+namespace rfb {
+
+  typedef double (*filter_func)(double x);
+
+  const double pi = 3.14159265358979;
+
+  const unsigned int scaleFilterNearestNeighbor = 0;
+  const unsigned int scaleFilterBilinear = 1;
+  const unsigned int scaleFilterBicubic = 2;
+  const unsigned int scaleFilterSinc = 3;
+
+  const unsigned int scaleFiltersMax = 10;
+
+  // Nearest neighbor filter function
+  double nearest_neighbor(double x) {
+    if (x < -0.5) return 0.0;
+    if (x < 0.5) return 1.0;
+    return 0.0;
+  }
+
+  // Linear filter function
+  double linear(double x) {
+    if (x < -1.0) return 0.0;
+    if (x < 0.0) return 1.0+x;
+    if (x < 1.0) return 1.0-x;
+    return 0.0;
+  }
+
+  // Cubic filter functions
+  double cubic(double x) {
+    double t;
+    if (x < -2.0) return 0.0;
+    if (x < -1.0) {t = 2.0+x; return t*t*t/6.0;}
+    if (x < 0.0) return (4.0+x*x*(-6.0+x*-3.0))/6.0;
+    if (x < 1.0) return (4.0+x*x*(-6.0+x*3.0))/6.0;
+    if (x < 2.0) {t = 2.0-x; return t*t*t/6.0;}
+    return 0.0;
+  }
+
+  // Sinc filter function
+  double sinc(double x) {
+    if (x == 0.0) return 1.0;
+    else return sin(pi*x)/(pi*x);
+  }
+
+  class ScaleFilter {
+  public:
+    char name[30];
+    int radius;
+    filter_func func;
+  };
+
+};
diff --git a/common/rfb/rfb.dsp b/common/rfb/rfb.dsp
index f24563e0..b8f6e47b 100644
--- a/common/rfb/rfb.dsp
+++ b/common/rfb/rfb.dsp
@@ -629,6 +629,10 @@ SOURCE=.\ScaledPixelBuffer.h
 # End Source File
 # Begin Source File
 
+SOURCE=.\ScaleFilters.h
+# End Source File
+# Begin Source File
+
 SOURCE=.\SConnection.h
 # End Source File
 # Begin Source File
-- 
2.39.5