1 files changed, 98 insertions, 0 deletions
diff --git a/src/graphics/FilterFastDownscale.cpp b/src/graphics/FilterFastDownscale.cpp
new file mode 100644
index 0000000..9ed9900
--- /dev/null
+++ b/src/graphics/FilterFastDownscale.cpp
@@ -0,0 +1,98 @@
+//
+//  libavg - Media Playback Engine. 
+//  Copyright (C) 2003-2014 Ulrich von Zadow
+//
+//  This library is free software; you can redistribute it and/or
+//  modify it under the terms of the GNU Lesser General Public
+//  License as published by the Free Software Foundation; either
+//  version 2 of the License, or (at your option) any later version.
+//
+//  This library 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
+//  Lesser General Public License for more details.
+//
+//  You should have received a copy of the GNU Lesser General Public
+//  License along with this library; if not, write to the Free Software
+//  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+//
+//  Current versions can be found at www.libavg.de
+//
+
+#include "FilterFastDownscale.h"
+#include "Pixeldefs.h"
+
+#include "../base/Exception.h"
+
+#include <iostream>
+
+namespace avg {
+
+using namespace std;
+    
+FilterFastDownscale::FilterFastDownscale(int factor) 
+    : Filter(),
+      m_Factor(factor)
+{
+}
+
+FilterFastDownscale::~FilterFastDownscale()
+{
+
+}
+
+BitmapPtr FilterFastDownscale::apply(BitmapPtr pBmpSrc) 
+{
+    AVG_ASSERT(pBmpSrc->getPixelFormat() == I8);
+    BitmapPtr pBmpDest = BitmapPtr(new Bitmap(pBmpSrc->getSize()/m_Factor, I8,
+             pBmpSrc->getName()));
+    unsigned char * pSrcLine = pBmpSrc->getPixels();
+    unsigned char * pDestLine = pBmpDest->getPixels();
+    IntPoint size = pBmpDest->getSize();
+    int srcStride = pBmpSrc->getStride();
+    for (int y = 0; y < size.y; ++y) {
+        unsigned char * pSrcPixel = pSrcLine;
+        unsigned char * pDstPixel = pDestLine;
+        switch (m_Factor) {
+            case 2:
+                for (int x = 0; x < size.x; ++x) {
+                    int dstPixel= int(*pSrcPixel)+int(*(pSrcPixel+1))
+                            +int(*(pSrcPixel+srcStride))+int(*(pSrcPixel+srcStride+1));
+                    *pDstPixel = (dstPixel+2)/4;
+                    pSrcPixel += 2;
+                    pDstPixel++;
+                }
+                break;
+            case 3:
+                for (int x = 0; x < size.x; ++x) {
+                    int dstPixel= int(*pSrcPixel)+int(*(pSrcPixel+1))+int(*(pSrcPixel+2))
+                            +int(*(pSrcPixel+srcStride))+int(*(pSrcPixel+srcStride+1))
+                                    +int(*(pSrcPixel+srcStride+2))
+                            +int(*(pSrcPixel+srcStride*2))+int(*(pSrcPixel+srcStride*2+1))
+                                    +int(*(pSrcPixel+srcStride*2+2));
+                    *pDstPixel = (dstPixel+4)/9;
+                    pSrcPixel += 3;
+                    pDstPixel++;
+                }
+                break;
+            default:
+                for (int x = 0; x < size.x; ++x) {
+                    int dstPixel=0;
+                    for (int y1 = 0; y1 < m_Factor; y1++) {
+                        for (int x1 = 0; x1 < m_Factor; x1++) {
+                            dstPixel+= (int)(*(pSrcPixel+srcStride*y1+x1));
+                        }
+                    }
+                    *pDstPixel = (dstPixel+(m_Factor*m_Factor)/2)/(m_Factor*m_Factor);
+                    pSrcPixel += m_Factor;
+                    pDstPixel++;
+                }
+                break;
+        }
+        pSrcLine = pSrcLine + pBmpSrc->getStride()*m_Factor;
+        pDestLine = pDestLine + pBmpDest->getStride();
+    }
+    return pBmpDest;
+}
+
+} // namespace