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/*
* _ _ _ _ _____
* __ ____| |_ __ _ __ | |_ _ __ _(_)_ __ __| |_ ___ _|___ /
* \ \ / / _` | '__|____| '_ \| | | | |/ _` | | '_ \ _____ / _` \ \/ / '__||_ \
* \ V / (_| | | |_____| |_) | | |_| | (_| | | | | |_____| (_| |> <| | ___) |
* \_/ \__,_|_| | .__/|_|\__,_|\__, |_|_| |_| \__,_/_/\_\_| |____/
* |_| |___/
*
* Copyright (C) 2009 Christian Gmeiner
*
* This file is part of vdr-plugin-dxr3.
*
* vdr-plugin-dxr3 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 version 2.
*
* vdr-plugin-dxr3 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 dxr3-plugin. If not, see <http://www.gnu.org/licenses/>.
*
*/
#include "scaler.h"
#include <vdr/osd.h>
// scaling based on article "Image Scaling With Bresenham" by Thiadmer Riemersma
// http://www.ddj.com/184405045
static void scaleLine(const tIndex *src, tIndex *dest, int srcWidth, int destWidth)
{
int numPixels = destWidth;
int intPart = srcWidth / destWidth;
int fractPart = srcWidth % destWidth;
int e = 0;
while (numPixels-- > 0) {
*dest++ = *src;
src += intPart;
e += fractPart;
if (e >= destWidth) {
e -= destWidth;
src++;
}
}
}
static void scaleRect(const tIndex *src, tIndex *dest, int srcWidth, int srcHeight, int destWidth, int destHeight)
{
int numPixels = destHeight;
int intPart = (srcHeight / destHeight) * srcWidth;
int fractPart = srcHeight % destHeight;
int e = 0;
while (numPixels-- > 0) {
scaleLine(src, dest, srcWidth, destWidth);
dest += destWidth;
src += intPart;
e += fractPart;
if (e >= destHeight) {
e -= destHeight;
src += srcWidth;
}
}
}
cBitmap *cScaler::scaleBitmap(cBitmap *source, int width, int height)
{
cBitmap *scaled = new cBitmap(width, height, 4, 0, 0);
int osdWidth = source->Width();
int osdHeight = source->Height();
const tIndex *src = source->Data(0, 0);
tIndex *dest = (tIndex *)scaled->Data(0, 0);
scaleRect(src, dest, osdWidth, osdHeight, width, height);
return scaled;
}
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