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/* 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.
//
//
namespace rfb {
#define SCALE_ERROR (1e-7)
#define BITS_OF_CHANEL 8
#define BITS_OF_WEIGHT 14
#define FINALSHIFT (2 * BITS_OF_WEIGHT - BITS_OF_CHANEL)
#define WEIGHT_OF_ONE (1 << BITS_OF_WEIGHT)
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 scaleFilterMaxNumber = 2;
const unsigned int defaultScaleFilter = scaleFilterBilinear;
//
// -=- Scale filters structures and routines
//
// Scale filter stuct
typedef struct {
char name[30]; // Filter name
double radius; // Radius where filter function is nonzero
filter_func func; // Pointer to filter function
} SFilter;
// Scale filter weight table
typedef struct {
short i0, i1; // Filter function interval, [i0..i1)
short *weight; // Weight coefficients on the filter function interval
} SFilterWeightTab;
// ScaleFilters class helps us using a set of 1-d scale filters.
class ScaleFilters {
public:
ScaleFilters() { initFilters(); };
SFilter &operator[](unsigned int filter_id);
int getFilterIdByName(char *filterName);
void makeWeightTabs(int filter, int src_x, int dst_x, SFilterWeightTab **weightTabs);
protected:
void initFilters();
SFilter create(const char *name_, double radius_, filter_func func_);
SFilter filters[scaleFilterMaxNumber+1];
};
};
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