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// SPDX-License-Identifier: GPL-2.0-or-later
#ifndef SEEN_NR_FILTER_UTILS_H
#define SEEN_NR_FILTER_UTILS_H
/**
* @file
* Definition of functions needed by several filters.
*/
/*
* Authors:
* Jean-Rene Reinhard <jr@komite.net>
*
* Copyright (C) 2007 authors
*
* Released under GNU GPL v2+, read the file 'COPYING' for more information.
*/
namespace Inkscape {
namespace Filters {
/**
* Clamps an integer value to a value between 0 and 255. Needed by filters where
* rendering computations can lead to component values out of bound.
*
* \return 0 if the value is smaller than 0, 255 if it is greater 255, else v
* \param v the value to clamp
*/
inline int clamp(int const val) {
if (val < 0) return 0;
if (val > 255) return 255;
return val;
}
/**
* Clamps an integer value to a value between 0 and 255^3.
*
* \return 0 if the value is smaller than 0, 255^3 (16581375) if it is greater than 255^3, else v
* \param v the value to clamp
*/
inline int clamp3(int const val) {
if (val < 0) return 0;
if (val > 16581375) return 16581375;
return val;
}
/**
* Macro to use the clamp function with double inputs and unsigned char output
*/
#define CLAMP_D_TO_U8(v) (unsigned char) clamp((int)round((v)))
/**
* Clamps an integer to a value between 0 and alpha. Useful when handling
* images with premultiplied alpha, as setting some of RGB channels
* to a value bigger than alpha confuses the alpha blending in Inkscape
* \return 0 if val is negative, alpha if val is bigger than alpha, val otherwise
* \param val the value to clamp
* \param alpha the maximum value to clamp to
*/
inline int clamp_alpha(int const val, int const alpha) {
if (val < 0) return 0;
if (val > alpha) return alpha;
return val;
}
/**
* Macro to use the clamp function with double inputs and unsigned char output
*/
#define CLAMP_D_TO_U8_ALPHA(v,a) (unsigned char) clamp_alpha((int)round((v)),(a))
} /* namespace Filters */
} /* namespace Inkscape */
#endif /* __NR_FILTER_UTILS_H__ */
/*
Local Variables:
mode:c++
c-file-style:"stroustrup"
c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
indent-tabs-mode:nil
fill-column:99
End:
*/
// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :
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