36d9047104b5881ca587a71ade77b1f21d083bc4Jon A. Cruz * Definition of functions needed by several filters.
0f1b8f53ed81c3a02f55223cd3eb359f123bc565kiirala * Jean-Rene Reinhard <jr@komite.net>
0f1b8f53ed81c3a02f55223cd3eb359f123bc565kiirala * Copyright (C) 2007 authors
0f1b8f53ed81c3a02f55223cd3eb359f123bc565kiirala * Released under GNU GPL, read the file 'COPYING' for more information
0f1b8f53ed81c3a02f55223cd3eb359f123bc565kiirala * Clamps an integer value to a value between 0 and 255. Needed by filters where
0f1b8f53ed81c3a02f55223cd3eb359f123bc565kiirala * rendering computations can lead to component values out of bound.
0f1b8f53ed81c3a02f55223cd3eb359f123bc565kiirala * \return 0 if the value is smaller than 0, 255 if it is greater 255, else v
0f1b8f53ed81c3a02f55223cd3eb359f123bc565kiirala * \param v the value to clamp
ebf4167e4f3ec3ca9f5ece6c5316abc209a9f049kiirala if (val < 0) return 0;
9e48bcf8c4a1baf69228357a2921b48a6bb72b93tavmjong * Clamps an integer value to a value between 0 and 255^3.
9e48bcf8c4a1baf69228357a2921b48a6bb72b93tavmjong * \return 0 if the value is smaller than 0, 255^3 (16581375) if it is greater than 255^3, else v
9e48bcf8c4a1baf69228357a2921b48a6bb72b93tavmjong * \param v the value to clamp
ebf4167e4f3ec3ca9f5ece6c5316abc209a9f049kiirala if (val < 0) return 0;
0f1b8f53ed81c3a02f55223cd3eb359f123bc565kiirala * Macro to use the clamp function with double inputs and unsigned char output
0f1b8f53ed81c3a02f55223cd3eb359f123bc565kiirala#define CLAMP_D_TO_U8(v) (unsigned char) clamp((int)round((v)))
aec7a0781472450c98c74c107a9a36528dbb9872kiirala * Clamps an integer to a value between 0 and alpha. Useful when handling
aec7a0781472450c98c74c107a9a36528dbb9872kiirala * images with premultiplied alpha, as setting some of RGB channels
aec7a0781472450c98c74c107a9a36528dbb9872kiirala * to a value bigger than alpha confuses the alpha blending in Inkscape
aec7a0781472450c98c74c107a9a36528dbb9872kiirala * \return 0 if val is negative, alpha if val is bigger than alpha, val otherwise
aec7a0781472450c98c74c107a9a36528dbb9872kiirala * \param val the value to clamp
aec7a0781472450c98c74c107a9a36528dbb9872kiirala * \param alpha the maximum value to clamp to
ebf4167e4f3ec3ca9f5ece6c5316abc209a9f049kiiralainline int clamp_alpha(int const val, int const alpha) {
ebf4167e4f3ec3ca9f5ece6c5316abc209a9f049kiirala if (val < 0) return 0;
423740a942b7c6ce5313bfd4d09fe02c4feabbe7jaspervdg * Macro to use the clamp function with double inputs and unsigned char output
423740a942b7c6ce5313bfd4d09fe02c4feabbe7jaspervdg#define CLAMP_D_TO_U8_ALPHA(v,a) (unsigned char) clamp_alpha((int)round((v)),(a))
d9a7c806ee7f408ddb61ff4f233c9d96111ee2b5johanengelen} /* namespace Filters */
d9a7c806ee7f408ddb61ff4f233c9d96111ee2b5johanengelen} /* namespace Inkscape */
0f1b8f53ed81c3a02f55223cd3eb359f123bc565kiirala#endif /* __NR_FILTER_UTILS_H__ */
0f1b8f53ed81c3a02f55223cd3eb359f123bc565kiirala Local Variables:
0f1b8f53ed81c3a02f55223cd3eb359f123bc565kiirala c-file-style:"stroustrup"
0f1b8f53ed81c3a02f55223cd3eb359f123bc565kiirala c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
0f1b8f53ed81c3a02f55223cd3eb359f123bc565kiirala indent-tabs-mode:nil
0f1b8f53ed81c3a02f55223cd3eb359f123bc565kiirala fill-column:99
a4030d5ca449e7e384bc699cd249ee704faaeab0Chris Morgan// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :