/**
 * Copyright (c) 2003 Billy Biggs <vektor@dumbterm.net>
 *
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 *
 * Last updated Mon Jun 16 13:12:17 ADT 2003 by vektor
 *  - Initial release.
 */

#ifndef HUEROTATE_H_INCLUDED
#define HUEROTATE_H_INCLUDED

#ifdef __cplusplus
extern "C" {
#endif

/**
 * This rotates the hue of a given scanline of sRGB pixels using the hue
 * angle from the CIELAB colourspace.  This can be used to shift the
 * colours of an image in a reasonably perceptually uniform colourspace.
 *
 * The input should conform to the sRGB standard, http://www.srgb.com/
 *
 * Take care in that the conversion is lossy due to quantization to 8
 * bits per channel.
 */

/**
 * Rotates the hue of a 24bit per pixel scanline, RGB component ordering
 * (in memory, src[ 0 ] == R).
 *
 * Angle is in radians between 0 and (2.0 * M_PI).
 */
void hue_rotate_scanline_rgb24( uint8_t *dst, uint8_t *src, int width, double angle );

/**
 * Rotates the hue of a 32bit per pixel scanline, RGBA component
 * ordering (in memory, src[ 0 ] == R, src[ 3 ] == A).  We assume that
 * the colour is non-premultiplied, and take note that for premultiplied
 * alpha this would get more complicated, since you can end up with a
 * brighter colour after the rotation.  We only touch colour, the alpha
 * channel is simply copied from source to destination.
 *
 * Angle is in radians between 0 and (2.0 * M_PI).
 */
void hue_rotate_scanline_rgba32( uint8_t *dst, uint8_t *src, int width, double angle );

#ifdef __cplusplus
};
#endif
#endif /* HUEROTATE_H_INCLUDED */