#include <stdexcept>		/* std::domain_error(-) */
#include "igs_ifx_common.h" /* igs::image::rgba */
//------------------------------------------------------------
namespace
{
template <class T>
void change_channel_(
	T *ima, const int pix_size, const int channels)
{
	for (int ii = 0; ii < pix_size; ++ii, ima += channels) {
		ima[0] = ~ima[0];
	}
}
template <class T>
void change_multiplied_rgb(
	T *ima, T *alp, const int pix_size, const int channels)
{
	for (int ii = 0; ii < pix_size; ++ii, ima += channels, alp += channels) {
		if (alp[0] < ima[0]) {
			ima[0] = 0;
		} else {
			ima[0] = alp[0] - ima[0];
		}
	}
}
template <class T>
void change_template_(
	T *ima,
	const int hh,
	const int ww,
	const int ch,
	const bool *sw /* each channels switch */
	)
{
	const int sz = hh * ww;

	if (igs::image::rgba::siz == ch) {
		using namespace igs::image::rgba;
		if (sw[0]) {
			change_multiplied_rgb(&ima[red], &ima[alp], sz, ch);
		}
		if (sw[1]) {
			change_multiplied_rgb(&ima[gre], &ima[alp], sz, ch);
		}
		if (sw[2]) {
			change_multiplied_rgb(&ima[blu], &ima[alp], sz, ch);
		}
		if (sw[3]) {
			change_channel_(&ima[alp], sz, ch);
		}
	} else if (igs::image::rgb::siz == ch) {
		using namespace igs::image::rgb;
		if (sw[0]) {
			change_channel_(&ima[red], sz, ch);
		}
		if (sw[1]) {
			change_channel_(&ima[gre], sz, ch);
		}
		if (sw[2]) {
			change_channel_(&ima[blu], sz, ch);
		}
	} else if (1 == ch) { /* Grayscale */
		if (sw[0]) {
			change_channel_(&ima[0], sz, ch);
		}
	}
}
}
//------------------------------------------------------------
#include <limits>
#include "igs_negate.h"
void igs::negate::change(
	unsigned char *image_array,
	const int height,
	const int width,
	const int channels,
	const int bits,
	const bool *sw_array /* each channel switch  */
	)
{
	if ((igs::image::rgba::siz != channels) &&
		(igs::image::rgb::siz != channels) &&
		(1 != channels) /* bit(monoBW) */
		) {
		throw std::domain_error("Bad channels,Not rgba/rgb/grayscale");
	}
	if (std::numeric_limits<unsigned char>::digits == bits) {
		change_template_(
			image_array,
			height, width, channels, sw_array);
	} else if (std::numeric_limits<unsigned short>::digits == bits) {
		change_template_(
			reinterpret_cast<unsigned short *>(image_array),
			height, width, channels, sw_array);
	} else if (1 == bits) {
		const int bi = width * channels * bits;
		const int dg = std::numeric_limits<unsigned char>::digits;
		const int sl_bytes = bi / dg + ((0 != (bi % dg)) ? 1 : 0);
		const int image_size = height * sl_bytes;
		for (int ii = 0; ii < image_size; ++ii) {
			image_array[ii] = ~image_array[ii];
		}
	} else {
		throw std::domain_error("Bad bits,Not uchar/ushort/bit");
	}
}