double xavix_state::hue2rgb(double p, double q, double t)
{
	if (t < 0) t += 1;
	if (t > 1) t -= 1;
	if (t < 1 / 6.0f) return p + (q - p) * 6 * t;
	if (t < 1 / 2.0f) return q;
	if (t < 2 / 3.0f) return p + (q - p) * (2 / 3.0f - t) * 6;
	return p;
}


void xavix_state::handle_palette(screen_device &screen, bitmap_ind16 &bitmap, const rectangle &cliprect)
{
	// not verified
	int offs = 0;
	for (int index = 0; index < 257; index++)
	{
		uint16_t dat;
			
		if (index < 256)
		{
			dat = m_palram_sh[offs];
			dat |= m_palram_l[offs] << 8;
		}
		else
		{
			dat = m_colmix_sh[0];
			dat |= m_colmix_l[0] << 8;
		}

		offs++;

		int l_raw = (dat & 0x1f00) >> 8;
		int sl_raw =(dat & 0x00e0) >> 5;
		int h_raw = (dat & 0x001f) >> 0;

		//if (h_raw > 24)
		//  logerror("hraw >24 (%02x)\n", h_raw);

		//if (l_raw > 17)
		//  logerror("lraw >17 (%02x)\n", l_raw);

		//if (sl_raw > 7)
		//  logerror("sl_raw >5 (%02x)\n", sl_raw);

		double l = (double)l_raw / 17.0f;
		double s = (double)sl_raw / 7.0f;
		double h = (double)h_raw / 24.0f;

		double r, g, b;

		if (s == 0) {
			r = g = b = l; // greyscale
		}
		else {
			double q = l < 0.5f ? l * (1 + s) : l + s - l * s;
			double p = 2 * l - q;
			r = hue2rgb(p, q, h + 1 / 3.0f);
			g = hue2rgb(p, q, h);
			b = hue2rgb(p, q, h - 1 / 3.0f);
		}

		int r_real = r * 255.0f;
		int g_real = g * 255.0f;
		int b_real = b * 255.0f;

		m_palette->set_pen_color(index, r_real, g_real, b_real);

	}
}