/*
 * Copyright 2011, Blender Foundation.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 */

#include "stdosl.h"
#include "node_color.h"

color node_mix_blend(float t, color col1, color col2)
{
	return mix(col1, col2, t);
}

color node_mix_add(float t, color col1, color col2)
{
	return mix(col1, col1 + col2, t);
}

color node_mix_mul(float t, color col1, color col2)
{
	return mix(col1, col1 * col2, t);
}

color node_mix_screen(float t, color col1, color col2)
{
	float tm = 1.0 - t;

	return color(1.0) - (color(tm) + t * (color(1.0) - col2)) * (color(1.0) - col1);
}

color node_mix_overlay(float t, color col1, color col2)
{
	float tm = 1.0 - t;

	color outcol = col1;

	if (outcol[0] < 0.5)
		outcol[0] *= tm + 2.0 * t * col2[0];
	else
		outcol[0] = 1.0 - (tm + 2.0 * t * (1.0 - col2[0])) * (1.0 - outcol[0]);

	if (outcol[1] < 0.5)
		outcol[1] *= tm + 2.0 * t * col2[1];
	else
		outcol[1] = 1.0 - (tm + 2.0 * t * (1.0 - col2[1])) * (1.0 - outcol[1]);

	if (outcol[2] < 0.5)
		outcol[2] *= tm + 2.0 * t * col2[2];
	else
		outcol[2] = 1.0 - (tm + 2.0 * t * (1.0 - col2[2])) * (1.0 - outcol[2]);
	
	return outcol;
}

color node_mix_sub(float t, color col1, color col2)
{
	return mix(col1, col1 - col2, t);
}

color node_mix_div(float t, color col1, color col2)
{
	float tm = 1.0 - t;

	color outcol = col1;

	if (col2[0] != 0.0) outcol[0] = tm * outcol[0] + t * outcol[0] / col2[0];
	if (col2[1] != 0.0) outcol[1] = tm * outcol[1] + t * outcol[1] / col2[1];
	if (col2[2] != 0.0) outcol[2] = tm * outcol[2] + t * outcol[2] / col2[2];

	return outcol;
}

color node_mix_diff(float t, color col1, color col2)
{
	return mix(col1, abs(col1 - col2), t);
}

color node_mix_dark(float t, color col1, color col2)
{
	return min(col1, col2 * t);
}

color node_mix_light(float t, color col1, color col2)
{
	return max(col1, col2 * t);
}

color node_mix_dodge(float t, color col1, color col2)
{
	color outcol = col1;

	if (outcol[0] != 0.0) {
		float tmp = 1.0 - t * col2[0];
		if (tmp <= 0.0)
			outcol[0] = 1.0;
		else if ((tmp = outcol[0] / tmp) > 1.0)
			outcol[0] = 1.0;
		else
			outcol[0] = tmp;
	}
	if (outcol[1] != 0.0) {
		float tmp = 1.0 - t * col2[1];
		if (tmp <= 0.0)
			outcol[1] = 1.0;
		else if ((tmp = outcol[1] / tmp) > 1.0)
			outcol[1] = 1.0;
		else
			outcol[1] = tmp;
	}
	if (outcol[2] != 0.0) {
		float tmp = 1.0 - t * col2[2];
		if (tmp <= 0.0)
			outcol[2] = 1.0;
		else if ((tmp = outcol[2] / tmp) > 1.0)
			outcol[2] = 1.0;
		else
			outcol[2] = tmp;
	}

	return outcol;
}

color node_mix_burn(float t, color col1, color col2)
{
	float tmp, tm = 1.0 - t;

	color outcol = col1;

	tmp = tm + t * col2[0];
	if (tmp <= 0.0)
		outcol[0] = 0.0;
	else if ((tmp = (1.0 - (1.0 - outcol[0]) / tmp)) < 0.0)
		outcol[0] = 0.0;
	else if (tmp > 1.0)
		outcol[0] = 1.0;
	else
		outcol[0] = tmp;

	tmp = tm + t * col2[1];
	if (tmp <= 0.0)
		outcol[1] = 0.0;
	else if ((tmp = (1.0 - (1.0 - outcol[1]) / tmp)) < 0.0)
		outcol[1] = 0.0;
	else if (tmp > 1.0)
		outcol[1] = 1.0;
	else
		outcol[1] = tmp;

	tmp = tm + t * col2[2];
	if (tmp <= 0.0)
		outcol[2] = 0.0;
	else if ((tmp = (1.0 - (1.0 - outcol[2]) / tmp)) < 0.0)
		outcol[2] = 0.0;
	else if (tmp > 1.0)
		outcol[2] = 1.0;
	else
		outcol[2] = tmp;
	
	return outcol;
}

color node_mix_hue(float t, color col1, color col2)
{
	color outcol = col1;
	color hsv2 = rgb_to_hsv(col2);

	if (hsv2[1] != 0.0) {
		color hsv = rgb_to_hsv(outcol);
		hsv[0] = hsv2[0];
		color tmp = hsv_to_rgb(hsv); 

		outcol = mix(outcol, tmp, t);
	}

	return outcol;
}

color node_mix_sat(float t, color col1, color col2)
{
	float tm = 1.0 - t;

	color outcol = col1;

	color hsv = rgb_to_hsv(outcol);

	if (hsv[1] != 0.0) {
		color hsv2 = rgb_to_hsv(col2);

		hsv[1] = tm * hsv[1] + t * hsv2[1];
		outcol = hsv_to_rgb(hsv);
	}

	return outcol;
}

color node_mix_val(float t, color col1, color col2)
{
	float tm = 1.0 - t;

	color hsv = rgb_to_hsv(col1);
	color hsv2 = rgb_to_hsv(col2);

	hsv[2] = tm * hsv[2] + t * hsv2[2];

	return hsv_to_rgb(hsv);
}

color node_mix_color(float t, color col1, color col2)
{
	color outcol = col1;
	color hsv2 = rgb_to_hsv(col2);

	if (hsv2[1] != 0.0) {
		color hsv = rgb_to_hsv(outcol);
		hsv[0] = hsv2[0];
		hsv[1] = hsv2[1];
		color tmp = hsv_to_rgb(hsv); 

		outcol = mix(outcol, tmp, t);
	}

	return outcol;
}

color node_mix_soft(float t, color col1, color col2)
{
	float tm = 1.0 - t;

	color one = color(1.0);
	color scr = one - (one - col2) * (one - col1);

	return tm * col1 + t * ((one - col1) * col2 * col1 + col1 * scr);
}

color node_mix_linear(float t, color col1, color col2)
{
	color outcol = col1;

	if (col2[0] > 0.5)
		outcol[0] = col1[0] + t * (2.0 * (col2[0] - 0.5));
	else
		outcol[0] = col1[0] + t * (2.0 * (col2[0]) - 1.0);

	if (col2[1] > 0.5)
		outcol[1] = col1[1] + t * (2.0 * (col2[1] - 0.5));
	else
		outcol[1] = col1[1] + t * (2.0 * (col2[1]) - 1.0);

	if (col2[2] > 0.5)
		outcol[2] = col1[2] + t * (2.0 * (col2[2] - 0.5));
	else
		outcol[2] = col1[2] + t * (2.0 * (col2[2]) - 1.0);
	
	return outcol;
}

color node_mix_clamp(color col)
{
	color outcol = col;

	outcol[0] = clamp(col[0], 0.0, 1.0);
	outcol[1] = clamp(col[1], 0.0, 1.0);
	outcol[2] = clamp(col[2], 0.0, 1.0);

	return outcol;
}

shader node_mix(
	string type = "Mix",
	int Clamp = 0,
	float Fac = 0.5,
	color Color1 = 0.0,
	color Color2 = 0.0,
	output color Color = 0.0)
{
	float t = clamp(Fac, 0.0, 1.0);

	if (type == "Mix")
		Color = node_mix_blend(t, Color1, Color2);
	if (type == "Add")
		Color = node_mix_add(t, Color1, Color2);
	if (type == "Multiply")
		Color = node_mix_mul(t, Color1, Color2);
	if (type == "Screen")
		Color = node_mix_screen(t, Color1, Color2);
	if (type == "Overlay")
		Color = node_mix_overlay(t, Color1, Color2);
	if (type == "Subtract")
		Color = node_mix_sub(t, Color1, Color2);
	if (type == "Divide")
		Color = node_mix_div(t, Color1, Color2);
	if (type == "Difference")
		Color = node_mix_diff(t, Color1, Color2);
	if (type == "Darken")
		Color = node_mix_dark(t, Color1, Color2);
	if (type == "Lighten")
		Color = node_mix_light(t, Color1, Color2);
	if (type == "Dodge")
		Color = node_mix_dodge(t, Color1, Color2);
	if (type == "Burn")
		Color = node_mix_burn(t, Color1, Color2);
	if (type == "Hue")
		Color = node_mix_hue(t, Color1, Color2);
	if (type == "Saturation")
		Color = node_mix_sat(t, Color1, Color2);
	if (type == "Value")
		Color = node_mix_val (t, Color1, Color2);
	if (type == "Color")
		Color = node_mix_color(t, Color1, Color2);
	if (type == "Soft Light")
		Color = node_mix_soft(t, Color1, Color2);
	if (type == "Linear Light")
		Color = node_mix_linear(t, Color1, Color2);

	if (Clamp)
		Color = node_mix_clamp(Color);
}