/*
 * Copyright 2011-2013 Blender Foundation
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

CCL_NAMESPACE_BEGIN

ccl_device float3 svm_mix_blend(float t, float3 col1, float3 col2)
{
	return interp(col1, col2, t);
}

ccl_device float3 svm_mix_add(float t, float3 col1, float3 col2)
{
	return interp(col1, col1 + col2, t);
}

ccl_device float3 svm_mix_mul(float t, float3 col1, float3 col2)
{
	return interp(col1, col1 * col2, t);
}

ccl_device float3 svm_mix_screen(float t, float3 col1, float3 col2)
{
	float tm = 1.0f - t;
	float3 one = make_float3(1.0f, 1.0f, 1.0f);
	float3 tm3 = make_float3(tm, tm, tm);

	return one - (tm3 + t*(one - col2))*(one - col1);
}

ccl_device float3 svm_mix_overlay(float t, float3 col1, float3 col2)
{
	float tm = 1.0f - t;

	float3 outcol = col1;

	if(outcol.x < 0.5f)
		outcol.x *= tm + 2.0f*t*col2.x;
	else
		outcol.x = 1.0f - (tm + 2.0f*t*(1.0f - col2.x))*(1.0f - outcol.x);

	if(outcol.y < 0.5f)
		outcol.y *= tm + 2.0f*t*col2.y;
	else
		outcol.y = 1.0f - (tm + 2.0f*t*(1.0f - col2.y))*(1.0f - outcol.y);

	if(outcol.z < 0.5f)
		outcol.z *= tm + 2.0f*t*col2.z;
	else
		outcol.z = 1.0f - (tm + 2.0f*t*(1.0f - col2.z))*(1.0f - outcol.z);
	
	return outcol;
}

ccl_device float3 svm_mix_sub(float t, float3 col1, float3 col2)
{
	return interp(col1, col1 - col2, t);
}

ccl_device float3 svm_mix_div(float t, float3 col1, float3 col2)
{
	float tm = 1.0f - t;

	float3 outcol = col1;

	if(col2.x != 0.0f) outcol.x = tm*outcol.x + t*outcol.x/col2.x;
	if(col2.y != 0.0f) outcol.y = tm*outcol.y + t*outcol.y/col2.y;
	if(col2.z != 0.0f) outcol.z = tm*outcol.z + t*outcol.z/col2.z;

	return outcol;
}

ccl_device float3 svm_mix_diff(float t, float3 col1, float3 col2)
{
	return interp(col1, fabs(col1 - col2), t);
}

ccl_device float3 svm_mix_dark(float t, float3 col1, float3 col2)
{
	return min(col1, col2)*t + col1*(1.0f - t);
}

ccl_device float3 svm_mix_light(float t, float3 col1, float3 col2)
{
	return max(col1, col2*t);
}

ccl_device float3 svm_mix_dodge(float t, float3 col1, float3 col2)
{
	float3 outcol = col1;

	if(outcol.x != 0.0f) {
		float tmp = 1.0f - t*col2.x;
		if(tmp <= 0.0f)
			outcol.x = 1.0f;
		else if((tmp = outcol.x/tmp) > 1.0f)
			outcol.x = 1.0f;
		else
			outcol.x = tmp;
	}
	if(outcol.y != 0.0f) {
		float tmp = 1.0f - t*col2.y;
		if(tmp <= 0.0f)
			outcol.y = 1.0f;
		else if((tmp = outcol.y/tmp) > 1.0f)
			outcol.y = 1.0f;
		else
			outcol.y = tmp;
	}
	if(outcol.z != 0.0f) {
		float tmp = 1.0f - t*col2.z;
		if(tmp <= 0.0f)
			outcol.z = 1.0f;
		else if((tmp = outcol.z/tmp) > 1.0f)
			outcol.z = 1.0f;
		else
			outcol.z = tmp;
	}

	return outcol;
}

ccl_device float3 svm_mix_burn(float t, float3 col1, float3 col2)
{
	float tmp, tm = 1.0f - t;

	float3 outcol = col1;

	tmp = tm + t*col2.x;
	if(tmp <= 0.0f)
		outcol.x = 0.0f;
	else if((tmp = (1.0f - (1.0f - outcol.x)/tmp)) < 0.0f)
		outcol.x = 0.0f;
	else if(tmp > 1.0f)
		outcol.x = 1.0f;
	else
		outcol.x = tmp;

	tmp = tm + t*col2.y;
	if(tmp <= 0.0f)
		outcol.y = 0.0f;
	else if((tmp = (1.0f - (1.0f - outcol.y)/tmp)) < 0.0f)
		outcol.y = 0.0f;
	else if(tmp > 1.0f)
		outcol.y = 1.0f;
	else
		outcol.y = tmp;

	tmp = tm + t*col2.z;
	if(tmp <= 0.0f)
		outcol.z = 0.0f;
	else if((tmp = (1.0f - (1.0f - outcol.z)/tmp)) < 0.0f)
		outcol.z = 0.0f;
	else if(tmp > 1.0f)
		outcol.z = 1.0f;
	else
		outcol.z = tmp;
	
	return outcol;
}

ccl_device float3 svm_mix_hue(float t, float3 col1, float3 col2)
{
	float3 outcol = col1;

	float3 hsv2 = rgb_to_hsv(col2);

	if(hsv2.y != 0.0f) {
		float3 hsv = rgb_to_hsv(outcol);
		hsv.x = hsv2.x;
		float3 tmp = hsv_to_rgb(hsv); 

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

	return outcol;
}

ccl_device float3 svm_mix_sat(float t, float3 col1, float3 col2)
{
	float tm = 1.0f - t;

	float3 outcol = col1;

	float3 hsv = rgb_to_hsv(outcol);

	if(hsv.y != 0.0f) {
		float3 hsv2 = rgb_to_hsv(col2);

		hsv.y = tm*hsv.y + t*hsv2.y;
		outcol = hsv_to_rgb(hsv);
	}

	return outcol;
}

ccl_device float3 svm_mix_val(float t, float3 col1, float3 col2)
{
	float tm = 1.0f - t;

	float3 hsv = rgb_to_hsv(col1);
	float3 hsv2 = rgb_to_hsv(col2);

	hsv.z = tm*hsv.z + t*hsv2.z;

	return hsv_to_rgb(hsv);
}

ccl_device float3 svm_mix_color(float t, float3 col1, float3 col2)
{
	float3 outcol = col1;
	float3 hsv2 = rgb_to_hsv(col2);

	if(hsv2.y != 0.0f) {
		float3 hsv = rgb_to_hsv(outcol);
		hsv.x = hsv2.x;
		hsv.y = hsv2.y;
		float3 tmp = hsv_to_rgb(hsv); 

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

	return outcol;
}

ccl_device float3 svm_mix_soft(float t, float3 col1, float3 col2)
{
	float tm = 1.0f - t;

	float3 one = make_float3(1.0f, 1.0f, 1.0f);
	float3 scr = one - (one - col2)*(one - col1);

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

ccl_device float3 svm_mix_linear(float t, float3 col1, float3 col2)
{
	return col1 + t*(2.0f*col2 + make_float3(-1.0f, -1.0f, -1.0f));
}

ccl_device float3 svm_mix_clamp(float3 col)
{
	float3 outcol = col;

	outcol.x = saturate(col.x);
	outcol.y = saturate(col.y);
	outcol.z = saturate(col.z);

	return outcol;
}

ccl_device_noinline float3 svm_mix(NodeMix type, float fac, float3 c1, float3 c2)
{
	float t = saturate(fac);

	switch(type) {
		case NODE_MIX_BLEND: return svm_mix_blend(t, c1, c2);
		case NODE_MIX_ADD: return svm_mix_add(t, c1, c2);
		case NODE_MIX_MUL: return svm_mix_mul(t, c1, c2);
		case NODE_MIX_SCREEN: return svm_mix_screen(t, c1, c2);
		case NODE_MIX_OVERLAY: return svm_mix_overlay(t, c1, c2);
		case NODE_MIX_SUB: return svm_mix_sub(t, c1, c2);
		case NODE_MIX_DIV: return svm_mix_div(t, c1, c2);
		case NODE_MIX_DIFF: return svm_mix_diff(t, c1, c2);
		case NODE_MIX_DARK: return svm_mix_dark(t, c1, c2);
		case NODE_MIX_LIGHT: return svm_mix_light(t, c1, c2);
		case NODE_MIX_DODGE: return svm_mix_dodge(t, c1, c2);
		case NODE_MIX_BURN: return svm_mix_burn(t, c1, c2);
		case NODE_MIX_HUE: return svm_mix_hue(t, c1, c2);
		case NODE_MIX_SAT: return svm_mix_sat(t, c1, c2);
		case NODE_MIX_VAL: return svm_mix_val (t, c1, c2);
		case NODE_MIX_COLOR: return svm_mix_color(t, c1, c2);
		case NODE_MIX_SOFT: return svm_mix_soft(t, c1, c2);
		case NODE_MIX_LINEAR: return svm_mix_linear(t, c1, c2);
		case NODE_MIX_CLAMP: return svm_mix_clamp(c1);
	}

	return make_float3(0.0f, 0.0f, 0.0f);
}

ccl_device_inline float3 svm_brightness_contrast(float3 color, float brightness, float contrast)
{
	float a = 1.0f + contrast;
	float b = brightness - contrast*0.5f;

	color.x = max(a*color.x + b, 0.0f);
	color.y = max(a*color.y + b, 0.0f);
	color.z = max(a*color.z + b, 0.0f);

	return color;
}

CCL_NAMESPACE_END