#version 420
#extension GL_ARB_texture_gather : enable
// Adjustable Bloom + Tone Mapping + Adjustable Vibrance(Contrasty)

/*=============================Settings=====================================*/

#define adjust_bloom 1         // 0: disable, 1: enable.
const float bloomFactor = 0.7; // 1.0 is neutral

#define tone_mapping 0
// -1: disable, clamp bright detail but keep [0,1] intact, however clamping could lead to desaturation as well
// 0: (Wii U) BotW original
// 1: ACES Filmic
//--------------------"ACES Filmic" Parameters-----------------//
const float Exposure = 0.6;    // [0.0, 1.0+] Adjust exposure
//---------------------------------------------------------------//

#define post_process 2
// -1: disable
// 0: (Wii U) BotW original, only vibrance
// 1: Reshade Vibrance
// 2: Contrasty
// 3: Experimental, convert rgb to hsv then adjust saturation directly
//----------------"BotW original" vibrance adjust-------------//
const float satFactor = 0.29;   // 0.18 is neutral. Experimental, adjust native saturation
//---------------------------------------------------------------//
//-----------------"Reshade Vibrance" Parameters--------------//
const float Vibrance = 0.40;   // Saturates (or desaturates if you use negative values) the pixels depending on their original saturation.
const vec3 VibranceRGBBalance = vec3(1.0,1.0,1.0); // A per channel multiplier to the Vibrance strength so you can give more boost to certain colors over others.
//---------------------------------------------------------------//
//---------------------"Contrasty" Parameters-----------------//
const float gamma = 0.81;      // 1.0 is neutral. Botw is already colour graded at this stage
const float exposure = 1.17;   // 1.0 is neutral
const float vibrance = 0.45;   // 0.0 is neutral  
const float crushContrast = 0.004; // 0.0 is neutral. Use small increments, loss of shadow detail 
//---------------------------------------------------------------//
//------------------------"hsv experiment"---------------------//
const float satScale = 1.5;    // 1.0 is neutral
//---------------------------------------------------------------//

/*==========================================================================*/


// shader bd8bba59e2149449 // bloom(add), tonemap, saturate
uniform ivec4 uf_remappedPS[1];
layout(binding = 0) uniform sampler2D textureUnitPS0; //bloom
layout(binding = 1) uniform sampler2D textureUnitPS1; //texture, hdr
layout(location = 0) in vec4 passParameterSem0;
layout(location = 0) out vec4 passPixelColor0;
uniform vec2 uf_fragCoordScale;

float getL601(vec3 rgb) {
	return dot(rgb,vec3(0.2989,0.5866,0.1145));
}

float getL709(vec3 rgb) {
	return dot(rgb,vec3(0.2126,0.7152,0.0722));
}

vec3 BotWToneMap(vec3 color) {
	float Lumn = getL601(color);
	vec4 exptm = 1.0 - exp(-vec4(color,Lumn));
	vec3 cpre = exptm.w / Lumn * color;
	vec3 colorldr = mix(cpre,exptm.rgb,vec3(pow(exptm.w,2.0)));//refine
	return colorldr;
}

vec3 ACESFilm(vec3 color) {
	color *= Exposure;
	return (color*(2.51*color+0.03))/(color*(2.43*color+0.59)+0.14);
}

vec3 BotWVibrance(vec3 color) {
	float avg = (color.r + color.g + color.b)/3.0;
	float maxc = max(color.r, max(color.g,color.b));
	float w = 1.0 - pow(1.0 - 2.0 * avg, 2.0);
	float weight = 1.0 + w * satFactor;
	vec3 satcolor = mix(vec3(maxc), color, weight);
	return satcolor;
}

vec3 ReshadeVibrance(vec3 color) {
	float max_color = max(color.r, max(color.g, color.b)); // Find the strongest color
	float min_color = min(color.r, min(color.g, color.b)); // Find the weakest color
	float luma = getL709(color);
	float color_saturation = max_color - min_color; // The difference between the two is the saturation
	vec3 coeffVibrance = VibranceRGBBalance * Vibrance;
	color = mix(vec3(luma), color, 1.0 + (coeffVibrance * (1.0 - (sign(coeffVibrance) * color_saturation))));
	return color;
}

vec3 Contrasty(vec3 fColour) {
	fColour = max(vec3(0.0), fColour - vec3(crushContrast));
	fColour = clamp(exposure * fColour, 0.0, 1.0);
	fColour = pow(fColour, vec3(1.0 / gamma));
	float luminance = getL601(fColour);
	float mn = min(min(fColour.r, fColour.g), fColour.b);
	float mx = max(max(fColour.r, fColour.g), fColour.b);
	float sat = (1.0-(mx - mn)) * (1.0-mx) * luminance * 5.0;
	vec3 lightness = vec3((mn + mx)/2.0);
	// vibrance
	fColour = mix(fColour, mix(fColour, lightness, -vibrance), sat);
	return fColour;
}

vec3 rgb2hsv(vec3 c) {
	vec4 K = vec4(0.0, -1.0 / 3.0, 2.0 / 3.0, -1.0);
	vec4 p = mix(vec4(c.bg, K.wz), vec4(c.gb, K.xy), step(c.b, c.g));
	vec4 q = mix(vec4(p.xyw, c.r), vec4(c.r, p.yzx), step(p.x, c.r));

	float d = q.x - min(q.w, q.y);
	float e = 1.0e-10;
	return vec3(abs(q.z + (q.w - q.y) / (6.0 * d + e)), d / (q.x + e), q.x);
}
vec3 hsv2rgb(vec3 c) {
	vec4 K = vec4(1.0, 2.0 / 3.0, 1.0 / 3.0, 3.0);
	vec3 p = abs(fract(c.xxx + K.xyz) * 6.0 - K.www);
	return c.z * mix(K.xxx, clamp(p - K.xxx, 0.0, 1.0), c.y);
}

vec3 HSV(vec3 color) {
	vec3 hsv = rgb2hsv(color);
	hsv.y = pow(hsv.y, 1.0/satScale);
	color = hsv2rgb(hsv);
	return color;
}

void main()
{
vec3 bloom = texture(textureUnitPS0, passParameterSem0.xy).xyz;
vec3 color = texture(textureUnitPS1, passParameterSem0.xy).xyz;

#if (adjust_bloom == 1)
bloom *= bloomFactor;
#endif

color += bloom;

#if (tone_mapping == -1)
color = clamp(color,0.0,1.0);
#elif (tone_mapping == 0)
color = BotWToneMap(color);
#elif (tone_mapping == 1)
color = ACESFilm(color);
#endif

#if (post_process == 0)
color = BotWVibrance(color);
#elif (post_process == 1)
color = ReshadeVibrance(color);
#elif (post_process == 2)
color = Contrasty(color);
#elif (post_process == 3)
color = HSV(color);
#endif

// export
passPixelColor0 = vec4(color, passParameterSem0.w);
}