#ifndef __TONEMAPPING__
|
#define __TONEMAPPING__
|
|
#include "ACES.cginc"
|
|
// Set to 1 to use the full reference ACES tonemapper. This should only be used for research
|
// purposes and it's quite heavy and generally overkill.
|
#define TONEMAPPING_USE_FULL_ACES 0
|
|
//
|
// Neutral tonemapping (Hable/Hejl/Frostbite)
|
// Input is linear RGB
|
//
|
half3 NeutralCurve(half3 x, half a, half b, half c, half d, half e, half f)
|
{
|
return ((x * (a * x + c * b) + d * e) / (x * (a * x + b) + d * f)) - e / f;
|
}
|
|
half3 NeutralTonemap(half3 x, half4 params1, half4 params2)
|
{
|
// ACES supports negative color values and WILL output negative values when coming from ACES or ACEScg
|
// Make sure negative channels are clamped to 0.0 as this neutral tonemapper can't deal with them properly
|
x = max((0.0).xxx, x);
|
|
// Tonemap
|
half a = params1.x;
|
half b = params1.y;
|
half c = params1.z;
|
half d = params1.w;
|
half e = params2.x;
|
half f = params2.y;
|
half whiteLevel = params2.z;
|
half whiteClip = params2.w;
|
|
half3 whiteScale = (1.0).xxx / NeutralCurve(whiteLevel, a, b, c, d, e, f);
|
x = NeutralCurve(x * whiteScale, a, b, c, d, e, f);
|
x *= whiteScale;
|
|
// Post-curve white point adjustment
|
x /= whiteClip.xxx;
|
|
return x;
|
}
|
|
//
|
// Filmic tonemapping (ACES fitting, unless TONEMAPPING_USE_FULL_ACES is set to 1)
|
// Input is ACES2065-1 (AP0 w/ linear encoding)
|
//
|
half3 FilmicTonemap(half3 aces)
|
{
|
#if TONEMAPPING_USE_FULL_ACES
|
|
half3 oces = RRT(aces);
|
half3 odt = ODT_RGBmonitor_100nits_dim(oces);
|
return odt;
|
|
#else
|
|
// --- Glow module --- //
|
half saturation = rgb_2_saturation(aces);
|
half ycIn = rgb_2_yc(aces);
|
half s = sigmoid_shaper((saturation - 0.4) / 0.2);
|
half addedGlow = 1.0 + glow_fwd(ycIn, RRT_GLOW_GAIN * s, RRT_GLOW_MID);
|
aces *= addedGlow;
|
|
// --- Red modifier --- //
|
half hue = rgb_2_hue(aces);
|
half centeredHue = center_hue(hue, RRT_RED_HUE);
|
half hueWeight;
|
{
|
//hueWeight = cubic_basis_shaper(centeredHue, RRT_RED_WIDTH);
|
hueWeight = Pow2(smoothstep(0.0, 1.0, 1.0 - abs(2.0 * centeredHue / RRT_RED_WIDTH)));
|
}
|
|
aces.r += hueWeight * saturation * (RRT_RED_PIVOT - aces.r) * (1.0 - RRT_RED_SCALE);
|
|
// --- ACES to RGB rendering space --- //
|
half3 acescg = max(0.0, ACES_to_ACEScg(aces));
|
|
// --- Global desaturation --- //
|
//acescg = mul(RRT_SAT_MAT, acescg);
|
acescg = lerp(dot(acescg, AP1_RGB2Y).xxx, acescg, RRT_SAT_FACTOR.xxx);
|
|
// Luminance fitting of *RRT.a1.0.3 + ODT.Academy.RGBmonitor_100nits_dim.a1.0.3*.
|
// https://github.com/colour-science/colour-unity/blob/master/Assets/Colour/Notebooks/CIECAM02_Unity.ipynb
|
// RMSE: 0.0012846272106
|
const half a = 278.5085;
|
const half b = 10.7772;
|
const half c = 293.6045;
|
const half d = 88.7122;
|
const half e = 80.6889;
|
half3 x = acescg;
|
half3 rgbPost = (x * (a * x + b)) / (x * (c * x + d) + e);
|
|
// Scale luminance to linear code value
|
// half3 linearCV = Y_2_linCV(rgbPost, CINEMA_WHITE, CINEMA_BLACK);
|
|
// Apply gamma adjustment to compensate for dim surround
|
half3 linearCV = darkSurround_to_dimSurround(rgbPost);
|
|
// Apply desaturation to compensate for luminance difference
|
//linearCV = mul(ODT_SAT_MAT, color);
|
linearCV = lerp(dot(linearCV, AP1_RGB2Y).xxx, linearCV, ODT_SAT_FACTOR.xxx);
|
|
// Convert to display primary encoding
|
// Rendering space RGB to XYZ
|
half3 XYZ = mul(AP1_2_XYZ_MAT, linearCV);
|
|
// Apply CAT from ACES white point to assumed observer adapted white point
|
XYZ = mul(D60_2_D65_CAT, XYZ);
|
|
// CIE XYZ to display primaries
|
linearCV = mul(XYZ_2_REC709_MAT, XYZ);
|
|
return linearCV;
|
|
#endif
|
}
|
|
#endif // __TONEMAPPING__
|
