1 #ifndef UNITY_COLOR_INCLUDED
2 #define UNITY_COLOR_INCLUDED
4 #include "Packages/com.unity.render-pipelines.core/ShaderLibrary/ACES.hlsl"
6 //-----------------------------------------------------------------------------
7 // Gamma space - Assume positive values
8 //-----------------------------------------------------------------------------
11 real Gamma20ToLinear(real c)
16 real3 Gamma20ToLinear(real3 c)
21 real4 Gamma20ToLinear(real4 c)
23 return real4(Gamma20ToLinear(c.rgb), c.a);
26 real LinearToGamma20(real c)
31 real3 LinearToGamma20(real3 c)
36 real4 LinearToGamma20(real4 c)
38 return real4(LinearToGamma20(c.rgb), c.a);
42 real Gamma22ToLinear(real c)
44 return PositivePow(c, 2.2);
47 real3 Gamma22ToLinear(real3 c)
49 return PositivePow(c.rgb, real3(2.2, 2.2, 2.2));
52 real4 Gamma22ToLinear(real4 c)
54 return real4(Gamma22ToLinear(c.rgb), c.a);
57 real LinearToGamma22(real c)
59 return PositivePow(c, 0.454545454545455);
62 real3 LinearToGamma22(real3 c)
64 return PositivePow(c.rgb, real3(0.454545454545455, 0.454545454545455, 0.454545454545455));
67 real4 LinearToGamma22(real4 c)
69 return real4(LinearToGamma22(c.rgb), c.a);
73 real SRGBToLinear(real c)
75 real linearRGBLo = c / 12.92;
76 real linearRGBHi = PositivePow((c + 0.055) / 1.055, 2.4);
77 real linearRGB = (c <= 0.04045) ? linearRGBLo : linearRGBHi;
81 real2 SRGBToLinear(real2 c)
83 real2 linearRGBLo = c / 12.92;
84 real2 linearRGBHi = PositivePow((c + 0.055) / 1.055, real2(2.4, 2.4));
85 real2 linearRGB = (c <= 0.04045) ? linearRGBLo : linearRGBHi;
89 real3 SRGBToLinear(real3 c)
91 real3 linearRGBLo = c / 12.92;
92 real3 linearRGBHi = PositivePow((c + 0.055) / 1.055, real3(2.4, 2.4, 2.4));
93 real3 linearRGB = (c <= 0.04045) ? linearRGBLo : linearRGBHi;
97 real4 SRGBToLinear(real4 c)
99 return real4(SRGBToLinear(c.rgb), c.a);
102 real LinearToSRGB(real c)
104 real sRGBLo = c * 12.92;
105 real sRGBHi = (PositivePow(c, 1.0/2.4) * 1.055) - 0.055;
106 real sRGB = (c <= 0.0031308) ? sRGBLo : sRGBHi;
110 real2 LinearToSRGB(real2 c)
112 real2 sRGBLo = c * 12.92;
113 real2 sRGBHi = (PositivePow(c, real2(1.0/2.4, 1.0/2.4)) * 1.055) - 0.055;
114 real2 sRGB = (c <= 0.0031308) ? sRGBLo : sRGBHi;
118 real3 LinearToSRGB(real3 c)
120 real3 sRGBLo = c * 12.92;
121 real3 sRGBHi = (PositivePow(c, real3(1.0/2.4, 1.0/2.4, 1.0/2.4)) * 1.055) - 0.055;
122 real3 sRGB = (c <= 0.0031308) ? sRGBLo : sRGBHi;
126 real4 LinearToSRGB(real4 c)
128 return real4(LinearToSRGB(c.rgb), c.a);
131 // TODO: Seb - To verify and refit!
132 // Ref: http://chilliant.blogspot.com.au/2012/08/srgb-approximations-for-hlsl.html?m=1
133 real FastSRGBToLinear(real c)
135 return c * (c * (c * 0.305306011 + 0.682171111) + 0.012522878);
138 real2 FastSRGBToLinear(real2 c)
140 return c * (c * (c * 0.305306011 + 0.682171111) + 0.012522878);
143 real3 FastSRGBToLinear(real3 c)
145 return c * (c * (c * 0.305306011 + 0.682171111) + 0.012522878);
148 real4 FastSRGBToLinear(real4 c)
150 return real4(FastSRGBToLinear(c.rgb), c.a);
153 real FastLinearToSRGB(real c)
155 return saturate(1.055 * PositivePow(c, 0.416666667) - 0.055);
158 real2 FastLinearToSRGB(real2 c)
160 return saturate(1.055 * PositivePow(c, 0.416666667) - 0.055);
163 real3 FastLinearToSRGB(real3 c)
165 return saturate(1.055 * PositivePow(c, 0.416666667) - 0.055);
168 real4 FastLinearToSRGB(real4 c)
170 return real4(FastLinearToSRGB(c.rgb), c.a);
173 //-----------------------------------------------------------------------------
175 //-----------------------------------------------------------------------------
177 // Convert rgb to luminance
178 // with rgb in linear space with sRGB primaries and D65 white point
179 real Luminance(real3 linearRgb)
181 return dot(linearRgb, real3(0.2126729, 0.7151522, 0.0721750));
184 real Luminance(real4 linearRgba)
186 return Luminance(linearRgba.rgb);
189 real AcesLuminance(real3 linearRgb)
191 return dot(linearRgb, AP1_RGB2Y);
194 real AcesLuminance(real4 linearRgba)
196 return AcesLuminance(linearRgba.rgb);
199 // Scotopic luminance approximation - input is in XYZ space
200 // Note: the range of values returned is approximately [0;4]
201 // "A spatial postprocessing algorithm for images of night scenes"
202 // William B. Thompson, Peter Shirley, and James A. Ferwerda
203 real ScotopicLuminance(real3 xyzRgb)
208 return Y * (1.33 * (1.0 + (Y + Z) / X) - 1.68);
211 real ScotopicLuminance(real4 xyzRgba)
213 return ScotopicLuminance(xyzRgba.rgb);
216 // This function take a rgb color (best is to provide color in sRGB space)
217 // and return a YCoCg color in [0..1] space for 8bit (An offset is apply in the function)
218 // Ref: http://www.nvidia.com/object/real-time-ycocg-dxt-compression.html
219 #define YCOCG_CHROMA_BIAS (128.0 / 255.0)
220 real3 RGBToYCoCg(real3 rgb)
223 YCoCg.x = dot(rgb, real3(0.25, 0.5, 0.25));
224 YCoCg.y = dot(rgb, real3(0.5, 0.0, -0.5)) + YCOCG_CHROMA_BIAS;
225 YCoCg.z = dot(rgb, real3(-0.25, 0.5, -0.25)) + YCOCG_CHROMA_BIAS;
230 real3 YCoCgToRGB(real3 YCoCg)
233 real Co = YCoCg.y - YCOCG_CHROMA_BIAS;
234 real Cg = YCoCg.z - YCOCG_CHROMA_BIAS;
244 // Following function can be use to reconstruct chroma component for a checkboard YCoCg pattern
245 // Reference: The Compact YCoCg Frame Buffer
246 real YCoCgCheckBoardEdgeFilter(real centerLum, real2 a0, real2 a1, real2 a2, real2 a3)
248 real4 lum = real4(a0.x, a1.x, a2.x, a3.x);
249 // Optimize: real4 w = 1.0 - step(30.0 / 255.0, abs(lum - centerLum));
250 real4 w = 1.0 - saturate((abs(lum.xxxx - centerLum) - 30.0 / 255.0) * HALF_MAX);
251 real W = w.x + w.y + w.z + w.w;
252 // handle the special case where all the weights are zero.
253 return (W == 0.0) ? a0.y : (w.x * a0.y + w.y* a1.y + w.z* a2.y + w.w * a3.y) / W;
256 // Converts linear RGB to LMS
257 real3 LinearToLMS(real3 x)
259 const real3x3 LIN_2_LMS_MAT = {
260 3.90405e-1, 5.49941e-1, 8.92632e-3,
261 7.08416e-2, 9.63172e-1, 1.35775e-3,
262 2.31082e-2, 1.28021e-1, 9.36245e-1
265 return mul(LIN_2_LMS_MAT, x);
268 real3 LMSToLinear(real3 x)
270 const real3x3 LMS_2_LIN_MAT = {
271 2.85847e+0, -1.62879e+0, -2.48910e-2,
272 -2.10182e-1, 1.15820e+0, 3.24281e-4,
273 -4.18120e-2, -1.18169e-1, 1.06867e+0
276 return mul(LMS_2_LIN_MAT, x);
279 // Hue, Saturation, Value
283 // Lum [0.0, HALF_MAX]
284 real3 RgbToHsv(real3 c)
286 const real4 K = real4(0.0, -1.0 / 3.0, 2.0 / 3.0, -1.0);
287 real4 p = lerp(real4(c.bg, K.wz), real4(c.gb, K.xy), step(c.b, c.g));
288 real4 q = lerp(real4(p.xyw, c.r), real4(c.r, p.yzx), step(p.x, c.r));
289 real d = q.x - min(q.w, q.y);
290 const real e = 1.0e-4;
291 return real3(abs(q.z + (q.w - q.y) / (6.0 * d + e)), d / (q.x + e), q.x);
294 real3 HsvToRgb(real3 c)
296 const real4 K = real4(1.0, 2.0 / 3.0, 1.0 / 3.0, 3.0);
297 real3 p = abs(frac(c.xxx + K.xyz) * 6.0 - K.www);
298 return c.z * lerp(K.xxx, saturate(p - K.xxx), c.y);
301 real RotateHue(real value, real low, real hi)
310 // SMPTE ST.2084 (PQ) transfer functions
311 // 1.0 = 100nits, 100.0 = 10knits
312 #define DEFAULT_MAX_PQ 100.0
320 static const ParamsPQ PQ =
322 2610.0 / 4096.0 / 4.0, // N
323 2523.0 / 4096.0 * 128.0, // M
324 3424.0 / 4096.0, // C1
325 2413.0 / 4096.0 * 32.0, // C2
326 2392.0 / 4096.0 * 32.0, // C3
329 real3 LinearToPQ(real3 x, real maxPQValue)
331 x = PositivePow(x / maxPQValue, PQ.N);
332 real3 nd = (PQ.C1 + PQ.C2 * x) / (1.0 + PQ.C3 * x);
333 return PositivePow(nd, PQ.M);
336 real3 LinearToPQ(real3 x)
338 return LinearToPQ(x, DEFAULT_MAX_PQ);
341 real3 PQToLinear(real3 x, real maxPQValue)
343 x = PositivePow(x, rcp(PQ.M));
344 real3 nd = max(x - PQ.C1, 0.0) / (PQ.C2 - (PQ.C3 * x));
345 return PositivePow(nd, rcp(PQ.N)) * maxPQValue;
348 real3 PQToLinear(real3 x)
350 return PQToLinear(x, DEFAULT_MAX_PQ);
353 // Alexa LogC converters (El 1000)
354 // See http://www.vocas.nl/webfm_send/964
355 // Max range is ~58.85666
357 // Set to 1 to use more precise but more expensive log/linear conversions. I haven't found a proper
358 // use case for the high precision version yet so I'm leaving this to 0.
359 #define USE_PRECISE_LOGC 0
364 real a, b, c, d, e, f;
367 static const ParamsLogC LogC =
378 real LinearToLogC_Precise(real x)
382 o = LogC.c * log10(LogC.a * x + LogC.b) + LogC.d;
384 o = LogC.e * x + LogC.f;
388 real3 LinearToLogC(real3 x)
392 LinearToLogC_Precise(x.x),
393 LinearToLogC_Precise(x.y),
394 LinearToLogC_Precise(x.z)
397 return LogC.c * log10(LogC.a * x + LogC.b) + LogC.d;
401 real LogCToLinear_Precise(real x)
404 if (x > LogC.e * LogC.cut + LogC.f)
405 o = (pow(10.0, (x - LogC.d) / LogC.c) - LogC.b) / LogC.a;
407 o = (x - LogC.f) / LogC.e;
411 real3 LogCToLinear(real3 x)
415 LogCToLinear_Precise(x.x),
416 LogCToLinear_Precise(x.y),
417 LogCToLinear_Precise(x.z)
420 return (pow(10.0, (x - LogC.d) / LogC.c) - LogC.b) / LogC.a;
424 //-----------------------------------------------------------------------------
426 //-----------------------------------------------------------------------------
428 // Fast reversible tonemapper
429 // http://gpuopen.com/optimized-reversible-tonemapper-for-resolve/
430 real FastTonemapPerChannel(real c)
432 return c * rcp(c + 1.0);
435 real2 FastTonemapPerChannel(real2 c)
437 return c * rcp(c + 1.0);
440 real3 FastTonemap(real3 c)
442 return c * rcp(Max3(c.r, c.g, c.b) + 1.0);
445 real4 FastTonemap(real4 c)
447 return real4(FastTonemap(c.rgb), c.a);
450 real3 FastTonemap(real3 c, real w)
452 return c * (w * rcp(Max3(c.r, c.g, c.b) + 1.0));
455 real4 FastTonemap(real4 c, real w)
457 return real4(FastTonemap(c.rgb, w), c.a);
460 real FastTonemapPerChannelInvert(real c)
462 return c * rcp(1.0 - c);
465 real2 FastTonemapPerChannelInvert(real2 c)
467 return c * rcp(1.0 - c);
470 real3 FastTonemapInvert(real3 c)
472 return c * rcp(1.0 - Max3(c.r, c.g, c.b));
475 real4 FastTonemapInvert(real4 c)
477 return real4(FastTonemapInvert(c.rgb), c.a);
480 #ifndef SHADER_API_GLES
482 // scaleOffset = (1 / lut_size, lut_size - 1)
483 real3 ApplyLut3D(TEXTURE3D_PARAM(tex, samplerTex), real3 uvw, real2 scaleOffset)
485 uvw.xyz = uvw.xyz * scaleOffset.yyy * scaleOffset.xxx + scaleOffset.xxx * 0.5;
486 return SAMPLE_TEXTURE3D_LOD(tex, samplerTex, uvw, 0.0).rgb;
491 // scaleOffset = (1 / lut_width, 1 / lut_height, lut_height - 1)
492 real3 ApplyLut2D(TEXTURE2D_PARAM(tex, samplerTex), real3 uvw, real3 scaleOffset)
494 // Strip format where `height = sqrt(width)`
495 uvw.z *= scaleOffset.z;
496 real shift = floor(uvw.z);
497 uvw.xy = uvw.xy * scaleOffset.z * scaleOffset.xy + scaleOffset.xy * 0.5;
498 uvw.x += shift * scaleOffset.y;
500 SAMPLE_TEXTURE2D_LOD(tex, samplerTex, uvw.xy, 0.0).rgb,
501 SAMPLE_TEXTURE2D_LOD(tex, samplerTex, uvw.xy + real2(scaleOffset.y, 0.0), 0.0).rgb,
507 // Returns the default value for a given position on a 2D strip-format color lookup table
508 // params = (lut_height, 0.5 / lut_width, 0.5 / lut_height, lut_height / lut_height - 1)
509 real3 GetLutStripValue(real2 uv, real4 params)
513 color.r = frac(uv.x * params.x);
514 color.b = uv.x - color.r / params.x;
516 return color * params.w;
519 // Neutral tonemapping (Hable/Hejl/Frostbite)
520 // Input is linear RGB
521 real3 NeutralCurve(real3 x, real a, real b, real c, real d, real e, real f)
523 return ((x * (a * x + c * b) + d * e) / (x * (a * x + b) + d * f)) - e / f;
526 real3 NeutralTonemap(real3 x)
532 const real d = 0.272;
535 const real whiteLevel = 5.3;
536 const real whiteClip = 1.0;
538 real3 whiteScale = (1.0).xxx / NeutralCurve(whiteLevel, a, b, c, d, e, f);
539 x = NeutralCurve(x * whiteScale, a, b, c, d, e, f);
542 // Post-curve white point adjustment
548 // Raw, unoptimized version of John Hable's artist-friendly tone curve
549 // Input is linear RGB
550 real EvalCustomSegment(real x, real4 segmentA, real2 segmentB)
552 const real kOffsetX = segmentA.x;
553 const real kOffsetY = segmentA.y;
554 const real kScaleX = segmentA.z;
555 const real kScaleY = segmentA.w;
556 const real kLnA = segmentB.x;
557 const real kB = segmentB.y;
559 real x0 = (x - kOffsetX) * kScaleX;
560 real y0 = (x0 > 0.0) ? exp(kLnA + kB * log(x0)) : 0.0;
561 return y0 * kScaleY + kOffsetY;
564 real EvalCustomCurve(real x, real3 curve, real4 toeSegmentA, real2 toeSegmentB, real4 midSegmentA, real2 midSegmentB, real4 shoSegmentA, real2 shoSegmentB)
571 segmentA = toeSegmentA;
572 segmentB = toeSegmentB;
574 else if (x < curve.z)
576 segmentA = midSegmentA;
577 segmentB = midSegmentB;
581 segmentA = shoSegmentA;
582 segmentB = shoSegmentB;
585 return EvalCustomSegment(x, segmentA, segmentB);
588 // curve: x: inverseWhitePoint, y: x0, z: x1
589 real3 CustomTonemap(real3 x, real3 curve, real4 toeSegmentA, real2 toeSegmentB, real4 midSegmentA, real2 midSegmentB, real4 shoSegmentA, real2 shoSegmentB)
591 real3 normX = x * curve.x;
593 ret.x = EvalCustomCurve(normX.x, curve, toeSegmentA, toeSegmentB, midSegmentA, midSegmentB, shoSegmentA, shoSegmentB);
594 ret.y = EvalCustomCurve(normX.y, curve, toeSegmentA, toeSegmentB, midSegmentA, midSegmentB, shoSegmentA, shoSegmentB);
595 ret.z = EvalCustomCurve(normX.z, curve, toeSegmentA, toeSegmentB, midSegmentA, midSegmentB, shoSegmentA, shoSegmentB);
599 // Filmic tonemapping (ACES fitting, unless TONEMAPPING_USE_FULL_ACES is set to 1)
600 // Input is ACES2065-1 (AP0 w/ linear encoding)
601 #define TONEMAPPING_USE_FULL_ACES 0
603 float3 AcesTonemap(float3 aces)
605 #if TONEMAPPING_USE_FULL_ACES
607 float3 oces = RRT(aces);
608 float3 odt = ODT_RGBmonitor_100nits_dim(oces);
613 // --- Glow module --- //
614 float saturation = rgb_2_saturation(aces);
615 float ycIn = rgb_2_yc(aces);
616 float s = sigmoid_shaper((saturation - 0.4) / 0.2);
617 float addedGlow = 1.0 + glow_fwd(ycIn, RRT_GLOW_GAIN * s, RRT_GLOW_MID);
620 // --- Red modifier --- //
621 float hue = rgb_2_hue(aces);
622 float centeredHue = center_hue(hue, RRT_RED_HUE);
625 //hueWeight = cubic_basis_shaper(centeredHue, RRT_RED_WIDTH);
626 hueWeight = smoothstep(0.0, 1.0, 1.0 - abs(2.0 * centeredHue / RRT_RED_WIDTH));
627 hueWeight *= hueWeight;
630 aces.r += hueWeight * saturation * (RRT_RED_PIVOT - aces.r) * (1.0 - RRT_RED_SCALE);
632 // --- ACES to RGB rendering space --- //
633 float3 acescg = max(0.0, ACES_to_ACEScg(aces));
635 // --- Global desaturation --- //
636 //acescg = mul(RRT_SAT_MAT, acescg);
637 acescg = lerp(dot(acescg, AP1_RGB2Y).xxx, acescg, RRT_SAT_FACTOR.xxx);
639 // Luminance fitting of *RRT.a1.0.3 + ODT.Academy.RGBmonitor_100nits_dim.a1.0.3*.
640 // https://github.com/colour-science/colour-unity/blob/master/Assets/Colour/Notebooks/CIECAM02_Unity.ipynb
641 // RMSE: 0.0012846272106
642 const float a = 278.5085;
643 const float b = 10.7772;
644 const float c = 293.6045;
645 const float d = 88.7122;
646 const float e = 80.6889;
648 float3 rgbPost = (x * (a * x + b)) / (x * (c * x + d) + e);
650 // Scale luminance to linear code value
651 // float3 linearCV = Y_2_linCV(rgbPost, CINEMA_WHITE, CINEMA_BLACK);
653 // Apply gamma adjustment to compensate for dim surround
654 float3 linearCV = darkSurround_to_dimSurround(rgbPost);
656 // Apply desaturation to compensate for luminance difference
657 //linearCV = mul(ODT_SAT_MAT, color);
658 linearCV = lerp(dot(linearCV, AP1_RGB2Y).xxx, linearCV, ODT_SAT_FACTOR.xxx);
660 // Convert to display primary encoding
661 // Rendering space RGB to XYZ
662 float3 XYZ = mul(AP1_2_XYZ_MAT, linearCV);
664 // Apply CAT from ACES white point to assumed observer adapted white point
665 XYZ = mul(D60_2_D65_CAT, XYZ);
667 // CIE XYZ to display primaries
668 linearCV = mul(XYZ_2_REC709_MAT, XYZ);
675 #endif // UNITY_COLOR_INCLUDED