gecko-dev/gfx/layers/d3d11/BlendingHelpers.hlslh

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/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 4 -*-
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
// Helper functions.
float hardlight(float dest, float src) {
if (src <= 0.5) {
return dest * (2.0 * src);
} else {
// Note: we substitute (2*src-1) into the screen formula below.
return 2.0 * dest + 2.0 * src - 1.0 - 2.0 * dest * src;
}
}
float dodge(float dest, float src) {
if (dest == 0.0) {
return 0.0;
} else if (src == 1.0) {
return 1.0;
} else {
return min(1.0, dest / (1.0 - src));
}
}
float burn(float dest, float src) {
if (dest == 1.0) {
return 1.0;
} else if (src == 0.0) {
return 0.0;
} else {
return 1.0 - min(1.0, (1.0 - dest) / src);
}
}
float darken(float dest) {
if (dest <= 0.25) {
return ((16.0 * dest - 12.0) * dest + 4.0) * dest;
} else {
return sqrt(dest);
}
}
float softlight(float dest, float src) {
if (src <= 0.5) {
return dest - (1.0 - 2.0 * src) * dest * (1.0 - dest);
} else {
return dest + (2.0 * src - 1.0) * (darken(dest) - dest);
}
}
float Lum(float3 c) {
return dot(float3(0.3, 0.59, 0.11), c);
}
float3 ClipColor(float3 c) {
float L = Lum(c);
float n = min(min(c.r, c.g), c.b);
float x = max(max(c.r, c.g), c.b);
if (n < 0.0) {
c = L + (((c - L) * L) / (L - n));
}
if (x > 1.0) {
c = L + (((c - L) * (1.0 - L)) / (x - L));
}
return c;
}
float3 SetLum(float3 c, float L) {
float d = L - Lum(c);
return ClipColor(float3(
c.r + d,
c.g + d,
c.b + d));
}
float Sat(float3 c) {
return max(max(c.r, c.g), c.b) - min(min(c.r, c.g), c.b);
}
// To use this helper, re-arrange rgb such that r=min, g=mid, and b=max.
float3 SetSatInner(float3 c, float s) {
if (c.b > c.r) {
c.g = (((c.g - c.r) * s) / (c.b - c.r));
c.b = s;
} else {
c.gb = float2(0.0, 0.0);
}
return float3(0.0, c.g, c.b);
}
float3 SetSat(float3 c, float s) {
if (c.r <= c.g) {
if (c.g <= c.b) {
c.rgb = SetSatInner(c.rgb, s);
} else if (c.r <= c.b) {
c.rbg = SetSatInner(c.rbg, s);
} else {
c.brg = SetSatInner(c.brg, s);
}
} else if (c.r <= c.b) {
c.grb = SetSatInner(c.grb, s);
} else if (c.g <= c.b) {
c.gbr = SetSatInner(c.gbr, s);
} else {
c.bgr = SetSatInner(c.bgr, s);
}
return c;
}
float3 BlendMultiply(float3 dest, float3 src) {
return dest * src;
}
float3 BlendScreen(float3 dest, float3 src) {
return dest + src - (dest * src);
}
float3 BlendOverlay(float3 dest, float3 src) {
return float3(
hardlight(src.r, dest.r),
hardlight(src.g, dest.g),
hardlight(src.b, dest.b));
}
float3 BlendDarken(float3 dest, float3 src) {
return min(dest, src);
}
float3 BlendLighten(float3 dest, float3 src) {
return max(dest, src);
}
float3 BlendColorDodge(float3 dest, float3 src) {
return float3(
dodge(dest.r, src.r),
dodge(dest.g, src.g),
dodge(dest.b, src.b));
}
float3 BlendColorBurn(float3 dest, float3 src) {
return float3(
burn(dest.r, src.r),
burn(dest.g, src.g),
burn(dest.b, src.b));
}
float3 BlendHardLight(float3 dest, float3 src) {
return float3(
hardlight(dest.r, src.r),
hardlight(dest.g, src.g),
hardlight(dest.b, src.b));
}
float3 BlendSoftLight(float3 dest, float3 src) {
return float3(
softlight(dest.r, src.r),
softlight(dest.g, src.g),
softlight(dest.b, src.b));
}
float3 BlendDifference(float3 dest, float3 src) {
return abs(dest - src);
}
float3 BlendExclusion(float3 dest, float3 src) {
return dest + src - 2.0 * dest * src;
}
float3 BlendHue(float3 dest, float3 src) {
return SetLum(SetSat(src, Sat(dest)), Lum(dest));
}
float3 BlendSaturation(float3 dest, float3 src) {
return SetLum(SetSat(dest, Sat(src)), Lum(dest));
}
float3 BlendColor(float3 dest, float3 src) {
return SetLum(src, Lum(dest));
}
float3 BlendLuminosity(float3 dest, float3 src) {
return SetLum(dest, Lum(src));
}