From 553165f10d9ca8219228213f2918b5cd060a1073 Mon Sep 17 00:00:00 2001 From: unknown Date: Mon, 12 Dec 2022 19:53:26 -0800 Subject: [PATCH] add mixbox for metal --- README.md | 2 +- shaders/README.md | 40 ++++++++++ shaders/mixbox.metal | 169 +++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 210 insertions(+), 1 deletion(-) create mode 100644 shaders/mixbox.metal diff --git a/README.md b/README.md index 2b8c9f0..0f1acc5 100644 --- a/README.md +++ b/README.md @@ -23,7 +23,7 @@ Mixbox is shipping in Rebelle 5 Pro as the [Rebelle Pigments](https://www.escape - [Rust](rust): add `mixbox = "2.0.0"` to your Cargo.toml - [Unity](unity): add package from git url `git://github.com/scrtwpns/mixbox.git#upm` - [Godot](godot): copy `godot\addons` to the root of your project -- [Shaders](shaders): load `mixbox_lut.png` as texture and paste the Mixbox `.glsl`/`.hlsl` code into your shader +- [Shaders](shaders): load `mixbox_lut.png` as texture and include `mixbox.glsl`/`.hlsl`/`.metal` code into your shader ## Pigment Colors | Pigment | | RGB | Float RGB | Linear RGB | diff --git a/shaders/README.md b/shaders/README.md index ab3b7e9..b9ee852 100644 --- a/shaders/README.md +++ b/shaders/README.md @@ -77,6 +77,46 @@ float3 MixThree(float3 rgb1, float3 rgb2, float3 rgb3) } ``` +## Metal Shader +```metal +#include +using namespace metal; + +// uncomment the following line if you work in linear space +// #define MIXBOX_COLORSPACE_LINEAR + +#include "mixbox.metal" + +fragment float4 // load "mixbox_lut.png" into texture 0 +fragment_main(texture2d mixbox_lut [[texture(0)]]) +{ + float3 rgb1 = float3(0, 0.129, 0.522); // blue + float3 rgb2 = float3(0.988, 0.827, 0); // yellow + + float t = 0.5; // mixing ratio + + float3 rgb_mix = mixbox_lerp(mixbox_lut, rgb1, rgb2, t); + + return float4(rgb_mix, 1.0); +} +``` +```metal +float3 mix_three(texture2d mixbox_lut, + float3 rgb1, float3 rgb2, float3 rgb3) +{ + mixbox_latent z1 = mixbox_rgb_to_latent(mixbox_lut, rgb1); + mixbox_latent z2 = mixbox_rgb_to_latent(mixbox_lut, rgb2); + mixbox_latent z3 = mixbox_rgb_to_latent(mixbox_lut, rgb3); + + // mix together 30% of rgb1, 60% of rgb2, and 10% of rgb3 + mixbox_latent z_mix = 0.3*z1 + 0.6*z2 + 0.1*z3; + + float3 rgb_mix = mixbox_latent_to_rgb(z_mix); + + return rgb_mix; +} +``` + ## Pigment Colors | Pigment | | RGB | Float RGB | Linear RGB | | --- | --- |:----:|:----:|:----:| diff --git a/shaders/mixbox.metal b/shaders/mixbox.metal new file mode 100644 index 0000000..de5295c --- /dev/null +++ b/shaders/mixbox.metal @@ -0,0 +1,169 @@ +// ========================================================== +// MIXBOX 2.0 (c) 2022 Secret Weapons. All rights reserved. +// License: Creative Commons Attribution-NonCommercial 4.0 +// Authors: Sarka Sochorova and Ondrej Jamriska +// ========================================================== +// +// BASIC USAGE +// +// float3 rgb = mixbox_lerp(lut, rgb1, rgb2, t); +// +// MULTI-COLOR MIXING +// +// mixbox_latent z1 = mixbox_rgb_to_latent(lut, rgb1); +// mixbox_latent z2 = mixbox_rgb_to_latent(lut, rgb2); +// mixbox_latent z3 = mixbox_rgb_to_latent(lut, rgb3); +// +// // mix 30% of rgb1, 60% of rgb2, and 10% of rgb3 +// mixbox_latent z_mix = 0.3*z1 + 0.6*z2 + 0.1*z3; +// +// float3 rgb_mix = mixbox_latent_to_rgb(z_mix); +// +// PIGMENT COLORS +// +// Cadmium Yellow 0.996, 0.925, 0.000 +// Hansa Yellow 0.988, 0.827, 0.000 +// Cadmium Orange 1.000, 0.412, 0.000 +// Cadmium Red 1.000, 0.153, 0.008 +// Quinacridone Magenta 0.502, 0.008, 0.180 +// Cobalt Violet 0.306, 0.000, 0.259 +// Ultramarine Blue 0.098, 0.000, 0.349 +// Cobalt Blue 0.000, 0.129, 0.522 +// Phthalo Blue 0.051, 0.106, 0.267 +// Phthalo Green 0.000, 0.235, 0.196 +// Permanent Green 0.027, 0.427, 0.086 +// Sap Green 0.420, 0.580, 0.016 +// Burnt Sienna 0.482, 0.282, 0.000 +// +// LICENSING +// +// If you want to obtain commercial license, please +// contact us at: mixbox@scrtwpns.com +// + +#ifndef MIXBOX_INCLUDED +#define MIXBOX_INCLUDED + +#include + +typedef metal::float3x3 mixbox_latent; + +inline float3 mixbox_eval_polynomial(float3 c) +{ + float c0 = c[0]; + float c1 = c[1]; + float c2 = c[2]; + float c3 = 1.0 - (c0 + c1 + c2); + + float c00 = c0 * c0; + float c11 = c1 * c1; + float c22 = c2 * c2; + float c01 = c0 * c1; + float c02 = c0 * c2; + float c12 = c1 * c2; + float c33 = c3 * c3; + + return (c0*c00) * float3(+0.07717053, +0.02826978, +0.24832992) + + (c1*c11) * float3(+0.95912302, +0.80256528, +0.03561839) + + (c2*c22) * float3(+0.74683774, +0.04868586, +0.00000000) + + (c3*c33) * float3(+0.99518138, +0.99978149, +0.99704802) + + (c00*c1) * float3(+0.04819146, +0.83363781, +0.32515377) + + (c01*c1) * float3(-0.68146950, +1.46107803, +1.06980936) + + (c00*c2) * float3(+0.27058419, -0.15324870, +1.98735057) + + (c02*c2) * float3(+0.80478189, +0.67093710, +0.18424500) + + (c00*c3) * float3(-0.35031003, +1.37855826, +3.68865000) + + (c0*c33) * float3(+1.05128046, +1.97815239, +2.82989073) + + (c11*c2) * float3(+3.21607125, +0.81270228, +1.03384539) + + (c1*c22) * float3(+2.78893374, +0.41565549, -0.04487295) + + (c11*c3) * float3(+3.02162577, +2.55374103, +0.32766114) + + (c1*c33) * float3(+2.95124691, +2.81201112, +1.17578442) + + (c22*c3) * float3(+2.82677043, +0.79933038, +1.81715262) + + (c2*c33) * float3(+2.99691099, +1.22593053, +1.80653661) + + (c01*c2) * float3(+1.87394106, +2.05027182, -0.29835996) + + (c01*c3) * float3(+2.56609566, +7.03428198, +0.62575374) + + (c02*c3) * float3(+4.08329484, -1.40408358, +2.14995522) + + (c12*c3) * float3(+6.00078678, +2.55552042, +1.90739502); +} + +inline float mixbox_srgb_to_linear(float x) +{ + return (x >= 0.04045) ? metal::pow((x + 0.055) / 1.055, 2.4) : x/12.92; +} + +inline float mixbox_linear_to_srgb(float x) +{ + return (x >= 0.0031308) ? 1.055*metal::pow(x, 1.0/2.4) - 0.055 : 12.92*x; +} + +inline float3 mixbox_srgb_to_linear(float3 rgb) +{ + return float3(mixbox_srgb_to_linear(rgb.r), + mixbox_srgb_to_linear(rgb.g), + mixbox_srgb_to_linear(rgb.b)); +} + +inline float3 mixbox_linear_to_srgb(float3 rgb) +{ + return float3(mixbox_linear_to_srgb(rgb.r), + mixbox_linear_to_srgb(rgb.g), + mixbox_linear_to_srgb(rgb.b)); +} + +inline mixbox_latent mixbox_rgb_to_latent(metal::texture2d mixbox_lut, float3 rgb) +{ +#ifdef MIXBOX_COLORSPACE_LINEAR + rgb = mixbox_linear_to_srgb(metal::saturate(rgb)); +#else + rgb = metal::saturate(rgb); +#endif + + float x = rgb.r * 63.0; + float y = rgb.g * 63.0; + float z = rgb.b * 63.0; + + float iz = metal::floor(z); + + float x0 = metal::fmod(iz, 8.0) * 64.0; + float y0 = metal::floor(iz / 8.0) * 64.0; + + float x1 = metal::fmod(iz + 1.0, 8.0) * 64.0; + float y1 = metal::floor((iz + 1.0) / 8.0) * 64.0; + + float2 uv0 = float2(x0 + x + 0.5, y0 + y + 0.5) / 512.0; + float2 uv1 = float2(x1 + x + 0.5, y1 + y + 0.5) / 512.0; + + constexpr metal::sampler lut_sampler(metal::mag_filter::linear, metal::min_filter::linear, metal::mip_filter::none); + + if (mixbox_lut.sample(lut_sampler, float2(0.5, 0.5) / 512.0).b < 0.1) + { + uv0.y = 1.0 - uv0.y; + uv1.y = 1.0 - uv1.y; + } + + float3 c = metal::mix(mixbox_lut.sample(lut_sampler, uv0).rgb, mixbox_lut.sample(lut_sampler, uv1).rgb, z - iz); + + return mixbox_latent(c, rgb - mixbox_eval_polynomial(c), float3(0.0, 0.0, 0.0)); +} + +inline float3 mixbox_latent_to_rgb(mixbox_latent latent) +{ + float3 rgb = metal::saturate(mixbox_eval_polynomial(latent[0]) + latent[1]); + +#ifdef MIXBOX_COLORSPACE_LINEAR + return mixbox_srgb_to_linear(rgb); +#else + return rgb; +#endif +} + +inline float3 mixbox_lerp(metal::texture2d mixbox_lut, float3 color1, float3 color2, float t) +{ + return mixbox_latent_to_rgb((1.0-t)*mixbox_rgb_to_latent(mixbox_lut, color1) + t*mixbox_rgb_to_latent(mixbox_lut, color2)); +} + +inline float4 mixbox_lerp(metal::texture2d mixbox_lut, float4 color1, float4 color2, float t) +{ + return float4(mixbox_lerp(mixbox_lut, color1.rgb, color2.rgb, t), metal::mix(color1.a, color2.a, t)); +} + +#endif