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README.md

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+# Mixbox: Practical Pigment Mixing for Digital Painting
+
+<p align="center">
+  <img src="https://scrtwpns.com/mixbox/teaser.jpg"/>
+</p>
+
+Mixbox is a pigment mixing black-box. You pass RGB colors in and get the mixed RGB out.
+Internally, Mixbox treats the colors as if they were made of actual real-world pigments.
+It uses the Kubelka & Munk theory to predict the color of the resulting mixture.
+This way, Mixbox achieves that blue and yellow mix to green, the same way real pigments do.
+
+* Paper: https://scrtwpns.com/mixbox.pdf<br>
+* Video: https://youtu.be/9egCAxhOHg4<br>
+* Talk: https://youtu.be/k91cDhpCOpg<br>
+
+## Usage
+The simplest way to use Mixbox is with the *lerp* interface:
+```c++
+#include <stdio.h>
+#include "mixbox.h"
+
+int main()
+{
+
+  unsigned char r1=252, g1=211, b1=0;  // bright yellow
+  unsigned char r2=0,   g2=0,   b2=96; // deep blue
+  float t = 0.5;
+  unsigned char r,g,b;
+  
+  mixbox_lerp_srgb8(r1,g1,b1,   // first color
+                    r2,g2,b2,   // second color
+                    t,          // mixing ratio
+                    &r,&g,&b);  // result
+
+  printf("%d %d %d\n",r,g,b);
+}
+```
+Alternatively, one can use the *latent* interface. This allows mixing multiple RGB colors at once using arbitrary weights:
+
+```c++
+float latent1[MIXBOX_NUMLATENTS];
+float latent2[MIXBOX_NUMLATENTS];
+float latentMix[MIXBOX_NUMLATENTS];
+
+mixbox_srgb8_to_latent(r1,g1,b1,latent1);
+mixbox_srgb8_to_latent(r2,g2,b2,latent2);
+
+for(int i=0;i<MIXBOX_NUMLATENTS;i++)
+{ 
+  latentMix[i] = (1.0f-t)*latent1[i] + t*latent2[i]; 
+}
+
+mixbox_latent_to_srgb8(latentMix,&r,&g,&b);  
+```
+
+## License
+Copyright (c) 2021, Secret Weapons. All rights reserved.<br>
+This code is for non-commercial use only. It is provided for research and evaluation purposes.<br>
+If you wish to obtain commercial license, please contact: mixbox@scrtwpns.com
+

mixbox.h

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+// MIXBOX v1.2 (c) 2021 Secret Weapons
+// This is for non-commercial use only.
+// Contact: mixbox@scrtwpns.com
+
+#ifndef MIXBOX_H_
+#define MIXBOX_H_
+
+#define MIXBOX_NUMLATENTS 7
+
+void mixbox_lerp_srgb8(unsigned char r1,unsigned char g1,unsigned char b1,
+                       unsigned char r2,unsigned char g2,unsigned char b2,
+                       float t,
+                       unsigned char* out_r,unsigned char* out_g,unsigned char* out_b);
+
+void mixbox_lerp_srgb32f(float r1,float g1,float b1,
+                         float r2,float g2,float b2,
+                         float t,
+                         float* out_r,float* out_g,float* out_b);
+
+void mixbox_srgb8_to_latent(unsigned char r,unsigned char g,unsigned char b,float* out_latent);
+void mixbox_latent_to_srgb8(float* latent,unsigned char* out_r,unsigned char* out_g,unsigned char* out_b);
+
+void mixbox_srgb32f_to_latent(float r,float g,float b,float* out_latent);
+void mixbox_latent_to_srgb32f(float* latent,float* out_r,float* out_g,float* out_b);
+
+
+void mixbox_lerp_srgb8_dither(unsigned char r1,unsigned char g1,unsigned char b1,
+                              unsigned char r2,unsigned char g2,unsigned char b2,
+                              float t,
+                              float dither_r,float dither_g,float dither_b,
+                              unsigned char* out_r,unsigned char* out_g,unsigned char* out_b);
+
+void mixbox_latent_to_srgb8_dither(float* latent,float dither_r,float dither_g,float dither_b,unsigned char* out_r,unsigned char* out_g,unsigned char* out_b);
+
+#endif