Could I have some help with a red-green color blind shader?

[lividhen]

This is what I have so far, I dont know any glsl pretty much at all. I also don't fully understand what im doing here, this has been cobbled together from a bunch of different sources. It does not look right at all. Completely blown out and some of the colors such as purple cant be seen on a white background. I have just been messing with the values for the last little bit but nothing looks right. If someone could help explain why that is happening that'd be great 😅

precision highp float;
varying vec2 v_texcoord;
uniform sampler2D tex;

const float gamma = 1.0;

void main() {
  vec4 pixColor = texture2D(tex, v_texcoord);

  //color matrix
  const mat4 colorMatrix = mat4(
    vec4(0.92, 0.44, 0.11, 0.0),  //r
    vec4(0.8, 0.7, 0.42, 0.0),   //g
    vec4(0.0, 0.15, 1.25, 0.0),   // b
    vec4(0.0, 0.0, 0.0, 1.0) //a
  );
  vec4 transformedColor = colorMatrix * pixColor;
  transformedColor.rgb = pow(transformedColor.rgb, vec3(gamma));
  gl_FragColor =  vec4(transformedColor.rgb, transformedColor.a);

[loqusion]

I also know next to nothing about glsl 😅. Does this work well for you? (You may have to change the mode or augment in other ways)

I'd be interested in adding some shaders (+ updating the readme) that assist those with color blindness so that no one has to reinvent the wheel.

[lividhen]

I will try that and see how it works. I have been searching for a color blind shader for hyprland for a while but haven't found anything so adding it to the readme and making it more accessible to people would be awesome!

[lividhen]

Got it working thanks to the resource you linked @loqusion !
Here is what I ended up with. If I could get feedback from people with different types or more intense red green color blindness that'd be great as mine is only very slight.

Shader

//Color blind shader for hyprland.
//Based off the shader :  https://godotshaders.com/shader/colorblindness-correction-shader/.

precision highp float;
varying vec2 v_texcoord;
uniform sampler2D tex;

//Intensity of filter (1.0 - 0.0)
const float intensity = 1.0;

// Color correction mode
// 0 - Protanopia
// 1 - Deutranopia
// 2 - Tritanopia
const int mode = 1;

void main()
{
  vec4 pixColor = texture2D(tex, v_texcoord);

  float L = (17.8824 * pixColor.r) + (43.5161 * pixColor.g) + (4.11935 * pixColor.b);
  float M = (3.45565 * pixColor.r) + (27.1554 * pixColor.g) + (3.86714 * pixColor.b);
  float S = (0.0299566 * pixColor.r) + (0.184309 * pixColor.g) + (1.46709 * pixColor.b);

  float l, m, s;
  if (mode == 0) //Protanopia
  {
    l = 0.0 * L + 2.02344 * M + -2.52581 * S;
    m = 0.0 * L + 1.0 * M + 0.0 * S;
    s = 0.0 * L + 0.0 * M + 1.0 * S;
  }
  
  if (mode == 1) //Deuteranopia
  {
    l = 1.0 * L + 0.0 * M + 0.0 * S;
    m = 0.494207 * L + 0.0 * M + 1.24827 * S;
    s = 0.0 * L + 0.0 * M + 1.0 * S;
  }

  if (mode == 2) //Tritanopia
  {
    l = 1.0 * L + 0.0 * M + 0.0 * S;
    m = 0.0 * L + 1.0 * M + 0.0 * S;
    s = -0.395913 * L + 0.801109 * M + 0.0 * S;
  }

  vec4 error;
  error.r = (0.0809444479 * l) + (-0.130504409 * m) + (0.116721066 * s);
  error.g = (-0.0102485335 * l) + (0.0540193266 * m) + (-0.113614708 * s);
  error.b = (-0.000365296938 * l) + (-0.00412161469 * m) + (0.693511405 * s);
  error.a = 1.0;
  vec4 diff = pixColor - error;
  vec4 correction;
  correction.r = 0.0;
  correction.g = (diff.r * 0.7) + (diff.g * 1.0);
  correction.b = (diff.r * 0.7) + (diff.b * 1.0);
  correction = pixColor + correction;
  correction.a = pixColor.a * intensity;

  gl_FragColor = correction;
}

[loqusion]

@lividhen Do you think it would be useful for hyprshade to provide configurable intensity, so that people don't have to modify the shader by hand? There could be a field in hyprland.toml, e.g.:

[[shades]]
name = "color-filter"
[shades.config]
type = "protanopia" # "protanopia", "deuteranopia", "tritanopia"
intensity = 1.0     # 0.0 - 1.0

(I also added configurable type here to avoid the need to include multiple shader files)

On a separate note, do you have any suggestions for what to name the shader?

[lividhen]

Yeah having a config would be great! Don't really have a good name besides color blind mode or color blind shader. Probably doesn't need to be much more than that.