// Protanopia -- red-blind.
//
// Panama's accessibility color filters. Selected by the `colorFilter`
// preference; hypr/looks.lua maps the enum to this path at config time and
// services/SystemSettings.qml does the same live.
//
// The matrix is the feColorMatrix set the mock uses, which is the widely
// carried HCIRN-derived one: it redistributes the red channel into the two the
// eye can still separate, so a red/green pair that was one colour becomes two
// distinguishable ones. It is a CORRECTION, not a simulation -- the point is to
// make the screen readable, not to show what protanopia looks like.
//
// Row-major here, column-major to GLSL: mat3 takes its arguments column by
// column, so the transpose below is the matrix as written in the SVG.

#version 300 es

precision mediump float;
in vec2 v_texcoord;
layout(location = 0) out vec4 fragColor;
uniform sampler2D tex;

const mat3 protanopia = mat3(
    0.567, 0.558, 0.000,
    0.433, 0.442, 0.242,
    0.000, 0.000, 0.758
);

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

    fragColor = vec4(clamp(protanopia * pixColor.rgb, 0.0, 1.0), pixColor.a);
}