graph-layout/vendor/gioui.org/shader/gio/zcover.frag.1.glsl150

#version 150

struct Gradient
{
    vec4 color1;
    vec4 color2;
};

uniform Gradient _gradient;

uniform sampler2D cover;

out vec4 fragColor;
in vec2 vUV;
in vec2 vCoverUV;

void main()
{
    fragColor = mix(_gradient.color1, _gradient.color2, vec4(clamp(vUV.x, 0.0, 1.0)));
    float c = min(abs(texture(cover, vCoverUV).x), 1.0);
    fragColor *= c;
}