MapLibreParticleLab/shaders/drawable.fill_outline.fragment.glsl

layout (std140) uniform FillOutlineInterpolateUBO {
    highp float u_outline_color_t;
    highp float u_opacity_t;
    highp float interp_pad1;
    highp float interp_pad2;
};
layout (std140) uniform FillEvaluatedPropsUBO {
    highp vec4 u_color;
    highp vec4 u_outline_color;
    highp float u_opacity;
    highp float u_fade;
    highp float u_from_scale;
    highp float u_to_scale;
};

in vec2 v_pos;

#pragma mapbox: define highp vec4 outline_color
#pragma mapbox: define lowp float opacity

void main() {
    #pragma mapbox: initialize highp vec4 outline_color
    #pragma mapbox: initialize lowp float opacity

    float dist = length(v_pos - gl_FragCoord.xy);
    float alpha = 1.0 - smoothstep(0.0, 1.0, dist);
    fragColor = outline_color * (alpha * opacity);

#ifdef OVERDRAW_INSPECTOR
    fragColor = vec4(1.0);
#endif
}