#version 440

layout(location = 0) in vec2 qt_TexCoord0;
layout(location = 0) out vec4 fragColor;

layout(std140, binding = 0) uniform buf {
    mat4 qt_Matrix;
    float qt_Opacity;
    // 0.0 = no threat, 1.0 = max lockout
    float uThreat;
    // 0.0-1.0 heartbeat pulse (0 when inactive)
    float uPulse;
    // accent/threat color
    vec4 uColor;
};

layout(binding = 1) uniform sampler2D source;

void main() {
    vec2 uv = qt_TexCoord0;
    float threat = clamp(uThreat, 0.0, 1.0);
    float pulse = clamp(uPulse, 0.0, 1.0);

    // Combined intensity: base threat + heartbeat spike
    float intensity = threat + pulse * threat * 0.4;

    // Chromatic aberration - RGB channel split increasing with threat
    float aberration = intensity * 0.02;
    float r = texture(source, uv + vec2(aberration, 0.0)).r;
    float g = texture(source, uv).g;
    float b = texture(source, uv - vec2(aberration, 0.0)).b;
    float a = texture(source, uv).a;
    vec4 tex = vec4(r, g, b, a);

    // Vignette - radial darkening from edges, creeping inward with threat
    vec2 center = uv - 0.5;
    float dist = length(center * vec2(1.0, 0.7)); // wider horizontally
    // Inner edge shrinks as threat rises (0.8 -> 0.35)
    float vigInner = mix(0.8, 0.35, intensity);
    // Outer edge also shrinks (1.1 -> 0.7)
    float vigOuter = mix(1.1, 0.7, intensity);
    float vig = smoothstep(vigInner, vigOuter, dist);

    // Red tint on the vignette area - translucent blend
    vec3 threatColor = uColor.rgb;
    vec3 tinted = mix(tex.rgb, threatColor * 0.12, vig * intensity * 0.6);

    // Darken edges - softer
    tinted *= 1.0 - vig * intensity * 0.35;

    fragColor = vec4(tinted, tex.a) * qt_Opacity;
}