#version 330 core

in vec2 uv;
out vec4 outColor;

uniform sampler2D ColorTexture;
uniform sampler2D DepthTexture;
uniform float time;
uniform float chromaSpeed;
uniform float chromaSaturation;
uniform float chromaBrightness;

// HSV to RGB conversion
vec3 hsv2rgb(vec3 c) {
    vec4 K = vec4(1.0, 2.0 / 3.0, 1.0 / 3.0, 3.0);
    vec3 p = abs(fract(c.xxx + K.xyz) * 6.0 - K.www);
    return c.z * mix(K.xxx, clamp(p - K.xxx, 0.0, 1.0), c.y);
}

// Create rainbow effect
vec3 createChromaEffect(vec2 coord, float t) {
    // Combine vertical and horizontal gradients for more dynamic effect
    float hue = fract(coord.y * 0.5 + coord.x * 0.3 + t * chromaSpeed);

    // Add wave pattern for more visual interest
    float wave = sin(coord.y * 10.0 + t * 3.0) * 0.05;
    hue += wave;

    // Convert HSV to RGB
    vec3 chromaColor = hsv2rgb(vec3(hue, chromaSaturation, chromaBrightness));

    return chromaColor;
}

void main() {
    vec4 originalColor = texture(ColorTexture, uv);
    vec2 texelSize = 1.0 / textureSize(DepthTexture, 0);

    // Optimized depth-based masking - cross pattern
    float centerDepth = texture(DepthTexture, uv).r;
    float minDepth = centerDepth;

    minDepth = min(minDepth, texture(DepthTexture, uv + vec2(-texelSize.x, 0.0)).r);
    minDepth = min(minDepth, texture(DepthTexture, uv + vec2(texelSize.x, 0.0)).r);
    minDepth = min(minDepth, texture(DepthTexture, uv + vec2(0.0, -texelSize.y)).r);
    minDepth = min(minDepth, texture(DepthTexture, uv + vec2(0.0, texelSize.y)).r);

    float mask = smoothstep(0.99, 0.98, minDepth);

    if (mask < 0.01) {
        discard;
    }

    // Create chroma effect
    vec3 chromaColor = createChromaEffect(uv, time);

    // Add slight pulsing to make it more alive
    float pulse = 0.9 + sin(time * 4.0) * 0.1;
    chromaColor *= pulse;

    vec4 effectColor = vec4(chromaColor, 1.0);

    // Mix original color with chroma effect
    vec4 finalHandColor = mix(originalColor, effectColor, 0.85);

    outColor = vec4(finalHandColor.rgb, mask);
}