//go:build ignore

//kage:unit pixels

package main

var Time float

func Fragment(dstPos vec4, srcPos vec2, color vec4) vec4 {
    // Normalize coordinates to center (0.5, 0.5)
    center := vec2(0.5, 0.5)
    uv := srcPos - center

    // Distance from center
    dist := length(uv)

    // Bubble distortion: radial displacement based on time
    wave := sin(dist*20.0 - Time*2.0) * 0.03
    distortedUV := uv * (1.0 + wave)
    distortedUV += center

    // Sample original texture with distortion
    original := imageSrc0At(distortedUV)

    // Bubble edge glow
    bubbleEdge := 1.0 - smoothstep(0.25, 0.45, dist)
    glow := bubbleEdge * vec4(0.3, 0.8, 1.0, 0.6)

    // Soft inner highlight
    inner := 1.0 - smoothstep(0.0, 0.3, dist)
    highlight := inner * vec4(0.5, 0.9, 1.0, 0.15)

    // Combine: original image with bubble effects overlaid
    result := original * (1.0 - bubbleEdge*0.4) + glow + highlight

    return result * color
}