{
    "name": "Galaxy Spiral",
    "description": "Spiralgalaxie mit Partikel-Sternen",
    "vertex_shader": "attribute vec2 a_position;\nvoid main() {\n    gl_Position = vec4(a_position, 0.0, 1.0);\n}",
    "fragment_shader": "precision mediump float;\nuniform float u_time;\nuniform vec2 u_resolution;\nuniform vec2 u_mouseNorm;\nuniform float u_zoom;\n\nfloat hash(float n) { return fract(sin(n) * 43758.5453123); }\n\nvoid main() {\n    vec2 uv = (gl_FragCoord.xy - 0.5 * u_resolution.xy) \/ u_resolution.y;\n    uv \/= u_zoom;\n    float t = u_time * 0.1;\n    float angle = atan(uv.y, uv.x);\n    float radius = length(uv);\n    float spiral = sin(angle * 3.0 + radius * 8.0 - t * 5.0);\n    float arms = smoothstep(0.3, 0.7, spiral) * exp(-radius * 1.5);\n    vec3 core = vec3(1.0, 0.9, 0.7) * exp(-radius * 4.0);\n    vec3 armCol = vec3(0.3, 0.5, 0.9) * arms;\n    vec3 starCol = vec3(0.0);\n    for (float i = 0.0; i < 50.0; i++) {\n        float a = hash(i) * 6.2831 + t * (0.1 + hash(i + 100.0) * 0.3);\n        float r = hash(i + 50.0) * 1.5;\n        vec2 starPos = vec2(cos(a), sin(a)) * r;\n        float star = smoothstep(0.02, 0.0, length(uv - starPos));\n        starCol += vec3(0.8 + hash(i)*0.2, 0.8, 1.0) * star;\n    }\n    vec3 col = core + armCol + starCol * 0.3;\n    float mouseDist = length(uv - (u_mouseNorm - 0.5) * vec2(u_resolution.x\/u_resolution.y, 1.0) \/ u_zoom);\n    col += vec3(1.0, 0.8, 0.5) * smoothstep(0.15, 0.0, mouseDist) * 0.5;\n    gl_FragColor = vec4(col, 1.0);\n}"
}