/**
 * Procedural sky shader — fullscreen triangle with atmospheric gradient + sun disc.
 * Writes z = 1.0 (far plane) so all geometry draws on top.
 */
export declare const SKY_SHADER = "\nstruct SkyUniforms {\n  invVP: mat4x4<f32>,\n  sunDir: vec4<f32>,\n  zenithColor: vec4<f32>,\n  horizonColor: vec4<f32>,\n  groundColor: vec4<f32>,\n  params: vec4<f32>,  // x = sunIntensity, y = groundFalloff\n};\n\n@group(0) @binding(0) var<uniform> sky: SkyUniforms;\n\nstruct VertexOutput {\n  @builtin(position) position: vec4<f32>,\n  @location(0) ndc: vec2<f32>,\n};\n\nvar<private> pos: array<vec2<f32>, 3> = array(\n  vec2(-1.0, -1.0),\n  vec2( 3.0, -1.0),\n  vec2(-1.0,  3.0),\n);\n\n@vertex\nfn vs(@builtin(vertex_index) i: u32) -> VertexOutput {\n  var out: VertexOutput;\n  let p = pos[i];\n  out.position = vec4(p, 1.0, 1.0);  // z = 1.0 \u2192 far plane\n  out.ndc = p;\n  return out;\n}\n\n@fragment\nfn fs(input: VertexOutput) -> @location(0) vec4<f32> {\n  // Reconstruct world-space ray direction from NDC\n  let clipNear = vec4(input.ndc, 0.0, 1.0);\n  let clipFar  = vec4(input.ndc, 1.0, 1.0);\n  let worldNear = sky.invVP * clipNear;\n  let worldFar  = sky.invVP * clipFar;\n  let near3 = worldNear.xyz / worldNear.w;\n  let far3  = worldFar.xyz / worldFar.w;\n  let dir = normalize(far3 - near3);\n\n  // Atmospheric gradient: blend zenith \u2192 horizon based on elevation\n  let up = vec3(0.0, 1.0, 0.0);\n  let elevation = dot(dir, up);\n  let t = clamp(elevation, 0.0, 1.0);\n  let gradient = mix(sky.horizonColor.rgb, sky.zenithColor.rgb, sqrt(t));\n\n  // Below horizon: fade quickly to ground color\n  let falloff = sky.params.y;\n  let belowT = clamp(-elevation * falloff, 0.0, 1.0);\n  let skyColor = mix(gradient, sky.groundColor.rgb, belowT * belowT);\n\n  // Sun disc + glow\n  let sunDir = normalize(sky.sunDir.xyz);\n  let cosAngle = dot(dir, sunDir);\n  let sunIntensity = sky.params.x;\n\n  // Sharp sun disc (angular radius ~0.5 degrees = cos(0.00873) \u2248 0.99996)\n  let discMask = smoothstep(0.9997, 0.9999, cosAngle);\n  let sunDisc = discMask * sunIntensity * 20.0;\n\n  // Soft glow around sun\n  let glow = pow(max(cosAngle, 0.0), 256.0) * sunIntensity * 4.0;\n  let outerGlow = pow(max(cosAngle, 0.0), 32.0) * sunIntensity * 0.3;\n\n  let sunColor = vec3(1.0, 0.95, 0.85);\n  let finalColor = skyColor + sunColor * (sunDisc + glow + outerGlow);\n\n  return vec4(finalColor, 1.0);\n}\n";
/** Size of the SkyUniforms buffer in bytes (mat4 + 5×vec4 = 16+4+4+4+4+4 = 36 floats = 144). */
export declare const SKY_UNIFORM_SIZE = 144;
//# sourceMappingURL=sky-shader.d.ts.map