/**
 * Procedural sky background — a single fullscreen triangle drawn at the far
 * plane (reverse-Z: z = 0) before any geometry. Analytic zenith/horizon/
 * ground gradient plus a sun disc + glow, driven by the same sun direction
 * the geometry lighting uses.
 *
 * Tonemapping note: the geometry shader applies ACES + gamma at the end of
 * its fragment stage (not in a post pass), so the sky must apply the same
 * curve here or it would read as a different "film stock" than the model.
 */
export declare const skyShaderSource = "\n        struct SkyUniforms {\n          camRight: vec3<f32>,\n          tanHalfFovX: f32,\n          camUp: vec3<f32>,\n          tanHalfFovY: f32,\n          camForward: vec3<f32>,\n          exposure: f32,\n          sunDirection: vec3<f32>,\n          sunIntensity: f32,\n          zenithColor: vec3<f32>,\n          _pad0: f32,\n          horizonColor: vec3<f32>,\n          _pad1: f32,\n          groundColor: vec3<f32>,\n          _pad2: f32,\n        }\n        @binding(0) @group(0) var<uniform> sky: SkyUniforms;\n\n        struct VertexOutput {\n          @builtin(position) position: vec4<f32>,\n          @location(0) ndc: vec2<f32>,\n        }\n\n        @vertex\n        fn vs_main(@builtin(vertex_index) vi: u32) -> VertexOutput {\n          // Fullscreen triangle: (-1,-1), (3,-1), (-1,3).\n          let x = f32((vi << 1u) & 2u) * 2.0 - 1.0;\n          let y = f32(vi & 2u) * 2.0 - 1.0;\n          var out: VertexOutput;\n          // z = 0 is the far plane under reverse-Z, so any geometry drawn\n          // later wins the depth test without the sky writing depth.\n          out.position = vec4<f32>(x, y, 0.0, 1.0);\n          out.ndc = vec2<f32>(x, y);\n          return out;\n        }\n\n        // Same ACES filmic curve as the geometry fragment shader.\n        fn acesTonemap(c: vec3<f32>) -> vec3<f32> {\n          let a = 2.51;\n          let b = 0.03;\n          let cc = 2.43;\n          let d = 0.59;\n          let e = 0.14;\n          return clamp((c * (a * c + b)) / (c * (cc * c + d) + e), vec3<f32>(0.0), vec3<f32>(1.0));\n        }\n\n        struct FragmentOutput {\n          @location(0) color: vec4<f32>,\n          // Matches the pass's object-id attachment clear value so the sky\n          // never registers as a pickable entity.\n          @location(1) objectIdEncoded: vec4<f32>,\n        }\n\n        @fragment\n        fn fs_main(input: VertexOutput) -> FragmentOutput {\n          // Per-pixel view ray from the camera basis. Used for orthographic\n          // cameras too \u2014 parallel rays would collapse the sky to a single\n          // colour, so a perspective-style fan reads better in both modes.\n          let dir = normalize(\n            sky.camForward\n            + input.ndc.x * sky.tanHalfFovX * sky.camRight\n            + input.ndc.y * sky.tanHalfFovY * sky.camUp\n          );\n          let elevation = dir.y;\n\n          // Horizon \u2192 zenith gradient with a slow falloff near the horizon.\n          let zenithMix = pow(clamp(elevation, 0.0, 1.0), 0.45);\n          var color = mix(sky.horizonColor, sky.zenithColor, zenithMix);\n\n          // Below the horizon: fade quickly into the ground colour.\n          let groundMix = smoothstep(0.0, -0.1, elevation);\n          color = mix(color, sky.groundColor, groundMix);\n\n          // Sun disc + glow. The disc is slightly oversized vs the real\n          // ~0.53\u00B0 sun so it stays visible at typical canvas resolutions.\n          let cosSun = dot(dir, sky.sunDirection);\n          let disc = smoothstep(0.99985, 0.99995, cosSun);\n          let glow = pow(max(cosSun, 0.0), 350.0) * 0.5\n                   + pow(max(cosSun, 0.0), 24.0) * 0.12;\n          // Hide the disc once the sun sets, and never draw it on the ground.\n          let sunVisible = smoothstep(-0.06, 0.02, sky.sunDirection.y) * (1.0 - groundMix);\n          let sunTint = vec3<f32>(1.0, 0.92, 0.78);\n          color += (disc * 6.0 + glow) * max(sky.sunIntensity, 0.0) * sunVisible * sunTint;\n\n          // Match the geometry pipeline: exposure \u2192 ACES \u2192 gamma.\n          color *= sky.exposure;\n          color = acesTonemap(color);\n          color = pow(color, vec3<f32>(1.0 / 2.2));\n\n          var out: FragmentOutput;\n          out.color = vec4<f32>(color, 1.0);\n          out.objectIdEncoded = vec4<f32>(0.0, 0.0, 0.0, 0.0);\n          return out;\n        }\n      ";
//# sourceMappingURL=sky.wgsl.d.ts.map