export declare const GradientFunctionsShader = "\nfloat rand(vec2 n) {\n\treturn fract(sin(dot(n, vec2(12.9898, 4.1414))) * 43758.5453);\n}\n\n#include <dithering_pars_fragment>\n#define MAX_GRADIENT_STOPS 4\n#define PI 3.14159265359\n\n// Paint Types.\n#define PAINT_TYPE_SOLID 0\n#define PAINT_TYPE_GRADIENT 1\n\n// Gradient Types.\n#define GRADIENT_TYPE_LINEAR 0\n#define GRADIENT_TYPE_RADIAL 1\n#define GRADIENT_TYPE_ANGULAR 2\n#define GRADIENT_TYPE_DIAMOND 3\n\n// Interpolate color stops across a 1D scalar index range [0..1].\n// Shared by both fill meshes and radius/distance edge blended vectors (like Shadows).\nvec4 mixGradientStops(\n    float t,\n    int numStops,\n    float stops[MAX_GRADIENT_STOPS],\n    vec4 colors[MAX_GRADIENT_STOPS]\n) {\n    if (numStops < 1) return vec4(0.0);\n    if (numStops < 2) return colors[0];\n\n    float finalT = clamp(t, 0.0, 1.0);\n    vec4 color = colors[0];\n\n    for (int i = 0; i < MAX_GRADIENT_STOPS - 1; i++) {\n        if (i >= numStops - 1) break;\n\n        float t0 = stops[i];\n        float t1 = stops[i+1];\n\n        if (finalT >= t0 && finalT <= t1) {\n            float range = t1 - t0;\n            float localT = (finalT - t0) / max(0.0001, range);\n            color = mix(colors[i], colors[i+1], localT);\n            break;\n        }\n    }\n\n    // Boundary checks.\n    if (finalT < stops[0]) color = colors[0];\n    if (finalT > stops[numStops-1]) color = colors[numStops-1];\n\n    return color;\n}\n\nvec4 getGradientColor(\n    vec2 uv,\n    vec2 resolution,\n    int type,\n    vec2 center,\n    vec2 scale,\n    float rotation,\n    int numStops,\n    float stops[MAX_GRADIENT_STOPS],\n    vec4 colors[MAX_GRADIENT_STOPS]\n) {\n    if (numStops < 1) return vec4(0.0);\n    if (numStops < 2) return colors[0];\n\n    // 1. Transform UV.\n    // Center logic: user provided center (default 0.5, 0.5).\n    // We shift UV so that center is at (0,0).\n    vec2 p = uv - center;\n\n    // Rotation.\n    float c = cos(-rotation);\n    float s = sin(-rotation);\n    mat2 rot = mat2(c, -s, s, c);\n    p = rot * p;\n\n    // Scale.\n    // Expand feature = Divide coord.\n    vec2 safeScale = vec2(\n        abs(scale.x) < 0.001 ? 0.001 : scale.x,\n        abs(scale.y) < 0.001 ? 0.001 : scale.y\n    );\n    p = p / safeScale;\n\n    // 2. Calculate t (0 to 1 position in gradient).\n    float t = 0.0;\n\n    if (type == GRADIENT_TYPE_LINEAR) {\n        // Defined along X axis (after rotation).\n        // Maps x range [-0.5, 0.5] to [0.0, 1.0].\n        t = p.x + 0.5;\n    }\n    else if (type == GRADIENT_TYPE_RADIAL) {\n        // Distance from center.\n        // t=0 at center. t=1 at radius 0.5.\n        t = length(p) * 2.0;\n    }\n    else if (type == GRADIENT_TYPE_ANGULAR) {\n        // Conic gradient.\n        // atan(y, x). range -PI to PI.\n        // Standard math angle (0 = Right, CCW).\n        float angle = atan(-p.y, p.x);\n        // Map to 0..1.\n        t = (angle / (2.0 * PI)) + 0.5;\n    }\n    else if (type == GRADIENT_TYPE_DIAMOND) {\n        // |x| + |y| (Manhattan distance).\n        // Edge at 0.5 => |0.5| + |0| = 0.5.\n        // t = (abs x + abs y) * 2.\n        t = (abs(p.x) + abs(p.y)) * 2.0;\n    }\n\n    // Clamp t.\n    t = clamp(t, 0.0, 1.0);\n\n    return mixGradientStops(t, numStops, stops, colors);\n}\n";