import { float, int, ivec2, sampler2D, samplerCube, vec2, vec3, vec4 } from "./ShaderTypes";
/**
 * samples a normal map and remaps values from 0 -> 1 to -1 -> 1
 * @param normalMap the normal map to be sampled
 * @param uv the coordinates used to sample the normal map
 * @returns rgb color values from normal map
 */
export declare const sampleNormalMap: (normalMap: sampler2D, uv: vec2) => vec3 | string;
/**
 * Gets an index for the current texel on an fbo texture
 * @param fboTex the fbo texture
 * @param texCoord the texel coordinates - usually ivec2(gl_FragCoord.xy)
 * @returns the index of the current texel
 */
export declare const getFboIndex: (fboTex: sampler2D, texCoord: ivec2) => int | string;
/**
 * samples environment map reflections in world space
 * @param envMap the environment map cube texture
 * @param eyeVec the vector from the fragment pos towards the camera
 * @param normal the surface normal
 * @returns a vec3 with colors of the reflected cube map
 */
export declare const reflectEnvMap: (envMap: samplerCube, eyeVec: vec3, normal: vec3) => vec3 | string;
/**
 * samples refracted environment map
 * @param envMap the environment map cube texture
 * @param viewVec the vector from the camera towards the fragment
 * @param normal the surface normal
 * @param refractionIndex the index of refraction (1.33 for water, higher for denser materials)
 * @returns the refracted env map texture
 */
export declare const refractEnvMap: (envMap?: samplerCube, viewVec?: vec3, normal?: vec3, refractionIndex?: float) => vec3 | string;
/**
 * samples refracted texture
 * @param envMap the environment map cube texture
 * @param screenUv the screen space UV coords
 * @param viewVec the vector from the camera towards the fragment
 * @param normal the surface normal
 * @param refractionIndex the index of refraction (1.33 for water, higher for denser materials)
 * @returns the refracted texture
 */
export declare const refractTexture: (envMap?: samplerCube, screenUv?: vec2, viewVec?: vec3, normal?: vec3, refractionIndex?: float) => vec3 | string;
/**
 * offsets UVs in the -z direction in tangent space to create a parallax effect
 * @param uv regular tangent space uv coordinates
 * @param tangentSpaceViewDir the view direction in tangent space
 * @param offsetScale how far the new UV will be offset
 * @returns new UV values with z offset
 */
export declare const parallaxOffsetUV: (uv: vec2, tangentSpaceViewDir: vec3, offsetScale: float) => vec2 | string;
/**
 * Use a lookup table texture to easily adjust color values. Ensure the LUT texture
 * has min and mag filters set to THREE.LinearFilter for best results
 * @param originalColor the input color value
 * @param lutTexture the look up table texture
 * @returns recolored values based on the provided lookup table
 */
export declare const lookupTable: (originalColor: vec4, lutTexture: sampler2D) => vec4 | any;
export declare const blur5: (image?: sampler2D, uv?: vec2, resolution?: vec2, direction?: vec2) => vec4 | any;
export declare const blur9: (image?: sampler2D, uv?: vec2, resolution?: vec2, direction?: vec2) => vec4 | any;
export declare const blur13: (image?: sampler2D, uv?: vec2, resolution?: vec2, direction?: vec2) => vec4 | any;
export declare const uvToPolar: () => string;
export declare const TextureFunctions: {
    sampleNormalMap: (normalMap: sampler2D, uv: vec2) => vec3 | string;
    getFboIndex: (fboTex: sampler2D, texCoord: ivec2) => int | string;
    reflectEnvMap: (envMap: samplerCube, eyeVec: vec3, normal: vec3) => vec3 | string;
    refractEnvMap: (envMap?: samplerCube, viewVec?: vec3, normal?: vec3, refractionIndex?: float) => vec3 | string;
    refractTexture: (envMap?: samplerCube, screenUv?: vec2, viewVec?: vec3, normal?: vec3, refractionIndex?: float) => vec3 | string;
    parallaxOffsetUV: (uv: vec2, tangentSpaceViewDir: vec3, offsetScale: float) => vec2 | string;
    lookupTable: (originalColor: vec4, lutTexture: sampler2D) => vec4 | any;
    blur5: (image?: sampler2D, uv?: vec2, resolution?: vec2, direction?: vec2) => vec4 | any;
    blur9: (image?: sampler2D, uv?: vec2, resolution?: vec2, direction?: vec2) => vec4 | any;
    blur13: (image?: sampler2D, uv?: vec2, resolution?: vec2, direction?: vec2) => vec4 | any;
};