import { TextureBase } from '@awayjs/renderer';
import { DiffuseBasicMethod, _Shader_DiffuseBasicMethod } from './DiffuseBasicMethod';
/**
 * DiffuseGradientMethod is an alternative to DiffuseBasicMethod in which the shading can be modulated with a gradient
 * to introduce color-tinted shading as opposed to the single-channel diffuse strength. This can be used as a crude
 * approximation to subsurface scattering (for instance, the mid-range shading for skin can be tinted red to similate
 * scattered light within the skin attributing to the final colour)
 */
export declare class DiffuseGradientMethod extends DiffuseBasicMethod {
    private _gradient;
    static assetType: string;
    /**
     * @inheritDoc
     */
    get assetType(): string;
    /**
     * A texture that contains the light colour based on the angle. This can be used to change the light colour
     * due to subsurface scattering when the surface faces away from the light.
     */
    get gradient(): TextureBase;
    set gradient(value: TextureBase);
    /**
     * Creates a new DiffuseGradientMethod object.
     * @param gradient A texture that contains the light colour based on the angle. This can be used to change
     * the light colour due to subsurface scattering when the surface faces away from the light.
     */
    constructor(gradient: TextureBase);
}
import { ShaderRegisterCache, ShaderRegisterData, ShaderRegisterElement } from '@awayjs/stage';
import { _Render_RenderableBase, ChunkVO } from '@awayjs/renderer';
import { LightingShader } from '../shaders/LightingShader';
/**
 * _Shader_DiffuseGradientMethod is an alternative to _Shader_DiffuseBasicMethod in which the shading can be modulated with a gradient
 * to introduce color-tinted shading as opposed to the single-channel diffuse strength. This can be used as a crude
 * approximation to subsurface scattering (for instance, the mid-range shading for skin can be tinted red to similate
 * scattered light within the skin attributing to the final colour)
 */
export declare class _Shader_DiffuseGradientMethod extends _Shader_DiffuseBasicMethod {
    private _gradient;
    /**
     * Creates a new _Shader_DiffuseGradientMethod object.
     * @param gradient A texture that contains the light colour based on the angle. This can be used to change
     * the light colour due to subsurface scattering when the surface faces away from the light.
     */
    init(method: DiffuseGradientMethod, shader: LightingShader): void;
    _initVO(chunkVO: ChunkVO): void;
    /**
     * @inheritDoc
     */
    _initConstants(): void;
    /**
     * @inheritDoc
     */
    _getFragmentPreLightingCode(registerCache: ShaderRegisterCache, sharedRegisters: ShaderRegisterData): string;
    /**
     * @inheritDoc
     */
    _getFragmentCodePerLight(lightDirReg: ShaderRegisterElement, lightColReg: ShaderRegisterElement, registerCache: ShaderRegisterCache, sharedRegisters: ShaderRegisterData): string;
    /**
     * @inheritDoc
     */
    _activate(): void;
    /**
     * @inheritDoc
     */
    _setRenderState(renderState: _Render_RenderableBase): void;
}
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