import { MethodBase, _Shader_MethodBase } from './MethodBase';

/**
 * EffectRimLightMethod provides a method to add rim lighting to a material.
 * This adds a glow-like effect to edges of objects.
 */
export class EffectRimLightMethod extends MethodBase {
	public static ADD: string = 'add';
	public static MULTIPLY: string = 'multiply';
	public static MIX: string = 'mix';

	private _color: number;
	private _strength: number;
	private _power: number;
	private _blendMode: string;

	public static assetType: string = '[asset EffectRimLightMethod]';

	/**
	 * @inheritDoc
	 */
	public get assetType(): string {
		return EffectRimLightMethod.assetType;
	}

	/**
	 * The color of the rim light.
	 */
	public get color(): number {
		return this._color;
	}

	public set color(value: number) {
		if (this._power == value)
			return;

		this._color = value;

		this.invalidate();
	}

	/**
	 * The strength of the rim light.
	 */
	public get strength(): number {
		return this._strength;
	}

	public set strength(value: number) {
		if (this._strength == value)
			return;

		this._strength = value;

		this.invalidate();
	}

	/**
	 * The power of the rim light. Higher values will result in a higher edge fall-off.
	 */
	public get power(): number {
		return this._power;
	}

	public set power(value: number) {
		if (this._power == value)
			return;

		this._power = value;

		this.invalidate();
	}

	/**
	 * The blend mode with which to add the light to the object.
	 *
	 * EffectRimLightMethod.MULTIPLY multiplies the rim light with the material's colour.
	 * EffectRimLightMethod.ADD adds the rim light with the material's colour.
	 * EffectRimLightMethod.MIX provides normal alpha blending.
	 */
	public get blendMode(): string {
		return this._blendMode;
	}

	public set blendMode(value: string) {
		if (this._blendMode == value)
			return;

		this._blendMode = value;

		this.invalidateShaderProgram();
	}

	/**
	 * Creates a new <code>EffectRimLightMethod</code> object.
	 *
	 * @param color The colour of the rim light.
	 * @param strength The strength of the rim light.
	 * @param power The power of the rim light. Higher values will result in a higher edge fall-off.
	 * @param blend The blend mode with which to add the light to the object.
	 */
	constructor(color: number = 0xffffff, strength: number = .4, power: number = 2, blend: string = 'mix') {
		super();

		this._blendMode = blend;
		this._strength = strength;
		this._power = power;

		this._color = color;
	}
}

import { ShaderRegisterCache, ShaderRegisterData, ShaderRegisterElement } from '@awayjs/stage';

import { ShaderBase, ChunkVO } from '@awayjs/renderer';

/**
 * _Shader_EffectRimLightMethod provides a method to add rim lighting to a material. This adds a glow-like effect to edges of objects.
 */
export class _Shader_EffectRimLightMethod extends _Shader_MethodBase {
	private _method: EffectRimLightMethod;
	private _shader: ShaderBase;

	private _rimColorIndex: number;

	/**
     * Creates a new EffectEnvMapChunk.
     */
	public init(method: EffectRimLightMethod, shader: ShaderBase): void {
		super.init(method, shader);

		this._method = method;
		this._shader = shader;
	}

	/**
     * @inheritDoc
     */
	public _initVO(chunkVO: ChunkVO): void {
		chunkVO.needsNormals = true;
		chunkVO.needsView = true;
	}

	/**
     * @inheritDoc
     */
	public _activate(): void {
		if (this._invalid) {
			const index: number = this._rimColorIndex;
			const data: Float32Array = this._shader.fragmentConstantData;
			const color: number = this._method.color;

			data[index] = ((color >> 16) & 0xff) / 0xff;
			data[index + 1] = ((color >> 8) & 0xff) / 0xff;
			data[index + 2] = (color & 0xff) / 0xff;
			data[index + 3] = 1;

			data[index + 4] = this._method.strength;
			data[index + 5] = this._method.power;
		}
	}

	/**
     * @inheritDoc
     */
	public _getFragmentCode(targetReg: ShaderRegisterElement, registerCache: ShaderRegisterCache, sharedRegisters: ShaderRegisterData): string {
		const dataRegister: ShaderRegisterElement = registerCache.getFreeFragmentConstant();
		const dataRegister2: ShaderRegisterElement = registerCache.getFreeFragmentConstant();
		const temp: ShaderRegisterElement = registerCache.getFreeFragmentVectorTemp();
		let code: string = '';

		this._rimColorIndex = dataRegister.index * 4;

		code += 'dp3 ' + temp + '.x, ' + sharedRegisters.viewDirFragment + '.xyz, ' + sharedRegisters.normalFragment + '.xyz\n' +
            'sat ' + temp + '.x, ' + temp + '.x\n' +
            'sub ' + temp + '.x, ' + dataRegister + '.w, ' + temp + '.x\n' +
            'pow ' + temp + '.x, ' + temp + '.x, ' + dataRegister2 + '.y\n' +
            'mul ' + temp + '.x, ' + temp + '.x, ' + dataRegister2 + '.x\n' +
            'sub ' + temp + '.x, ' + dataRegister + '.w, ' + temp + '.x\n' +
            'mul ' + targetReg + '.xyz, ' + targetReg + '.xyz, ' + temp + '.x\n' +
            'sub ' + temp + '.w, ' + dataRegister + '.w, ' + temp + '.x\n';

		if (this._method.blendMode == EffectRimLightMethod.ADD) {
			code += 'mul ' + temp + '.xyz, ' + temp + '.w, ' + dataRegister + '.xyz\n' +
                'add ' + targetReg + '.xyz, ' + targetReg + '.xyz, ' + temp + '.xyz\n';
		} else if (this._method.blendMode == EffectRimLightMethod.MULTIPLY) {
			code += 'mul ' + temp + '.xyz, ' + temp + '.w, ' + dataRegister + '.xyz\n' +
                'mul ' + targetReg + '.xyz, ' + targetReg + '.xyz, ' + temp + '.xyz\n';
		} else {
			code += 'sub ' + temp + '.xyz, ' + dataRegister + '.xyz, ' + targetReg + '.xyz\n' +
                'mul ' + temp + '.xyz, ' + temp + '.xyz, ' + temp + '.w\n' +
                'add ' + targetReg + '.xyz, ' + targetReg + '.xyz, ' + temp + '.xyz\n';
		}

		return code;
	}
}

ShaderBase.registerAbstraction(_Shader_EffectRimLightMethod, EffectRimLightMethod);