/**
 * Renders a scene with a camera
 * @param graphics GameLib.D3.Graphics
 * @param apiRenderTarget GameLib.D3.API.RenderTarget
 * @constructor
 */
GameLib.D3.RenderTarget = function (
    graphics,
    apiRenderTarget
) {

    this.graphics = graphics;
    this.graphics.isNotThreeThrow();

    if (GameLib.Utils.UndefinedOrNull(apiRenderTarget)) {
        apiRenderTarget = {};
    }

	if (apiRenderTarget instanceof GameLib.D3.RenderTarget) {
		return apiRenderTarget;
	}

    GameLib.D3.API.RenderTarget.call(
        this,
        apiRenderTarget.id,
        apiRenderTarget.name,
        apiRenderTarget.width,
        apiRenderTarget.height,
        apiRenderTarget.minFilter,
        apiRenderTarget.magFilter,
        apiRenderTarget.format,
        apiRenderTarget.stencilBuffer,
        apiRenderTarget.texture
    );

    this.buildIdToObject();

    this.instance = this.createInstance();
};

GameLib.D3.RenderTarget.prototype = Object.create(GameLib.D3.API.RenderTarget.prototype);
GameLib.D3.RenderTarget.prototype.constructor = GameLib.D3.RenderTarget;

/**
 * Some constants (based on THREE.js constants - update if needed)
 * @type {number}
 */
GameLib.D3.RenderTarget.LINEAR_FILTER   = 1006;
GameLib.D3.RenderTarget.RGB_FORMAT      = 1022;
GameLib.D3.RenderTarget.RGBA_FORMAT     = 1023;

/**
 * Creates a Render Target instance
 * @param update
 * @returns {*}
 */
GameLib.D3.RenderTarget.prototype.createInstance = function(update) {

    var instance = null;

    if (update) {
        instance = this.instance;
        instance.width = this.width;
        instance.height = this.height;
        instance.minFilter = this.minFilter;
        instance.magFilter = this.magFilter;
        instance.format = this.format;
        instance.stencilBuffer = this.stencilBuffer;
        instance.texture = this.texture.instance;
        instance.texture.needsUpdate = true;
    } else {
        instance = new THREE.WebGLRenderTarget(
            this.width,
            this.height,
            {
                minFilter : this.minFilter,
                magFilter : this.magFilter,
                format : this.format,
                stencilBuffer : this.stencilBuffer
            }
        );

        if (this.texture instanceof GameLib.D3.Texture && this.texture.instance) {
            instance.texture = this.texture.instance;
        }
    }

    return instance;
};

/**
 * updates instance
 */
GameLib.D3.RenderTarget.prototype.updateInstance = function() {
    this.instance = this.createInstance(true);
};

/**
 * Render Target to API Render Target
 * @returns {GameLib.D3.API.RenderTarget}
 */
GameLib.D3.RenderTarget.prototype.toApiObject = function() {

    var apiRenderTarget = new GameLib.D3.API.RenderTarget(
        this.id,
        this.name,
        this.width,
        this.height,
        this.minFilter,
        this.magFilter,
        this.format,
        this.stencilBuffer,
        GameLib.Utils.IdOrNull(this.texture),
        GameLib.Utils.IdOrNull(this.parentEntity)
    );

    return apiRenderTarget;
};

/**
 *
 * @param graphics
 * @param objectComponent
 * @returns {GameLib.D3.RenderTarget}
 * @constructor
 */
GameLib.D3.RenderTarget.FromObjectComponent = function(graphics, objectComponent) {

    var apiRenderTarget = GameLib.D3.API.RenderTarget.FromObjectComponent(objectComponent);

    return new GameLib.D3.RenderTarget(
        graphics,
        apiRenderTarget
    );
};