@smoud/tiny/src/textures/RenderTexture3.js

Fast and tiny JavaScript library for HTML5 game and playable ads creation.

import { FrameBuffer } from '../renderers/webgl/utils/FrameBuffer';
import { BaseTexture } from './BaseTexture';
import { Texture } from './Texture';
import { CanvasBuffer } from '../utils/CanvasBuffer';
import { Rectangle } from '../math/shapes/Rectangle';
import { Vec2 } from '../math/Vec2';

/**
 * @author Mat Groves http://matgroves.com/ @Doormat23
 */

/**
 * A RenderTexture is a special texture that allows any Pixi display object to be rendered to it.
 *
 * __Hint__: All DisplayObjects (i.e. Sprites) that render to a RenderTexture should be preloaded otherwise black rectangles will be drawn instead.
 *
 * A RenderTexture takes a snapshot of any Display Object given to its render method. The position and rotation of the given Display Objects is ignored. For example:
 *
 *    var renderTexture = new RenderTexture(800, 600);
 *    var sprite = PIXI.Sprite.fromImage("spinObj_01.png");
 *    sprite.position.x = 800/2;
 *    sprite.position.y = 600/2;
 *    sprite.anchor.x = 0.5;
 *    sprite.anchor.y = 0.5;
 *    renderTexture.render(sprite);
 *
 * The Sprite in this case will be rendered to a position of 0,0. To render this sprite at its actual position a DisplayObjectContainer should be used:
 *
 *    var doc = new PIXI.DisplayObjectContainer();
 *    doc.addChild(sprite);
 *    renderTexture.render(doc);  // Renders to center of renderTexture
 *
 * @class RenderTexture
 * @extends Texture
 * @constructor
 * @param width {Number} The width of the render texture
 * @param height {Number} The height of the render texture
 * @param renderer {CanvasRenderer|WebGLRenderer} The renderer used for this RenderTexture
 * @param resolution {Number} The resolution of the texture being generated
 * @param scaleMode {Number} See {{#crossLink "PIXI/scaleModes:property"}}PIXI.scaleModes{{/crossLink}} for possible values
 */
var RenderTexture = function (width, height, renderer, resolution, scaleMode) {
    /**
     * The with of the render texture
     *
     * @property width
     * @type Number
     */
    this.width = width || 100;

    /**
     * The height of the render texture
     *
     * @property height
     * @type Number
     */
    this.height = height || 100;

    /**
     * The Resolution of the texture.
     *
     * @property resolution
     * @type Number
     */
    resolution = resolution || 1;

    /**
     * The framing rectangle of the render texture
     *
     * @property frame
     * @type Rectangle
     */
    // this.frame = new Rectangle(0, 0, this.width * resolution, this.height * resolution);

    /**
     * This is the area of the BaseTexture image to actually copy to the Canvas / WebGL when rendering,
     * irrespective of the actual frame size or placement (which can be influenced by trimmed texture atlases)
     *
     * @property crop
     * @type Rectangle
     */
    // this.crop = new Rectangle(0, 0, this.width * resolution, this.height * resolution);

    var multResolution = Math.max(1, resolution);

    /**
     * The base texture object that this texture uses
     *
     * @property base
     * @type BaseTexture
     */
    var baseTexture = new BaseTexture();
    baseTexture.width = this.width * multResolution;
    baseTexture.height = this.height * multResolution;
    // baseTexture._glTextures = [];
    baseTexture.resolution = resolution;

    baseTexture.scaleMode = scaleMode || 0;

    baseTexture.valid = true;

    window.rt = this;

    /**
     * The renderer this RenderTexture uses. A RenderTexture can only belong to one renderer at the moment if its webGL.
     *
     * @property renderer
     * @type CanvasRenderer|WebGLRenderer
     */
    this.renderer = renderer || Tiny.defaultRenderer;

    if (this.renderer.gl) {
        var gl = this.renderer.gl;
        baseTexture._dirty[gl.id] = false;

        this.textureBuffer = new FrameBuffer(
            gl,
            this.width * resolution,
            this.height * resolution,
            baseTexture.scaleMode
        );
        baseTexture._glTextures[gl.id] = this.textureBuffer.texture;

        this.projection = new Vec2(this.width * multResolution * 0.5, -this.height * multResolution * 0.5);
    } else {
        this.render = this.renderCanvas;
        this.textureBuffer = new CanvasBuffer(this.width * resolution, this.height * resolution);
        baseTexture.source = this.textureBuffer.canvas;
    }

    Texture.call(
        this,
        baseTexture,
        new Rectangle(0, 0, Math.floor(this.width * resolution), Math.floor(this.height * resolution))
    );

    // this.resolution = resolution;

    /**
     * @property valid
     * @type Boolean
     */
    this.valid = true;

    this._updateUvs();
};

RenderTexture.prototype = Object.create(Texture.prototype);
RenderTexture.prototype.constructor = RenderTexture;

/**
 * Resizes the RenderTexture.
 *
 * @method resize
 * @param width {Number} The width to resize to.
 * @param height {Number} The height to resize to.
 * @param updateBase {Boolean} Should the base.width and height values be resized as well?
 */
RenderTexture.prototype.resize = function (width, height, updateBase) {
    if (width === this.width && height === this.height) return;

    this.valid = width > 0 && height > 0;

    this.width = width;
    this.height = height;

    this.frame.width = this.crop.width = width * this.base.resolution;
    this.frame.height = this.crop.height = height * this.base.resolution;

    if (updateBase) {
        this.base.width = this.width * this.base.resolution;
        this.base.height = this.height * this.base.resolution;
    }

    if (this.renderer.gl) {
        this.projection.x = this.width / 2;
        this.projection.y = -this.height / 2;
    }

    if (!this.valid) return;

    this.textureBuffer.resize(this.width, this.height);
};

/**
 * Clears the RenderTexture.
 *
 * @method clear
 */
RenderTexture.prototype.clear = function () {
    if (!this.valid) return;

    if (this.renderer.gl) {
        this.renderer.gl.bindFramebuffer(this.renderer.gl.FRAMEBUFFER, this.textureBuffer.frameBuffer);
    }

    this.textureBuffer.clear();
};

/**
 * This function will draw the display object to the texture.
 *
 * @method render
 * @param displayObject {DisplayObject} The display object to render this texture on
 * @param [matrix] {Matrix} Optional matrix to apply to the display object before rendering.
 * @param [clear] {Boolean} If true the texture will be cleared before the displayObject is drawn
 * @private
 */
RenderTexture.prototype.render = function (displayObject, matrix, clear) {
    if (!this.valid) return;
    //TOOD replace position with matrix..

    //Lets create a nice matrix to apply to our display object. Frame buffers come in upside down so we need to flip the matrix
    var wt = displayObject.worldTransform;
    wt.identity();
    wt.translate(0, this.projection.y * 2);
    if (matrix) wt.append(matrix);
    wt.scale(1, -1);

    // setWorld Alpha to ensure that the object is renderer at full opacity
    displayObject.worldAlpha = 1;

    // Time to update all the children of the displayObject with the new matrix..
    var children = displayObject.children;

    for (var i = 0, j = children.length; i < j; i++) {
        children[i].updateTransform();
    }

    // time for the webGL fun stuff!
    var gl = this.renderer.gl;

    gl.viewport(0, 0, this.width * this.base.resolution, this.height * this.base.resolution);

    gl.bindFramebuffer(gl.FRAMEBUFFER, this.textureBuffer.frameBuffer);

    if (clear) this.textureBuffer.clear();

    this.renderer.spriteBatch.dirty = true;

    var realResolution = this.renderer.resolution;
    this.renderer.resolution = this.base.resolution;
    this.renderer.renderObject(displayObject, this.projection, this.textureBuffer.frameBuffer);
    this.renderer.resolution = realResolution;

    this.renderer.spriteBatch.dirty = true;

    wt.identity();
};

/**
 * Will return a HTML Image of the texture
 *
 * @method getImage
 * @return {Image}
 */
RenderTexture.prototype.getImage = function () {
    var image = new Image();
    image.src = this.getBase64();
    return image;
};

/**
 * Will return a a base64 encoded string of this texture. It works by calling RenderTexture.getCanvas and then running toDataURL on that.
 *
 * @method getBase64
 * @return {String} A base64 encoded string of the texture.
 */
RenderTexture.prototype.getBase64 = function () {
    return this.getCanvas().toDataURL();
};

/**
 * Creates a Canvas element, renders this RenderTexture to it and then returns it.
 *
 * @method getCanvas
 * @return {HTMLCanvasElement} A Canvas element with the texture rendered on.
 */
RenderTexture.prototype.getCanvas = function () {
    if (this.renderer.gl) {
        var gl = this.renderer.gl;
        var width = this.textureBuffer.width;
        var height = this.textureBuffer.height;

        var webGLPixels = new Uint8Array(4 * width * height);

        gl.bindFramebuffer(gl.FRAMEBUFFER, this.textureBuffer.frameBuffer);
        gl.readPixels(0, 0, width, height, gl.RGBA, gl.UNSIGNED_BYTE, webGLPixels);
        gl.bindFramebuffer(gl.FRAMEBUFFER, null);

        var tempCanvas = new CanvasBuffer(width, height);
        var canvasData = tempCanvas.context.getImageData(0, 0, width, height);
        canvasData.data.set(webGLPixels);

        tempCanvas.context.putImageData(canvasData, 0, 0);

        return tempCanvas.canvas;
    } else {
        return this.textureBuffer.canvas;
    }
};

export { RenderTexture };