Source: packages/core/src/framebuffer/Framebuffer.js

import { Runner } from '@pixi/runner';
import { BaseTexture } from '../textures/BaseTexture';
import { DepthResource } from '../textures/resources/DepthResource';
import { FORMATS, MIPMAP_MODES, SCALE_MODES, TYPES, MSAA_QUALITY } from '@pixi/constants';
/**
 * Frame buffer used by the BaseRenderTexture
 *
 * @class
 * @memberof PIXI
 */
export class Framebuffer {
    /**
     * @param {number} width - Width of the frame buffer
     * @param {number} height - Height of the frame buffer
     */
    constructor(width, height) {
        /**
         * Width of framebuffer in pixels
         * @member {number}
         */
        this.width = Math.ceil(width || 100);
        /**
         * Height of framebuffer in pixels
         * @member {number}
         */
        this.height = Math.ceil(height || 100);
        this.stencil = false;
        this.depth = false;
        this.dirtyId = 0;
        this.dirtyFormat = 0;
        this.dirtySize = 0;
        this.depthTexture = null;
        this.colorTextures = [];
        this.glFramebuffers = {};
        this.disposeRunner = new Runner('disposeFramebuffer');
        /**
         * Desired number of samples for antialiasing. 0 means AA should not be used.
         *
         * Experimental WebGL2 feature, allows to use antialiasing in individual renderTextures.
         * Antialiasing is the same as for main buffer with renderer `antialias:true` options.
         * Seriously affects GPU memory consumption and GPU performance.
         *
         *```js
         * renderTexture.framebuffer.multisample = PIXI.MSAA_QUALITY.HIGH;
         * //...
         * renderer.render(renderTexture, myContainer);
         * renderer.framebuffer.blit(); // copies data from MSAA framebuffer to texture
         *  ```
         *
         * @member {PIXI.MSAA_QUALITY}
         * @default PIXI.MSAA_QUALITY.NONE
         */
        this.multisample = MSAA_QUALITY.NONE;
    }
    /**
     * Reference to the colorTexture.
     *
     * @member {PIXI.BaseTexture[]}
     * @readonly
     */
    get colorTexture() {
        return this.colorTextures[0];
    }
    /**
     * Add texture to the colorTexture array
     *
     * @param {number} [index=0] - Index of the array to add the texture to
     * @param {PIXI.BaseTexture} [texture] - Texture to add to the array
     */
    addColorTexture(index = 0, texture) {
        // TODO add some validation to the texture - same width / height etc?
        this.colorTextures[index] = texture || new BaseTexture(null, {
            scaleMode: SCALE_MODES.NEAREST,
            resolution: 1,
            mipmap: MIPMAP_MODES.OFF,
            width: this.width,
            height: this.height,
        });
        this.dirtyId++;
        this.dirtyFormat++;
        return this;
    }
    /**
     * Add a depth texture to the frame buffer
     *
     * @param {PIXI.BaseTexture} [texture] - Texture to add
     */
    addDepthTexture(texture) {
        /* eslint-disable max-len */
        this.depthTexture = texture || new BaseTexture(new DepthResource(null, { width: this.width, height: this.height }), {
            scaleMode: SCALE_MODES.NEAREST,
            resolution: 1,
            width: this.width,
            height: this.height,
            mipmap: MIPMAP_MODES.OFF,
            format: FORMATS.DEPTH_COMPONENT,
            type: TYPES.UNSIGNED_SHORT,
        });
        this.dirtyId++;
        this.dirtyFormat++;
        return this;
    }
    /**
     * Enable depth on the frame buffer
     */
    enableDepth() {
        this.depth = true;
        this.dirtyId++;
        this.dirtyFormat++;
        return this;
    }
    /**
     * Enable stencil on the frame buffer
     */
    enableStencil() {
        this.stencil = true;
        this.dirtyId++;
        this.dirtyFormat++;
        return this;
    }
    /**
     * Resize the frame buffer
     *
     * @param {number} width - Width of the frame buffer to resize to
     * @param {number} height - Height of the frame buffer to resize to
     */
    resize(width, height) {
        width = Math.ceil(width);
        height = Math.ceil(height);
        if (width === this.width && height === this.height)
            return;
        this.width = width;
        this.height = height;
        this.dirtyId++;
        this.dirtySize++;
        for (let i = 0; i < this.colorTextures.length; i++) {
            const texture = this.colorTextures[i];
            const resolution = texture.resolution;
            // take into acount the fact the texture may have a different resolution..
            texture.setSize(width / resolution, height / resolution);
        }
        if (this.depthTexture) {
            const resolution = this.depthTexture.resolution;
            this.depthTexture.setSize(width / resolution, height / resolution);
        }
    }
    /**
     * Disposes WebGL resources that are connected to this geometry
     */
    dispose() {
        this.disposeRunner.emit(this, false);
    }
    /**
     * Destroys and removes the depth texture added to this framebuffer.
     */
    destroyDepthTexture() {
        if (this.depthTexture) {
            this.depthTexture.destroy();
            this.depthTexture = null;
            ++this.dirtyId;
            ++this.dirtyFormat;
        }
    }
}