585 lines
17 KiB
JavaScript
585 lines
17 KiB
JavaScript
/**
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* @module ol/webgl/Helper
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*/
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import {getUid} from '../util.js';
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import {EXTENSIONS as WEBGL_EXTENSIONS} from '../webgl.js';
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import Disposable from '../Disposable.js';
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import {includes} from '../array.js';
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import {listen, unlistenAll} from '../events.js';
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import {clear} from '../obj.js';
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import {ARRAY_BUFFER, ELEMENT_ARRAY_BUFFER, TEXTURE_2D, TEXTURE_WRAP_S, TEXTURE_WRAP_T} from '../webgl.js';
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import ContextEventType from '../webgl/ContextEventType.js';
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import {
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create as createTransform,
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reset as resetTransform,
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rotate as rotateTransform,
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scale as scaleTransform,
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translate as translateTransform
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} from "../transform";
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import {create, fromTransform} from "../vec/mat4";
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import WebGLBuffer from "./Buffer";
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import WebGLVertex from "./Vertex";
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import WebGLFragment from "./Fragment";
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import WebGLPostProcessingPass from "./PostProcessingPass";
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/**
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* @typedef {Object} BufferCacheEntry
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* @property {import("./Buffer.js").default} buf
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* @property {WebGLBuffer} buffer
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*/
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export const DefaultUniform = {
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PROJECTION_MATRIX: 'u_projectionMatrix',
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OFFSET_SCALE_MATRIX: 'u_offsetScaleMatrix',
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OFFSET_ROTATION_MATRIX: 'u_offsetRotateMatrix',
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OPACITY: 'u_opacity'
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};
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export const DefaultAttrib = {
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POSITION: 'a_position',
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TEX_COORD: 'a_texCoord',
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OPACITY: 'a_opacity',
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ROTATE_WITH_VIEW: 'a_rotateWithView',
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OFFSETS: 'a_offsets'
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};
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/**
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* @classdesc
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* A WebGL context for accessing low-level WebGL capabilities.
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* Will handle attributes, uniforms, buffers, textures, frame buffers.
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* The context will always render to a frame buffer in order to allow post-processing.
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*/
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class WebGLHelper extends Disposable {
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/**
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*/
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constructor(opt_options) {
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super();
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const options = opt_options || {};
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/**
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* @private
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* @type {HTMLCanvasElement}
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*/
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this.canvas_ = document.createElement('canvas');
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this.canvas_.style.position = 'absolute';
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/**
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* @private
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* @type {WebGLRenderingContext}
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*/
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this.gl_ = this.canvas_.getContext('webgl');
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/**
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* @private
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* @type {!Object<string, BufferCacheEntry>}
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*/
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this.bufferCache_ = {};
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/**
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* @private
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* @type {!Object<string, WebGLShader>}
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*/
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this.shaderCache_ = {};
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/**
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* @private
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* @type {!Object<string, WebGLProgram>}
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*/
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this.programCache_ = {};
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/**
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* @private
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* @type {WebGLProgram}
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*/
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this.currentProgram_ = null;
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/**
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* @type {boolean}
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*/
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this.hasOESElementIndexUint = includes(WEBGL_EXTENSIONS, 'OES_element_index_uint');
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// use the OES_element_index_uint extension if available
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if (this.hasOESElementIndexUint) {
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this.gl_.getExtension('OES_element_index_uint');
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}
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listen(this.canvas_, ContextEventType.LOST,
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this.handleWebGLContextLost, this);
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listen(this.canvas_, ContextEventType.RESTORED,
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this.handleWebGLContextRestored, this);
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/**
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* @private
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* @type {import("../transform.js").Transform}
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*/
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this.projectionMatrix_ = createTransform();
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/**
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* @private
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* @type {import("../transform.js").Transform}
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*/
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this.offsetRotateMatrix_ = createTransform();
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/**
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* @private
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* @type {import("../transform.js").Transform}
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*/
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this.offsetScaleMatrix_ = createTransform();
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/**
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* @private
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* @type {Array<number>}
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*/
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this.tmpMat4_ = create();
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/**
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* @private
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* @type {Object.<string, WebGLUniformLocation>}
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*/
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this.uniformLocations_;
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/**
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* @private
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* @type {Object.<string, number>}
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*/
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this.attribLocations_;
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/**
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* Holds info about custom uniforms used in the post processing pass
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* @type {Array<{value: *, texture?: WebGLTexture}>}
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* @private
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*/
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this.uniforms_ = [];
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options.uniforms && Object.keys(options.uniforms).forEach(function(name) {
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this.uniforms_.push({
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name: name,
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value: options.uniforms[name]
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});
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}.bind(this));
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// initialize post processes from options
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// if none given, use a default one
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const gl = this.getGL();
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this.postProcessPasses = options.postProcesses ? options.postProcesses.map(function(options) {
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return new WebGLPostProcessingPass({
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webGlContext: gl,
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scaleRatio: options.scaleRatio,
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vertexShader: options.vertexShader,
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fragmentShader: options.fragmentShader,
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uniforms: options.uniforms
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});
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}) : [new WebGLPostProcessingPass({ webGlContext: gl })];
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}
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/**
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* Just bind the buffer if it's in the cache. Otherwise create
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* the WebGL buffer, bind it, populate it, and add an entry to
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* the cache.
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* TODO: improve this, the logic is unclear: we want A/ to bind a buffer and B/ to flush data in it
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* @param {number} target Target.
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* @param {WebGLBuffer} buf Buffer.
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*/
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bindBuffer(target, buf) {
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const gl = this.getGL();
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const arr = buf.getArray();
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const bufferKey = getUid(buf);
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let bufferCache = this.bufferCache_[bufferKey];
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if (!bufferCache) {
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const buffer = gl.createBuffer();
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bufferCache = this.bufferCache_[bufferKey] = {
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buf: buf,
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buffer: buffer
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};
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}
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gl.bindBuffer(target, bufferCache.buffer);
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let /** @type {ArrayBufferView} */ arrayBuffer;
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if (target == ARRAY_BUFFER) {
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arrayBuffer = new Float32Array(arr);
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} else if (target == ELEMENT_ARRAY_BUFFER) {
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arrayBuffer = this.hasOESElementIndexUint ?
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new Uint32Array(arr) : new Uint16Array(arr);
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}
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gl.bufferData(target, arrayBuffer, buf.getUsage());
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}
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/**
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* @param {import("./Buffer.js").default} buf Buffer.
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*/
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deleteBuffer(buf) {
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const gl = this.getGL();
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const bufferKey = getUid(buf);
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const bufferCacheEntry = this.bufferCache_[bufferKey];
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if (!gl.isContextLost()) {
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gl.deleteBuffer(bufferCacheEntry.buffer);
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}
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delete this.bufferCache_[bufferKey];
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}
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/**
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* @inheritDoc
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*/
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disposeInternal() {
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unlistenAll(this.canvas_);
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const gl = this.getGL();
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if (!gl.isContextLost()) {
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for (const key in this.bufferCache_) {
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gl.deleteBuffer(this.bufferCache_[key].buffer);
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}
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for (const key in this.programCache_) {
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gl.deleteProgram(this.programCache_[key]);
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}
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for (const key in this.shaderCache_) {
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gl.deleteShader(this.shaderCache_[key]);
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}
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}
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}
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/**
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* Clear the buffer & set the viewport to draw
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*/
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prepareDraw(frameState) {
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const gl = this.getGL();
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const canvas = this.getCanvas();
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const size = frameState.size;
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const pixelRatio = frameState.pixelRatio;
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canvas.width = size[0] * pixelRatio;
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canvas.height = size[1] * pixelRatio;
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canvas.style.width = size[0] + 'px';
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canvas.style.height = size[1] + 'px';
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gl.useProgram(this.currentProgram_);
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// loop backwards in post processes list
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for (let i = this.postProcessPasses.length - 1; i >= 0; i--) {
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this.postProcessPasses[i].init(size, pixelRatio);
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}
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gl.bindTexture(gl.TEXTURE_2D, null);
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gl.clearColor(0.0, 0.0, 0.0, 0.0);
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gl.clear(gl.COLOR_BUFFER_BIT);
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gl.enable(gl.BLEND);
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gl.blendFunc(gl.ONE, gl.ONE_MINUS_SRC_ALPHA);
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this.applyFrameState(frameState)
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this.applyUniforms(frameState);
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}
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/**
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* @protected
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* @param {number} start Start index.
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* @param {number} end End index.
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*/
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drawElements(start, end) {
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const gl = this.getGL();
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const elementType = this.hasOESElementIndexUint ?
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gl.UNSIGNED_INT : gl.UNSIGNED_SHORT;
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const elementSize = this.hasOESElementIndexUint ? 4 : 2;
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const numItems = end - start;
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const offsetInBytes = start * elementSize;
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gl.drawElements(gl.TRIANGLES, numItems, elementType, offsetInBytes);
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}
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/**
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* Copy the frame buffer to the canvas
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*/
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finalizeDraw() {
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// apply post processes using the next one as target
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for (let i = 0; i < this.postProcessPasses.length; i++) {
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this.postProcessPasses[i].apply(this.postProcessPasses[i + 1] || null);
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}
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}
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/**
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* @return {HTMLCanvasElement} Canvas.
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*/
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getCanvas() {
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return this.canvas_;
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}
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/**
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* Get the WebGL rendering context
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* @return {WebGLRenderingContext} The rendering context.
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* @api
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*/
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getGL() {
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return this.gl_;
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}
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/**
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* Sets the matrices uniforms for a given frame state
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* @param {import("../PluggableMap.js").FrameState} frameState Frame state.
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*/
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applyFrameState(frameState) {
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const size = frameState.size;
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const rotation = frameState.viewState.rotation;
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const resolution = frameState.viewState.resolution;
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const center = frameState.viewState.center;
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// set the "uniform" values (coordinates 0,0 are the center of the view)
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const projectionMatrix = resetTransform(this.projectionMatrix_);
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scaleTransform(projectionMatrix, 2 / (resolution * size[0]), 2 / (resolution * size[1]));
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rotateTransform(projectionMatrix, -rotation);
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translateTransform(projectionMatrix, -center[0], -center[1]);
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const offsetScaleMatrix = resetTransform(this.offsetScaleMatrix_);
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scaleTransform(offsetScaleMatrix, 2 / size[0], 2 / size[1]);
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const offsetRotateMatrix = resetTransform(this.offsetRotateMatrix_);
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if (rotation !== 0) {
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rotateTransform(offsetRotateMatrix, -rotation);
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}
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this.setUniformMatrixValue(DefaultUniform.PROJECTION_MATRIX, fromTransform(this.tmpMat4_, projectionMatrix));
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this.setUniformMatrixValue(DefaultUniform.OFFSET_SCALE_MATRIX, fromTransform(this.tmpMat4_, offsetScaleMatrix));
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this.setUniformMatrixValue(DefaultUniform.OFFSET_ROTATION_MATRIX, fromTransform(this.tmpMat4_, offsetRotateMatrix));
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}
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// todo
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applyUniforms(frameState) {
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const gl = this.getGL();
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let value;
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let textureSlot = 0;
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this.uniforms_.forEach(function(uniform) {
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value = typeof uniform.value === 'function' ? uniform.value(frameState) : uniform.value;
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// apply value based on type
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if (value instanceof HTMLCanvasElement || value instanceof ImageData) {
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// create a texture & put data
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if (!uniform.texture) {
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uniform.texture = gl.createTexture();
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}
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gl.activeTexture(gl[`TEXTURE${textureSlot}`]);
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gl.bindTexture(gl.TEXTURE_2D, uniform.texture);
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gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.LINEAR);
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gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.CLAMP_TO_EDGE);
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gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.CLAMP_TO_EDGE);
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if (value instanceof ImageData) {
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gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGBA, gl.RGBA, value.width, value.height, 0,
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gl.UNSIGNED_BYTE, new Uint8Array(value.data));
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} else {
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gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGBA, gl.RGBA, gl.UNSIGNED_BYTE, value);
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}
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// fill texture slots
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gl.uniform1i(this.getUniformLocation(uniform.name), textureSlot++);
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} else if (Array.isArray(value)) {
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switch (value.length) {
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case 2:
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gl.uniform2f(this.getUniformLocation(uniform.name), value[0], value[1]);
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return;
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case 3:
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gl.uniform3f(this.getUniformLocation(uniform.name), value[0], value[1], value[2]);
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return;
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case 4:
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gl.uniform4f(this.getUniformLocation(uniform.name), value[0], value[1], value[2], value[3]);
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return;
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}
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} else if (typeof value === 'number') {
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gl.uniform1f(this.getUniformLocation(uniform.name), value);
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}
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}.bind(this));
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}
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/**
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* Get shader from the cache if it's in the cache. Otherwise, create
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* the WebGL shader, compile it, and add entry to cache.
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* @param {import("./Shader.js").default} shaderObject Shader object.
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* @return {WebGLShader} Shader.
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*/
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getShader(shaderObject) {
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const shaderKey = getUid(shaderObject);
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if (shaderKey in this.shaderCache_) {
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return this.shaderCache_[shaderKey];
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} else {
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const gl = this.getGL();
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const shader = gl.createShader(shaderObject.getType());
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gl.shaderSource(shader, shaderObject.getSource());
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gl.compileShader(shader);
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if (!gl.getShaderParameter(shader, gl.COMPILE_STATUS)) {
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console.error(`Shader compilation failed - log:\n${gl.getShaderInfoLog(shader)}`);
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}
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this.shaderCache_[shaderKey] = shader;
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return shader;
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}
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}
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/**
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* Use a program. If the program is already in use, this will return `false`.
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* @param {WebGLProgram} program Program.
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* @return {boolean} Changed.
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* @api
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*/
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useProgram(program) {
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if (program == this.currentProgram_) {
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return false;
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} else {
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const gl = this.getGL();
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gl.useProgram(program);
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this.currentProgram_ = program;
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this.uniformLocations_ = {};
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this.attribLocations_ = {};
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return true;
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}
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}
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/**
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* Get the program from the cache if it's in the cache. Otherwise create
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* the WebGL program, attach the shaders to it, and add an entry to the
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* cache.
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* @param {import("./Fragment.js").default} fragmentShaderObject Fragment shader.
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* @param {import("./Vertex.js").default} vertexShaderObject Vertex shader.
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* @return {WebGLProgram} Program.
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*/
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getProgram(fragmentShaderObject, vertexShaderObject) {
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const programKey = getUid(fragmentShaderObject) + '/' + getUid(vertexShaderObject);
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if (programKey in this.programCache_) {
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return this.programCache_[programKey];
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} else {
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const gl = this.getGL();
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const program = gl.createProgram();
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gl.attachShader(program, this.getShader(fragmentShaderObject));
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gl.attachShader(program, this.getShader(vertexShaderObject));
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gl.linkProgram(program);
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this.programCache_[programKey] = program;
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return program;
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}
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}
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/**
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* Will get the location from the shader or the cache
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* @param {string} name Uniform name
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* @return {WebGLUniformLocation} uniformLocation
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*/
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getUniformLocation(name) {
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if (!this.uniformLocations_[name]) {
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this.uniformLocations_[name] = this.getGL().getUniformLocation(this.currentProgram_, name);
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}
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return this.uniformLocations_[name];
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}
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/**
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* Will get the location from the shader or the cache
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* @param {string} name Attribute name
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* @return {number} attribLocation
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*/
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getAttributeLocation(name) {
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if (!this.attribLocations_[name]) {
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this.attribLocations_[name] = this.getGL().getAttribLocation(this.currentProgram_, name);
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}
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return this.attribLocations_[name];
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}
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/**
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* Give a value for a standard float uniform
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* @param {string} uniform Uniform name
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* @param {number} value Value
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*/
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setUniformFloatValue(uniform, value) {
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this.getGL().uniform1f(this.getUniformLocation(uniform), value);
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}
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/**
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* Give a value for a standard matrix4 uniform
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* @param {string} uniform Uniform name
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* @param {Array<number>} value Matrix value
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*/
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setUniformMatrixValue(uniform, value) {
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this.getGL().uniformMatrix4fv(this.getUniformLocation(uniform), false, value);
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}
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/**
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* Will set the currently bound buffer to an attribute of the shader program
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* @param {string} attribName
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* @param {number} size Number of components per attributes
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* @param {number} type UNSIGNED_INT, UNSIGNED_BYTE, UNSIGNED_SHORT or FLOAT
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* @param {number} stride Stride in bytes (0 means attribs are packed)
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* @param {number} offset Offset in bytes
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*/
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enableAttributeArray(attribName, size, type, stride, offset) {
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this.getGL().enableVertexAttribArray(this.getAttributeLocation(attribName));
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this.getGL().vertexAttribPointer(this.getAttributeLocation(attribName), size, type,
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false, stride, offset);
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}
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/**
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* FIXME empty description for jsdoc
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*/
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handleWebGLContextLost() {
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clear(this.bufferCache_);
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clear(this.shaderCache_);
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clear(this.programCache_);
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this.currentProgram_ = null;
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}
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/**
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* FIXME empty description for jsdoc
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*/
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handleWebGLContextRestored() {
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}
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// TODO: shutdown program
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/**
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* @param {number=} opt_wrapS wrapS.
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* @param {number=} opt_wrapT wrapT.
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* @return {WebGLTexture} The texture.
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*/
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createTextureInternal(opt_wrapS, opt_wrapT) {
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const gl = this.getGL();
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const texture = gl.createTexture();
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gl.bindTexture(gl.TEXTURE_2D, texture);
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gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.LINEAR);
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gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.LINEAR);
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if (opt_wrapS !== undefined) {
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gl.texParameteri(
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TEXTURE_2D, TEXTURE_WRAP_S, opt_wrapS);
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}
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if (opt_wrapT !== undefined) {
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gl.texParameteri(
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TEXTURE_2D, TEXTURE_WRAP_T, opt_wrapT);
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}
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return texture;
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}
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/**
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* @param {number} width Width.
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* @param {number} height Height.
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* @param {number=} opt_wrapS wrapS.
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* @param {number=} opt_wrapT wrapT.
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* @return {WebGLTexture} The texture.
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|
*/
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createEmptyTexture(width, height, opt_wrapS, opt_wrapT) {
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const gl = this.getGL();
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const texture = this.createTextureInternal( opt_wrapS, opt_wrapT);
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gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGBA, width, height, 0, gl.RGBA, gl.UNSIGNED_BYTE, null);
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return texture;
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|
}
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/**
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* @param {HTMLCanvasElement|HTMLImageElement|HTMLVideoElement} image Image.
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|
* @param {number=} opt_wrapS wrapS.
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|
* @param {number=} opt_wrapT wrapT.
|
|
* @return {WebGLTexture} The texture.
|
|
*/
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createTexture(image, opt_wrapS, opt_wrapT) {
|
|
const gl = this.getGL();
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const texture = this.createTextureInternal(opt_wrapS, opt_wrapT);
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gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGBA, gl.RGBA, gl.UNSIGNED_BYTE, image);
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|
return texture;
|
|
}
|
|
}
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export default WebGLHelper;
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