Files
openlayers/src/ol/webgl/TileTexture.js
2022-04-08 14:17:22 +01:00

392 lines
11 KiB
JavaScript

/**
* @module ol/webgl/TileTexture
*/
import DataTile from '../DataTile.js';
import EventTarget from '../events/Target.js';
import EventType from '../events/EventType.js';
import ImageTile from '../ImageTile.js';
import ReprojTile from '../reproj/Tile.js';
import TileState from '../TileState.js';
import WebGLArrayBuffer from './Buffer.js';
import {ARRAY_BUFFER, STATIC_DRAW} from '../webgl.js';
import {toSize} from '../size.js';
/**
* @param {WebGLRenderingContext} gl The WebGL context.
* @param {WebGLTexture} texture The texture.
* @param {boolean} interpolate Interpolate when resampling.
*/
function bindAndConfigure(gl, texture, interpolate) {
const resampleFilter = interpolate ? gl.LINEAR : gl.NEAREST;
gl.bindTexture(gl.TEXTURE_2D, texture);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_S, gl.CLAMP_TO_EDGE);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_WRAP_T, gl.CLAMP_TO_EDGE);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, resampleFilter);
gl.texParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, resampleFilter);
}
/**
* @param {WebGLRenderingContext} gl The WebGL context.
* @param {WebGLTexture} texture The texture.
* @param {HTMLImageElement|HTMLCanvasElement|HTMLVideoElement} image The image.
* @param {boolean} interpolate Interpolate when resampling.
*/
function uploadImageTexture(gl, texture, image, interpolate) {
bindAndConfigure(gl, texture, interpolate);
gl.texImage2D(gl.TEXTURE_2D, 0, gl.RGBA, gl.RGBA, gl.UNSIGNED_BYTE, image);
}
/**
* @param {import("./Helper.js").default} helper The WebGL helper.
* @param {WebGLTexture} texture The texture.
* @param {import("../DataTile.js").Data} data The pixel data.
* @param {import("../size.js").Size} size The pixel size.
* @param {number} bandCount The band count.
* @param {boolean} interpolate Interpolate when resampling.
*/
function uploadDataTexture(
helper,
texture,
data,
size,
bandCount,
interpolate
) {
const gl = helper.getGL();
let textureType;
let canInterpolate;
if (data instanceof Float32Array) {
textureType = gl.FLOAT;
helper.getExtension('OES_texture_float');
const extension = helper.getExtension('OES_texture_float_linear');
canInterpolate = extension !== null;
} else {
textureType = gl.UNSIGNED_BYTE;
canInterpolate = true;
}
bindAndConfigure(gl, texture, interpolate && canInterpolate);
const bytesPerRow = data.byteLength / size[1];
let unpackAlignment = 1;
if (bytesPerRow % 8 === 0) {
unpackAlignment = 8;
} else if (bytesPerRow % 4 === 0) {
unpackAlignment = 4;
} else if (bytesPerRow % 2 === 0) {
unpackAlignment = 2;
}
let format;
switch (bandCount) {
case 1: {
format = gl.LUMINANCE;
break;
}
case 2: {
format = gl.LUMINANCE_ALPHA;
break;
}
case 3: {
format = gl.RGB;
break;
}
case 4: {
format = gl.RGBA;
break;
}
default: {
throw new Error(`Unsupported number of bands: ${bandCount}`);
}
}
const oldUnpackAlignment = gl.getParameter(gl.UNPACK_ALIGNMENT);
gl.pixelStorei(gl.UNPACK_ALIGNMENT, unpackAlignment);
gl.texImage2D(
gl.TEXTURE_2D,
0,
format,
size[0],
size[1],
0,
format,
textureType,
data
);
gl.pixelStorei(gl.UNPACK_ALIGNMENT, oldUnpackAlignment);
}
/**
* @type {CanvasRenderingContext2D}
*/
let pixelContext = null;
function createPixelContext() {
const canvas = document.createElement('canvas');
canvas.width = 1;
canvas.height = 1;
pixelContext = canvas.getContext('2d');
}
/**
* @typedef {import("../DataTile.js").default|ImageTile|ReprojTile} TileType
*/
/**
* @typedef {Object} Options
* @property {TileType} tile The tile.
* @property {import("../tilegrid/TileGrid.js").default} grid Tile grid.
* @property {import("../webgl/Helper.js").default} helper WebGL helper.
* @property {number} [tilePixelRatio=1] Tile pixel ratio.
* @property {number} [gutter=0] The size in pixels of the gutter around image tiles to ignore.
*/
class TileTexture extends EventTarget {
/**
* @param {Options} options The tile texture options.
*/
constructor(options) {
super();
/**
* @type {TileType}
*/
this.tile;
/**
* @type {Array<WebGLTexture>}
*/
this.textures = [];
this.handleTileChange_ = this.handleTileChange_.bind(this);
/**
* @type {import("../size.js").Size}
*/
this.size = toSize(options.grid.getTileSize(options.tile.tileCoord[0]));
/**
* @type {number}
* @private
*/
this.tilePixelRatio_ = options.tilePixelRatio || 1;
/**
* @type {number}
* @private
*/
this.gutter_ = options.gutter || 0;
/**
* @type {number}
*/
this.bandCount = NaN;
/**
* @type {import("../webgl/Helper.js").default}
* @private
*/
this.helper_ = options.helper;
const coords = new WebGLArrayBuffer(ARRAY_BUFFER, STATIC_DRAW);
coords.fromArray([
0, // P0
1,
1, // P1
1,
1, // P2
0,
0, // P3
0,
]);
this.helper_.flushBufferData(coords);
/**
* @type {WebGLArrayBuffer}
*/
this.coords = coords;
this.setTile(options.tile);
}
/**
* @param {TileType} tile Tile.
*/
setTile(tile) {
if (tile !== this.tile) {
if (this.tile) {
this.tile.removeEventListener(EventType.CHANGE, this.handleTileChange_);
}
this.tile = tile;
this.textures.length = 0;
this.loaded = tile.getState() === TileState.LOADED;
if (this.loaded) {
this.uploadTile_();
} else {
if (tile instanceof ImageTile) {
const image = tile.getImage();
if (image instanceof Image && !image.crossOrigin) {
image.crossOrigin = 'anonymous';
}
}
tile.addEventListener(EventType.CHANGE, this.handleTileChange_);
}
}
}
uploadTile_() {
const helper = this.helper_;
const gl = helper.getGL();
const tile = this.tile;
if (tile instanceof ImageTile || tile instanceof ReprojTile) {
const texture = gl.createTexture();
this.textures.push(texture);
this.bandCount = 4;
uploadImageTexture(gl, texture, tile.getImage(), tile.interpolate);
return;
}
const pixelSize = [
(this.size[0] + 2 * this.gutter_) * this.tilePixelRatio_,
(this.size[1] + 2 * this.gutter_) * this.tilePixelRatio_,
];
const data = tile.getData();
const isFloat = data instanceof Float32Array;
const pixelCount = pixelSize[0] * pixelSize[1];
const DataType = isFloat ? Float32Array : Uint8Array;
const bytesPerElement = DataType.BYTES_PER_ELEMENT;
const bytesPerRow = data.byteLength / pixelSize[1];
this.bandCount = Math.floor(bytesPerRow / bytesPerElement / pixelSize[0]);
const textureCount = Math.ceil(this.bandCount / 4);
if (textureCount === 1) {
const texture = gl.createTexture();
this.textures.push(texture);
uploadDataTexture(
helper,
texture,
data,
pixelSize,
this.bandCount,
tile.interpolate
);
return;
}
const textureDataArrays = new Array(textureCount);
for (let textureIndex = 0; textureIndex < textureCount; ++textureIndex) {
const texture = gl.createTexture();
this.textures.push(texture);
const bandCount =
textureIndex < textureCount - 1 ? 4 : this.bandCount % 4;
textureDataArrays[textureIndex] = new DataType(pixelCount * bandCount);
}
let dataIndex = 0;
let rowOffset = 0;
const colCount = pixelSize[0] * this.bandCount;
for (let rowIndex = 0; rowIndex < pixelSize[1]; ++rowIndex) {
for (let colIndex = 0; colIndex < colCount; ++colIndex) {
const dataValue = data[rowOffset + colIndex];
const pixelIndex = Math.floor(dataIndex / this.bandCount);
const bandIndex = colIndex % this.bandCount;
const textureIndex = Math.floor(bandIndex / 4);
const textureData = textureDataArrays[textureIndex];
const bandCount = textureData.length / pixelCount;
const textureBandIndex = bandIndex % 4;
textureData[pixelIndex * bandCount + textureBandIndex] = dataValue;
++dataIndex;
}
rowOffset += bytesPerRow / bytesPerElement;
}
for (let textureIndex = 0; textureIndex < textureCount; ++textureIndex) {
const texture = this.textures[textureIndex];
const textureData = textureDataArrays[textureIndex];
const bandCount = textureData.length / pixelCount;
uploadDataTexture(
helper,
texture,
textureData,
pixelSize,
bandCount,
tile.interpolate
);
}
}
handleTileChange_() {
if (this.tile.getState() === TileState.LOADED) {
this.loaded = true;
this.uploadTile_();
this.dispatchEvent(EventType.CHANGE);
}
}
disposeInternal() {
const gl = this.helper_.getGL();
this.helper_.deleteBuffer(this.coords);
for (let i = 0; i < this.textures.length; ++i) {
gl.deleteTexture(this.textures[i]);
}
this.tile.removeEventListener(EventType.CHANGE, this.handleTileChange_);
}
/**
* Get data for a pixel. If the tile is not loaded, null is returned.
* @param {number} col The column index.
* @param {number} row The row index.
* @return {import("../DataTile.js").Data|null} The data.
*/
getPixelData(col, row) {
if (!this.loaded) {
return null;
}
const gutter = Math.round(this.tilePixelRatio_ * this.gutter_);
col = Math.floor(this.tilePixelRatio_ * col) + gutter;
row = Math.floor(this.tilePixelRatio_ * row) + gutter;
if (this.tile instanceof DataTile) {
const data = this.tile.getData();
let size = this.size;
if (gutter > 0) {
size = [size[0] + 2 * this.gutter_, size[1] + 2 * this.gutter_];
}
const pixelsPerRow = Math.floor(this.tilePixelRatio_ * size[0]);
if (data instanceof DataView) {
const bytesPerPixel = data.byteLength / (size[0] * size[1]);
const offset = row * pixelsPerRow * bytesPerPixel + col * bytesPerPixel;
const buffer = data.buffer.slice(offset, offset + bytesPerPixel);
return new DataView(buffer);
}
const offset = row * pixelsPerRow * this.bandCount + col * this.bandCount;
return data.slice(offset, offset + this.bandCount);
}
if (!pixelContext) {
createPixelContext();
}
pixelContext.clearRect(0, 0, 1, 1);
let data;
const image = this.tile.getImage();
try {
pixelContext.drawImage(image, col, row, 1, 1, 0, 0, 1, 1);
data = pixelContext.getImageData(0, 0, 1, 1).data;
} catch (err) {
pixelContext = null;
return null;
}
return data;
}
}
export default TileTexture;