Files
openlayers/src/ol/layer/WebGLTile.js

528 lines
17 KiB
JavaScript

/**
* @module ol/layer/WebGLTile
*/
import BaseTileLayer from './BaseTile.js';
import LayerProperty from '../layer/Property.js';
import SourceState from '../source/State.js';
import WebGLTileLayerRenderer, {
Attributes,
Uniforms,
} from '../renderer/webgl/TileLayer.js';
import {
PALETTE_TEXTURE_ARRAY,
ValueTypes,
expressionToGlsl,
getStringNumberEquivalent,
uniformNameForVariable,
} from '../style/expressions.js';
import {assign} from '../obj.js';
/**
* @typedef {import("../source/DataTile.js").default|import("../source/TileImage.js").default} SourceType
*/
/**
* @typedef {Object} Style
* Translates tile data to rendered pixels.
*
* @property {Object<string, (string|number)>} [variables] Style variables. Each variable must hold a number or string. These
* variables can be used in the `color`, `brightness`, `contrast`, `exposure`, `saturation` and `gamma`
* {@link import("../style/expressions.js").ExpressionValue expressions}, using the `['var', 'varName']` operator.
* To update style variables, use the {@link import("./WebGLTile.js").default#updateStyleVariables} method.
* @property {import("../style/expressions.js").ExpressionValue} [color] An expression applied to color values.
* @property {import("../style/expressions.js").ExpressionValue} [brightness=0] Value used to decrease or increase
* the layer brightness. Values range from -1 to 1.
* @property {import("../style/expressions.js").ExpressionValue} [contrast=0] Value used to decrease or increase
* the layer contrast. Values range from -1 to 1.
* @property {import("../style/expressions.js").ExpressionValue} [exposure=0] Value used to decrease or increase
* the layer exposure. Values range from -1 to 1.
* @property {import("../style/expressions.js").ExpressionValue} [saturation=0] Value used to decrease or increase
* the layer saturation. Values range from -1 to 1.
* @property {import("../style/expressions.js").ExpressionValue} [gamma=1] Apply a gamma correction to the layer.
* Values range from 0 to infinity.
*/
/**
* @typedef {Object} Options
* @property {Style} [style] Style to apply to the layer.
* @property {string} [className='ol-layer'] A CSS class name to set to the layer element.
* @property {number} [opacity=1] Opacity (0, 1).
* @property {boolean} [visible=true] Visibility.
* @property {import("../extent.js").Extent} [extent] The bounding extent for layer rendering. The layer will not be
* rendered outside of this extent.
* @property {number} [zIndex] The z-index for layer rendering. At rendering time, the layers
* will be ordered, first by Z-index and then by position. When `undefined`, a `zIndex` of 0 is assumed
* for layers that are added to the map's `layers` collection, or `Infinity` when the layer's `setMap()`
* method was used.
* @property {number} [minResolution] The minimum resolution (inclusive) at which this layer will be
* visible.
* @property {number} [maxResolution] The maximum resolution (exclusive) below which this layer will
* be visible.
* @property {number} [minZoom] The minimum view zoom level (exclusive) above which this layer will be
* visible.
* @property {number} [maxZoom] The maximum view zoom level (inclusive) at which this layer will
* be visible.
* @property {number} [preload=0] Preload. Load low-resolution tiles up to `preload` levels. `0`
* means no preloading.
* @property {SourceType} [source] Source for this layer.
* @property {Array<SourceType>|function(import("../extent.js").Extent, number):Array<SourceType>} [sources] Array
* of sources for this layer. Takes precedence over `source`. Can either be an array of sources, or a function that
* expects an extent and a resolution (in view projection units per pixel) and returns an array of sources. See
* {@link module:ol/source.sourcesFromTileGrid} for a helper function to generate sources that are organized in a
* pyramid following the same pattern as a tile grid. **Note:** All sources must have the same band count and content.
* @property {import("../PluggableMap.js").default} [map] Sets the layer as overlay on a map. The map will not manage
* this layer in its layers collection, and the layer will be rendered on top. This is useful for
* temporary layers. The standard way to add a layer to a map and have it managed by the map is to
* use {@link module:ol/Map~Map#addLayer}.
* @property {boolean} [useInterimTilesOnError=true] Use interim tiles on error.
* @property {number} [cacheSize=512] The internal texture cache size. This needs to be large enough to render
* two zoom levels worth of tiles.
*/
/**
* @typedef {Object} ParsedStyle
* @property {string} vertexShader The vertex shader.
* @property {string} fragmentShader The fragment shader.
* @property {Object<string,import("../webgl/Helper.js").UniformValue>} uniforms Uniform definitions.
* @property {Array<import("../webgl/PaletteTexture.js").default>} paletteTextures Palette textures.
*/
/**
* @param {Style} style The layer style.
* @param {number} [bandCount] The number of bands.
* @return {ParsedStyle} Shaders and uniforms generated from the style.
*/
function parseStyle(style, bandCount) {
const vertexShader = `
attribute vec2 ${Attributes.TEXTURE_COORD};
uniform mat4 ${Uniforms.TILE_TRANSFORM};
uniform float ${Uniforms.TEXTURE_PIXEL_WIDTH};
uniform float ${Uniforms.TEXTURE_PIXEL_HEIGHT};
uniform float ${Uniforms.TEXTURE_RESOLUTION};
uniform float ${Uniforms.TEXTURE_ORIGIN_X};
uniform float ${Uniforms.TEXTURE_ORIGIN_Y};
uniform float ${Uniforms.DEPTH};
varying vec2 v_textureCoord;
varying vec2 v_mapCoord;
void main() {
v_textureCoord = ${Attributes.TEXTURE_COORD};
v_mapCoord = vec2(
${Uniforms.TEXTURE_ORIGIN_X} + ${Uniforms.TEXTURE_RESOLUTION} * ${Uniforms.TEXTURE_PIXEL_WIDTH} * v_textureCoord[0],
${Uniforms.TEXTURE_ORIGIN_Y} - ${Uniforms.TEXTURE_RESOLUTION} * ${Uniforms.TEXTURE_PIXEL_HEIGHT} * v_textureCoord[1]
);
gl_Position = ${Uniforms.TILE_TRANSFORM} * vec4(${Attributes.TEXTURE_COORD}, ${Uniforms.DEPTH}, 1.0);
}
`;
/**
* @type {import("../style/expressions.js").ParsingContext}
*/
const context = {
inFragmentShader: true,
variables: [],
attributes: [],
stringLiteralsMap: {},
functions: {},
bandCount: bandCount,
};
const pipeline = [];
if (style.color !== undefined) {
const color = expressionToGlsl(context, style.color, ValueTypes.COLOR);
pipeline.push(`color = ${color};`);
}
if (style.contrast !== undefined) {
const contrast = expressionToGlsl(
context,
style.contrast,
ValueTypes.NUMBER
);
pipeline.push(
`color.rgb = clamp((${contrast} + 1.0) * color.rgb - (${contrast} / 2.0), vec3(0.0, 0.0, 0.0), vec3(1.0, 1.0, 1.0));`
);
}
if (style.exposure !== undefined) {
const exposure = expressionToGlsl(
context,
style.exposure,
ValueTypes.NUMBER
);
pipeline.push(
`color.rgb = clamp((${exposure} + 1.0) * color.rgb, vec3(0.0, 0.0, 0.0), vec3(1.0, 1.0, 1.0));`
);
}
if (style.saturation !== undefined) {
const saturation = expressionToGlsl(
context,
style.saturation,
ValueTypes.NUMBER
);
pipeline.push(`
float saturation = ${saturation} + 1.0;
float sr = (1.0 - saturation) * 0.2126;
float sg = (1.0 - saturation) * 0.7152;
float sb = (1.0 - saturation) * 0.0722;
mat3 saturationMatrix = mat3(
sr + saturation, sr, sr,
sg, sg + saturation, sg,
sb, sb, sb + saturation
);
color.rgb = clamp(saturationMatrix * color.rgb, vec3(0.0, 0.0, 0.0), vec3(1.0, 1.0, 1.0));
`);
}
if (style.gamma !== undefined) {
const gamma = expressionToGlsl(context, style.gamma, ValueTypes.NUMBER);
pipeline.push(`color.rgb = pow(color.rgb, vec3(1.0 / ${gamma}));`);
}
if (style.brightness !== undefined) {
const brightness = expressionToGlsl(
context,
style.brightness,
ValueTypes.NUMBER
);
pipeline.push(
`color.rgb = clamp(color.rgb + ${brightness}, vec3(0.0, 0.0, 0.0), vec3(1.0, 1.0, 1.0));`
);
}
/** @type {Object<string,import("../webgl/Helper").UniformValue>} */
const uniforms = {};
const numVariables = context.variables.length;
if (numVariables > 1 && !style.variables) {
throw new Error(
`Missing variables in style (expected ${context.variables})`
);
}
for (let i = 0; i < numVariables; ++i) {
const variableName = context.variables[i];
if (!(variableName in style.variables)) {
throw new Error(`Missing '${variableName}' in style variables`);
}
const uniformName = uniformNameForVariable(variableName);
uniforms[uniformName] = function () {
let value = style.variables[variableName];
if (typeof value === 'string') {
value = getStringNumberEquivalent(context, value);
}
return value !== undefined ? value : -9999999; // to avoid matching with the first string literal
};
}
const uniformDeclarations = Object.keys(uniforms).map(function (name) {
return `uniform float ${name};`;
});
const textureCount = Math.ceil(bandCount / 4);
uniformDeclarations.push(
`uniform sampler2D ${Uniforms.TILE_TEXTURE_ARRAY}[${textureCount}];`
);
if (context.paletteTextures) {
uniformDeclarations.push(
`uniform sampler2D ${PALETTE_TEXTURE_ARRAY}[${context.paletteTextures.length}];`
);
}
const functionDefintions = Object.keys(context.functions).map(function (
name
) {
return context.functions[name];
});
const fragmentShader = `
#ifdef GL_FRAGMENT_PRECISION_HIGH
precision highp float;
#else
precision mediump float;
#endif
varying vec2 v_textureCoord;
varying vec2 v_mapCoord;
uniform vec4 ${Uniforms.RENDER_EXTENT};
uniform float ${Uniforms.TRANSITION_ALPHA};
uniform float ${Uniforms.TEXTURE_PIXEL_WIDTH};
uniform float ${Uniforms.TEXTURE_PIXEL_HEIGHT};
uniform float ${Uniforms.RESOLUTION};
uniform float ${Uniforms.ZOOM};
${uniformDeclarations.join('\n')}
${functionDefintions.join('\n')}
void main() {
if (
v_mapCoord[0] < ${Uniforms.RENDER_EXTENT}[0] ||
v_mapCoord[1] < ${Uniforms.RENDER_EXTENT}[1] ||
v_mapCoord[0] > ${Uniforms.RENDER_EXTENT}[2] ||
v_mapCoord[1] > ${Uniforms.RENDER_EXTENT}[3]
) {
discard;
}
vec4 color = texture2D(${
Uniforms.TILE_TEXTURE_ARRAY
}[0], v_textureCoord);
${pipeline.join('\n')}
if (color.a == 0.0) {
discard;
}
gl_FragColor = color;
gl_FragColor.rgb *= gl_FragColor.a;
gl_FragColor *= ${Uniforms.TRANSITION_ALPHA};
}`;
return {
vertexShader: vertexShader,
fragmentShader: fragmentShader,
uniforms: uniforms,
paletteTextures: context.paletteTextures,
};
}
/**
* @classdesc
* For layer sources that provide pre-rendered, tiled images in grids that are
* organized by zoom levels for specific resolutions.
* Note that any property set in the options is set as a {@link module:ol/Object~BaseObject}
* property on the layer object; for example, setting `title: 'My Title'` in the
* options means that `title` is observable, and has get/set accessors.
*
* @extends BaseTileLayer<SourceType, WebGLTileLayerRenderer>
* @fires import("../render/Event.js").RenderEvent
* @api
*/
class WebGLTileLayer extends BaseTileLayer {
/**
* @param {Options} opt_options Tile layer options.
*/
constructor(opt_options) {
const options = opt_options ? assign({}, opt_options) : {};
const style = options.style || {};
delete options.style;
const cacheSize = options.cacheSize;
delete options.cacheSize;
super(options);
/**
* @type {Array<SourceType>|function(import("../extent.js").Extent, number):Array<SourceType>}
* @private
*/
this.sources_ = options.sources;
/**
* @type {SourceType|null}
* @private
*/
this.renderedSource_ = null;
/**
* @type {number}
* @private
*/
this.renderedResolution_ = NaN;
/**
* @type {Style}
* @private
*/
this.style_ = style;
/**
* @type {number}
* @private
*/
this.cacheSize_ = cacheSize;
/**
* @type {Object<string, (string|number)>}
* @private
*/
this.styleVariables_ = this.style_.variables || {};
this.addChangeListener(LayerProperty.SOURCE, this.handleSourceUpdate_);
}
/**
* Gets the sources for this layer, for a given extent and resolution.
* @param {import("../extent.js").Extent} extent Extent.
* @param {number} resolution Resolution.
* @return {Array<SourceType>} Sources.
*/
getSources(extent, resolution) {
const source = this.getSource();
return this.sources_
? typeof this.sources_ === 'function'
? this.sources_(extent, resolution)
: this.sources_
: source
? [source]
: [];
}
/**
* @return {SourceType} The source being rendered.
*/
getRenderSource() {
return this.renderedSource_ || this.getSource();
}
/**
* @return {import("../source/State.js").default} Source state.
*/
getSourceState() {
const source = this.getRenderSource();
return source ? source.getState() : SourceState.UNDEFINED;
}
/**
* @private
*/
handleSourceUpdate_() {
if (this.getSource()) {
this.setStyle(this.style_);
}
}
/**
* @private
* @return {number} The number of source bands.
*/
getSourceBandCount_() {
const max = Number.MAX_SAFE_INTEGER;
const sources = this.getSources([-max, -max, max, max], max);
return sources && sources.length && 'bandCount' in sources[0]
? sources[0].bandCount
: 4;
}
createRenderer() {
const parsedStyle = parseStyle(this.style_, this.getSourceBandCount_());
return new WebGLTileLayerRenderer(this, {
vertexShader: parsedStyle.vertexShader,
fragmentShader: parsedStyle.fragmentShader,
uniforms: parsedStyle.uniforms,
cacheSize: this.cacheSize_,
paletteTextures: parsedStyle.paletteTextures,
});
}
/**
* @param {import("../PluggableMap").FrameState} frameState Frame state.
* @param {Array<SourceType>} sources Sources.
* @return {HTMLElement} Canvas.
*/
renderSources(frameState, sources) {
const layerRenderer = this.getRenderer();
let canvas;
for (let i = 0, ii = sources.length; i < ii; ++i) {
this.renderedSource_ = sources[i];
if (layerRenderer.prepareFrame(frameState)) {
canvas = layerRenderer.renderFrame(frameState);
}
}
return canvas;
}
/**
* @param {?import("../PluggableMap.js").FrameState} frameState Frame state.
* @param {HTMLElement} target Target which the renderer may (but need not) use
* for rendering its content.
* @return {HTMLElement} The rendered element.
*/
render(frameState, target) {
this.rendered = true;
const viewState = frameState.viewState;
const sources = this.getSources(frameState.extent, viewState.resolution);
let ready = true;
for (let i = 0, ii = sources.length; i < ii; ++i) {
const source = sources[i];
const sourceState = source.getState();
if (sourceState == SourceState.LOADING) {
const onChange = () => {
if (source.getState() == SourceState.READY) {
source.removeEventListener('change', onChange);
this.changed();
}
};
source.addEventListener('change', onChange);
}
ready = ready && sourceState == SourceState.READY;
}
const canvas = this.renderSources(frameState, sources);
if (this.getRenderer().renderComplete && ready) {
// Fully rendered, done.
this.renderedResolution_ = viewState.resolution;
return canvas;
}
// Render sources from previously fully rendered frames
if (this.renderedResolution_ > 0.5 * viewState.resolution) {
const altSources = this.getSources(
frameState.extent,
this.renderedResolution_
).filter((source) => !sources.includes(source));
if (altSources.length > 0) {
return this.renderSources(frameState, altSources);
}
}
return canvas;
}
/**
* Update the layer style. The `updateStyleVariables` function is a more efficient
* way to update layer rendering. In cases where the whole style needs to be updated,
* this method may be called instead. Note that calling this method will also replace
* any previously set variables, so the new style also needs to include new variables,
* if needed.
* @param {Style} style The new style.
*/
setStyle(style) {
this.styleVariables_ = style.variables || {};
this.style_ = style;
const parsedStyle = parseStyle(this.style_, this.getSourceBandCount_());
const renderer = this.getRenderer();
renderer.reset({
vertexShader: parsedStyle.vertexShader,
fragmentShader: parsedStyle.fragmentShader,
uniforms: parsedStyle.uniforms,
paletteTextures: parsedStyle.paletteTextures,
});
this.changed();
}
/**
* Update any variables used by the layer style and trigger a re-render.
* @param {Object<string, number>} variables Variables to update.
* @api
*/
updateStyleVariables(variables) {
assign(this.styleVariables_, variables);
this.changed();
}
}
/**
* Clean up underlying WebGL resources.
* @function
* @api
*/
WebGLTileLayer.prototype.dispose;
export default WebGLTileLayer;