maplibre-gl
Version:
BSD licensed community fork of mapbox-gl, a WebGL interactive maps library
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text/typescript
/*
* Generates the following:
* - data/array_types.js, which consists of:
* - StructArrayLayout_* subclasses, one for each underlying memory layout we need
* - Named exports mapping each conceptual array type (e.g., CircleLayoutArray) to its corresponding StructArrayLayout class
* - Particular, named StructArray subclasses, when fancy struct accessors are needed (e.g. CollisionBoxArray)
*/
;
import * as fs from 'fs';
import * as util from '../src/util/util';
import {createLayout, viewTypes} from '../src/util/struct_array';
import type {ViewType, StructArrayLayout} from '../src/util/struct_array';
import posAttributes from '../src/data/pos_attributes';
import pos3dAttributes from '../src/data/pos3d_attributes';
import rasterBoundsAttributes from '../src/data/raster_bounds_attributes';
import circleAttributes from '../src/data/bucket/circle_attributes';
import fillAttributes from '../src/data/bucket/fill_attributes';
import fillExtrusionAttributes from '../src/data/bucket/fill_extrusion_attributes';
import {lineLayoutAttributes} from '../src/data/bucket/line_attributes';
import {lineLayoutAttributesExt} from '../src/data/bucket/line_attributes_ext';
import {patternAttributes} from '../src/data/bucket/pattern_attributes';
// symbol layer specific arrays
import {
symbolLayoutAttributes,
dynamicLayoutAttributes,
placementOpacityAttributes,
collisionBox,
collisionBoxLayout,
collisionCircleLayout,
collisionVertexAttributes,
quadTriangle,
placement,
symbolInstance,
glyphOffset,
lineVertex,
textAnchorOffset
} from '../src/data/bucket/symbol_attributes';
const typeAbbreviations = {
'Int8': 'b',
'Uint8': 'ub',
'Int16': 'i',
'Uint16': 'ui',
'Int32': 'l',
'Uint32': 'ul',
'Float32': 'f'
};
const arraysWithStructAccessors = [];
const arrayTypeEntries = new Set();
const layoutCache = {};
function normalizeMembers(members, usedTypes) {
return members.map((member) => {
if (usedTypes && !usedTypes.has(member.type)) {
usedTypes.add(member.type);
}
return util.extend(member, {
size: sizeOf(member.type),
view: member.type.toLowerCase()
});
});
}
// - If necessary, write the StructArrayLayout_* class for the given layout
// - If `includeStructAccessors`, write the fancy subclass
// - Add an entry for `name` in the array type registry
function createStructArrayType(name: string, layout: StructArrayLayout, includeStructAccessors: boolean = false) {
const hasAnchorPoint = layout.members.some(m => m.name === 'anchorPointX');
// create the underlying StructArrayLayout class exists
const layoutClass = createStructArrayLayoutType(layout);
const arrayClass = `${camelize(name)}Array`;
if (includeStructAccessors) {
const usedTypes = new Set(['Uint8']);
const members = normalizeMembers(layout.members, usedTypes);
arraysWithStructAccessors.push({
arrayClass,
members,
size: layout.size,
usedTypes,
hasAnchorPoint,
layoutClass,
includeStructAccessors
});
} else {
arrayTypeEntries.add(`export class ${arrayClass} extends ${layoutClass} {}`);
}
}
function createStructArrayLayoutType({members, size, alignment}) {
const usedTypes = new Set(['Uint8']);
members = normalizeMembers(members, usedTypes);
// combine consecutive 'members' with same underlying type, summing their
// component counts
if (!alignment || alignment === 1) members = members.reduce((memo, member) => {
if (memo.length > 0 && memo[memo.length - 1].type === member.type) {
const last = memo[memo.length - 1];
return memo.slice(0, -1).concat(util.extend({}, last, {
components: last.components + member.components,
}));
}
return memo.concat(member);
}, []);
const key = `${members.map(m => `${m.components}${typeAbbreviations[m.type]}`).join('')}${size}`;
const className = `StructArrayLayout${key}`;
if (!layoutCache[key]) {
layoutCache[key] = {
className,
members,
size,
usedTypes
};
}
return className;
}
function sizeOf(type: ViewType): number {
return viewTypes[type].BYTES_PER_ELEMENT;
}
function camelize (str) {
return str.replace(/(?:^|[-_])(.)/g, (_, x) => {
return /^[0-9]$/.test(x) ? _ : x.toUpperCase();
});
}
createStructArrayType('pos', posAttributes);
createStructArrayType('pos3d', pos3dAttributes);
createStructArrayType('raster_bounds', rasterBoundsAttributes);
// layout vertex arrays
const layoutAttributes = {
circle: circleAttributes,
fill: fillAttributes,
'fill-extrusion': fillExtrusionAttributes,
heatmap: circleAttributes,
line: lineLayoutAttributes,
lineExt: lineLayoutAttributesExt,
pattern: patternAttributes
};
for (const name in layoutAttributes) {
createStructArrayType(`${name.replace(/-/g, '_')}_layout`, layoutAttributes[name]);
}
createStructArrayType('symbol_layout', symbolLayoutAttributes);
createStructArrayType('symbol_dynamic_layout', dynamicLayoutAttributes);
createStructArrayType('symbol_opacity', placementOpacityAttributes);
createStructArrayType('collision_box', collisionBox, true);
createStructArrayType('collision_box_layout', collisionBoxLayout);
createStructArrayType('collision_circle_layout', collisionCircleLayout);
createStructArrayType('collision_vertex', collisionVertexAttributes);
createStructArrayType('quad_triangle', quadTriangle);
createStructArrayType('placed_symbol', placement, true);
createStructArrayType('symbol_instance', symbolInstance, true);
createStructArrayType('glyph_offset', glyphOffset, true);
createStructArrayType('symbol_line_vertex', lineVertex, true);
createStructArrayType('text_anchor_offset', textAnchorOffset, true);
// feature index array
createStructArrayType('feature_index', createLayout([
// the index of the feature in the original vectortile
{type: 'Uint32', name: 'featureIndex'},
// the source layer the feature appears in
{type: 'Uint16', name: 'sourceLayerIndex'},
// the bucket the feature appears in
{type: 'Uint16', name: 'bucketIndex'}
]), true);
// triangle index array
createStructArrayType('triangle_index', createLayout([
{type: 'Uint16', name: 'vertices', components: 3}
]));
// line index array
createStructArrayType('line_index', createLayout([
{type: 'Uint16', name: 'vertices', components: 2}
]));
// line strip index array
createStructArrayType('line_strip_index', createLayout([
{type: 'Uint16', name: 'vertices', components: 1}
]));
// paint vertex arrays
// used by SourceBinder for float properties
createStructArrayLayoutType(createLayout([{
name: 'dummy name (unused for StructArrayLayout)',
type: 'Float32',
components: 1
}], 4));
// used by SourceBinder for color properties and CompositeBinder for float properties
createStructArrayLayoutType(createLayout([{
name: 'dummy name (unused for StructArrayLayout)',
type: 'Float32',
components: 2
}], 4));
// used by CompositeBinder for color properties
createStructArrayLayoutType(createLayout([{
name: 'dummy name (unused for StructArrayLayout)',
type: 'Float32',
components: 4
}], 4));
const layouts = Object.keys(layoutCache).map(k => layoutCache[k]);
function emitStructArrayLayout(locals) {
const output = [];
const {
className,
members,
size,
usedTypes
} = locals;
const structArrayLayoutClass = className;
output.push(
`/**
* @internal
* Implementation of the StructArray layout:`);
for (const member of members) {
output.push(
` * [${member.offset}] - ${member.type}[${member.components}]`);
}
output.push(
` *
*/
class ${structArrayLayoutClass} extends StructArray {`);
for (const type of usedTypes) {
output.push(
` ${type.toLowerCase()}: ${type}Array;`);
}
output.push(`
_refreshViews() {`);
for (const type of usedTypes) {
output.push(
` this.${type.toLowerCase()} = new ${type}Array(this.arrayBuffer);`);
}
output.push(
' }');
// prep for emplaceBack: collect type sizes and count the number of arguments
// we'll need
const bytesPerElement = size;
const usedTypeSizes = [];
const argNames = [];
const argNamesTyped = [];
for (const member of members) {
if (usedTypeSizes.indexOf(member.size) < 0) {
usedTypeSizes.push(member.size);
}
for (let c = 0; c < member.components; c++) {
// arguments v0, v1, v2, ... are, in order, the components of
// member 0, then the components of member 1, etc.
const name = `v${argNames.length}`;
argNames.push(name);
argNamesTyped.push(`${name}: number`);
}
}
output.push(
`
public emplaceBack(${argNamesTyped.join(', ')}) {
const i = this.length;
this.resize(i + 1);
return this.emplace(i, ${argNames.join(', ')});
}
public emplace(i: number, ${argNamesTyped.join(', ')}) {`);
for (const size of usedTypeSizes) {
output.push(
` const o${size.toFixed(0)} = i * ${(bytesPerElement / size).toFixed(0)};`);
}
let argIndex = 0;
for (const member of members) {
for (let c = 0; c < member.components; c++) {
// The index for `member` component `c` into the appropriate type array is:
// this.{TYPE}[o{SIZE} + MEMBER_OFFSET + {c}] = v{X}
// where MEMBER_OFFSET = ROUND(member.offset / size) is the per-element
// offset of this member into the array
const index = `o${member.size.toFixed(0)} + ${(member.offset / member.size + c).toFixed(0)}`;
output.push(
` this.${member.view}[${index}] = v${argIndex++};`);
}
}
output.push(
` return i;
}
}
${structArrayLayoutClass}.prototype.bytesPerElement = ${size};
register('${structArrayLayoutClass}', ${structArrayLayoutClass});
`);
return output.join('\n');
}
function emitStructArray(locals) {
const output = [];
const {
arrayClass,
members,
size,
hasAnchorPoint,
layoutClass,
includeStructAccessors
} = locals;
const structTypeClass = arrayClass.replace('Array', 'Struct');
const structArrayClass = arrayClass;
const structArrayLayoutClass = layoutClass;
// collect components
const components = [];
for (const member of members) {
for (let c = 0; c < member.components; c++) {
let name = member.name;
if (member.components > 1) {
name += c;
}
components.push({name, member, component: c});
}
}
// exceptions for which we generate accessors on the array rather than a separate struct for performance
const useComponentGetters = structArrayClass === 'GlyphOffsetArray' || structArrayClass === 'SymbolLineVertexArray';
if (includeStructAccessors && !useComponentGetters) {
output.push(
`/** @internal */
class ${structTypeClass} extends Struct {
_structArray: ${structArrayClass};`);
for (const {name, member, component} of components) {
const elementOffset = `this._pos${member.size.toFixed(0)}`;
const componentOffset = (member.offset / member.size + component).toFixed(0);
const index = `${elementOffset} + ${componentOffset}`;
const componentAccess = `this._structArray.${member.view}[${index}]`;
output.push(
` get ${name}() { return ${componentAccess}; }`);
// generate setters for properties that are updated during runtime symbol placement; others are read-only
if (name === 'crossTileID' || name === 'placedOrientation' || name === 'hidden') {
output.push(
` set ${name}(x: number) { ${componentAccess} = x; }`);
}
}
// Special case used for the CollisionBoxArray type
if (hasAnchorPoint) {
output.push(
' get anchorPoint() { return new Point(this.anchorPointX, this.anchorPointY); }');
}
output.push(
`}
${structTypeClass}.prototype.size = ${size};
export type ${structTypeClass.replace('Struct', '')} = ${structTypeClass};
`);
} // end 'if (includeStructAccessors)'
output.push(
`/** @internal */
export class ${structArrayClass} extends ${structArrayLayoutClass} {`);
if (useComponentGetters) {
for (const member of members) {
for (let c = 0; c < member.components; c++) {
if (!includeStructAccessors) continue;
let name = `get${member.name}`;
if (member.components > 1) {
name += c;
}
const componentOffset = (member.offset / member.size + c).toFixed(0);
const componentStride = size / member.size;
output.push(
` ${name}(index: number) { return this.${member.view}[index * ${componentStride} + ${componentOffset}]; }`);
}
}
} else if (includeStructAccessors) { // get(i)
output.push(
` /**
* Return the ${structTypeClass} at the given location in the array.
* @param index The index of the element.
*/
get(index: number): ${structTypeClass} {
return new ${structTypeClass}(this, index);
}`);
}
output.push(
`}
register('${structArrayClass}', ${structArrayClass});
`);
return output.join('\n');
}
fs.writeFileSync('src/data/array_types.g.ts',
`// This file is generated. Edit build/generate-struct-arrays.ts, then run \`npm run codegen\`.
import {Struct, StructArray} from '../util/struct_array';
import {register} from '../util/web_worker_transfer';
import Point from '@mapbox/point-geometry';
${layouts.map(emitStructArrayLayout).join('\n')}
${arraysWithStructAccessors.map(emitStructArray).join('\n')}
${[...arrayTypeEntries].join('\n')}
export {
${layouts.map(layout => layout.className).join(',\n ')}
};
`);