@orca-fe/x-map/esm/defs.js

import { mat4, vec3 } from 'gl-matrix';
import { MercatorMax } from './utils/coord';
export const SVG_OFFSET_TOP = -1000;
/* 512 的 viewport 映射到 墨卡托坐标系 */
export const matrixWebMercator = mat4.create();
// WebMercatorViewport 的尺寸是512，需要用512对墨卡托尺寸计算缩放比例
export const mercatorScale = 512 / MercatorMax / 2;
// 偏移中心位置
mat4.translate(matrixWebMercator, matrixWebMercator, vec3.fromValues(256, 256, 0));
// 将矩阵乘以缩放值，变成墨卡托矩阵
mat4.scale(matrixWebMercator, matrixWebMercator, vec3.fromValues(mercatorScale, mercatorScale, mercatorScale));
// // 偏移到墨卡托中心
// mat4.translate(matrixWebMercator, matrixWebMercator, vec3.fromValues(mercatorCenter[0], mercatorCenter[1], 0));