regl-shape/lib/update-dash-texture.js

2D shape shader for regl

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.updateDashTextureAndGetLength = void 0;
const dashMult = 2;
const defaultDashData = new Uint8Array(8).fill(255);
function updateDashTextureAndGetLength(texture, dashes) {
    let dashLength = 0;
    let dashData = null;
    if (dashes.length < 2) {
        dashLength = 1;
        dashData = defaultDashData;
    }
    else {
        dashLength = 0;
        for (let i = 0; i < dashes.length; ++i) {
            dashLength += dashes[i];
        }
        dashData = new Uint8Array(dashLength * dashMult);
        let ptr = 0;
        let fillColor = 255;
        // repeat texture two times to provide smooth 0-step
        for (let k = 0; k < 2; k++) {
            for (let i = 0; i < dashes.length; ++i) {
                for (let j = 0, l = dashes[i] * dashMult * 0.5; j < l; ++j) {
                    dashData[ptr++] = fillColor;
                }
                fillColor ^= 255;
            }
        }
    }
    texture({
        channels: 1,
        data: dashData,
        width: dashData.length,
        height: 1,
        mag: "linear",
        min: "linear",
    });
    return dashLength;
}
exports.updateDashTextureAndGetLength = updateDashTextureAndGetLength;