uintshapegenerator.js

/**
 * Variable Bit-Depth Generator
 * @param {string} shape - 'lorenz', 'thomas', 'noise'
 * @param {number} depth - 8, 16, 32
 * @param {num} number of points
 * @param {littleEndian} true or false
 */
function uintShapeGenerator(shape, depth, num, littleEndian ) {
    const compSize = depth / 8;
    const buf = new ArrayBuffer(num * compSize * 3);
    const v = new DataView(buf);
    
    const writeMethod = depth === 32 ? 'setUint32' : depth === 16 ? 'setUint16' : 'setUint8';
    const maxVal = depth === 32 ? 4294967295 : depth === 16 ? 65535 : 255;
    
    let x=0.1, y=0, z=0;

    for(let i=0; i<num; i++) {
        if (shape === 'lorenz') {
            let dx=10*(y-x), dy=x*(28-z)-y, dz=x*y-(8/3)*z;
            x+=dx*0.005; y+=dy*0.005; z+=dz*0.005;
            // Map to [0, 1] then to Max range
            const nx = (x+25)/50, ny = (y+30)/60, nz = z/50;
            v[writeMethod](i*compSize*3, nx * maxVal, littleEndian);
            v[writeMethod](i*compSize*3 + compSize, ny * maxVal, littleEndian);
            v[writeMethod](i*compSize*3 + compSize*2, nz * maxVal, littleEndian);
        } else if (shape === 'thomas') {
            const b=0.208186;
            let dx=Math.sin(y)-b*x, dy=Math.sin(z)-b*y, dz=Math.sin(x)-b*z;
            x+=dx*0.05; y+=dy*0.05; z+=dz*0.05;
            v[writeMethod](i*compSize*3, ((x+2.5)/5) * maxVal, littleEndian);
            v[writeMethod](i*compSize*3 + compSize, ((y+2.5)/5) * maxVal, littleEndian);
            v[writeMethod](i*compSize*3 + compSize*2, ((z+2.5)/5) * maxVal, littleEndian);
        } else {
            v[writeMethod](i*compSize*3, Math.random() * maxVal, littleEndian);
            v[writeMethod](i*compSize*3 + compSize, Math.random() * maxVal, littleEndian);
            v[writeMethod](i*compSize*3 + compSize*2, Math.random() * maxVal, littleEndian);
        }
    }
    return buf;
}