openjscad V2 rounded top

rounded_top.js

/**
 * Extrude rounded top From Slices
 * @description Demonstrating the advanced extrusion using slices to create rounded top
 * @tags extrude, slice, slices, extrudefromslices, callback
 * @authors Davor Hrg
 * @licence MIT License
 */


const { circle, square, roundedRectangle } = require('@jscad/modeling').primitives
const { translate } = require('@jscad/modeling').transforms
const { geom2 } = require('@jscad/modeling').geometries
const { extrudeFromSlices, slice } = require('@jscad/modeling').extrusions
const { mat4 } = require('@jscad/modeling').maths

const main = () => {
  // demonstrates manipulating the original base through translation and scale to build a 3D geometry
  const roundTop = (base, {height=4, r1=0.2, r1Percent=0, rx=0.1, ry=0, segments=1}) => {
    if(r1Percent) r1 = r1Percent * height;
    ry = ry || rx;
    // radius is for one side, and scale factor is for both
    rx = rx*2; 
    ry = ry*2;


    var numberOfSlices = 2 + segments;
    var step = 1/(numberOfSlices-1);
    var angleDelta = Math.PI / (segments) / 2 ;
    var angleDelta2 = 180 / (segments) / 2 ;
 

    var startH = height - r1;

    var baseSlice = slice.fromSides(geom2.toSides(base))

    return extrudeFromSlices({
      numberOfSlices,
      callback: (progress, counter, baseSlice) => {
        var h = progress * height;
        let scaleX = 1;
        let scaleY = 1;

        if(progress == 1){ // top slice (counter = numSlices-1)
          scaleX = 1 - rx;
          scaleY = 1 - ry;
        }else if(progress == step){ // first top slice (counter = 1)
          h = startH;
        }else if(progress > step){ // curve (counter = 2,3,4...)
          var angle = (counter -1) * angleDelta;
          h = height - r1 + (Math.sin(angle) * r1);
          scaleX = 1 - rx + (Math.cos(angle) * rx);
          scaleY = 1 - rx + (Math.cos(angle) * ry);
        }else{
          // bottom slice (counter = 0)
        }
        
        const scaleMatrix = mat4.fromScaling([scaleX, scaleY, 1])
        const transformMatrix = mat4.fromTranslation([0, 0, h])
        return slice.transform(mat4.multiply(scaleMatrix, transformMatrix), baseSlice)

      }
    }, baseSlice)
  }

  var circles = [3,5,8,32];
  var ret = [
    roundTop(square({size:4}), {height:4, r1Percent:0.2, rx:0.2, segments:1}),
    translate( [8,0,0],
      roundTop(roundedRectangle({size:[4,4], roundRadius:0.2*4, segments:4}), {height:4, r1Percent:0.2, rx:0.2, segments:1})
    )
  ];

  for(var j=0; j<circles.length; j++){
    for(var i=0; i<4; i++){
      ret.push(translate( [16+j*8,i*8,0],
          roundTop(circle({radius:2.5, segments:circles[j]}), {height:4, r1Percent:0.2, rx:0.2, segments:(i*2 || 1)})
        ));    
    }
  }
  for(var i=1; i<4; i++){
    ret.push(translate([0,i*8,0],
        roundTop(square({size:4}), {height:4, r1Percent:0.2, rx:0.2, segments:i*2})
      ));            
    ret.push(translate( [8,i*8,0],
        roundTop(roundedRectangle({size:[4,4], roundRadius:0.2*4, segments:i*2*4}), {height:4, r1Percent:0.2, rx:0.2, segments:i*2})
      ));
  }


  return ret;
}

module.exports = { main }