Function getNormal

engine/src/VertexBridge.js:92–104

(x0, y0, x1, y1)

    }

    function getNormal(x0, y0, x1, y1) {
      let direction = getDirection(x0, y0, x1, y1);
      let normalizedVector = vec2.normalize(vec2.create(), direction);
      let perpVector = vec2.rotate(vec2.create(), normalizedVector, vec2.create(), Math.PI/2);
      let offsetVector = perpVector; // vec2.scale(vec2.create(), perpVector, normalDistance);
      let normalX = -1 * offsetVector[0];
      let normalY = offsetVector[1];

      return {
        x: normalX,
        y: normalY
      };
    }

    for (let n=0; n<numEdges; n++) {
      let pointIndex0 = edges[n].from;