Method _addCap

src/webgl/p5.Geometry.js:1560–1572

* Adds the vertices and vertex attributes for two triangles representing the * stroke cap of a line. A fragment shader is responsible for displaying the * appropriate cap style within the rectangle they make. * * The lineSides buffer will include the following values for the points on

(point, tangent, color)

   * @chainable
   */
  _addCap(point, tangent, color) {
    const ptArray = point.array();
    const tanInArray = tangent.array();
    const tanOutArray = [0, 0, 0];
    for (let i = 0; i < 6; i++) {
      this.lineVertices.push(...ptArray);
      this.lineTangentsIn.push(...tanInArray);
      this.lineTangentsOut.push(...tanOutArray);
      this.lineVertexColors.push(...color);
    }
    this.lineSides.push(-1, 2, -2, 1, 2, -1);
    return this;
  }

  /**
   * Adds the vertices and vertex attributes for four triangles representing a