getVerticesFromExtremes(shape, light){
    const { position: center, vertices } = shape;
    const { position } = light;

    // Construct a vector pointing from the light to the object.
    const axis = new Vector(center.x - position.x, center.y - position.y); 

    // Compute offsets to center the light in this axis-oriented coordinates system.
    const onShift = position.x * axis.x + position.y * axis.y;
    const offShift = position.x * axis.y - position.y * axis.x;

    let minSlope = Infinity;
    let maxSlope = -Infinity;
 
    let minIndex = 0;
    let maxIndex = 0;

    vertices.forEach((vertex, index) => {
      // Put this vertex into a light-centered coordinate system.
      // First, measuring its (scaled) distance in front of the light:
      const onAxis = vertex.x * axis.x + vertex.y * axis.y - onShift;

      // Skip vertices behind / in the plane of the light.
      if (onAxis <= 0) continue;

      // Then measuring its (scaled) offset above or below the line through
      // the center of this object.
      const offAxis = vertex.x * axis.y - vertex.y * axis.x - offShift;

      // Compute the slope of the line from the light to the vertex.
      const slope = offAxis / onAxis;
      
      if (slope < minSlope) {
          minSlope = slope;
          minIndex = index;
      }

      if (slope > maxSlope) {
          maxSlope = slope;
          maxIndex = index;
      }
    });

    if(minIndex > maxIndex) return {
      min: maxIndex,
      max: minIndex
    }

    return {
      min: minIndex,
      max: maxIndex
    }
  }

  getVerticesFromExtremes(shape, light) {
    const { center, vertices } = shape;
    const { position } = light;

    // Construct a vector pointing from the light to the object.
    const axis = new Vector(center.x - position.x, center.y - position.y); 

    // Compute offsets to center the light in this axis-oriented coordinates system.
    const onShift = position.x * axis.x + position.y * axis.y;
    const offShift = position.x * axis.y - position.y * axis.x;

    let minSlope = Infinity;
    let maxSlope = -Infinity;
 
    let minIndex = 0;
    let maxIndex = 0;

    for(let index = 0; index < vertices.length; index++){
      const vertex = {
        x: vertices[index].x + center.x,
        y: vertices[index].y + center.y
      };

      // Add the shape's global position to the vertex

      // Put this vertex into a light-centered coordinate system.
      // First, measuring its (scaled) distance in front of the light:
      const onAxis = vertex.x * axis.x + vertex.y * axis.y - onShift;

      // Skip vertices behind / in the plane of the light.
      if (onAxis <= 0) return;

      // Then measuring its (scaled) offset above or below the line through
      // the center of this object.
      const offAxis = vertex.x * axis.y - vertex.y * axis.x - offShift;

      // Compute the slope of the line from the light to the vertex.
      const slope = offAxis / onAxis;
      
      if (slope < minSlope) {
          minSlope = slope;
          minIndex = index;
      }

      if (slope > maxSlope) {
          maxSlope = slope;
          maxIndex = index;
      }
    }

    if(minIndex > maxIndex) return {
      min: maxIndex,
      max: minIndex
    }

    return {
      min: minIndex,
      max: maxIndex
    }
  }