LedStrip.swift

//===----------------------------------------------------------------------===//
//
// This source file is part of the Swift open source project
//
// Copyright (c) 2023 Apple Inc. and the Swift project authors.
// Licensed under Apache License v2.0 with Runtime Library Exception
//
// See https://swift.org/LICENSE.txt for license information
//
//===----------------------------------------------------------------------===//

// A simple "overlay" to provide nicer APIs in Swift
struct LedStrip {
  private let handle: led_strip_handle_t

  init(gpioPin: Int, maxLeds: Int) {
    var handle = led_strip_handle_t(bitPattern: 0)
    var stripConfig = led_strip_config_t(
      strip_gpio_num: Int32(gpioPin),
      max_leds: UInt32(maxLeds),
      led_pixel_format: LED_PIXEL_FORMAT_GRB,
      led_model: LED_MODEL_WS2812,
      flags: .init(invert_out: 0)
    )
    var spiConfig = led_strip_spi_config_t(
      clk_src: SPI_CLK_SRC_DEFAULT,
      spi_bus: SPI2_HOST,
      flags: .init(with_dma: 1)
    )
    guard led_strip_new_spi_device(&stripConfig, &spiConfig, &handle) == ESP_OK,
      let handle = handle
    else { fatalError("cannot configure spi device") }
    self.handle = handle
  }

  struct Color {
    static var white = Color(r: 255, g: 255, b: 255)
    static var lightWhite = Color(r: 16, g: 16, b: 16)
    static var lightRandom: Color {
      Color(
        r: .random(in: 0...16), g: .random(in: 0...16), b: .random(in: 0...16))
    }
    static var off = Color(r: 0, g: 0, b: 0)

    var r, g, b: UInt8
  }

  func setPixel(index: Int, color: Color) {
    led_strip_set_pixel(
      handle, UInt32(index), UInt32(color.r), UInt32(color.g), UInt32(color.b))
  }

  func refresh() { led_strip_refresh(handle) }

  func clear() { led_strip_clear(handle) }
}