/**
 * Color represented by RGB (0.0-1.0) components
 */
export type Color = {
  r: number;
  g: number;
  b: number;
};

/**
 * Displayable character, with background and foreground color taken from the palette
 */
export type Char = {
  ch: string;
  bg: number;
  fg: number;
};

/**
 * Display protocol, to allow the UI to draw things on "screen"
 */
export interface Display {
  /**
   * Setup the palette for color display
   *
   * If the display supports the whole RGB range, it may return the array as-is.
   * If the display only supports a limited palette, it may return only supported colors.
   *
   * From this call forward, colors will be received by numbered index in the returned array.
   */
  setupPalette(colors: readonly Color[]): Promise<readonly Color[]>;

  /**
   * Clear the whole screen
   */
  clear(): Promise<void>;
}