capabilities.hpp

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#pragma once
 
#include "epaper/drivers/driver.hpp"
#include <concepts>
#include <cstddef>
 
namespace epaper {
 
template <typename Driver> struct driver_traits;
// Base template is empty/undefined to force specialization
// Or we can leave it undefined so it fails instantiation if not specialized.
 
template <typename T>
concept DriverTraits = requires {
  requires std::convertible_to<decltype(driver_traits<T>::max_mode), DisplayMode>;
  requires std::convertible_to<decltype(driver_traits<T>::supports_grayscale), bool>;
  requires std::convertible_to<decltype(driver_traits<T>::supports_partial_refresh), bool>;
  requires std::convertible_to<decltype(driver_traits<T>::supports_power_control), bool>;
  requires std::convertible_to<decltype(driver_traits<T>::supports_wake_from_sleep), bool>;
  requires std::convertible_to<decltype(driver_traits<T>::max_width), std::size_t>;
  requires std::convertible_to<decltype(driver_traits<T>::max_height), std::size_t>;
};
 
template <typename Driver>
  requires DriverTraits<Driver>
[[nodiscard]] constexpr auto supports_display_mode(DisplayMode mode) noexcept -> bool {
  // Always support single-bit BW
  if (mode == DisplayMode::BlackWhite) {
    return true;
  }
 
  // Grayscale support is explicit
  if (mode == DisplayMode::Grayscale4) {
    return driver_traits<Driver>::supports_grayscale;
  }
 
  // For color modes (BWR, BWY, Spectra6), strict matching is required.
  // Inequality (<=) is unsafe because modes like BWR(2) and BWY(3) are mutually exclusive,
  // not hierarchical. A Spectra6(5) driver might not support legacy BWR(2) commands.
  return mode == driver_traits<Driver>::max_mode;
}
 
} // namespace epaper