Extra2D/include/graphics/alpha_mask.h

#pragma once

#include <core/rect.h>
#include <core/types.h>
#include <core/vec2.h>
#include <vector>

namespace extra2d {

// ============================================================================
// Alpha 遮罩 - 存储图片的非透明区域信息
// ============================================================================
class AlphaMask {
public:
  AlphaMask() = default;
  AlphaMask(int width, int height);

  /// 从像素数据创建遮罩
  static AlphaMask createFromPixels(const uint8_t *pixels, int width,
                                    int height, int channels);

  /// 获取指定位置的透明度（0-255）
  uint8_t getAlpha(int x, int y) const;

  /// 检查指定位置是否不透明
  bool isOpaque(int x, int y, uint8_t threshold = 128) const;

  /// 检查指定位置是否在遮罩范围内
  bool isValid(int x, int y) const;

  /// 获取遮罩尺寸
  int width() const { return width_; }
  int height() const { return height_; }
  Size size() const {
    return Size(static_cast<float>(width_), static_cast<float>(height_));
  }

  /// 获取原始数据
  const std::vector<uint8_t> &getData() const { return data_; }

  /// 检查遮罩是否有效
  bool isValid() const { return !data_.empty() && width_ > 0 && height_ > 0; }

private:
  int width_ = 0;
  int height_ = 0;
  std::vector<uint8_t> data_; // Alpha值数组
};

} // namespace extra2d