import cv2
import sys

img = cv2.imread(sys.argv[1] if len(sys.argv) > 1 else "_capture.jpg")
if img is None:
    print("找不到图片")
    sys.exit(1)

H, W = img.shape[:2]
points = []
labels = ["A 近左", "B 近右", "C 远左", "D 远右"]

def on_click(event, x, y, flags, param):
    if event == cv2.EVENT_LBUTTONDOWN and len(points) < 4:
        points.append((x, y))
        cv2.circle(img, (x, y), 4, (0, 0, 255), -1)
        cv2.putText(img, labels[len(points)-1], (x+8, y-8),
                    cv2.FONT_HERSHEY_SIMPLEX, 0.5, (0, 255, 255), 1)
        print(f"  {labels[len(points)-1]}: ({x:4d}, {y:4d})")
        if len(points) == 4:
            print("\n--- 标定数据 ---")
            for i, p in enumerate(points):
                print(f"{labels[i]}: ({p[0]:4d}, {p[1]:4d})")
            # 换算到 80x60
            sx, sy = 80/W, 60/H
            print(f"\n80x60 处理分辨率:")
            for i, p in enumerate(points):
                print(f"{labels[i]}: ({int(p[0]*sx):3d}, {int(p[1]*sy):3d})")
            print("\n按任意键退出...")

cv2.namedWindow("calib", cv2.WINDOW_NORMAL)
cv2.setMouseCallback("calib", on_click)

print(f"图片 {W}x{H}，按 A B C D 顺序点击 4 个点:")
print("  A=近处左边界  B=近处右边界  C=远处左边界  D=远处右边界\n")

while True:
    cv2.imshow("calib", img)
    if cv2.waitKey(20) != -1 or len(points) >= 4:
        break

cv2.waitKey(0)
cv2.destroyAllWindows()