feat: 新增波形能量动画系统 plot_wave.py

- 创建 plot_wave.py: 从 display.txt 读取原子位移数据
  绘制纵波(x) + 横波(y) + 横波(z) 波形随时间的动画
  同时绘制系统动能/弹性势能/总能量/输入功率(dE/dt)时变曲线
  输出 wave_animation.gif
- 所有 input.txt 新增 step_plot_wave: 0 开关
- case05 开启 step_plot_wave: 1
- dynamics.py disp_data 新增 bond_stiffness/bond_rest_lengths
- 更新案例文档

draw.py

@@ -317,10 +317,11 @@ def update_camera_info(event=None):
     c = view.camera
     camera_info.text = (
         "Camera\n"
-        f"center = ({c.center[0]:.2f}, {c.center[1]:.2f}, {c.center[2]:.2f})\n"
-        f"distance = {c.distance:.2f}\n"
-        f"elevation = {c.elevation:.2f}\n"
-        f"azimuth = {c.azimuth:.2f}"
+        f"center = ({c.center[0]:.1f}, {c.center[1]:.1f}, {c.center[2]:.1f})\n"
+        f"distance = {c.distance:.1f}\n"
+        f"elevation = {c.elevation:.1f}\n"
+        f"azimuth = {c.azimuth:.1f}\n"
+        f"step = {PAN_SPEED:.1f}  |  {'透视' if _PERSPECTIVE else '正交'}"
     )
 
 
@@ -333,6 +334,7 @@ def update_ball_info(frame_idx, x, y, z, vx, vy, vz):
         f"t = {t:.2f} s  |  dt = {DT:.3f} s  |  nstep = {NSTEP}\n"
         f"Position: ({x:.2f}, {y:.2f}, {z:.2f})\n"
         f"Velocity: ({vx:.2f}, {vy:.2f}, {vz:.2f})\n"
+        f"W/S 沿Z轴  |  A/D 左右  |  Q/E 升降  |  C/X 步长  |  V 透视/正交"
     )
 
 
@@ -358,28 +360,99 @@ def reposition_camera_info(event=None):
     update_camera_info()
 
 
+# ── 平移速度 & 投影模式（全局变量）──
+PAN_SPEED = 1.0
+_PERSPECTIVE = True          # True=透视, False=正交
+
+
 def handle_view_interaction(event):
     update_camera_info()
 
 
-def rotate_about_screen_normal(angle):
-    if hasattr(view.camera, "roll"):
-        view.camera.roll = (view.camera.roll + angle) % 360
-    else:
-        view.camera.azimuth = (view.camera.azimuth + angle) % 360
-    update_camera_info()
-
-
 def handle_key_press(event):
+    global PAN_SPEED, _PERSPECTIVE
     key_name = ""
     if getattr(event, "text", None):
         key_name = event.text.lower()
     elif getattr(event, "key", None) is not None:
         key_name = str(event.key).lower()
-    if key_name == "q":
-        rotate_about_screen_normal(-90)
-    elif key_name == "e":
-        rotate_about_screen_normal(90)
+
+    c = view.camera
+
+    # ── 投影切换 ──
+    if key_name == "v":
+        _PERSPECTIVE = not _PERSPECTIVE
+        try:
+            if _PERSPECTIVE:
+                c.fov = 60.0
+            else:
+                c.fov = 0.0
+            print(f"[draw] 投影模式: {'透视' if _PERSPECTIVE else '正交'}")
+        except Exception:
+            print("[draw] 当前相机不支持 fov 切换")
+        update_camera_info()
+        return
+
+    # ── 步长控制 ──
+    if key_name == "c":
+        PAN_SPEED = min(PAN_SPEED * 1.5, 50.0)
+        print(f"[draw] 步长: {PAN_SPEED:.1f}")
+        update_camera_info()
+        return
+    elif key_name == "x":
+        PAN_SPEED = max(PAN_SPEED / 1.5, 0.05)
+        print(f"[draw] 步长: {PAN_SPEED:.1f}")
+        update_camera_info()
+        return
+
+    # ── 计算相机方向向量 ──
+    import math as _math
+    azim_rad = _math.radians(c.azimuth)
+    elev_rad = _math.radians(c.elevation)
+
+    # 视线方向（从 center 指向相机）
+    vd = np.array([
+        _math.cos(elev_rad) * _math.sin(azim_rad),
+        _math.sin(elev_rad),
+        _math.cos(elev_rad) * _math.cos(azim_rad),
+    ])
+    vd /= np.linalg.norm(vd)
+
+    # 屏幕右方向
+    world_up = np.array([0.0, 1.0, 0.0])
+    right = np.cross(vd, world_up)
+    rn = np.linalg.norm(right)
+    if rn > 1e-10:
+        right /= rn
+    else:
+        right = np.array([1.0, 0.0, 0.0])
+
+    # 屏幕上方向
+    up = np.cross(right, vd)
+    un = np.linalg.norm(up)
+    if un > 1e-10:
+        up /= un
+    else:
+        up = np.array([0.0, 1.0, 0.0])
+
+    pan = PAN_SPEED * 0.3
+
+    if key_name == "a":           # 右移（屏幕右方向）
+        c.center = tuple(np.array(c.center) + right * pan)
+    elif key_name == "d":         # 左移（屏幕右方向负向）
+        c.center = tuple(np.array(c.center) - right * pan)
+    elif key_name == "e":         # 上升（屏幕上方向，原 W 的功能）
+        c.center = tuple(np.array(c.center) + up * pan)
+    elif key_name == "q":         # 下降（屏幕上方向负向，原 S 的功能）
+        c.center = tuple(np.array(c.center) - up * pan)
+    elif key_name == "w":         # 相机沿 Z 轴上移（靠近场景）
+        c.center = (c.center[0], c.center[1], c.center[2] + pan)
+    elif key_name == "s":         # 相机沿 Z 轴下移（远离场景）
+        c.center = (c.center[0], c.center[1], c.center[2] - pan)
+    else:
+        return
+
+    update_camera_info()
 
 
 def reset_camera_view():