我正在尝试用Python的 imgui_bundle cartopy应用，尽管我在做一个 ndarray，我仍然收到一个错误，提示需要一个 numpy.ndarray，尽管当我 type() 时，它说它是一个 numpy.ndarray。单纯在只有cartopy的情况下做一个 show() 时，地图确实会显示。现在我想在 imgui 中实现并使其具有交互性（即让用户鼠标悬停以识别经纬度）。单独的 imgui 部分（不显示地图）也能工作，cartopy的编码（不带 gltexture 的部分，只是一个简单的 show()）也能工作。现在当我尝试把两者结合起来时，就不行了：

import io
import os
import numpy as np
import matplotlib.pyplot as plt
import cartopy
import cartopy.crs as ccrs
import cartopy.feature as cfeature
from imgui_bundle import imgui, immvision, ImVec2, immapp

class MapApp:
    def __init__(self):
        # Base map bounding box
        self.base_lat_min, self.base_lat_max = 3, 5
        self.base_lon_min, self.base_lon_max = -10, -7

        # Current zoom extents start as base extents
        self.lat_min, self.lat_max = self.base_lat_min, self.base_lat_max
        self.lon_min, self.lon_max = self.base_lon_min, self.base_lon_max

        self.fig, self.ax = plt.subplots(figsize=(8, 6), subplot_kw={'projection': ccrs.PlateCarree()})
        self.texture_id = None
        self.needs_redraw = True

        self.width, self.height = 800, 600  # Image display size

        self.zoom_factor = 1.0  # 1.0 means no zoom
        cartopy.config['pre_existing_data_dir'] = os.getcwd()
        cartopy.config['data_dir'] = os.getcwd()

    def update_map_texture(self):
        self.ax.clear()
        self.ax.set_extent([self.lon_min, self.lon_max, self.lat_min, self.lat_max], crs=ccrs.PlateCarree())
        self.ax.coastlines('50m')
        self.ax.add_feature(cfeature.BORDERS, linestyle=':')
        self.ax.add_feature(cfeature.LAND, facecolor='lightgray')
        self.ax.add_feature(cfeature.OCEAN, facecolor='lightblue')

        canvas = self.fig.canvas
        canvas.draw()
        w, h = canvas.get_width_height()
        print(f"w: {w}, h: {h}")
        buf = canvas.tostring_argb()
        img_array = np.frombuffer(buf, dtype=np.uint8).reshape(h, w, 4)
        img_array = img_array[:, :, [1, 2, 3, 0]]
        print(F"img_array.shape({img_array.size}): {img_array.shape} type: {type(img_array)}")
        if self.texture_id is None:
            self.texture_id = immvision.GlTexture(img_array)
            print(f"texture_id: {self.texture_id}")
        else:
            immvision.GlTexture.update_from_image(self.texture_id, img_array, False)

        self.needs_redraw = False

    def gui(self):
        imgui.begin("Interactive Map with Zoom")

        if self.needs_redraw or self.texture_id is None:
            self.update_map_texture()

        imgui.image(self.texture_id, ImVec2(self.width, self.height))

        # Mouse position and coordinate display
        mouse_pos = imgui.get_mouse_pos()
        window_pos = imgui.get_window_position()
        cursor_pos = imgui.get_cursor_pos()
        image_pos = (window_pos.x + cursor_pos.x, window_pos.y + cursor_pos.y)

        rel_x = mouse_pos.x - image_pos[0]
        rel_y = mouse_pos.y - image_pos[1]

        if 0 <= rel_x < self.width and 0 <= rel_y < self.height:
            lon = self.lon_min + (rel_x / self.width) * (self.lon_max - self.lon_min)
            lat = self.lat_max - (rel_y / self.height) * (self.lat_max - self.lat_min)
            imgui.text(f"Mouse Lon: {lon:.4f}  Lat: {lat:.4f}")

        imgui.end()

if __name__ == "__main__":
    app = MapApp()
    immapp.run(gui_function=app.gui, window_title="imgui Cartopy Map with Zoom")

我得到的错误是：

    self.texture_id = immvision.GlTexture(img_array)
                      ~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^
TypeError: __init__(): incompatible function arguments. The following argument types are supported:
    1. __init__(self) -> None
    2. __init__(self, image: numpy.ndarray, is_color_order_bgr: bool = False) -> None
    3. __init__(self, other: imgui_bundle._imgui_bundle.immvision.GlTexture) -> None

Invoked with types: imgui_bundle._imgui_bundle.immvision.GlTexture, ndarray

尽管我的打印语句显示它是一个 numpy.ndarray：

w: 800, h: 600
img_array.shape(1920000): (600, 800, 4) type: <class 'numpy.ndarray'>

我到底少了什么？

解决方案

不知道为什么，但当我创建新数组时代码就能工作

img_array = np.zeros((self.height, self.width, 4), dtype=np.uint8)

看起来它的大小、形状、dtype都相同，但出于某种原因它就能工作。

我还发现把你的数组转换为 np.array() 时代码也能工作

img_array = np.frombuffer(buf, dtype=np.uint8).reshape(h, w, 4)

img_array = np.array(img_array)

我只能猜测原始的 img_array 会把数据保留为内存中不同位置的视图，但C/C++代码可能需要一个在连续内存中的对象。

差异显示为 img_array.flags。

顺便说一句：

代码里还有其他问题。

它需要 get_window_pos() 而不是 get_window_position()。 (小笔误)

另一个问题是 immvision.GlTexture(img_array) 给出对象 GlTexture，不是数字 texture ID，变量 self.texture_id 可能会让人误解，因为在某些地方它需要 self.texture_id.texture_id 才能得到真正的 texture ID。

在某个地方它还需要得到 texture ref 而不是 texture id

imgui.image(
    imgui.ImTextureRef(self.texture_id.texture_id),
    ImVec2(self.width, self.height),
)

修改后我得到这个：

完整可运行的代码：

import io
import os

import numpy as np
import matplotlib.pyplot as plt
import cartopy
import cartopy.crs as ccrs
import cartopy.feature as cfeature
from imgui_bundle import imgui, immvision, ImVec2, immapp


def info(arr):
    print("--- arr ---")
    print(f"size: {arr.size}")
    print(f"shape: {arr.shape}")
    print(f"type: {type(arr)}")
    print(f"dtype: {arr.dtype}")
    print(f"strides: {arr.strides}")
    print(f"flags:\n{arr.flags}", end="")
    print(f"base: {arr.base}")
    print("---")


class MapApp:
    def __init__(self):
        # Base map bounding box
        self.base_lat_min, self.base_lat_max = 3, 5
        self.base_lon_min, self.base_lon_max = -10, -7

        # Current zoom extents start as base extents
        self.lat_min, self.lat_max = self.base_lat_min, self.base_lat_max
        self.lon_min, self.lon_max = self.base_lon_min, self.base_lon_max

        self.fig, self.ax = plt.subplots(
            figsize=(8, 6), subplot_kw={"projection": ccrs.PlateCarree()}
        )
        self.texture = None
        self.needs_redraw = True

        self.width, self.height = 800, 600  # Image display size

        self.zoom_factor = 1.0  # 1.0 means no zoom
        cartopy.config["pre_existing_data_dir"] = os.getcwd()
        cartopy.config["data_dir"] = os.getcwd()

    def update_map_texture(self):
        self.ax.clear()
        self.ax.set_extent(
            [self.lon_min, self.lon_max, self.lat_min, self.lat_max],
            crs=ccrs.PlateCarree(),
        )
        self.ax.coastlines("50m")
        self.ax.add_feature(cfeature.BORDERS, linestyle=":")
        self.ax.add_feature(cfeature.LAND, facecolor="lightgray")
        self.ax.add_feature(cfeature.OCEAN, facecolor="lightblue")

        canvas = self.fig.canvas
        canvas.draw()
        w, h = canvas.get_width_height()
        print(f"w: {w}, h: {h}")

        buf = canvas.tostring_argb()
        img_array = np.frombuffer(buf, dtype=np.uint8).reshape(h, w, 4)
        # img_array = np.zeros((self.height, self.width, 4), dtype=np.uint8)
        info(img_array)

        img_array = np.array(img_array)
        info(img_array)

        if self.texture is None:
            self.texture = immvision.GlTexture(img_array)
            print(
                f"texture: {self.texture} | texture.texture_id: {self.texture.texture_id}"
            )
        else:
            immvision.GlTexture.update_from_image(self.texture, img_array, False)

        self.needs_redraw = False

    def gui(self):
        imgui.begin("Interactive Map with Zoom")

        if self.needs_redraw or self.texture is None:
            self.update_map_texture()

        imgui.image(
            imgui.ImTextureRef(
                self.texture.texture_id
            ),  # needs `.texture_id` and `ImTextureRef()`
            ImVec2(self.width, self.height),
        )

        # Mouse position and coordinate display
        mouse_pos = imgui.get_mouse_pos()
        window_pos = imgui.get_window_pos()  # ERROR: position
        cursor_pos = imgui.get_cursor_pos()
        image_pos = (window_pos.x + cursor_pos.x, window_pos.y + cursor_pos.y)

        rel_x = mouse_pos.x - image_pos[0]
        rel_y = mouse_pos.y - image_pos[1]

        if 0 <= rel_x < self.width and 0 <= rel_y < self.height:
            lon = self.lon_min + (rel_x / self.width) * (self.lon_max - self.lon_min)
            lat = self.lat_max - (rel_y / self.height) * (self.lat_max - self.lat_min)
            imgui.text(f"Mouse Lon: {lon:.4f}  Lat: {lat:.4f}")

        imgui.end()


if __name__ == "__main__":
    app = MapApp()
    immapp.run(gui_function=app.gui, window_title="imgui Cartopy Map with Zoom")

关于 np.zeros() 的思路，我在演示 demos_python/demos_imgui_explorer/implot3d_demo.py 中看到的，我是在GitHub的仓库 imgui_bundle 找到的。还有更多演示。