修改色域画图及重绘方式

app/plots/gamut_background.py

@@ -0,0 +1,165 @@
+"""CIE 色度图底图渲染与缓存。
+
+将"重型图像渲染"（colour-science 的谱迹颜色填充）与"轻量框架数据层"
+（参考/实测三角形、标签、覆盖率）解耦。
+
+底图：
+- 仅在首次调用或缓存失效时通过 colour-science 渲染一次；
+- 渲染结果保存为 numpy RGBA 数组，同时落盘到 settings/cache/，
+  下次启动直接 imread 加载，避免重新跑色彩科学计算。
+
+调用方在每次绘图时只需 `ax.imshow(bg, extent=bbox)`，再叠加自己的矢量层。
+"""
+
+from __future__ import annotations
+
+import hashlib
+import os
+import threading
+from typing import Tuple
+
+import numpy as np
+
+# 谱迹底图分辨率（边长，单位像素）。1024 对于 14 inch 画布足够细腻，
+# 文件大小 ~1-2MB，单次渲染 ~0.5-1 s，缓存后毫秒级加载。
+_DIAGRAM_RES = 1024
+
+# 缓存版本号：当渲染参数或风格调整时递增，强制重新生成。
+_CACHE_VERSION = "v1"
+
+_BBox = Tuple[float, float, float, float]  # (xmin, xmax, ymin, ymax)
+
+_CIE1931_BBOX: _BBox = (0.0, 0.8, 0.0, 0.9)
+_CIE1976_BBOX: _BBox = (0.0, 0.65, 0.0, 0.6)
+
+
+_memory_cache: dict[str, np.ndarray] = {}
+_lock = threading.Lock()
+
+
+def _cache_dir() -> str:
+    # 项目根目录通过本文件位置反推：app/plots/ -> 项目根
+    here = os.path.dirname(os.path.abspath(__file__))
+    root = os.path.abspath(os.path.join(here, "..", ".."))
+    d = os.path.join(root, "settings", "cache")
+    os.makedirs(d, exist_ok=True)
+    return d
+
+
+def _cache_key(kind: str, bbox: _BBox) -> str:
+    sig = f"{kind}|{bbox}|{_DIAGRAM_RES}|{_CACHE_VERSION}"
+    h = hashlib.md5(sig.encode("utf-8")).hexdigest()[:10]
+    return f"chromaticity_{kind}_{h}.npy"
+
+
+def _cache_path(kind: str, bbox: _BBox) -> str:
+    return os.path.join(_cache_dir(), _cache_key(kind, bbox))
+
+
+def _render_chromaticity(kind: str, bbox: _BBox) -> np.ndarray:
+    """通过 colour-science 离屏渲染谱迹底图，返回 RGBA float 数组。"""
+    # 延迟导入：仅在缓存未命中时支付 colour.plotting 的加载开销。
+    import matplotlib
+    prev_backend = matplotlib.get_backend()
+    try:
+        matplotlib.use("Agg", force=True)
+    except Exception:
+        pass
+
+    import matplotlib.pyplot as plt
+    from colour.plotting import (
+        plot_chromaticity_diagram_CIE1931,
+        plot_chromaticity_diagram_CIE1976UCS,
+    )
+
+    xmin, xmax, ymin, ymax = bbox
+    aspect = (xmax - xmin) / (ymax - ymin)
+    height = _DIAGRAM_RES
+    width = int(round(height * aspect))
+
+    fig = plt.figure(figsize=(width / 100.0, height / 100.0), dpi=100)
+    ax = fig.add_axes([0.0, 0.0, 1.0, 1.0])
+
+    if kind == "cie1931":
+        plot_chromaticity_diagram_CIE1931(
+            axes=ax, show=False, title=False,
+            tight_layout=False, transparent_background=True,
+            bounding_box=bbox,
+        )
+    elif kind == "cie1976":
+        plot_chromaticity_diagram_CIE1976UCS(
+            axes=ax, show=False, title=False,
+            tight_layout=False, transparent_background=True,
+            bounding_box=bbox,
+        )
+    else:
+        plt.close(fig)
+        raise ValueError(f"unknown diagram kind: {kind!r}")
+
+    ax.set_xlim(xmin, xmax)
+    ax.set_ylim(ymin, ymax)
+    ax.set_axis_off()
+    ax.set_position([0.0, 0.0, 1.0, 1.0])
+
+    fig.canvas.draw()
+    # 从 canvas 抓取 RGBA 数组
+    buf = np.asarray(fig.canvas.buffer_rgba()).copy()
+    plt.close(fig)
+
+    try:
+        matplotlib.use(prev_backend, force=True)
+    except Exception:
+        pass
+
+    return buf
+
+
+def _load_or_render(kind: str, bbox: _BBox) -> np.ndarray:
+    key = _cache_key(kind, bbox)
+    with _lock:
+        if key in _memory_cache:
+            return _memory_cache[key]
+
+        disk = _cache_path(kind, bbox)
+        if os.path.isfile(disk):
+            try:
+                arr = np.load(disk)
+                _memory_cache[key] = arr
+                return arr
+            except Exception:
+                # 缓存损坏则重新渲染
+                try:
+                    os.remove(disk)
+                except OSError:
+                    pass
+
+        arr = _render_chromaticity(kind, bbox)
+        _memory_cache[key] = arr
+        try:
+            np.save(disk, arr)
+        except Exception:
+            pass
+        return arr
+
+
+def get_cie1931_background() -> Tuple[np.ndarray, _BBox]:
+    """返回 (RGBA 数组, bbox)，可直接 ax.imshow(arr, extent=[*bbox])。"""
+    return _load_or_render("cie1931", _CIE1931_BBOX), _CIE1931_BBOX
+
+
+def get_cie1976_background() -> Tuple[np.ndarray, _BBox]:
+    return _load_or_render("cie1976", _CIE1976_BBOX), _CIE1976_BBOX
+
+
+def clear_cache(*, disk: bool = False) -> None:
+    """清空内存缓存（可选连同磁盘）。供调试/样式调整时使用。"""
+    with _lock:
+        _memory_cache.clear()
+        if disk:
+            d = _cache_dir()
+            for name in os.listdir(d):
+                if name.startswith("chromaticity_") and name.endswith(".npy"):
+                    try:
+                        os.remove(os.path.join(d, name))
+                    except OSError:
+                        pass