feat(pkg): opencv module → windows (import opencv.cv/dnn on windows)

pkgs/o/opencv.lua

@@ -10,9 +10,11 @@
 -- Optional features (0.0.4+, mcpp#243 forwarding): `dnn` adds the
 -- import opencv.dnn; interface and forwards compat.opencv/dnn; `unifont`
 -- forwards compat.opencv/unifont — `opencv = { features = ["dnn"] }`.
--- linux + macOS: the module tarball is OS-neutral; compat.opencv is per-OS
-    -- (linux/macosx full). v0.0.6 added the clang static-inline export forwarding
-    -- layer so clang (macOS) can import opencv.cv. windows: module needs videoio.
+-- 3-platform: the module tarball is OS-neutral; compat.opencv is per-OS (all
+    -- three now full — videoio everywhere, dnn on linux/macOS/windows). v0.0.6's
+    -- clang static-inline export forwarding layer lets clang (macOS + windows
+    -- clang-cl) import opencv.cv; windows dnn uses the built-in fast_gemm backend
+    -- (compat.opencv skips mlas there — its x86 asm is GAS/ELF, not COFF).
 --
 package = {
     spec        = "1",
@@ -42,6 +44,15 @@ package = {
                 sha256 = "adebd6b1e7a434bf8d744a6fc191725466467ae13b4d7ee1c01d5a8e21bbf2eb",
             },
         },
+        windows = {
+            ["0.0.6"] = {
+                url    = {
+                    GLOBAL = "https://github.com/Sunrisepeak/opencv-m/archive/refs/tags/v0.0.6.tar.gz",
+                    CN     = "https://gitcode.com/mcpp-res/opencv/releases/download/v0.0.6/opencv-m-0.0.6.tar.gz",
+                },
+                sha256 = "adebd6b1e7a434bf8d744a6fc191725466467ae13b4d7ee1c01d5a8e21bbf2eb",
+            },
+        },
     },
 
     -- (no `mcpp` field -- default lookup will find <verdir>/*/mcpp.toml)

tests/examples/opencv-module-dnn/mcpp.toml

@@ -19,4 +19,8 @@ opencv = { version = "0.0.6", features = ["dnn"] }
 [target.'cfg(macos)'.dependencies]
 opencv = { version = "0.0.6", features = ["dnn"] }
 
+# windows: `import opencv.dnn;` on windows-x86_64 (fast_gemm backend).
+[target.'cfg(windows)'.dependencies]
+opencv = { version = "0.0.6", features = ["dnn"] }
+
 

tests/examples/opencv-module-dnn/tests/opencv_dnn_iface.cpp

@@ -4,7 +4,7 @@
 // Linux-only (see mcpp.toml). Not named dnn.cpp (would collide with the dep's
 // modules/dnn/src/dnn.cpp — #240 family). Import-only (import std + the opencv
 // modules): no textual headers, matching the ffmpeg-module member convention.
-#if defined(__linux__) || defined(__APPLE__)
+#if defined(__linux__) || defined(__APPLE__) || defined(_WIN32)
 import std;
 import opencv.cv;
 import opencv.dnn;

tests/examples/opencv-module/mcpp.toml

@@ -21,3 +21,7 @@ opencv = "0.0.6"
 
 [target.'cfg(macos)'.dependencies]
 opencv = "0.0.6"
+
+# windows: import opencv.cv on windows-x86_64 (clang-cl; module tarball OS-neutral).
+[target.'cfg(windows)'.dependencies]
+opencv = "0.0.6"

tests/examples/opencv-module/tests/opencv_module.cpp

@@ -3,7 +3,7 @@
 // replacement operator surface: Size comparison via != crosses the module
 // boundary — the v0.0.1 regression scenario), PNG+JPEG codec roundtrips,
 // videoio registry. Linux-only (see mcpp.toml).
-#if defined(__linux__) || defined(__APPLE__)
+#if defined(__linux__) || defined(__APPLE__) || defined(_WIN32)
 import std;
 import opencv.cv;