fix Mat.size is not correct #170

lib/src/core/mat.dart

@@ -289,17 +289,13 @@ class Mat extends CvStruct<cvg.Mat> {
         return p.value;
       });
 
-  /// ([rows], [cols])
-  List<int> get size => [rows, cols];
-
-  // List<int> get shape {
-  //   return cvRunArena<List<int>>((arena) {
-  //     final s = arena<cvg.VecI32>();
-  //     cvRun(() => cffiCore.Mat_Size(ref, s));
-  //     final vec = VecI32.fromPointer(s.value);
-  //     return vec.toList();
-  //   });
-  // }
+  /// Mat.size
+  VecI32 get size {
+    final p = calloc<cvg.VecI32>();
+    cvRun(() => ccore.Mat_Size(ref, p));
+    final vec = VecI32.fromPointer(p);
+    return vec;
+  }
 
   /// ([rows], [cols], [channels])
   List<int> get shape => [rows, cols, channels];

src/core/core.cpp

@@ -350,7 +350,7 @@ CvStatus *Mat_Size(Mat m, VecI32 *rval) {
   BEGIN_WRAP
   auto size = m.ptr->size;
   int *ptr = new int[size.dims()];
-  memcpy(ptr, size.p, size.dims());
+  memcpy(ptr, size.p, size.dims() * sizeof(int));
   *rval = {ptr, static_cast<size_t>(size.dims())};
   END_WRAP
 }

test/imgcodecs_test.dart

@@ -27,10 +27,12 @@ void main() async {
     final cvImage = cv.imread("test/images/circles.jpg", flags: cv.IMREAD_COLOR);
     expect((cvImage.width, cvImage.height), (512, 512));
     final (success, buf) = cv.imencode(".png", cvImage);
+    expect(success, true);
     expect(buf.length, greaterThan(0));
     await File("test/images_out/test_imencode.png").writeAsBytes(buf);
     final params = [cv.IMWRITE_PNG_COMPRESSION, 9].i32;
     final (success1, buf1) = cv.imencode(".png", cvImage, params: params);
+    expect(success1, true);
     expect(buf1.length, greaterThan(0));
 
     final cvimgDecode = cv.imdecode(buf, cv.IMREAD_COLOR);