From 7b34f21e4f154220ec1397eee50ab7635d718223 Mon Sep 17 00:00:00 2001
From: ser1zw <azariahsawtikes@gmail.com>
Date: Sat, 30 Apr 2016 16:49:12 +0900
Subject: [PATCH] add cv::setIdentity

---
 ext/opencv/mat.cpp | 24 ++++++++++++++++++++++++
 test/test_mat.rb   | 13 +++++++++++++
 2 files changed, 37 insertions(+)

diff --git a/ext/opencv/mat.cpp b/ext/opencv/mat.cpp
index 8dd39ba..243befc 100644
--- a/ext/opencv/mat.cpp
+++ b/ext/opencv/mat.cpp
@@ -933,6 +933,29 @@ namespace rubyopencv {
       return mat2obj(dstptr, CLASS_OF(self));
     }
 
+    /*
+     * Initializes a scaled identity matrix.
+     *
+     * @overload set_identity(s = Scalar.new(1))
+     * @param s [Scalar] Value to assign to diagonal elements.
+     * @return [Mat] +self+
+     * @opencv_func cv::setIdentity
+     */
+    VALUE rb_set_identity(int argc, VALUE *argv, VALUE self) {
+      VALUE s = Qnil;
+      rb_scan_args(argc, argv, "01", &s);
+      cv::Mat* selfptr = obj2mat(self);
+      cv::Scalar s_value = NIL_P(s) ? cv::Scalar(1) : *(Scalar::obj2scalar(s));
+      try {
+	cv::setIdentity(*selfptr, s_value);
+      }
+      catch (cv::Exception& e) {
+	Error::raise(e);
+      }
+
+      return self;
+    }
+
     void init() {
       VALUE opencv = rb_define_module("Cv");
 
@@ -993,6 +1016,7 @@ namespace rubyopencv {
 
       rb_define_method(rb_klass, "convert_scale_abs", RUBY_METHOD_FUNC(rb_convert_scale_abs), -1);
       rb_define_method(rb_klass, "convert_to", RUBY_METHOD_FUNC(rb_convert_to), -1);
+      rb_define_method(rb_klass, "set_identity", RUBY_METHOD_FUNC(rb_set_identity), -1);
     }
   }
 }
diff --git a/test/test_mat.rb b/test/test_mat.rb
index d060ccc..b932d38 100755
--- a/test/test_mat.rb
+++ b/test/test_mat.rb
@@ -566,4 +566,17 @@ class TestMat < OpenCVTestCase
       m.set_to(s1, DUMMY_OBJ)
     }
   end
+
+  def test_set_identity
+    m = Mat::zeros(3, 3, CV_8U)
+    m.set_identity(Scalar.new(10))
+    expected = "<Cv::Mat:3x3,depth=0,channels=1,\n[ 10,   0,   0;\n   0,  10,   0;\n   0,   0,  10]>"
+    assert_equal(expected, m.to_s)
+    m.set_identity
+    expected = "<Cv::Mat:3x3,depth=0,channels=1,\n[  1,   0,   0;\n   0,   1,   0;\n   0,   0,   1]>"
+    assert_equal(expected, m.to_s)
+    assert_raise(TypeError) {
+      m.set_identity(DUMMY_OBJ)
+    }
+  end
 end