From 27818da2494511435d5f99be343ec280be8cd256 Mon Sep 17 00:00:00 2001
From: Chih-Wei Chang <me@cwchang.me>
Date: Tue, 17 Feb 2015 00:14:10 +0800
Subject: [PATCH] Add *mat64.Dense to cv::Mat converter.

---
 gocv/gocv.go       | 17 ++++++++++++++++-
 gocv/gocv_core.cpp | 21 +++++++++++++++++++++
 gocv/gocv_core.hpp |  5 +++++
 gocv/gocv_core.i   |  9 ++++++---
 gocv/gocv_test.go  | 10 ++++++++++
 5 files changed, 58 insertions(+), 4 deletions(-)
 create mode 100644 gocv/gocv_core.cpp
 create mode 100644 gocv/gocv_core.hpp

diff --git a/gocv/gocv.go b/gocv/gocv.go
index 82196d6..05ab78c 100644
--- a/gocv/gocv.go
+++ b/gocv/gocv.go
@@ -29,7 +29,7 @@ func NewGcvSize2f64(x, y float64) GcvSize2f64_ {
 	return NewGcvSize2f64_(float64(x), float64(y))
 }
 
-// Convert Mat, which defined by SWIG, to mat64.Dense.
+// Convert Mat, which defined by SWIG, to *mat64.Dense.
 // The reason is the latter is much easier to handle
 // in Go.
 // GcvMat is assumed to be 2-dimensional matrix.
@@ -52,3 +52,18 @@ func MatToMat64(mat Mat) *mat64.Dense {
 
 	return mat64.NewDense(row, col, data)
 }
+
+// Convert *mat64.Dense to Mat
+func ToMat(mat *mat64.Dense) Mat {
+	row, col := mat.Dims()
+
+	rawData := NewGcvFloat64Vector(int64(row * col))
+
+	for i := 0; i < row; i++ {
+		for j := 0; j < col; j++ {
+			rawData.Set(i*col+j, mat.At(i, j))
+		}
+	}
+
+	return ToMat_(row, col, rawData)
+}
diff --git a/gocv/gocv_core.cpp b/gocv/gocv_core.cpp
new file mode 100644
index 0000000..d5b4256
--- /dev/null
+++ b/gocv/gocv_core.cpp
@@ -0,0 +1,21 @@
+#include <opencv2/opencv.hpp>
+#include <opencv2/core/core.hpp>
+#include <iostream>
+#include <vector>
+
+#include "gocv_core.hpp"
+
+cv::Mat ToMat_(int row, int col, std::vector<double> data) {
+        assert(row * col == data.size());
+
+        cv::Mat mat = cv::Mat(row, col, CV_64F);
+
+        for (int i = 0; i < row; ++i) {
+                for (int j = 0; j < col; ++j) {
+                        mat.at<double>(i, j) = data[i*col + j];
+                }
+
+        }
+
+        return mat;
+}
diff --git a/gocv/gocv_core.hpp b/gocv/gocv_core.hpp
new file mode 100644
index 0000000..9210e09
--- /dev/null
+++ b/gocv/gocv_core.hpp
@@ -0,0 +1,5 @@
+#include <opencv2/opencv.hpp>
+#include <vector>
+#include <iostream>
+
+cv::Mat ToMat_(int row, int col, std::vector<double> data);
diff --git a/gocv/gocv_core.i b/gocv/gocv_core.i
index f14232c..47e782e 100644
--- a/gocv/gocv_core.i
+++ b/gocv/gocv_core.i
@@ -1,9 +1,11 @@
-%include "std_vector.i"
-
 %{
 #include "opencv2/core/core.hpp"
+#include "gocv_core.hpp"
 %}
 
+%include "std_vector.i"
+%include "gocv_core.hpp"
+
 /* Classes defined in core.hpp */
 namespace cv {
 
@@ -295,5 +297,6 @@ namespace std {
    %template(GcvPoint2f32Vector) vector<cv::Point2f>;
 
    %template(GcvIntVector) vector<int>;
-   %template(GcvFloatVector) vector<float>;
+   %template(GcvFloat32Vector) vector<float>;
+   %template(GcvFloat64Vector) vector<double>;
 };
diff --git a/gocv/gocv_test.go b/gocv/gocv_test.go
index 228cba8..4c082fb 100644
--- a/gocv/gocv_test.go
+++ b/gocv/gocv_test.go
@@ -4,6 +4,7 @@ import (
 	"testing"
 
 	"github.com/davecgh/go-spew/spew"
+	"github.com/gonum/matrix/mat64"
 )
 
 func TestNewGcvPoint3f32(t *testing.T) {
@@ -26,3 +27,12 @@ func TestMat(t *testing.T) {
 	mat2 := NewMat(mat)
 	spew.Dump(mat2)
 }
+
+func TestToMat(t *testing.T) {
+	mat := mat64.NewDense(3, 2, []float64{
+		0, 1,
+		1.23, 4,
+		-12.3, -4,
+	})
+	spew.Dump(ToMat(mat))
+}