Refactoring: move "norm" to Geometry.kt and add test

app/src/main/java/org/mydomain/myscan/DocumentDetection.kt

@@ -25,7 +25,6 @@ import org.opencv.core.Size
 import org.opencv.imgproc.Imgproc
 import kotlin.math.abs
 import kotlin.math.max
-import kotlin.math.sqrt
 
 fun detectDocumentQuad(mask: Bitmap, minQuadAreaRatio: Double = 0.02): Quad? {
     val mat = Mat()
@@ -143,8 +142,3 @@ fun Point.toCv(): org.opencv.core.Point {
     return org.opencv.core.Point(x.toDouble(), y.toDouble())
 }
 
-private fun norm(p1: Point, p2: Point): Double {
-    val dx = (p2.x - p1.x)
-    val dy = (p2.y - p1.y)
-    return sqrt(dx.toDouble() * dx + dy * dy)
-}

app/src/main/java/org/mydomain/myscan/Geometry.kt

@@ -15,10 +15,21 @@
 package org.mydomain.myscan
 
 import kotlin.math.atan2
+import kotlin.math.sqrt
 
 data class Point(val x: Int, val y: Int)
 
-data class Line(val from: Point, val to: Point)
+data class Line(val from: Point, val to: Point) {
+    fun norm(): Double {
+        return norm(from, to)
+    }
+}
+
+fun norm(p1: Point, p2: Point): Double {
+    val dx = (p2.x - p1.x)
+    val dy = (p2.y - p1.y)
+    return sqrt(dx.toDouble() * dx + dy * dy)
+}
 
 data class Quad(
     val topLeft: Point,

app/src/test/java/org/mydomain/myscan/GeometryTest.kt

@@ -0,0 +1,27 @@
+/*
+ * Copyright 2025 Pierre-Yves Nicolas
+ *
+ * This program is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the Free
+ * Software Foundation, either version 3 of the License, or (at your option)
+ * any later version.
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ * You should have received a copy of the GNU General Public License along with
+ * this program. If not, see <https://www.gnu.org/licenses/>.
+ */
+package org.mydomain.myscan
+
+import org.assertj.core.api.Assertions.assertThat
+import org.junit.Test
+
+class GeometryTest {
+
+    @Test
+    fun line() {
+        assertThat(Line(Point(0, 0), Point(10, 0)).norm()).isEqualTo(10.0)
+        assertThat(Line(Point(1, 2), Point(4, 6)).norm()).isEqualTo(5.0)
+    }
+}