From 041db45a84896e3a66601081f58241f1247c3800 Mon Sep 17 00:00:00 2001
From: Laurent Lienher <laurent.lienher@camptocamp.com>
Date: Wed, 17 Jul 2019 13:22:32 +0200
Subject: [PATCH] Simplify code

---
 contribs/gmf/src/editing/Snapping.js |  2 +-
 src/interaction/MeasureLength.js     | 39 +++++++++++-----------------
 2 files changed, 16 insertions(+), 25 deletions(-)

diff --git a/contribs/gmf/src/editing/Snapping.js b/contribs/gmf/src/editing/Snapping.js
index 6d247b99add8..bbb8829f4421 100644
--- a/contribs/gmf/src/editing/Snapping.js
+++ b/contribs/gmf/src/editing/Snapping.js
@@ -121,7 +121,7 @@ class CustomSnap extends olInteractionSnap {
     super(options);
     this.modifierPressed = false;
     document.body.addEventListener('keydown', (evt) => {
-      this.modifierPressed = evt.keyCode === 17;
+      this.modifierPressed = evt.keyCode === 17; // Ctrl key
     });
     document.body.addEventListener('keyup', () => {
       this.modifierPressed = false;
diff --git a/src/interaction/MeasureLength.js b/src/interaction/MeasureLength.js
index 21cccdebf3de..895c1830fd99 100644
--- a/src/interaction/MeasureLength.js
+++ b/src/interaction/MeasureLength.js
@@ -31,7 +31,7 @@ const exports = function(format, gettextCatalog, options = /** @type {ngeox.inte
   if (modifierPressed === undefined) {
     modifierPressed = false;
     document.body.addEventListener('keydown', (evt) => {
-      modifierPressed = evt.keyCode === 17;
+      modifierPressed = evt.keyCode === 17; // Ctrl key
     });
     document.body.addEventListener('keyup', () => {
       modifierPressed = false;
@@ -124,15 +124,7 @@ exports.prototype.linestringGeometryFunction = function(source, coordinates, opt
           to[1] = b[1];
 
           // intersection calculation
-          const result = {
-            x: 0.0,
-            y: 0.0
-          };
-          const intersectionPoint = this.computeLineSegmentIntersection(from[0], from[1], to[0], to[1], point1[0], point1[1], point2[0], point2[1], result);
-          if (intersectionPoint !== undefined) {
-            to[0] = intersectionPoint.x;
-            to[1] = intersectionPoint.y;
-          }
+          this.computeLineSegmentIntersection(from, to, point1, point2, to);
         });
       });
     }
@@ -162,22 +154,21 @@ exports.prototype.handleMeasure = function(callback) {
 /**
  * Compute the intersection between 2 segments
  *
- * @param {Number} x00 The x coordinate of the first line's first vertex.
- * @param {Number} y00 The y coordinate of the first line's first vertex.
- * @param {Number} x01 The x coordinate of the first line's second vertex.
- * @param {Number} y01 The y coordinate of the first line's second vertex.
- * @param {Number} x10 The x coordinate of the second line's first vertex.
- * @param {Number} y10 The y coordinate of the second line's first vertex.
- * @param {Number} x11 The x coordinate of the second line's second vertex.
- * @param {Number} y11 The y coordinate of the second line's second vertex.
+ * @param {Number} line1vertex1 The coordinates of the first line's first vertex.
+ * @param {Number} line1vertex2 The coordinates of the first line's second vertex.
+ * @param {Number} line2vertex1 The coordinates of the second line's first vertex.
+ * @param {Number} line2vertex2 The coordinates of the second line's second vertex.
  * @param {Array<number>} [result] An existing array where the result will be copied. If this parameter
  *                     is undefined, a new array is created and returned.
  * @returns {Array<number> | undefined} The intersection point, undefined if there is no intersection point or lines are coincident.
  */
-exports.prototype.computeLineSegmentIntersection = function(x00, y00, x01, y01, x10, y10, x11, y11, result) {
-  const numerator1A = (x11 - x10) * (y00 - y10) - (y11 - y10) * (x00 - x10);
-  const numerator1B = (x01 - x00) * (y00 - y10) - (y01 - y00) * (x00 - x10);
-  const denominator1 = (y11 - y10) * (x01 - x00) - (x11 - x10) * (y01 - y00);
+exports.prototype.computeLineSegmentIntersection = function(line1vertex1, line1vertex2, line2vertex1, line2vertex2, result) {
+  const numerator1A = (line2vertex2[0] - line2vertex1[0]) * (line1vertex1[1] - line2vertex1[1])
+    - (line2vertex2[1] - line2vertex1[1]) * (line1vertex1[0] - line2vertex1[0]);
+  const numerator1B = (line1vertex2[0] - line1vertex1[0]) * (line1vertex1[1] - line2vertex1[1])
+    - (line1vertex2[1] - line1vertex1[1]) * (line1vertex1[0] - line2vertex1[0]);
+  const denominator1 = (line2vertex2[1] - line2vertex1[1]) * (line1vertex2[0] - line1vertex1[0])
+    - (line2vertex2[0] - line2vertex1[0]) * (line1vertex2[1] - line1vertex1[1]);
 
   // If denominator = 0, then lines are parallel. If denominator = 0 and both numerators are 0, then coincident
   if (denominator1 === 0) {
@@ -188,8 +179,8 @@ exports.prototype.computeLineSegmentIntersection = function(x00, y00, x01, y01,
   const  ub1 = numerator1B / denominator1;
 
   if (ua1 >= 0 && ua1 <= 1 && ub1 >= 0 && ub1 <= 1) {
-    result.x = x00 + ua1 * (x01 - x00);
-    result.y = y00 + ua1 * (y01 - y00);
+    result[0] = line1vertex1[0] + ua1 * (line1vertex2[0] - line1vertex1[0]);
+    result[1] = line1vertex1[1] + ua1 * (line1vertex2[1] - line1vertex1[1]);
     return result;
   }
 };