[chronojump] Cairo FindClosestPoint now finds using graph X,Y

[Xavier de Blas <xaviblas src gnome org>]

commit b49a2c7986eb2acbe69627d9b908ccfaec7d1351
Author: Xavier de Blas <xaviblas gmail com>
Date:   Tue Jan 14 13:45:50 2020 +0100

    Cairo FindClosestPoint now finds using graph X,Y

 src/gui/cairo/xy.cs | 19 +++++++++----------
 1 file changed, 9 insertions(+), 10 deletions(-)
---
diff --git a/src/gui/cairo/xy.cs b/src/gui/cairo/xy.cs
index ff042d2b..4d03ae70 100644
--- a/src/gui/cairo/xy.cs
+++ b/src/gui/cairo/xy.cs
@@ -360,7 +360,7 @@ public abstract class CairoXY
                */
 
                // 3) find closest point (including predicted point if any)
-               Point pClosest = findClosestRealPoint(realX, realY);
+               Point pClosest = findClosestGraphPoint(graphX, graphY);
 
                // 4) write text at right
                writeTextAtRight(line, "Selected:", false);
@@ -369,23 +369,22 @@ public abstract class CairoXY
 
                // 5) paint rectangle around that point
                g.Color = red;
-               g.Rectangle(
-                               calculatePaintX(pClosest.X,
-                                       graphWidth, absoluteMaxX, minX, totalMargins, totalMargins) -12,
-                               calculatePaintY(pClosest.Y,
-                                       graphHeight, absoluteMaxY, minY, totalMargins, totalMargins) -12,
-                               24, 24);
+               g.Rectangle(calculatePaintX(pClosest.X) -12, calculatePaintY(pClosest.Y) -12, 24, 24);
                g.Stroke();
                g.Color = black;
        }
 
-       private Point findClosestRealPoint(double realX, double realY)
+       /*
+        * using graphPoints and not real points because X and Y scale can be very different
+        * and this would be stranger for user to have a point selected far away to the "graph" closest point
+        */
+       private Point findClosestGraphPoint(double graphX, double graphY)
        {
                double distMin = 10000000;
                Point pClosest = point_l[0];
                foreach(Point p in point_l)
                {
-                       double dist = Math.Sqrt(Math.Pow(realX - p.X, 2) + Math.Pow(realY - p.Y, 2));
+                       double dist = Math.Sqrt(Math.Pow(graphX - calculatePaintX(p.X), 2) + Math.Pow(graphY 
- calculatePaintY(p.Y), 2));
                        if(dist < distMin)
                        {
                                distMin = dist;
@@ -394,7 +393,7 @@ public abstract class CairoXY
                }
 
                //also check predicted point if exits
-               if(predictedPointDone && Math.Sqrt(Math.Pow(realX - xAtMMaxY, 2) + Math.Pow(realY - yAtMMaxY, 
2)) < distMin)
+               if(predictedPointDone && Math.Sqrt(Math.Pow(graphX - calculatePaintX(xAtMMaxY), 2) + 
Math.Pow(graphY - calculatePaintY(yAtMMaxY), 2)) < distMin)
                        pClosest = new Point(xAtMMaxY, yAtMMaxY);
 
                return pClosest;