Fix object selection to work while in snap mode.

[architektonas] / src / object.cpp

diff --git a/src/object.cpp b/src/object.cpp
index 404d30576113a97ad9516b04677d087f81ad4346..93af822b8476008c2f60e6158955078cdaf38c0d 100644 (file)
--- a/src/object.cpp
+++ b/src/object.cpp
@@ -17,6 +17,7 @@
 
 #include "object.h"
 #include <stdlib.h>
+#include <math.h>
 
 // Initialize static variables
 bool Object::fixedAngle = false;
@@ -31,6 +32,7 @@ bool Object::ignoreClicks = false;
 bool Object::dontMove = false;
 bool Object::selectionInProgress = false;
 QRectF Object::selection;
+double Object::gridSpacing;
 
 
 Object::Object(): position(Vector(0, 0)), parent(0), type(OTObject),
@@ -291,3 +293,25 @@ void Object::SetSnapMode(bool state/*= true*/)
 {
        snapToGrid = state;
 }
+
+
+//
+// This looks strange, but it's really quite simple: We want a point that's
+// more than half-way to the next grid point to snap there while conversely we
+// want a point that's less than half-way to to the next grid point then snap
+// to the one before it. So we add half of the grid spacing to the point, then
+// divide by it so that we can remove the fractional part, then multiply it
+// back to get back to the correct answer.
+//
+Vector Object::SnapPointToGrid(Vector point)
+{
+       point += gridSpacing / 2.0;             // *This* adds to Z!!!
+       point /= gridSpacing;
+       point.x = floor(point.x);//need to fix this for negative numbers...
+       point.y = floor(point.y);
+       point.z = 0;                                    // Make *sure* Z doesn't go anywhere!!!
+       point *= gridSpacing;
+       return point;
+}
+
+